Circulating polymorphonuclear leukocytes increase expression of BPI in response to LPS or gram-negative sepsis. Subsequently, concentrations of plasma BPI and LBP increase. Because both LBP and BPI bind to LPS, it is suggested that endogenously derived plasma levels of BPI are likely to be inadequate to compete for LPS binding to the much more abundant LBP in the circulation.
The effects of altering the number and type of additional carbohydrate moieties on the pharmacokinetic and pharmacodynamic properties of FSH were examined in this report. A series of single-chain follitropins, containing variable numbers of additional N- (or O-) linked carbohydrates, were designed and expressed in Chinese hamster ovary cells. Proper folding, efficient receptor binding, and signal transduction were confirmed by in vitro assays. Pharmacokinetic and pharmacodynamic parameters were evaluated in immature female Sprague Dawley rats. Increasing the number of glycosylation sites with either N- (or O-) linked moieties extended the elimination half-life as much as 2-fold compared with recombinant human FSH (rhFSH). However, there was a maximum elimination half-life such that further glycosylation provided no additional lengthening of the half-life. Conversely, biopotency, as assessed by inhibin A levels 74 h post injection, and follicle production were significantly higher for the N-linked analogs. Rats stimulated with the longest acting analogs (either N- or O-linked) showed significantly higher ovarian weights than rats receiving a single injection of rhFSH. The analog containing four additional N-linked sites (rhFSH-N4) had the greatest number of large, preovulatory follicles. Although the half-life of rhFSH-N4 displayed no further enhancement beyond the other longest acting analogs, this analog exhibited significantly increased biopotency in rats. This work provides the basis for the generation of a series of reagents potentially useful for therapeutic applications.
We previously observed high levels of Brd2 (also known as female sterile homeotic related gene-1, Fsrg1) expression in several hormonally responsive tissues, including the ovary. Here, we report distinct localization patterns of Brd2 transcripts throughout ovarian folliculogenesis in normal mice as well as in two strains of mice with aberrant folliculogenesis: mice with mutated growth differentiation factor 9 (Gdf9) and follicle stimulating hormone beta (Fshb) genes. The highest level of expression was seen in granulosa cells of growing follicles. Within the oocyte, three patterns of Brd2 RNA localization were observed: diffuse distribution in both the cytoplasm and nucleus, then intense nuclear expression, followed by an absence of Brd2 transcripts from the nucleus. The transition from intense nuclear localization to nuclear exclusion was found to correlate with oocyte maturation and meiotic competence, as determined by nuclear chromatin patterns. These same expression patterns were also seen in oocytes from Gdf9(-/-) and Fshb(-/-) mice. Thus, Brd2 expression appears to correlate with stages of oocyte maturation, independent of FSH or GDF9 action and the subsequent disruption in normal follicle development in these models. The distinct patterns of Brd2 localization within the adult ovary supports a role for Brd2 in mitotic and possibly meiotic cell cycle regulation.
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