Analysis of alpha-synuclein, dopamine and parkin pathways in neuropathologically confirmed parkinsonian nigra.

in Acta Neuropathologica (2007), 113(3), 253-63

The identification of mutations that cause familial Parkinson's disease (PD) provides a framework for studies into pathways that may be perturbed also in the far more common, non-familial form of the ... [more ▼]

The identification of mutations that cause familial Parkinson's disease (PD) provides a framework for studies into pathways that may be perturbed also in the far more common, non-familial form of the disorder. Following this hypothesis, we have examined the gene regulatory network that links alpha-synuclein and parkin pathways with dopamine metabolism in neuropathologically verified cases of sporadic PD. By means of an in silico approach using a database of eukaryotic molecular interactions and a whole genome transcriptome dataset validated by qRT-PCR and histological methods, we found parkin and functionally associated genes to be up-regulated in the lateral substantia nigra (SN). In contrast, alpha-synuclein and ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) gene expression levels were significantly reduced in both the lateral and medial SN in PD. Gene expression for Septin 4, a member of the GTP-binding protein family involved in alpha-synuclein metabolism was elevated in the lateral parkinsonian SN. Additionally, catalase and mitogen-activated protein kinase 8 and poly(ADP-ribose) polymerase family member 1 (PARP1) known to function in DNA repair and cell death induction, all members of the dopamine synthesis pathway, were up-regulated in the lateral SN. In contrast, two additional PD-linked genes, glucocerebrosidase and nuclear receptor subfamily 4, group A, member 2 (NR4A2) showed reduced expression. We show that in sporadic PD, parkin, alpha-synuclein and dopamine pathways are co-deregulated. Alpha-synuclein is a member of all three gene regulatory networks. Our analysis results support the view that alpha-synuclein has a central role in the familial as well as the non-familial form of the disease and provide steps towards a pathway definition of PD. [less ▲]

Increased expression of the putative axon growth-repulsive extracellular matrix molecule, keratan sulphate proteoglycan, following traumatic injury of the adult rat spinal cord

in Acta Neuropathologica (2002), 104(6), 592-600

Keratan sulphate proteoglycan (KSPG) is a developmentally regulated barrier molecule, directing axonal growth during central nervous system (CNS) formation. The possible re-expression and functional ... [more ▼]

Keratan sulphate proteoglycan (KSPG) is a developmentally regulated barrier molecule, directing axonal growth during central nervous system (CNS) formation. The possible re-expression and functional significance of KSPG in preventing axon regeneration following spinal cord injury (SCI) is poorly understood. In the present investigation, the spatio-temporal expression of KSPG was studied following experimental SCI. There was no indication of sparing of axons at the lesion epicentre following severe compression injury. By 7 days post operation (p.o.) a diffuse increase of KSPG immunoreactivity (KSPG-IR) was observed in the parenchyma surrounding the lesion. This was followed by a delayed (21-28 days p.o.) and largely heterogeneous increase of KSPG-IR in the lesion epicentre, which revealed both cellular and extracellular matrix-like distribution patterns. Although no re-growth of anterogradely labelled corticospinal axons was observed, many 200-kDa neurofilament (NF)-positive axon could be detected growing into the connective tissue scar. This phase of spontaneous axonal re-growth was closely associated with a framework of glial cells (including Schwann cells from damaged local spinal nerve roots) that had migrated into the lesion site. The spontaneous nerve fibre re-growth could be detected in both KSPG-rich and KSPG-poor territories. The present data suggest that the lesion-induced up-regulation of KSPG-IR may have contributed to the lack of corticospinal axon re-growth. However, the lack of any direct spatio-temporal correlation between the distribution of raised KSPG-IR and spontaneous NF-positive axonal regeneration suggests that at least some populations of axons can resist the putative inhibitory effects of this extracellular matrix molecule. [less ▲]

Major histocompatibility complex class II expression by activated microglia caudal to lesions of descending tracts in the human spinal cord is not associated with a T cell response.

in Acta Neuropathologica (2000), 100(5), 528-36

Lesion-induced microglial/macrophage responses were investigated in post-mortem human spinal cord tissue of 20 patients who had died at a range of survival times after spinal trauma or brain infarction ... [more ▼]

Lesion-induced microglial/macrophage responses were investigated in post-mortem human spinal cord tissue of 20 patients who had died at a range of survival times after spinal trauma or brain infarction. Caudal to the spinal cord injury or brain infarction, a strong increase in the number of activated microglial cells was observed within the denervated intermediate grey matter and ventral horn of patients who died shortly after the insult (4-14 days). These cells were positive for the leucocyte common antigen (LCA) and for the major histocompatibility complex class II antigen (MHC II), with only a small proportion staining for the CD68 antigen. After longer survival times (1-4 months), MHC II-immunoreactivity (MHC II-IR) was clearly reduced in the grey matter but abundant in the white matter, specifically within the degenerating corticospinal tract, co-localising with CD68. In this fibre tract, elevated MHC II-IR and CD68-IR were still detectable 1 year after trauma or stroke. It is likely that the subsequent expression of CD68 on MHC II-positive microglia reflects the conversion to a macrophage phenotype, when cells are phagocytosing degenerating presynaptic terminals in grey matter target regions at early survival times and removing axonal and myelin debris in descending tracts at later survival times. No T or B cell invasion or involvement of co-stimulatory B7 molecules (CD80 and CD86) was observed. It is possible that the up-regulation of MHC II on microglia that lack the expression of B7 molecules may be responsible for the prevention of a T cell response, thus protecting the spinal cord from secondary tissue damage. [less ▲]

Idiopathic hypertrophic cranial pachymeningitis mimicking multiple meningiomas: case report and review of the literature.

in Acta Neuropathologica (1997), 94(4), 385-9

A case of idiopathic hypertrophic cranial pachymeningitis with an unusual and misleading manifestation is reported. Computed tomography scan, angiographic and magnetic resonance imaging findings were ... [more ▼]

A case of idiopathic hypertrophic cranial pachymeningitis with an unusual and misleading manifestation is reported. Computed tomography scan, angiographic and magnetic resonance imaging findings were suggestive of multiple meningeal neoplasms and a correct diagnosis was made only after meningeal biopsy. This 44-year-old patient had a previous history of an ill-defined systemic disorder associating episcleritis, erythroderma nodosa and multiple peripheral arthritis. We review previous reports of idiopathic cranial pachymeningitis with emphasis on radiological investigation techniques, histopathology and possible dysimmune mechanisms of pathogenesis. [less ▲]

Ventral porencephaly: a cerebral defect associated with multiple congenital anomalies.

in Acta Neuropathologica (1978), 42(3), 231-5

An infant with multiple congenital anomalies was found at autopsy to have a porencencephalic defect on the ventral surface of the left frontal lobe. The intracranial defect was seen in association with an ... [more ▼]

An infant with multiple congenital anomalies was found at autopsy to have a porencencephalic defect on the ventral surface of the left frontal lobe. The intracranial defect was seen in association with an anomalous configuration of the circle of Willis. The zone of tissue destruction corresponded to the vascular territory of the anterior choroidal and lenticulo-striate branches of the proximal middle cerebral arteries, which were absent on the left. The developmental anomaly of the circle of Willis may have predisposed to tissue destruction by compromising cerebral perfusion at midgestation, a stage of rapid brain growth. [less ▲]