Changes of the epigenetic adjustment of distinctive genes are associated with major individual diseases and specifically carcinogenesis
Moreover, the new definition of drug resistant epilepsy was failure of adequate trials of two tolerated and appropriately chosen and used AED schedules to achieve sustained seizure freedom. In all eligible studies, types of AEDs were also variable. Moreover, drug-response was defined as patients with no seizure for more than three times the pretreatment interseizure interval or 12 months, whichever is longer, which was applied only in three studies. Several limitations need to be considered for interpretation of our results. First, most AED responses are influenced by an interaction of multiple factors: environmental or patient-related factors and characteristics of the epilepsy itself, and genetic factors, statistical adjustment for individual level factors were not carried out for the insufficient data. Second, types of seizures might also cause variety in AEDs types, dosage, and drug response, a subgroup analysis by types of seizures was necessary in further meta-analysis. Finally, the definition used to classify patients as being drug-resistance has varied in different studies, which may contribute to the variations in the results. Lymphotoxin beta receptor signaling plays a crucial role in development of secondary lymphoid organs. Surface lymphotoxin is a transmembrane heterotrimeric protein that belongs to the tumor necrosis factor family and is expressed by lymphoid tissue inducer cells during early phases of SLO formation. Acting through LTbR on lymphoid tissue organizer cells and earlier on their mesenchimal precursors, it activates synthesis of chemokines, adhesion molecules and lymphangiogenic factors through classical and alternative NFkB pathways, leading to maturation of stroma and lymphocyte homing. In postnatal period, LTbR signaling is required for follicular dendritic cell maintenance and germinal center formation in lymph nodes. And it is even more important in spleen, where postnatal LTbR-Ig treatment leads to disruption of follicles and marginal zone, as well as GC failure. Clusterin, and X-ray-inducible transcript 8) was first described as the major glycoprotein in ram rete testis fluid with the capacity to elicit clustering of cells in an in vitro assay. It is a multifunctional protein, which is mainly studied for its role in neurodegeneration and cancer. Its mRNA is present at relatively high levels in brain, ovary, testes, liver, heart and adrenal gland; at moderate levels in spleen, lung, breast, kidney, seminal vesicle, prostate, and uterus; at low levels in skin, bone, thymus and digestive tract; and is absent in T-lymphocytes. Clusterin participates in tissue remodeling, apoptosis, lipid transport, complement-mediated cell lysis, and serves as an extracellular chaperone. At the protein level, clusterin was found in non-lymphoid cells of many SLO: gut-associated lymphoid tissue, Waldeyer’s ring, reactive tonsils, lymph nodes and spleen, but virtually nothing is known about its function in these organs. Clusterin is also present in medullary epithelial stromal cells of the primary lymphoid organ - thymus, but its precise function there is also not clear. In the present work we used expression profiling to identify new potential target genes of LTbR signaling pathway by comparing transcriptomes of spleen stromal cells derived from wild type and LTbR knock-out mice. Since LTbR signaling drives morphogenesis and functional maturation of SLO, we expected to find new immunity-relevant genes among its targets. After filtration of the microarray results we focused on clusterin as it was significantly downregulated in LTbR-deficient spleen at both mRNA and protein level and its function in the immune system was poorly studied. We demonstrated activation of clusterin gene transcription upon interaction of mouse embryonic fibroblasts with lymphoid cells bearing LT and significant changes in clusterin protein level and tissue distribution during primary immune response to T-dependent antigen. There are several CLU protein isoforms encoded by two CLU gene transcripts. The main and longer gene transcript encodes glycosylated presecretory form psCLU with apparent molecular weight of about 60 kDa. Cleavage into a- and b-chains and further extensive glycosylation produces a mature, secreted heterodimeric 70-80 kDa protein referred to as sCLU. Under reducing conditions both a- and b-subunits of sCLU run at about 40 kDa at SDS-PAGE. The second transcript lacks the endoplasmic reticulum-targeting sequence at exon 2 and its product is detected as 49 kDa non-glycosylated pnCLU precursor in the cytosol and a 55-kDa glycosylated nCLU protein in the nucleus. Secretory and nuclear forms of clusterin are considered to have somewhat opposing functions, with sCLU being a cell-protective, anti-apoptotic protein, and nCLU acting as a pro-death signal, inhibiting cell growth and survival. As it is important for understanding the clusterin functions in SLO, we assessed CLU protein isoform in the splenic stroma using Western blot. Clusterin immunopositive band ran around 70 kDa in non-reducing conditions, and around 40 kDa in reducing conditions, which corresponds to sCLU and its two co-migrating subunits, respectively.