Current understanding of metal ions in the pathogenesis of Alzheimer's disease.

Background: The homeostasis of metal ions, such as iron, copper, zinc and calcium, in the brain is crucial for maintaining normal physiological functions. Studies have shown that imbalance of these metal ions in the brain is closely related to the onset and progression of Alzheimer's disease (AD), the most common neurodegenerative disorder in the elderly. Main body: Erroneous deposition/distribution of the metal ions in different brain regions induces oxidative stress. The metal ions imbalance and oxidative stress together or independently promote amyloid-ß (Aß) overproduction by activating ß- or γ-secretases and inhibiting α-secretase, it also causes tau hyperphosphorylation by activating protein kinases, such as glycogen synthase kinase-3ß (GSK-3ß), cyclin-dependent protein kinase-5 (CDK5), mitogen-activated protein kinases (MAPKs), etc., and inhibiting protein phosphatase 2A (PP2A). The metal ions imbalances can also directly or indirectly disrupt organelles, causing endoplasmic reticulum (ER) stress; mitochondrial and autophagic dysfunctions, which can cause or aggravate Aß and tau aggregation/accumulation, and impair synaptic functions. Even worse, the metal ions imbalance-induced alterations can reversely exacerbate metal ions misdistribution and deposition. The vicious cycles between metal ions imbalances and Aß/tau abnormalities will eventually lead to a chronic neurodegeneration and cognitive deficits, such as seen in AD patients. Conclusion: The metal ions imbalance induces Aß and tau pathologies by directly or indirectly affecting multiple cellular/subcellular pathways, and the disrupted homeostasis can reversely aggravate the abnormalities of metal ions transportation/deposition. Therefore, adjusting metal balance by supplementing or chelating the metal ions may be potential in ameliorating AD pathologies, which provides new research directions for AD treatment.

[Prognostic significance of ERCC1 mRNA expression in patients with non-small cell lung cancer receiving platinum-based chemotherapy].

OBJECTIVE: To investigate the correlation of the mRNA expression level of excision repair cross-complementing group 1 (ERCC1) gene with clinicopathological parameters and clinical outcome in patients with non-small cell lung cancer (NSCLC) receiving platinum-based chemotherapy. METHODS: The mRNA expression of ERCC1 in formalin-fixed paraffin-embedded primary tumor specimens was measured by real-time quantitative reverse transcriptase polymerase chain reaction. The association between ERCC1 expression levels and clinicopathological parameters in NSCLC patients was analyzed. RESULTS: The median value of ERCC1 mRNA expression level compared with beta-actin in tumor specimens of 61 NSCLC patients was 0.48. There was no correlation between ERCC1 expression and clinicopathological parameters. Patients with low expression of ERCC1 mRNA (less than 0.35, 0.28, respectively) had a significantly longer median time to progression (TTP) (14.3 vs. 8.0 months, P = 0.028) and overall survival (OS) (28.4 vs. 12.9 months, P = 0.0064) than those with high expression. Multivariate analysis showed that a low ERCC1 mRNA expression was an independent factor for OS. CONCLUSION: Our findings suggest that intratumoral ERCC1 mRNA expression level, although is uncorrelated with clinicopathological parameters, is an independent predictive marker for survival of the patients with NSCLC receiving platinum-based chemotherapy, and may provide critical information for personalized chemotherapy.