Anti-parkinsonian agents, pramipexole (PPX) and ropinirole (ROP), have been reported to possess neuroprotective properties, both in vitro and in vivo. The mechanisms underlying neuroprotection afforded by the D3-preferring receptor agonists remain poorly understood. The present study demonstrates that incubation of primary mesencephalic cultures with PPX and ROP or the conditioned medium from PPX- or ROP-treated primary cultures induced a marked increase in the number of dopamine (DA) neurons in the cultures. Similar effects can be observed after incubating with the conditioned medium derived from PPX- and ROP-treated substantia nigra astroglia. Meanwhile, PPX and ROP can protect the primary cells from insult of 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of the neurotoxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). Furthermore, the neurotrophic effects of PPX and ROP on mesencephalic dopamine neurons could be significantly blocked by D3 receptor antagonist, but not by D2 receptor antagonist. Moreover, we found that the levels of glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) in the conditioned medium of mesencephalic cultures treated with PPX and ROP were significantly increased. Blocking GDNF and BDNF with the neutralizing antibodies, the neurotrophic effects of PPX and ROP were greatly diminished. These results suggest that D3 dopamine receptor-preferring agonists, PPX and ROP, exert neurotrophic effects on cultured DA neurons by modulating the production of endogenous GDNF and BDNF, which may participate in their neuroprotection.
Important antibody-independent pathogenic roles of B cells are emerging in autoimmune diseases, including multiple sclerosis (MS). The contrasting results of different treatments targeting B cells in patients (in spite of predictions of therapeutic benefits from animal models) call for a better understanding of the multiple roles that distinct human B cell responses likely play in MS. In recent years, both murine and human B cells have been identified with distinct functional properties related to their expression of particular cytokines. These have included regulatory (Breg) B cells (secreting interleukin (IL)-10 or IL-35) and pro-inflammatory B cells (secreting tumor necrosis factor α, LTα, IL-6, and granulocyte macrophage colony-stimulating factor). Better understanding of human cytokine-defined B cell responses is necessary in both health and diseases, such as MS. Investigation of their surface phenotype, distinct functions, and the mechanisms of regulation (both cell intrinsic and cell extrinsic) may help develop effective treatments that are more selective and safe. In this review, we focus on mechanisms by which cytokine-defined B cells contribute to the peripheral immune cascades that are thought to underlie MS relapses, and the impact of B cell-directed therapies on these mechanisms.
Inflammatory mediators may reflect a role of systemic inflammation in the neurodegenerative process of Parkinson's disease (PD). Interleukin-6 (IL-6) and chemokine ligand 5 (CCL5), also known as RANTES (regulated on activation, normal T cell expressed and secreted), have been implicated in neurodegenerative diseases including PD. Serum levels of RANTES and IL-6 of 78 consecutive PD patients and age-matched 80 controls were measured. Patients with PD had higher RANTES and IL-6 levels compared with the controls. We found that serum RANTES levels strongly correlated with Hoehn-Yahr score and disease duration in PD patients. This study indicated that patients with PD have an on-going systemic inflammatory profile where the elevated peripheral production of RANTES may play a role in the neurodegenerative process.
BackgroundA number of reports have described the presence of tuberculosis (TB) in neuromyelitis optica (NMO) patients. However, a definite association between the two conditions has not been conclusively demonstrated.MethodsTo investigate the association between NMO and TB in a Chinese population, we performed a retrospective review of hospital records of NMO patients, control patients and tuberculosis meningitis (TBM) patients from January 1, 1995 to December 31, 2011.ResultsThe frequency of preceding/simultaneous active pulmonary TB (PTB) was not significantly different between NMO patients (1.1%) and control groups (2.3% in myasthenia gravis, 1.1% in polymyositis or dermatomyositis, zero in idiopathic facial palsy and viral meningitis/meningoencephalitis). NMO cases differed from TBM cases in terms of demographics, course (recurrent or monophasic), cerebrospinal fluid analysis and magnetic resonance images. Two TBM patients shared partial clinical features with NMO (one of the TBM patients had a longitudinal extensive spinal cord lesion involving the holocord, and the other had optic neuritis before anti-tuberculosis treatment). NMO antibodies were only detected in NMO patients and not in TBM patients with myelitis or optic neuritis.ConclusionsWe could not confirm previous suggestions of the association between PTB and NMO. Direct infection of the central nervous system by TB may mimic NMO in some respects, but whether NMO-like symptoms that develop during the course of TB should be considered and diagnosed as NMO is open to discussion.
Neuromyelitis optica (NMO) is an immune-mediated disease of the central nervous system. Pruritus in patients with NMO has rarely been reported. We aimed to explore the characteristics and underlying mechanisms of pruritus in NMO patients. We reviewed the case records of 64 NMO patients who visited the Department of Neurology at the Third Hospital of Sun Yat-sen University between 2009 and 2015. Of the 64 aquaporin-4 antibody-positive NMO patients, 18 had pruritus. Spinal magnetic resonance imaging (MRI) showed lesions in all of these patients. A total of 13 patients presented with brain lesions, and four had lesions in the periaqueductal gray matter on cerebral MRI. However, the anatomical distribution of pruritus did not always correspond to the dermatomal distributions of the involved spinal cord segments. Pruritus was completely or partially relieved after treatment. Pruritus is not a rare occurrence and may be a characteristic feature of NMO.
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