Genetic analysis of MC1R variants in Chinese Han patients with sporadic Parkinson’s disease

Concussive head injury exacerbates neuropathology of sleep deprivation: Superior neuroprotection by co-administration of TiO2-nanowired cerebrolysin, alpha-melanocyte-stimulating hormone, and mesenchymal stem cells

Sleep deprivation (SD) is common in military personnel engaged in combat operations leading to brain dysfunction. Military personnel during acute or chronic SD often prone to traumatic brain injury (TBI) indicating the possibility of further exacerbating brain pathology. Several lines of evidence suggest that in both TBI and SD alpha-melanocyte-stimulating hormone (α-MSH) and brain-derived neurotrophic factor (BDNF) levels decreases in plasma and brain. Thus, a possibility exists that exogenous supplement of α-MSH and/or BDNF induces neuroprotection in SD compounded with TBI. In addition, mesenchymal stem cells (MSCs) are very portent in inducing neuroprotection in TBI. We examined the effects of concussive head injury (CHI) in SD on brain pathology. Furthermore, possible neuroprotective effects of α-MSH, MSCs and neurotrophic factors treatment were explored in a rat model of SD and CHI. Rats subjected to 48h SD with CHI exhibited higher leakage of BBB to Evans blue and radioiodine compared to identical SD or CHI alone. Brain pathology was also exacerbated in SD with CHI group as compared to SD or CHI alone together with a significant reduction in α-MSH and BDNF levels in plasma and brain and enhanced level of tumor necrosis factor-alpha (TNF-α). Exogenous administration of α-MSH (250μg/kg) together with MSCs (1×10⁶) and cerebrolysin (a balanced composition of several neurotrophic factors and active peptide fragments) (5mL/kg) significantly induced neuroprotection in SD with CHI. Interestingly, TiO₂ nanowired delivery of α-MSH (100μg), MSCs, and cerebrolysin (2.5mL/kg) induced enhanced neuroprotection with higher levels of α-MSH and BDNF and decreased the TNF-α in SD with CHI. These observations are the first to show that TiO₂ nanowired administration of α-MSH, MSCs and cerebrolysin induces superior neuroprotection following SD in CHI, not reported earlier. The clinical significance of our findings in light of the current literature is discussed.

Systematic analysis of genetic variants in patients with essential tremor

BACKGROUND

Essential tremor (ET), a prevalent neurological disorder, is featured by postural and kinetic tremors in upper limbs. Studies of twins and families indicate an important role for genetic factors in ET development. There are substantial overlaps between ET and Parkinson's disease (PD). The aim of this study was to examine the possible roles of genetic variants in ET development.

METHODS

A total of 200 Han Chinese ET patients and 432 ethnically matched normal controls were enrolled, and genetic analysis of 23 variants in 15 genes was performed.

RESULTS

Genotypic and allelic frequencies of the melanocortin 1 receptor gene (MC1R) variant rs34090186 showed statistically significant differences in ET patients and controls (p = 0.027 and 0.028, odds ratio = 2.789 and 2.744, 95% confidence interval: 1.084-7.179 and 1.075-7.005). No statistically significant difference was revealed in either genotypic or allelic distributions of other variants or haplotypes (all p > 0.05).

CONCLUSIONS

The discrepancies found in this study indicate the variant rs34090186 in the MC1R gene, some variants of which were reported to be related to increased risk of PD and melanoma, may play a risk role in ET, confirming a potential association between ET and PD. Evidence supporting ET-PD link will continue to accumulate and improve our understanding of any underlying mechanisms for both disorders.

Cutaneous malignant melanoma and Parkinson disease: Common pathways?

The mechanisms underlying the high prevalence of cutaneous malignant melanoma (CMM) in Parkinson disease (PD) are unclear, but plausibly involve common pathways. 129Ser-phosphorylated α-synuclein, a pathological PD hallmark, is abundantly expressed in CMM, but not in normal skin. In inherited PD, PARK genes harbor germline mutations; the same genes are somatically mutated in CMM, or their encoded proteins are involved in melanomagenesis. Conversely, genes associated with CMM affect PD risk. PD/CMM-targeted cells share neural crest origin and melanogenesis capability. Pigmentation gene variants may underlie their susceptibility. We review putative genetic intersections that may be suggestive of shared pathways in neurodegeneration/melanomagenesis. Ann Neurol 2016;80:811-820.

Genetic analysis of FGF20 variants in Chinese Han patients with essential tremor

Essential tremor (ET) is one of the most frequent neurological disorders with elusive etiology, typically characterized by postural and kinetic tremors. Evidence reveals that genetic components are implicated in the development of ET and there are some overlaps between ET and Parkinson's disease in clinical features and etiology. Variants in the fibroblast growth factor 20 gene (FGF20) have been reported to be associated with the risk of Parkinson's disease. To evaluate the association between the FGF20 gene variants and ET susceptibility, we conducted genetic analysis of five FGF20 variants (rs1721100, rs1989754, rs10089600, rs12720208, and rs17550360) in 200 patients with ET and 426 ethnically-matched Chinese Han normal controls. Statistical analysis did not identify significant differences in genotypic or allelic frequencies of variants between ET patients and normal controls (all P>0.05). No related haplotype was found to be related to the risk of ET. The findings indicate the FGF20 gene might not play a dominating role in the genetic predisposition to ET in Chinese Han population.