Analysis of expression profiling data suggests explanation for difficulties in finding biomarkers for nasal polyps
RHINOLOGY
Authors: Lee, Eun Jung; Gawel, Danuta R.; Lilja, Sandra; Li, Xinxiu; Schafer, Samuel; Sysoev, Oleg; Zhang, Huan; Benson, Mikael
Abstract
Background: Identification of clinically useful biomarkers for Nasal Polyposis in chronic rhinosinusitis (CRSwNP) has proven difficult. We analyzed gene expression profiling data to find explanations for this. Methods:We analyzed mRNA expression profiling data, GSE36830, of six uncinate tissues from healthy controls and six NP from CRSwNP patients. We performed Ingenuity Pathway Analysis (IPA) of differentially expressed genes to identify pathways and predicted upstream regulators. Results: We identified 1,608 differentially expressed genes and 177 significant pathways, of which Th1 and Th2 activation pathway and leukocyte extravasation signaling were most significant. We identified 75 upstream regulators whose activity was predicted to be upregulated.These included regulators of known pathogenic and therapeutic relevance, like IL-4. However, only seven of the 75 regulators were actually differentially expressed in NP, namely CSF1, TYROBP, CCL2, CCL11, SELP, ADORA3, ICAM1. Interestingly, these did not include IL-4, and four of the seven were receptors. This suggested a potential explanation for the discrepancy between the predicted and observed expression levels of the regulators, namely that the receptors, and not their ligands, were upregulated. Indeed, we found that 10 receptors of key predicted upstream regulators were upregulated, including IL4R. Conclusion: Our findings indicate that the difficulties in finding specific biomarkers for CRSwNP depend on the complex underlying mechanisms, which include multiple pathways and regulators, each of which may be subdivided into multiple components such as ligands, soluble and membrane-bound receptors. This suggests that combinations of biomarkers may be needed for CRSwNP diagnostics.
Targeting CCR3 to Reduce Amyloid-beta Production, Tau Hyperphosphorylation, and Synaptic Loss in a Mouse Model of Alzheimer's Disease
MOLECULAR NEUROBIOLOGY
Authors: Zhu, Chunyan; Xu, Bing; Sun, Xiaohong; Zhu, Qiwen; Sui, Yi
Abstract
The majority of Alzheimer's disease (AD) patients have a late onset, and chronic neuroinflammation, characterized by glial activation and secretion of pro-inflammatory cytokines and chemokines, plays a role in the pathogenesis of AD. The chemokine CCL11 has been shown to be a causative factor of cognitive decline in the process of aging, but little is known whether it is involved in the pathogenesis of AD. In the present study, we showed that CCR3, the receptor for CCL11, was expressed by hippocampal neurons and treatment of primary hippocampal neuronal cultures (14 days in vitro) with CCL11 resulted in activation of cyclin-dependent kinase 5 and glycogen synthase kinase-3 beta, associated with elevated tau phosphorylation at multiple sites. CCL11 treatment also induced the production of A beta and dendritic spine loss in the hippocampal neuronal cultures. All these effects were blocked by the CCR3 specific antagonist, GW766994. An age-dependent increase in CCL11, predominantly expressed by the activated microglia, was observed in the cerebrospinal fluid of both APP/PS1 double transgenic mice and wild-type (WT) littermates, with a markedly higher level in APP/PS1 double transgenic mice than that in WT littermates. Deletion of CCR3 in APP/PS1 double transgenic mice significantly reduced the phosphorylation of CDK5 and GSK3 beta, tau hyperphosphorylation, A beta deposition, microgliosis, astrogliosis, synaptic loss, and spatial learning and memory deficits. Thus, the age-related increase in CCL11 may be a risk factor of AD, and antagonizing CCR3 may bring therapeutic benefits to AD.