MEIS1 and BTBD9: genetic association with restless leg syndrome in end stage renal disease
JOURNAL OF MEDICAL GENETICS
Authors: Schormair, Barbara; Plag, Jens; Kaffe, Maria; Gross, Nadine; Czamara, Darina; Samtleben, Walter; Lichtner, Peter; Stroehle, Andreas; Stefanidis, Ioannis; Vainas, Andreas; Dardiotis, Efthimios; Sakkas, George K.; Gieger, Christian; Mueller-Myhsok, Bertram; Meitinger, Thomas; Heemann, Uwe; Hadjigeorgiou, Georgios M.; Oexle, Konrad; Winkelmann, Juliane
Abstract
Background Restless legs syndrome (RLS) is a sleep related movement disorder that occurs both in an idiopathic form and in symptomatic varieties. RLS is a frequent and distressing comorbidity in end stage renal disease (ESRD). For idiopathic RLS (iRLS), genetic risk factors have been identified, but their role in RLS in ESRD has not been investigated yet. Therefore, a case-control association study of these variants in ESRD patients was performed. Methods The study genotyped 10 iRLS associated variants at four loci encompassing the genes MEIS1, BTBD9, MAP2K5/SKOR1, and PTPRD, in two independent case-control samples from Germany and Greece using multiplex PCR and MALDI-TOF (matrix assisted laser desorption/ionisation time-of-flight) mass spectrometry. Statistical analysis was performed as logistic regression with age and gender as covariates. For the combined analysis a Cochran-Mantel-Haenszel test was applied. Results The study included 200 RLS-positive and 443 RLS-negative ESRD patients in the German sample, and 141 and 393 patients, respectively, in the Greek sample. In the German sample, variants in MEIS1 and BTBD9 were associated with RLS in ESRD (P-nom <= 0.004, ORs 1.52 and 1.55), whereas, in the Greek sample, there was a trend for association to MAP2K5/SKOR1 and BTBD9 (P-nom <= 0.08, ORs 1.41 and 1.33). In the combined analysis including all samples, BTBD9 was associated after correction for multiple testing (P-corrected=0.0013, OR 1.47). Conclusions This is the first demonstration of a genetic influence on RLS in ESRD patients with BTBD9 being significantly associated. The extent of the genetic predisposition could vary between different subgroups of RLS in ESRD.
Astrocyte-specific overexpressed gene signatures in response to methamphetamine exposure in vitro
JOURNAL OF NEUROINFLAMMATION
Authors: Bortell, Nikki; Basova, Liana; Semenova, Svetlana; Fox, Howard S.; Ravasi, Timothy; Marcondes, Maria Cecilia G.
Abstract
Background: Astrocyte activation is one of the earliest findings in the brain of methamphetamine ( Meth) abusers. Our goal in this study was to identify the characteristics of the astrocytic acute response to the drug, which may be critical in pathogenic outcomes secondary to the use. Methods: We developed an integrated analysis of gene expression data to study the acute gene changes caused by the direct exposure to Meth treatment of astrocytes in vitro, and to better understand how astrocytes respond, what are the early molecular markers associated with this response. We examined the literature in search of similar changes in gene signatures that are found in central nervous system disorders. Results: We identified overexpressed gene networks represented by genes of an inflammatory and immune nature and that are implicated in neuroactive ligand-receptor interactions. The overexpressed networks are linked to molecules that were highly upregulated in astrocytes by all doses of methamphetamine tested and that could play a role in the central nervous system. The strongest overexpressed signatures were the upregulation of MAP2K5, GPR65, and CXCL5, and the gene networks individually associated with these molecules. Pathway analysis revealed that these networks are involved both in neuroprotection and in neuropathology. We have validated several targets associated to these genes. Conclusions: Gene signatures for the astrocytic response to Meth were identified among the upregulated gene pool, using an in vitro system. The identified markers may participate in dysfunctions of the central nervous system but could also provide acute protection to the drug exposure. Further in vivo studies are necessary to establish the role of these gene networks in drug abuse pathogenesis.