Tumor necrosis factor-α inhibits the stimulatory effect of luteinizing hormone and prostaglandin E(2) on progesterone secretion by the bovine corpus luteum

Form of Supplemental Selenium Affects the Expression of mRNA Transcripts Encoding Selenoproteins, and Proteins Regulating Cholesterol Uptake, in the Corpus Luteum of Grazing Beef Cows

Selenium (Se)-deficient soils necessitate supplementation of this mineral to the diet of forage-grazing cattle. Functionally, Se is incorporated into selenoproteins, some of which function as important antioxidants. We have previously shown that the source of supplemental Se; inorganic (sodium selenite or sodium selenate; ISe), organic (selenomethionine or selenocysteine; OSe) or 1:1 mix of ISe and OSe (MIX), provided to Angus-cross cows affects concentrations of progesterone (P4) during the early luteal phase of the estrous cycle. In this study, we sought to investigate (1) the effect of form of Se on the expression of mRNA encoding selenoproteins in the corpus luteum (CL), and (2) whether this previously reported MIX-induced increase in P4 is the result of increased luteal expression of key steroidogenic transcripts. Following a Se depletion and repletion regimen, 3-year-old, non-lactating, Angus- cross cows were supplemented with either ISe as the industry standard, or MIX for at least 90 days, with the CL then retrieved on Day 7 post-estrus. Half of each CL was used for analysis of targeted mRNA transcripts and the remainder was dissociated for culture with select agonists. The expression of three selenoprotein transcripts and one selenoprotein P receptor was increased (p < 0.05), with an additional five transcripts tending to be increased (p < 0.10), in cows supplemented with MIX versus ISe. In cultures of luteal cells, hCG-induced increases in P4 (p < 0.05) were observed in CL obtained from ISe-supplemented cows. The abundance of steroidogenic transcripts in the CL was not affected by the form of Se, however, the abundance of mRNA encoding 2 key transcripts regulating cholesterol availability (Ldlr and Hsl) was increased (p < 0.05) in MIX-supplemented cows. Overall, the form of Se provided to cows is reported to affect the expression of mRNA encoding several selenoproteins in the CL, and that the form of Se-induced effects on luteal production of P4 appears to be the result of changes in cholesterol availability rather than a direct effect on the expression of steroidogenic enzymes within the CL.

Tumor necrosis factor-alpha promoter polymorphisms are associated with idiopathic primary ovarian insufficiency in Korean women

OBJECTIVE

To investigate the possible association between primary ovarian insufficiency (POI) and TNF-α gene polymorphisms in Korean women.

DESIGN

Case-control study.

SETTING

An urban university-based hospital in South Korea.

PATIENT(S)

A cohort of 135 Korean POI patients and 236 controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

We analyzed TNF-α gene variants of all participants using the polymerase chain reaction-restriction fragment length polymorphism assay.

RESULT(S)

The TNF-α -1031TC+CC, -238GA+AA, -1031TC+CC/-308GG, -1031TT/-308GA+AA, -1031TC+CC/-238GA+AA, and -308GG/-238GA+AA genotypes were significantly more frequent in POI patients than in controls. Among the haplotypes for the three TNF-α loci, the -1031C/-308G/-238A haplotype was more frequent in POI patients than in controls and conferred POI susceptibility. In analyses of two loci, the -1031T/-308A, -1031C/-308G, -1031C/-238A, and -308G/-238A haplotypes were more frequent in POI patients.

CONCLUSION(S)

The TNF-α -1031C and -238A alleles had strong association with POI. The TNF-α -308A allele showed limited significance for POI risk with the presence of the -1031T allele. Our data suggest that the minor alleles of TNF-α promoter polymorphisms may increase POI risk in Korean women.