Tacrolimus impairs airway mucociliary clearance of rats

OBJECTIVES

Tacrolimus (TAC) is the most widely used immunosuppressive agent after lung transplantation. Considering that the ciliary beat frequency (CBF) mainly depends on the cytoplasmic calcium concentration and that TAC can affect this due to its binding with the intracellular immunophilin FKBP12, we hypothesized that TAC could also impair the airway mucociliary clearance of rats.

METHODS

Sixty rats were divided into two groups (n = 30 each): Control = water; TAC = tacrolimus. After 7, 15 or 30 days of treatment, ten animals from each group were euthanized and the following parameters were studied: mucus transportability, CBF, mucociliary transport velocity (MCTV), and neutral and acid mucus production.

RESULTS

There was a significant decrease in CBF (Control vs TAC: 7 days, p = 0.008; 15 days, p = 0.007; 30 days, p = 0.001) and MCTV (Control vs TAC: 7 days, p = 0.004; 15 days, p < 0.001; 30 days, p < 0.001) in all immunosuppressed animals. TAC therapy also caused an increase in acid mucus production at all treatment times (Control vs TAC: 7 days, p = 0.001; 15 days, p = 0.043; 30 days, p = 0.001).

CONCLUSIONS

TAC impairs airway mucociliary clearance of rats.

Exposure to fine particulate matter in the air alters placental structure and the renin-angiotensin system

METHODS

Female Wistar rats were exposed to filtered air (F) or to concentrated fine particulate matter (P) for 15 days. After mating, the rats were divided into four groups and again exposed to F or P (FF, FP, PF, PP) beginning on day 6 of pregnancy. At embryonic day 19, the placenta was collected. The placental structure, the protein and gene expression of TGFβ1, VEGF-A, and its receptor Flk-1 and RAS were evaluated by indirect ELISA and quantitative real-time PCR.

RESULTS

Exposure to P decreased the placental mass, size, and surface area as well as the TGFβ1, VEGF-A and Flk-1 content. In the maternal portion of the placenta, angiotensin II (AngII) and its receptors AT1 (AT1R) and AT2 (AT2R) were decreased in the PF and PP groups. In the fetal portion of the placenta, AngII in the FP, PF and PP groups and AT2R in the PF and PP groups were decreased, but AT1R was increased in the FP group. VEGF-A gene expression was lower in the PP group than in the FF group.

CONCLUSIONS

Exposure to pollutants before and/or during pregnancy alters some characteristics of the placenta, indicating a possible impairment of trophoblast invasion and placental angiogenesis with possible consequences for the maternal-fetal interaction, such as a limitation of fetal nutrition and growth.