Ganoderma lucidum extract protects dopaminergic neurons through inhibiting the production of inflammatory mediators by activated microglia / 生理学报

Abundant evidence has suggested that neuroinflammation participates in the pathogenesis of Parkinson's disease (PD). The emerging evidence has supported that microglia may play key roles in the progressive neurodegeneration in PD and might be a promising therapeutic target. Ganoderma lucidum (GL), a traditional Chinese medicinal herb, has been shown potential neuroprotective effect in our clinical trials that lead us to speculate that it might possess potent anti-inflammatory and immunomodulating properties. To test this hypothesis, the present study investigated the potential neuroprotective effect of GL and underlying mechanism through inhibiting microglial activation using co-cultures of dopaminergic neurons and microglia. The cultures of microglia or MES23.5 cells alone or together were treated for 24 h with lipopolysaccharide (LPS, 0.25 μg/mL) as a positive control, GL extracts (50-400 μg/mL) or MES23.5 cell membrane fragments (150 μg/mL) were used in treatment groups. Microglia activation, microglia-derived harmful factors and [(3)H]dopamine ([(3)H]DA) uptake of MES23.5 cells were analyzed. The results showed that microglia were activated by LPS and MPP(+)-treated MES23.5 cell membrane fragments, respectively. Meanwhile, GL extracts significantly prevented the production of microglia-derived proinflammatory and cytotoxic factors, including nitric oxide, tumor necrosis factor-α (TNF-α) and interleukin 1β (IL-1β), in a dose-dependent manner and down-regulated the TNF-α and IL-1β expressions on mRNA level. In addition, GL extracts antagonized the reduction of [(3)H]DA uptake induced by MPP(+) and microglial activation. In conclusion, these results suggest that GL may be a promising agent for the treatment of PD through anti-inflammation.

Dual effects of different concentrations of alpha-synuclein on the neurotoxicity of 6-hydroxydopamine in SH-SY5Y cells / 生理学报

α-synuclein (α-SN) has been postulated to play a pivotal role in the pathogenesis of Parkinson's disease (PD). However, the physiological functions of α-SN and the molecular and cellular mechanisms underlying neuronal loss remain unclear. Recent studies suggest that α-SN plays dual roles of neuroprotection and neurotoxicity depending on its concentration or level of expression. In the present study, we explored the potential mechanisms for α-SN to regulate neuronal survival. α-SN at different concentrations (0.1 to 40 mumol/L) with or without 50 mumol/L 6-hydroxydopamine (6-OHDA) were added into the culture medium of the SH-SY5Y dopaminergic neural cells. The cell viability was measured on post-treatment day 1, 2 and 3. The activity of proteasome inhibited by α-SN was tested by a proteasome activity assay system after 2 h of α-SN treatment. According to the activity of proteasome inhibited by α-SN, the correlative dose of proteasome inhibitor--lactacystin (10 nmol/L to 5 mumol/L) with or without 50 mumol/L 6-OHDA were used and the cell viability was assayed on post-treatment day 1, 2 and 3. The results showed that α-SN played dual roles of neuroprotection and neurotoxicity depending on its concentration. At low concentration (0.1 to 5 mumol/L), α-SN promoted the proliferation and protected neurons against the neurotoxicity of 6-OHDA; in contrast, at high concentration (10 to 40 mumol/L), α-SN possessed cytotoxicity. The results of lactacystin treatment implied that the dual roles of α-SN were related to the moderate and strong inhibition of proteasome activity. The MEK1/2 specific inhibitor PD98059 completely blocked the protection of both α-SN and lactacystin, suggesting that MAPK pathway might be involved in the neuroprotection of α-SN.

Expression and significance of PCNA and p27 in benign prostate hypertrophy and prostate carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the expression of PCNA and p27 in human benign prostate hypertrophy (BPH) and prostate carcinoma (PCa) and their effect on the genesis and progression of the tumor.</p><p><b>METHODS</b>The paraffin-embedded sections of 30 cases with BPH and 37 cases with PCa were collected. The expression of p27 and PCNA protein were examined by S-P immunohistochemical method. Comparative analysis for BPH and pathological grade and clinical stage of PCa was performed.</p><p><b>RESULTS</b>The expression of PCNA in BPH (3.3%) was significantly lower than that in Pca (83.8%, P < 0.01). The expression of p27 in BPH (70.0%) was significantly higher than that in Pca (27.0%, P < 0.05). The expression of p27 was not correlated with histological grade and clinical stage in Pca (P > 0.05). An inverse correlation was found between p27 and PCNA expression in BPH (P < 0.01), while no correlation was found in Pca (P > 0.05).</p><p><b>CONCLUSION</b>The loss or decreased expression of p27 protein may be related to the genesis of benign prostate hypertrophy, but not to the development of prostate carcinoma; the overexpression of PCNA may play an important role in the malignant behavior and progression of prostate carcinoma.</p>