Evaluating Zinc importance on lymphocytes activity in hormone hypothyroid conditions.

KLECHA, A.; PAULAZO M.A.; STERLE, H.; DÍAZ FLAQUÉ M.C.; CAYROL M.F.; BARREIRO ARCOS, M.L.; CREMASCHI, G.

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedad Argentina de Investigación Clínica (SAIC) en conjunto con Sociedades de Biociencias

Immunity is modulated by a complex net of immune and neuroendocrine factors, among them, hypothyroidism leading to immunosupression. Aditionally, zinc (Zn) is a trace element which déficit induces a decrease in lymphocyte number and activity as well as adversely affects the synthesis, metabolism and action of thyroid hormones (TH). Our aim was to study in hyphothyroid conditions may alter zinc metabolism and if this is related to the impairment in T lymphocyte activity. We evaluated the impacto f hypothyroidism on Zn metabolism and its posible relationship with T cell activity. Hypothyroid mice showed lower levels of zinc in femur and lymph nodes tan controls. T3 reversion of the hypothyroid status, as well as Zn supplementation revert these effects (p≤0.05). Conversely, hormone hypothyroid conditions were not altered by Zn administration. In vitro, both TH and Zn depletion in culture (by Zn chelators) lead to a decreased response to Con A stimulus, effect sectively reverted by TH or Zn addition, respectively. Zn, but not TH déficit was able to induce lymphocyte apoptosis. In vivo Zn deficiency resembles hypothyroidism as it leads to an impared proliferation of T cells by selective mitogens. The role of intracellular signals actived by the mitogen stimulus was evaluated in T lymphocytes from hypothyroid mice before and after T3 or Zn replacement. We found decreased translocation of PKC to cell membranes respect to euthyroid mice and lower levels of p-ERK after Con A stimulus reverted by both T3 replacement and Zn supplementation (p≤0.01). Also, Zn supplementation was able to re-establish proliferative responses in a similar manner tan T3 replacement in lymphocytes from hypothyroid mice. Our results showed an important relationship between Zn deficiency and hypothyroidism mediated immunosupression, thus strengthening the relevance of Zn levels in hypothyroid mice.