Hemodialysis Affects Phenotype and Proliferation of CD4-Positive T Lymphocytes

CD4+ T lymphocytes of patients with chronic kidney disease (CKD) are characterized by reduced levels of crucial surface antigens and changes in the cell cycle parameters. Recombinant human erythropoietin (rhEPO) normalizes their altered phenotype and proliferative capacity. Mechanisms leading to the deficient responses of T lymphocytes are still not clear but it is postulated that immunological changes are deepened by hemodialysis (HD). Study of activation parameters of CD4+ T lymphocytes in hemodialyzed and predialysis CKD patients could bring insight into this problem. Two groups of patients, treated conservatively (predialysis, PD) and hemodialyzed (HD), as well as healthy controls, were included into the study; neither had received rhEPO. Proportions of main CD4+CD28+, CD4+CD25+, CD4+CD69+, CD4+CD95+, and CD4+HLA-DR+ lymphocyte subpopulations and proliferation kinetic parameters were measured with flow cytometry, both ex vivo and in vitro. No differences were seen in the proportions of main CD4+ lymphocyte subpopulations (CD4+CD28+, CD4+CD25+, CD4+HLA-DR+, CD4+CD69+, CD4+CD95+) between all examined groups ex vivo. CD4+ T lymphocytes of HD patients exhibited significantly decreased expression of co-stimulatory molecule CD28 and activation markers CD25 and CD69 after stimulation in vitro when compared with PD patients and healthy controls. HD patients showed also decreased percentage of CD4+CD28+ lymphocytes proliferating in vitro; these cells presented decreased numbers of finished divisions after 72 h of stimulation in vitro and had longer G0→G1 time when compared to healthy controls. CD4+ T lymphocytes of PD patients and healthy controls were characterized by similar cell cycle parameters. Our study shows that repeated hemodialysis procedure influences phenotype and proliferation parameters of CD4+ T lymphocytes

Fumarate modulates the immune/inflammatory response and rescues nerve cells and neurological function after stroke in rats.

BACKGROUND: Dimethyl fumarate (DMF), working via its metabolite monomethylfumarate (MMF), acts as a potent antioxidant and immunomodulator in animal models of neurologic disease and in patients with multiple sclerosis. These properties and their translational potential led us to investigate whether DMF/MMF could also protect at-risk and/or dying neurons in models of ischemic stroke in vitro and in vivo. Although the antioxidant effects have been partially addressed, the benefits of DMF immunomodulation after ischemic stroke still need to be explored. METHODS: In vitro neuronal culture with oxygen-glucose deprivation and rats with middle cerebral artery occlusion were subjected to DMF/MMF treatment. Live/dead cell counting and LDH assay, as well as behavioral deficits, plasma cytokine assay, western blots, real-time PCR (Q-PCR) and immunofluorescence staining, were used to evaluate the mechanisms and neurological outcomes. RESULTS: We found that MMF significantly rescued cortical neurons from oxygen-glucose deprivation (OGD) in culture and suppressed pro-inflammatory cytokines produced by primary mixed neuron/glia cultures subjected to OGD. In rats, DMF treatment significantly decreased infarction volume by nearly 40 % and significantly improved neurobehavioral deficits after middle cerebral artery occlusion (MCAO). In the acute early phase (72 h after MCAO), DMF induced the expression of transcription factor Nrf2 and its downstream mediator HO-1, important for the protection of infarcted cells against oxidative stress. In addition to its antioxidant role, DMF also acted as a potent immunomodulator, reducing the infiltration of neutrophils and T cells and the number of activated microglia/macrophages in the infarct region by more than 50 % by 7-14 days after MCAO. Concomitantly, the levels of potentially harmful pro-inflammatory cytokines were greatly reduced in the plasma and brain and in OGD neuron/glia cultures. CONCLUSIONS: We conclude that DMF is neuroprotective in experimental stroke because of its potent immunomodulatory and antioxidant effects and thus may be useful as a novel therapeutic agent to treat stroke in patients