Willin/FRMD6 Mediates Mitochondrial Dysfunction Relevant to Neuronal Aß Toxicity.

Willin/FRMD6 has been reported as a potential Alzheimer's disease (AD) risk gene in a series of genome-wide association and neuroimaging studies; however, the mechanisms underlying its potential role in AD pathogenesis remain unknown. Here, we demonstrate the direct effects of Aß on Willin/FRMD6 expression and position mitochondrial oxidative stress as a novel potential mechanism underlying the role of Willin/FRMD6 in AD pathogenesis. Specifically, using mouse hippocampal HT-22 cells and primary mouse neurons, we show that Aß induces downregulation of Willin/FRMD6 protein expression. Furthermore, we demonstrate that Willin/FRMD6 knockdown leads to mitochondrial dysfunction and fragmentation, as well as upregulation of ERK1/2 signaling, both of which are reported to be key early features of AD pathogenesis. Importantly, increasing Willin/FRMD6 expression was able to rescue Aß-induced abnormalities in mitochondrial morphology, function, and energetics. Thus, enhancing Willin/FRMD6 expression holds potential as a therapeutic strategy for protecting against Aß-induced mitochondrial and neuronal dysfunction.

Interaction between AhR and HIF-1 signaling pathways mediated by ARNT/HIF-1ß.

BACKGROUND: The main causes of lung cancer are smoking, environmental pollution and genetic susceptibility. It is an indisputable fact that PAHs are related to lung cancer, and benzo(a) pyrene is a representative of PAHs. The purpose of the current investigation was to investigate the interaction between AhR and HIF-1 signaling pathways in A549 cells, which provide some experimental basis for scientists to find drugs that block AhR and HIF-1 signaling pathway to prevent and treat cancer. METHODS: This project adopts the CYP1A1 signaling pathways and the expression of CYP1B1 is expressed as a measure of AhR strength index. The expression of VEGF and CAIX volume as a measure of the strength of the signal path HIF-1 indicators. Through the construction of plasmid vector, fluorescence resonance energy transfer, real-time quantitative PCR, western blotting and immunoprecipitation, the interaction between AhR signaling pathway and HIF-1 signaling pathway was observed. RESULTS: BaP can enhance the binding ability of HIF-1α protein to HIF-1ß/ARNT in a dose-dependent manner without CoCl2. However, the binding ability of AhR protein to HIF-1ß/ARNT is inhibited by HIF-1α signaling pathway in a dose-dependent manner with CoCl2. CONCLUSION: It is shown that activation of the AhR signaling pathway does not inhibit the HIF-1α signaling pathway, but activation of the HIF-1α signaling pathway inhibits the AhR signaling pathway.

Willin/FRMD6: A Multi-Functional Neuronal Protein Associated with Alzheimer's Disease.

The FERM domain-containing protein 6 (FRMD6), also known as Willin, is an upstream regulator of Hippo signaling that has recently been shown to modulate actin cytoskeleton dynamics and mechanical phenotype of neuronal cells through ERK signaling. Physiological functions of Willin/FRMD6 in the nervous system include neuronal differentiation, myelination, nerve injury repair, and vesicle exocytosis. The newly established neuronal role of Willin/FRMD6 is of particular interest given the mounting evidence suggesting a role for Willin/FRMD6 in Alzheimer's disease (AD), including a series of genome wide association studies that position Willin/FRMD6 as a novel AD risk gene. Here we describe recent findings regarding the role of Willin/FRMD6 in the nervous system and its actions in cellular perturbations related to the pathogenesis of AD.

Willin/FRMD6 Influences Mechanical Phenotype and Neuronal Differentiation in Mammalian Cells by Regulating ERK1/2 Activity.

Willin/FRMD6 is part of a family of proteins with a 4.1 ezrin-radixin-moesin (FERM) domain. It has been identified as an upstream activator of the Hippo pathway and, when aberrant in its expression, is associated with human diseases and disorders. Even though Willin/FRMD6 was originally discovered in the rat sciatic nerve, most studies have focused on its functional roles in cells outside of the nervous system, where Willin/FRMD6 is involved in the formation of apical junctional cell-cell complexes and in regulating cell migration. Here, we investigate the biochemical and biophysical role of Willin/FRMD6 in neuronal cells, employing the commonly used SH-SY5Y neuronal model cell system and combining biochemical measurements with Elastic Resonator Interference Stress Micropscopy (ERISM). We present the first direct evidence that Willin/FRMD6 expression influences both the cell mechanical phenotype and neuronal differentiation. By investigating cells with increased and decreased Willin/FRMD6 expression levels, we show that Willin/FRMD6 not only affects proliferation and migration capacity of cells but also leads to changes in cell morphology and an enhanced formation of neurite-like membrane extensions. These changes were accompanied by alterations of biophysical parameters such as cell force, the organization of actin stress fibers and the formation of focal adhesions. At the biochemical level, changes in Willin/FRMD6 expression inversely affected the activity of the extracellular signal-regulated kinases (ERK) pathway and downstream transcriptional factor NeuroD1, which seems to prime SH-SY5Y cells for retinoic acid (RA)-induced neuronal differentiation.

Association of CYP2E1 and NAT2 polymorphisms with lung cancer susceptibility among Mongolian and Han populations in the Inner Mongolian region.

PURPOSE: To explore associations of CYP2E1 and NAT2 polymorphisms with lung cancer susceptibility among Mongolian and Han populations in the Inner Mongolian region. MATERIALS AND METHODS: CYP2E1 and NAT2 polymorphisms were detected by PCR-RFLP in 930 lung cancer patients and 1000 controls. RESULTS: (1) Disequilibrium of the distribution of NAT2 polymorphism was found in lung cancer patients among Han and Mongolian populations (p=0.031). (2) Lung cancer risk was higher in individuals with c1, D allele of CYP2E1 RsaI/PstI, DraI polymorphisms and slow acetylation of NAT2 (c1 compared with c2, OR=1.382, 95%CI: 1.178- 1.587, p=0.003; D compared with C, OR=1.241, 95%CI: 1.053-1.419, P<0.001; slow acetylation compared with rapid acetylation, OR=1.359, 95%CI:1.042-1.768, p=0.056) (3) Compared with c2/c2 and rapid acetylation, c1/c1 together with slow acetylation synergetically increased risk of lung cancer 2.83 fold. (4) Smokers with CYP2E1 c1/c1, DD, and NAT2 slow acetylation have 2.365, 1.916, 1.841 fold lung cancer risk than others with c2/c2, CC and NAT2 rapid acetylation, respectively. (5) Han smokers with NAT2 slow acetylation have 1.974 fold lung cancer risk than others with rapid acetylation. CONCLUSIONS: Disequilibrium distribution of NAT2 polymorphism was found in lung cancer patients among Han and Mongolian populations. Besides, Han smokers with NAT2 slow acetylation may have higher lung cancer risk compared with rapid acetylation couterparts. CYP2E1 c1/ c1, DD and NAT2 slow acetylation, especially combined with smoking, contributes to the development of lung cancer. CYP2E1 c1/c1 or DD genotype and NAT2 slow acetylation have strong synergistic action in increasing lung cancer risk.

Association between +936 C>T gene polymorphism of vascular endothelial growth factor and lung cancer: a meta-analysis.

BACKGROUND: +936C>T polymorphism of vascular endothelial growth factor (VEGF) is one of the most investigated polymorphisms, it has been suggested that it plays a vital role in tumorigenesis. Intensive studies centering on the association between VEGF +936C>T polymorphism and lung cancer risk or lung cancer patients' overall survival were conducted in recent years, but with inconclusive and ambiguous results. OBJECTIVE AND METHODS: We investigated whether VEGF +936C>T polymorphism influences lung cancer risk and lung cancer patients' overall survival (OS) using pooled odds ratios (ORs) and hazard ratios (HRs) with their corresponding 95% confidence intervals (CI) under different genetic models. RESULTS: A total of 12 eligible studies were included. In the overall analysis, we didn't find any statistical evidence that +936C>T polymorphism was related to the risk of lung cancer in any genetic model. However, increased lung cancer risk was detected in adenocarcinoma subgroup (OR=1.532, 95%CI: 1.016-2.312, P=0.042). For an aggregate result of survival analysis, +936C>T polymorphism was linked to an unfavorable OS (HR=2.248, 95%CI: 1.257-4.017, P=0.006) under homozygous model (TT/CC).