B-cell lymphoma 6 expression significantly differs by the uterine preparation method used for frozen embryo transfer.

OBJECTIVE: To determine whether B-cell lymphoma 6 (BCL6), an endometriosis-associated marker postulated to predict poor pregnancy outcomes, is differentially expressed in the window of implantation with various uterine preparation regimens commonly used for frozen embryo transfers. DESIGN: A retrospective cohort study. SETTING: An academic center. PATIENT(S): Patients with infertility who underwent endometrial biopsy for BCL6 evaluation INTERVENTION(S): Exogenous estradiol and/or progesterone. MAIN OUTCOME MEASURE(S): Endometrial BCL6 histological score (HSCORE) and overexpression (HSCORE >1.4) RESULT(S): Two hundred and forty-four patients were included in the analysis: 76 patients were sampled in a natural menstrual cycle without exogenous hormone exposure (NC), 25 under a modified natural cycle embryo transfer protocol with choriogonadotropin alfa injection followed by luteal phase vaginal progesterone supplementation (mNC), and 143 under a programmed cycle embryo transfer protocol, with estradiol administration followed by addition of intramuscular progesterone-in-oil injections (PC). Median HSCORE (interquartile range) was the highest in NC (3.0 [1.8-3.6]). BCL6 expression was significantly lower in mNC (1.1 [0.4-2.1]) and PC groups (0.8 [0.3-1.3]) compared with NC. In addition, BCL6 overexpression (HSCORE >1.4) was observed in 80.3% of NC, 40.0 % of mNC, and 23.1 % of PC. After adjusting for covariates, the endometrium exposed to exogenous progesterone had significantly lower odds of BCL6 overexpression than that of a natural menstrual cycle (adjusted odds ratio, 0.12 [95% CI 0.04-0.35] for mNC; and odds ratio, 0.08 [95% CI 0.04-0.17] for PC). CONCLUSION(S): BCL6 expression differs by the type of uterine preparation method, with lower levels observed with exogenous progesterone exposure. The validity and utility of BCL6 testing under medicated endometrial state warrants further investigation.

The transcription factor interferon regulatory factor-1 mediates liver damage during ischemia-reperfusion injury.

Hepatic ischemia occurs in the settings of trauma, transplantation, and elective liver resections. The initiating events that account for local organ damage are only partially understood. Interferon (IFN) regulatory factor-1 (IRF-1) is a transcription factor that regulates the expression of a number of genes involved in both innate and acquired immunity; however, its function in liver injury is unknown. Therefore, the purpose of this study was to investigate the role of IRF-1 in hepatic ischemia-reperfusion (I/R) injury. In C57BL/6 mice undergoing 60 min of hepatic ischemia, IRF-1 protein expression increased as early as 1 h after reperfusion. IRF-1 knockout mice were significantly protected from hepatic I/R-induced damage compared with their wild-type controls. Hepatic I/R injury resulted in marked activation of the MAP kinase c-Jun NH(2)-terminal kinase (JNK) in wild-type mice but not IRF-1 knockout mice. IRF-1 knockout mice also exhibited significantly lower hepatic expression of TNF-alpha, IL-6, ICAM-1, and inducible nitric oxide synthase (iNOS) mRNA. Adenoviral delivery of IRF-1 into C57BL/6 mice resulted in increased liver damage even without an ischemic insult. This injury was associated with increased JNK activation and hepatic iNOS expression. Because IRF-1 contributed to liver injury, we also examined for inflammatory signals that regulated IRF-1 gene expression in cultured hepatocytes. Whereas IFN-gamma and IFN-beta were strong inducers of IRF-1 mRNA (>10-fold) in a time- and dose-dependent manner, TNF-alpha and IL-1beta also induced IRF-1 mRNA to a lesser extent (2- to 3-fold). IL-6 and lipopolysaccharide had no effect on IRF-1 expression. This study demonstrates that IRF-1 exerts a harmful role in hepatic I/R injury by modulating the expression of multiple inflammatory mediators. We further show that IRF-1-mediated injury involves the activation of JNK and that hepatocellular IRF-1 expression itself is regulated by specific cytokines.

Hepatic ischemia/reperfusion injury involves functional TLR4 signaling in nonparenchymal cells.

Endogenous ligands from damaged cells, so-called damage-associated molecular pattern molecules, can activate innate immunity via TLR4 signaling. Hepatic warm ischemia and reperfusion (I/R) injury and inflammation is largely TLR4 dependent. We produced TLR4 chimeric mice to assess whether the TLR4-dependent injury required TLR4 expression on liver parenchymal or nonparenchymal cells. Chimeric mice were produced by adoptive transfer of donor bone marrow cells into irradiated recipient animals using reciprocal combinations of TLR4 wild-type (WT; C3H/HeOuj) and TLR4 mutant (C3H/HeJ) mouse bone marrow. Wild-type chimeric mice bearing TLR4 mutant hemopoietic cells and TLR4 mutant mice transplanted with their own bone marrow-derived cells were protected from hepatic I/R and exhibited decreased JNK and NF-kappaB activation compared with WT chimeric mice transplanted with their own bone marrow. In contrast, TLR4 mutant mice transplanted with TLR4 WT bone marrow were not protected from liver I/R and demonstrated pronounced increases in JNK and NF-kappaB activation when compared with autochthonous transplanted mutant mice. In addition, depletion of phagocytes taking up gadolinium chloride failed to provide any additional protection to TLR4 mutant mice, but substantially reduced damage in WT mice after hepatic I/R. Together, these results demonstrate that TLR4 engagement on actively phagocytic nonparenchymal cells such as Kupffer cells is required for warm I/R-induced injury and inflammation in the liver.