Triple negative breast cancers (TNBCs) are highly aggressive and grow in response to sex steroid hormones despite lacking expression of the classical estrogen (E2) and progesterone (P4) receptors. Since P4 receptor membrane component 1 (PGRMC1) is expressed in breast cancer tumors and is known to mediate P4-induced cell survival, this study was designed to determine the expression of PGRMC1 in ...

Chloride permeability pathways and progesterone (P4) secretion elicited by human chorionic gonadotropin (hCG) in human granulosa cells were studied by electrophysiological techniques and single-cell volume, membrane potential and Ca2+i measurements. Reduction in extracellular Cl(-) and equimolar substitution by the membrane-impermeant anions glutamate or gluconate significantly increased hCG-st...

New treatments against severe bacterial infections are needed because the response to antibiotic treatment is slow in acute settings and is becoming less effective owing to the emergence of antibiotic-resistant pathogens. P4-mediated antibody therapy offers a unique treatment strategy that combines exogenous immunoglobulin with the immunoactivating peptide P4. In an acute model of pneumococcal ...

PURPOSE OF REVIEW P4 medicine denotes an evolving field of medicine encompassing predictive, preventive, personalized, and participatory medicine. Using the example of kidney allograft rejection because of donor-recipient incompatibility in human leukocyte antigens, this review outlines P4 medicine's relevance to the various stages of the kidney transplant cycle. SOURCES OF INFORMATION A sear...

We investigated the kinetics of 4N-acetyl-pentapeptides, Ac-P1, Ac-P2, Ac-P3, and Ac-P4, regarding inhibition of mushroom tyrosinase activity. The peptides sequences of Ac-P1, Ac-P2, Ac-P3, and Ac-P4 were Ac-RSRFK, Ac-KSRFR, Ac-KSSFR, and Ac-RSRFS, respectively. The 4N-acetyl-pentapeptides were able to reduce the oxidation of l-DOPA by tyrosinase in a dose-dependent manner. Of the 4N-acetyl-pen...

Several inositol-containing compounds play key roles in receptor-mediated cell signaling events. Here, we describe a function for a specific inositol polyphosphate, D-myo-inositol 1,4,5,6-tetrakisphosphate [Ins(1,4,5,6)P4], that is produced acutely in response to a receptor-independent process. Thus, infection of intestinal epithelial cells with the enteric pathogen Salmonella, but not with oth...

Progesterone (P4) is synthesized in the ovary and acts directly on granulosa cells of developing ovarian follicles to suppress their rate of mitosis and apoptosis. Granulosa cells do not express nuclear progesterone receptor (PGR) but rather progesterone receptor membrane component-1 (PGRMC1). PGRMC1 binds P4 and mediates P4's actions, as evidenced by PGRMC1 siRNA studies. PGRMC1 acts by bindin...

The aim of the present study is to understand the hormonal mechanisms of the effect of malnutrition on ovarian follicle functions. For this purpose, we examined the effect of malnutrition/serum deprivation, addition of metabolic hormones and gonadotropin (IGF-I, leptin and FSH) and their combination on the release of progesterone (P4), testosterone (T), estradiol (E2) and insulin-like growth fa...

Treatment of [WH(4)(κ(4)-P4)] (3: P4 = meso-o-C(6)H(4)(PPhCH(2)CH(2)PPh(2))(2)) with aryl isothiocyanate ArNCS at 50 °C afforded the dithiocarbonimidate-isocyanide complex [W(κ(2)-S(2)CNAr)(CNAr)(κ(4)-P4)] (4) in moderate yields. The reaction also produced ArNHCH(3) and a small amount of ArNH(2). The yield of the hydrodesulfurization product ArNHCH(3) increased when the reaction was conducted u...

A diurnal change of tuberoinfundibular dopaminergic (TIDA) neuronal activity exists in female rats, which is prerequisite for the estrogen-induced afternoon PRL surge. Because progesterone (P4) administered in the morning can advance and amplify the PRL surge, it is of interest to learn whether its action involves the TIDA neuron. In adult ovariectomized and estrogen-primed Sprague-Dawley rats,...