NOREPINEPHRINE MODULATES DAILY CLOCK EXPRESSION IN EX VIVO SPLENIC MACROPHAGES

CARGNELLUTTI E; ANZULOVICH AC

MENDOZA

Congreso; SBCuyo 2022; 2022

The time of day is critical to define the nature of the immune response since dysregulation of this mechanism can lead toinflammatory diseases or immunodeficiencies. In mammals, the central clock in the suprachiasmatic nucleus (SCN) synchronizes cell-auto ize and eliminatecirculating pathogens and orchestrate the development of the specific acquired immune response. However, the centralcircadian regulation of these splenic cells has not been completely elucidated yet. Communication between SCN andcells. Previously, other authors reported daily oscillation of NE in the spleen. In order to study the role of NE in theguanethidine administration. Animals were maintained under 12 h-light:12 h-dark conditions and ad libitum food/waterof saline solution or guanethidine, control (N = 4/ZT) and sympathectomized rats (N = 3/ZT) were euthanized at differenttimes during a 24-h period (ZT2, ZT6, ZT10, ZT14, ZT18, and ZT22), and the spleen was aseptically removed for exvivo cultures. The BMAL1 and ACTIN protein levels were analyzed by Western blot from splenic adherent cells. Timepointdata were computed by one-way analysis of variance (ANOVA) and followed by the Tukey post hoc test. Further,chronobiologic statistics were used for validating temporal changes as rhythms. Thus, each series of data were analyzedby the Cosinor method. Since BMAL-1 modulate Rev- , whichin turn represses Bmal-1 expression through the accessory loop of the molecular clock, the relative quantification of thisgene was evaluated by q-PCR, using s28 as reference gene. In this case, cDNA was obtained from ex vivo splenic adherentcells cultivated from control and sympathectomized rats, at ZT6, ZT14, and ZT 18. The Student t-test was used for thefrom control rats showed a daily oscillation of BMAL1 (%rhythm: 71.8), with its acrophase occurring in the middle of the light period. Noteworthy, the ex vivoguanethidine-treated animals lost the 24-h oscillation of BMAL1 and showed significantly lower levels of this clockfactor compared to the control. On the order hand, sympathectomized rats show a significantly higher Revexpression,at the three analyzed ZTs (P > 0.05), compared to the control group. Our results would indicate that exists aSCN regulation on the molecular clock in splenic adherent cells through the NE sympathetic pathway.