The results of the present study demonstrate, for the first time, the expression of TCTP in the human prostate and in prostate cancer cells, and suggest the involvement of the protein in key-processes such as apoptosis, cellular differentiation, and in the control of sperm functions.

Macrophage migration inhibitory factor (MIF) was originally identified for its capacity to inhibit the random migration of macrophages in vitro. To date, the role of MIF as a pro-inflammatory cytokine, pituitary hormone, and counter-regulator of glucocorticoid action on the immune response is commonly recognized. Although recent studies suggest an involvement of MIF in reproduction, no data exist on the expression of this cytokine in early human pregnancy. In this study, we evaluated the presence of MIF protein and mRNA in specimens of chorionic villi from first-trimester human placenta. Tissues were obtained at 6-10 wk of gestation and analyzed by Western blotting, reverse transcription-polymerase chain reaction, and immunohistochemistry. Our results demonstrate that human villous tissue is a novel site of MIF synthesis. In addition, immunohistochemical analysis identified MIF protein in the cytotrophoblasts of both the inner layer of villi and in the trophoblastic cell islands. We speculate that in view of its proinflammatory features, MIF might play a critical role in human implantation and in early embryonic development.

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The human uterine mucosa of early pregnancy is largely populated by CD56 bright natural killer (NK) cells (uterine (u) NK cells). The specific functions of these cells are still unknown, but their interaction and response to foetal trophoblasts are thought to be important for the establishment of a successful pregnancy. The study reported herein shows that uNK cells respond to, and produce, macrophage migration inhibitory factor (MIF), a cytokine highly expressed in the human placenta and in the cyclic and pregnant endometrium. Recombinant human MIF reduced in a dose-dependent manner the cytolytic activity of purified uNK cells against K562 cells. RT-PCR, Western blot analysis and ELISA demonstrated the synthesis and secretion of the cytokine by uNK cells. Double immunofluorescence staining showed the presence of MIF in uterine CD56 1 cells. Finally, neutralization of the endogenous cytokine by a polyclonal antibody resulted in a sharp increase in the cytolytic activity of uNK cells. These findings indicate the existence of a previously unrevealed paracrine and autocrine action of MIF on uNK cells and support its contribution to the immune privilege at the maternal-foetal interface.

The translationally controlled tumor protein (TPT1, also known as TCTP) is a highly conserved, abundantly expressed protein found in mammals as well as in a wide range of other organisms of both the animal and plant kingdom. Initially considered as a growth-related protein, later studies showed TPT1 is endowed with multiple biological activities, including calcium binding. The present study aimed to evaluate the expression of TPT1 in the human placenta and to examine the functional role of the protein in the calcium binding and homeostasis of trophoblast cells. Samples were analyzed by Western blot, reverse transcription-polymerase chain reaction and immunohistochemistry. The effect of TPT1 knockdown by small interfering RNA (siRNA) on calcium uptake and buffering was assessed in the HTR-8/SVneo cell line. TPT1 protein and mRNA were detected in first-trimester and term placenta. In the tissue, TPT1 was localized in the villous trophoblast. TPT1 expression significantly increased during gestation, with the higher protein and mRNA levels reached at term. Recombinant placental TPT1 bound calcium in vitro, while downregulation of the protein levels by siRNA in HTR-8/SVneo cells was associated with a reduced cellular calcium-uptake activity and buffering capacity. These data demonstrate, for the first time, the expression of TPT1 in the human placenta and support a direct role of the protein in placental calcium transport.