Marco Vercellino

Grey matter pathology in multiple sclerosis.

Abstract The aim of our study is to evaluate the extent and distribution of grey matter demyelinating lesions in multiple sclerosis (MS), addressing also neuronal loss and synaptic loss. Whole coronal sections of 6 MS brains and 6 control brains were selected. Immunohistochemistry was performed for myelin basic protein, neurofilaments, synaptophysin, ubiquitin, and activated caspase-3. Neuronal density and optical density of synaptophysin staining were estimated in cortical lesions and compared with those observed in corresponding areas of normal (i.e. nondemyelinated) cortex in the same section. Demyelinating lesions were observed in the cerebral cortex, in the thalamus, basal ganglia, and in the hippocampus. The percentage of demyelinated cortex was remarkable in 2 cases of secondary progressive MS (48% and 25.5%, respectively). Neuronal density was significantly reduced in cortical lesions (18-23% reduction), if compared with adjacent normal cortex, in the 2 cases showing the higher extent of cortical demyelination; in the same cases, very rare apoptotic neurons expressing caspase-3 were observed in cortical lesions and not in adjacent normal cortex. No significant decrease in optical density of synaptophysin staining was observed in cortical lesions. Grey matter demyelination and neuronal loss could contribute to disability and cognitive dysfunctions in MS.

Demyelination, Inflammation, and Neurodegeneration in Multiple Sclerosis Deep Gray Matter

Gray matter (GM) lesions are recognized as important components of the pathology of multiple sclerosis (MS), and involvement of the deep gray matter (DGM) is suggested by magnetic resonance imaging. The aims of this study were to determine the frequency and distribution of lesions and characterize the inflammatory and neurodegenerative changes in DGM of MS patients. Histochemistry, immunohistochemistry, and morphometry were performed on whole coronal sections of 14 MS and 12 control (6 normal, 6 from amyotrophic lateral sclerosis patients) brains. Demyelinating lesions were frequent in MS DGM; most often in the thalamus and caudate, but they were also seen in the putamen, pallidum, claustrum, amygdala, hypothalamus, and substantia nigra. Most DGM lesions involved both GM and white matter. Inflammation in active DGM lesions was similar to that in lesions only in white matter but was less intense, and there was a preponderance of activated microglia, scarce myelin-laden macrophages, and a lesser extent of axonal damage. Neuronal loss was observed both in DGM lesions and nondemyelinated DGM with neuron atrophy in nondemyelinated DGM. In conclusion, demyelination and neurodegenerative changes are common in MS DGM and may contribute to clinical impairment. Inflammation in DGM lesions is intermediate between the destructive inflammation of white matter lesions and the minimal inflammation of cortical lesions. We hypothesize that alterations of glutamate reuptake mechanisms may contribute to these differences.

Altered glutamate reuptake in relapsing-remitting and secondary progressive multiple sclerosis cortex: correlation with microglia infiltration, demyelination, and neuronal and synaptic damage.

Cortical involvement in multiple sclerosis (MS) is emerging as an important determinant of disease progression. The mechanisms responsible for MS cortical pathology are not fully characterized. The objective of this study was to assess the role of excitotoxicity in MS cortex, evaluating excitatory amino acid transporter (EAAT) expression and its relationship with demyelination, inflammation, gliosis, and neuronal and synaptic pathology. EAATs are essential in maintaining low extracellular glutamate concentrations and preventing excitotoxicity. Ten MS brains (3 relapsing-remitting MS cases and 7 secondary progressive MS cases) were evaluated by immunohistochemistry for myelin basic protein, CD68, HLA-DR, EAAT1, EAAT2, glial fibrillary acidic protein, phosphorylated c-Jun N-terminal kinase (pJNK), synaptophysin, and neurofilaments. Cortical lesions were frequently observed in MS brains in variable numbers and extensions. In cortical lesions, activated microglia infiltration correlated with focal loss of EAAT1, EAAT2, and synaptophysin immunostaining, and with neuronal immunostaining for pJNK, a protein involved in response to excitotoxic injury. No reduction of EAATs or synaptophysin immunostaining was observed in demyelinated cortex in the absence of activated microglia. Alterations of the mechanisms of glutamate reuptake are found in cortical MS lesions in the presence of activated microglia and are associated with signs of neuronal and synaptic damage suggestive of excitotoxicity. Excitotoxicity may be involved in the pathogenesis of demyelination and of neuronal and synaptic damage in MS cortex.

TDP-43 Redistribution is an Early Event in Sporadic Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder consisting of progressive loss of motor neurons. TDP‐43 has been identified as a component of ubiquitin‐immunoreactive inclusions of motor neurons in ALS. We focused on the diffuse cytoplasmic TDP‐43 immunoreactivity in ALS neurons, and quantitatively assessed it in comparison with skein/round TDP‐43 and ubiquitin immunostaining in motor neurons of 30 sporadic ALS cases. The percentage of spinal motor neurons with cytoplasmic TDP‐43 immunoreactivity was higher than that of ubiquitin‐immunoreactive ones. The percentage of TDP‐43‐positive motor neurons was independent of neuron counts in anterior horns, while the percentage of ubiquitinated neurons was inversely correlated. Aiming to define the cytosolic localization of TDP‐43, the immunoblot analysis of spinal cord and frontal cortex showed that full‐length TDP‐43, the 45 kDa form and ubiquitinated TDP‐43 are found in the soluble inclusion‐free fraction. The present data suggest that delocalization, accumulation and ubiquitination of TDP‐43 in the cytoplasm of motor neurons are early dysfunctions in the cascade of the events leading to motor neuron degeneration in ALS, preceding the formation of insoluble inclusion bodies. Being cytoplasmic accumulation an ongoing event during the course of the illness, a therapeutic approach to this incurable disease can be envisaged.

Fertility in patients with multiple sclerosis: current knowledge and future perspectives.

The issue of fertility in patients with multiple sclerosis (MS) has not been exhaustively studied. Epidemiological data have suggested that spontaneous fecundity might be reduced; several endocrine and sexual disturbances potentially interfering with reproduction have been evidenced in MS patients of both sexes. Moreover, some medical treatments used in MS (e. g., mitoxantrone, cyclophosphamide) may exert detrimental effects on spermatozoa as well as on oocytes, leading to early impairment of fertility. This review illustrates the factors potentially interfering with fertility in MS and discusses the therapeutic tools that may be used to promote fertility in these patients. The safety of hormonal therapies in MS is also examined. The current applications of assisted reproductive technology (ART) are discussed, including in vitro fertilisation (IVF) techniques. Currently available methods to preserve fertility in patients that undergo cytotoxic treatments by means of sperm/oocyte cryostorage or by ovarian fragment cryopreservation and autografting are considered.

Involvement of the choroid plexus in multiple sclerosis autoimmune inflammation: A neuropathological study

An immunological function has been proposed for the choroid plexus (CP). In multiple sclerosis (MS) brains, CPs show (immunohistochemistry to HLA-DR, CD3, CD20, CD68, VCAM-1, CD138) T lymphocytes in vessels and stroma, VCAM-1 expression on endothelia, intense HLA-DR immunostaining on cells in CP stroma, among CP epithelium and on epiplexus cells. CPs in control or amyotrophic lateral sclerosis brains do not show such inflammatory changes. Intense CP inflammation is observed in viral encephalitis. Changes in MS CPs suggest persisting immune activation, with intensity similar to acute encephalitis, even in MS phases in which neurodegeneration prevails. In MS, CPs could represent a site for lymphocyte entry in the CSF and for CSF antigens presentation.

Multiple sclerosis relapses: a multivariable analysis of residual disability determinants.

Background –  Recovery from multiple sclerosis (MS) relapses is variable. The factors influencing persistence of residual disability (RD) after a relapse are still to be thoroughly elucidated.

Expression and Genetic Analysis of MicroRNAs Involved in Multiple Sclerosis

Evidence underlines the importance of microRNAs (miRNAs) in the pathogenesis of multiple sclerosis (MS). Based on the fact that miRNAs are present in human biological fluids, we previously showed that miR-223, miR-23a and miR-15b levels were downregulated in the sera of MS patients versus controls. Here, the expression levels of these candidate miRNAs were determined in peripheral blood mononuclear cells (PBMCs) and the serum of MS patients, in addition to three genotyped single nucleotide polymorphisms (SNPs). Mapping in the genomic regions of miR-223, miR-23a and miR-15b genes, 399 cases and 420 controls were tested. Expression levels of miR-223 and miR-23a were altered in PBMCs from MS patients versus controls. Conversely, there were no differences in the expression levels of miR-15b. A significantly decreased genotypic frequency of miR-223 rs1044165 T/T genotype was observed in MS patients. Moreover, the allelic frequency of miR-23a rs3745453 C allele was significantly increased in patients versus controls. In contrast, there were no differences in the distribution of miR-15b SNP. In conclusion, our results suggest that miR-223 and miR-23a could play a role in the pathogenesis of MS. Moreover, miR-223 rs1044165 polymorphism likely acts as a protective factor, while miR-23a rs3745453 variant seems to act as a risk factor for MS.

Progranulin expression in brain tissue and cerebrospinal fluid levels in multiple sclerosis

Background: Progranulin (PGRN) is a fundamental neurotrophic factor, and is also involved in inflammation and wound repair. PGRN may have pro- or anti-inflammatory properties, depending upon proteolysis of the anti-inflammatory parent PGRN protein and the generation of pro-inflammatory granulin peptides. Objectives: Our objectives were as follows: (1) to evaluate the presence and distribution of PGRN in multiple sclerosis (MS) brain tissue, correlating it with demyelination and inflammation; (2) to evaluate cerebrospinal fluid (CSF) PGRN concentrations in patients with MS and controls, in relationship to the clinical features of the disease. Methods: Our study involved the following: (1) neuropathological study of PGRN on post-mortem tissue of 19 MS and six control brains; (2) evaluation of PGRN CSF concentration in 40 MS patients, 15 non-inflammatory controls and five inflammatory controls (viral encephalitis). Results: In active demyelinating lesions, PGRN was expressed on macrophages/microglia. In the normal-appearing white matter (NAWM), expression of PGRN was observed on activated microglia. PGRN was expressed by neurons and microglia in cortical lesions and in normal-appearing cortex. No expression of PGRN was observed in controls, except on neurons. PGRN CSF concentrations were significantly higher in patients with relapsing–remitting MS during relapses and in progressive MS patients, compared with relapsing–remitting MS patients during remissions and with non-inflammatory controls. Conclusions: PGRN is strongly expressed in MS brains, by macrophages/microglia in active lesions, and by activated microglia in the NAWM; PGRN CSF concentrations in MS are correspondingly increased in conditions of enhanced macrophage/microglia activation, such as during relapses and in progressive MS.

Neuropathology of Olfactory Ensheathing Cell Transplantation into the Brain of Two Amyotrophic Lateral Sclerosis (ALS) Patients

Although a large number of amyotrophic lateral sclerosis (ALS) patients have undergone transplantation procedures with olfactory ensheathing cells (OECs) in the Bejing Hospital, to our knowledge, no post‐mortem neuropathologic analyses have been performed. We examined the post‐mortem brain of two Italian patients affected by ALS who underwent cellular transplantation in Beijing with their consent. Our aim was to assess the events following the graft procedure to possibly support the rationale of the treatment strategy. The neuropathologic findings were analyzed on the basis of the limited awareness of the experimental conditions and discussed in relation to the safety, efficacy and long‐term outcome of the transplanted cells. Islands of quiescent, undifferentiated cells within the delivery track persisting for up to 12 months–24 months were found. Prominent glial and inflammatory reaction around the delivery track strongly supports the encasement of the graft. Evidence of axonal regeneration, neuronal differentiation and myelination was not seen. The surgical procedure of implantation was not compatible with a neurotrophic effect. The OEC transplantation did not modify the neuropathology of ALS in the two patients. In conclusion, the present neuropathologic analysis does not support a beneficial effect of fetal OEC implantation into the frontal lobes of ALS patients.