Adsa Logo White Adsa Title White

Gene expression in the uterus of heifers challenged with lipopolysaccharide.

E. Schmitt

Events

06-23-2020

Join E. Schmitt on this page for a live text chat!
6:00 PM - 8:00 PM GMT

Abstract:

T101
Gene expression in the uterus of heifers challenged with lipopolysaccharide.
J. Alvarado-Rinc�n, G. de Avila Ferronato, A. Stein Maffi, A. Amaral Barbosa, R. Klaus, J. Feij�, F. Del Pino, G. Bueno Luz, B. Garziera Gasperin, R. Gianella Mondadori, E. Schmitt*, V. Rohrig Rabassa, M. Nunes Correa, C. Cassal Brauner. N�cleo de Pesquisa, Ensino e Extens�o em Pecu�ria, UFPel Pelotas, RS, Brazil.

Even in subclinical form, infectious or metabolic diseases can cause an increase in lipopolysaccharide (LPS) in the bloodstream, which has been negatively associated with fertility. The aim of the study was to investigate the expression of genes associated with the uterine environment quality and inflammation in the uterus of heifers challenged with LPS. Beef heifers (n = 16) Bos taurus, healthy, 14 mo of age, in confinement system, were submitted to a hormonal protocol for follicular wave synchronization (Day-14: PGF2α; Day 0: insertion P4 device, Estradiol benzoate, and PGF2α). On d 0 the LPS group (n = 8) received 2 intravenous applications of 2 mL of saline solution containing 0.5 �g/kg of BW of LPS (E. Coli, Sigma Aldrich Missouri, USA) with an interval of 24h and the control group (n = 8) received 2 intravenous applications of 2 mL of saline solution with the same interval. The body temperature was measured at 0, 4, 24, and 28h. All animals were slaughtered on d 5, when uterine samples were collected. Relative expression was calculated using the RN18S1 and GAPDH genes as housekeeping, and genes associated with LPS recognition (TLR4), inflammatory response (IL-1β and TNF) and quality of the uterine environment (PTGS2 and NANOG) were evaluated. The body temperature of the LPS group was greater than the control, at 4h (39.9 � 0.2�C vs 39.1 � 0.1�C, P < 0.05) and at 28h (40.4�C � 0.3�C vs 39.3 � 0.1�C, P < 0.05). This result indicates that the dose of LPS used was able to generate a systemic inflammatory response 4h after each challenge. In addition, the LPS generated a decrease of 53% in the relative expression of PTGS2 (LPS: 0.47 � 0.18 vs Control: 1.0 � 0.13, P = 0.024) and of 92% for NANOG (LPS: 0.08 � 0.07 vs Control: 1.0 � 0.4, P = 0.020). However, TLR4, TNF, and IL�-1β were not affected by LPS. This is the first in vivo study to use this methodology (dose and interval) and it was found that directly or indirectly, the systemic challenge with LPS altered the expression of genes involved in the synthesis of E2 prostaglandin and cellular pluripotency, important mediators in the implementation of embryo and in the endometrial regeneration process.

Keywords: fertility, inflammation, LPS.