Effects of Diets Enriched in Linseed and Fish Oil on the Expression Pattern of Toll-Like Receptors 4 and Proinflammatory Cytokines on Gonadal Axis and Reproductive Organs in Rabbit Buck

Abstract

Infections of the genital tract can perturb the fertility in humans and animals. Pathogen recognition and activation of innate immunity onset through the pattern recognition receptor activation, such as Toll-like receptor 4 (TLR4), leading to the production of proinflammatory cytokines and mediators. TLR4 is expressed both on leukocytes and nonimmune cells. Rabbit TLR4 shows great similarity to its human counterpart. Moreover, the TLR4 signalling pathway could be modulated by long-chain polyunsaturated fatty acids (LC-PUFA). The objectives of this study were (i) to determine the expression levels of TLR4 and proinflammatory cytokines in the reproductive hypothalamic-gonadal axis of the male rabbit and (ii) to evaluate if the n-3 PUFA-enriched diets can modify their expression levels in the tissues and LC-PUFA profiles in seminal plasma. Fifteen rabbit bucks (n=5/experimental group) were fed with different diets: commercial standard (group C), rich in extruded linseed (10%, group L), and in fish oil (3%, group FO) for 110 days. TLR4, TNF-α, and IL-1β mRNA were ubiquitously expressed throughout the hypothalamic-gonadal axis. However, TLR4 mRNA expression was lower in the hypothalamus than the epididymis (P<0.01), seminal vesicles (P<0.01), and pituitary gland (P<0.05). Dietary enrichment in PUFA did not modify the gene expression profile nor the histological characteristics of the tissues. Conversely in seminal plasma, rabbits fed with L and FO had lower n-6 (P<0.05), LC-PUFA n-6 (P<0.05), and n-6/n-3 ratio (P<0.05) but higher n-3 (P<0.001) and LC-PUFA n-3 (P<0.01) compared to the control group. Our study builds a map of the gene expression of TRL4 and proinflammatory cytokines in the reproductive hypothalamic-gonadal axis of the male rabbit, fundamental step for understanding the immune defence mechanisms. Diets enriched in LC-PUFA did not affect basal gene expression but modulated sperm fatty acid composition. Finally, rabbit may be an excellent animal model to study the relationship between inflammation and infertility, and the nutritional modulation of immune functions.

Impact of Goji Berries (Lycium barbarum) Supplementation on the Energy Homeostasis of Rabbit Does: Uni- and Multivariate Approach

“…Beside several biological active compounds such as carotenoids, vitamins (riboflavin, thiamin and ascorbic acid) and flavonoids, goji berry is primarily rich in polysaccharides [1] which are responsible for the main beneficial pharmacological effects of the fruit both in vitro [5][6][7][8] and in vivo in various laboratory animal species [9,10] and in clinical trials in humans [11,12]. The effects of the goji berries are mainly studied in laboratory animals such as mice and rats [9,10,13] and only a few trials were conducted using the rabbit [14][15][16] although it is considered a useful experimental animal model [17][18][19][20][21][22]. Moreover, only a limited number of researches evaluated the effects of goji berry on the reproductive and productive performance, other than on the quality of meat, in livestock animals, rabbits included [15,16,[23][24][25].…”

Impact of Dietary Supplementation with Goji Berries (Lycium barbarum) on Microbiological Quality, Physico-Chemical, and Sensory Characteristics of Rabbit Meat

“…The use of nutraceutical products in breeding could be a marketing strategy that also meets the needs of animal welfare [ 21 ]. Furthermore, the rabbit is an excellent animal model for other species [ 25 , 26 ] that could benefit from the positive effects of goji berries.…”

The Prophylactic Use of Bovine Colostrum in a Murine Model of TNBS-Induced Colitis

“…Microbial recognition performed by immune and epithelial cells through the toll-like receptors is essential to begin the immune response and, at the same time, maintain a state of immune tolerance [13,14]. Specifically, toll-like receptors 4 (TLR4) are expressed on the surface of different intestinal cells and play a crucial role in several intestinal functions as well as in the host defense [14][15][16]. TLR4 recognizes lipopolysaccharides (LPS), which is the major component of the outer membrane of the cell wall of Gram-negative bacteria [15][16][17].…”

“…Specifically, toll-like receptors 4 (TLR4) are expressed on the surface of different intestinal cells and play a crucial role in several intestinal functions as well as in the host defense [14][15][16]. TLR4 recognizes lipopolysaccharides (LPS), which is the major component of the outer membrane of the cell wall of Gram-negative bacteria [15][16][17]. The interaction between TLR4 and LPS results in a cascade of intracellular signaling pathways leading to the activation of the nuclear factor kB (NF-kB) [13,14] and subsequently to the transcription of several genes involved in the host defense including those for the inflammatory cytokines, chemokines, and other inflammatory mediators [15,16,18].…”