LPS suppressed progesterone P4 and androstenedione A4 production with downregulation of steroidogenic enzyme transcripts when theca cells were stimulated with LH. These findings suggest a possible mechanism of ovarian dysfunction and subsequent infertility in cows with endometritis. Keywords: Androstenedione, Dairy cow, Lipopolysaccharide, Progesterone, Theca cells Uterine bacterial infection commonly occurs in postpartum dairy cows and perturbs uterine and ovarian function [ 1 ].
Cows with metritis display slower growth of the first postpartum dominant follicle and lower peripheral plasma estradiol E2 , and in ovulating animals, peripheral plasma progesterone P4 concentrations are lower [ 4 ]. Escherichia coli is among the main types of bacteria causing endometritis, and much of the tissue pathology is associated with the bacterial endotoxin lipopolysaccharide LPS [ 5 ].
LPS has been detected in the follicular fluid FF of cows with endometritis [ 6 ], suggesting a relationship between uterine inflammation, LPS production and follicular function. The first step in follicular biosynthesis of steroid hormones occurs in theca cells; P4 is synthesized by the conversion of cholesterol and is later converted into androstenedione A4. A4 diffuses through the basement membrane and is converted to E2 by granulosa cells [ 13 ].
In vitro studies have shown that LPS suppresses E2 production in granulosa cells from large and small follicles of bovine ovaries [ 6 , 14 ].
However, the effect of LPS on steroid production in theca cells is somewhat controversial; Taylor and Terranova have shown that LPS perturbs P4 and A4 production in rat ovarian theca cells [ 16 ], whereas A4 production of bovine theca cells was reported to be unaffected by LPS [ 6 ]. This discrepancy between these two studies might be due to the difference in species or the presence of LH stimulation.
In the study of Taylor and Terranova, steroid production of theca cells was stimulated by LH. After antrum formation, the steroidogenic functions of follicles are regulated by gonadotrophins [ 13 ] and locally produced factors such as E2 [ 17 ]. The objective of the present study was to determine the effect of LPS on steroid production of bovine theca cells under LH conditions, E2 conditions or both conditions. In addition, the distinct effect of LPS on theca cell function at different stages of follicular development was investigated.
Sample collection and classification of the developmental stage of follicles Ovaries of multiparous Holstein cows were obtained at a local slaughterhouse and placed in ice-cold PBS. All ovaries were collected from cows without any signs of uterine inflammation or from cows not within 3 weeks postpartum.
Healthy developing follicles were assessed as described by Metcalf et al. Follicular fluid FF was aspirated using a syringe with a gauge needle, and the follicle diameter was determined from the weight of the FF, as previously described by Murasawa et al. Theca cells were isolated from these follicles using the following method [ 21 ]. Briefly, follicles were opened by making a small incision on the surface, and theca cells were obtained by manually peeling the basal lamina.
Granulosa cells were removed from the peeled theca cells by gentle scraping with a medicine spatula. The complete removal of granulosa cells was confirmed under a stereomicroscope. In postpartum dairy cows, various inflammatory diseases depress reproductive performance. Lipopolysaccharide LPS derived from infections of the uterus or mammary gland with Gram-negative bacteria was shown to suppress steroid production in the granulosa cells of follicles in vitro.
The aim of the study was to investigate the relationship between LPS in ovarian follicular fluid and steroidogenesis by the theca and granulosa cells of the large follicles in vivo.
LPS concentration in the follicular fluid was measured using quantitative kinetic assay. Follicular steroidogenesis was evaluated by measuring the estradiol E2 and progesterone P4 concentration in follicular fluid and by analysing transcription levels of steroidogenesis-related genes in theca and granulosa cells. LPS concentration detected in follicular fluid ranged from 0.Mitkin, Angelo Palmigiano, Andrey A. Holmes, Sara M. Swierzko, Marcin A. Reproductive axis response to repeated lipopolysaccharide administration in peripubertal female rats. Effects of lipopolysaccharide and cyclosporin on the endocrine control of ovarian function.
International Journal of Infectious Diseases , 33,
Granulosa cells were removed from the peeled theca cells by gentle scraping with a medicine spatula. This article has been cited by other articles in PMC. Prolactin and lipopolysaccharide treatment increased apoptosis and atresia in rat ovarian follicles.
Nedospasov, Yuriy A. Katarzyna Kasperkiewicz, Anna S. Kruglov, Georgy B. The cell viability was measured with the trypan blue exclusion test. To induce and maintain P4 and A4 production by theca cells, we added a physiological concentration of LH 2. The tissues were collected at PND 39, then were applied to the standard paraffin section and hematoxylin-eosin staining method.
A strain of Yersinia pestis with a mutator phenotype from the Republic of Georgia.
Anisimov, A. Dispersed cells were washed twice with PBS. J Physiol Biochem. Healthy developing follicles were assessed as described by Metcalf et al. CYP11A1 is a cholesterol side-chain cleavage enzyme, commonly referred to as Pscc, and this is a mitochondrial enzyme that catalyzes conversion of cholesterol to pregnenolone. Skowronski, Kevin P.
Each medium contained 0, 0. Differential impact of lipopolysaccharide defects caused by loss of RfaH in Yersinia pseudotuberculosis and Yersinia pestis. Our findings that chronic LPS exposure elicits the changes in the expressions of steroidogenesis-related genes in rat ovary support this hypothesis. Abstract In postpartum dairy cows, lipopolysaccharide LPS derived from gram-negative bacteria such as Escherichia coli causes uterine inflammation and leads to ovarian dysfunction.
In postpartum dairy cows, various inflammatory diseases depress reproductive performance. The wells were then washed twice with PBS to remove unattached cells. Differential impact of lipopolysaccharide defects caused by loss of RfaH in Yersinia pseudotuberculosis and Yersinia pestis. Sviriaeva, Nikita A.
Dillon, John Bertin, Peter J. Systemic LPS treatment over a period of 6 days induced a state of constant dioestrus and decreased circulating concentrations of progesterone and estradiol, and resulted in significantly fewer large preovulatory follicles in adult rats Shakil et al. Oyler, Courtney E. Neonatal lipopolysaccharide exposure delays puberty and alters hypothalamic Kiss1 and Kiss1r mRNA expression in the female rat. The aim of the study was to investigate the relationship between LPS in ovarian follicular fluid and steroidogenesis by the theca and granulosa cells of the large follicles in vivo. Neonatal LPS exposure resulted in the down-regulation of Kiss1 expression in the mPOA of prepubertal females rats, suggesting that the mPOA population of kisspeptin neurones play a pivotal role in controlling the onset of puberty, and that their function can be affected by neonatal stress such as immune challenge Knox et al.
The wells were then washed twice with PBS to remove unattached cells. The aim of the study was to investigate the relationship between LPS in ovarian follicular fluid and steroidogenesis by the theca and granulosa cells of the large follicles in vivo.
The objective of the present study was to determine the effect of LPS on steroid production of bovine theca cells under LH conditions, E2 conditions or both conditions.