Suppressive Role of Lactoferrin in Overweight-Related Female Fertility Problems.

The secretory glycoprotein lactoferrin (LF) is suggested to ameliorate overweight regardless of non-genetic or genetic mechanisms. Although maternal overweight represents a key predictor of offspring growth, the efficacy of LF on fertility problems in overweight and obese mothers remains unknown. To address this issue, we examined the effect of LF ingestion by analyzing overweight mice (Institute of Cancer Research (ICR) mice with high-fat diets; HF mice) and obese mice (leptin-deficient mice with type II diabetes; ob/ob mice). Plasma insulin, leptin, glucose, and cholesterol levels were measured, and thermal imaging and histological analysis were employed. The litter size of HF females was reduced due to miscarriage, which was reversed by LF ingestion. In addition, LF ingestion suppressed overweight prevalence in their offspring. The component analysis of the maternal blood demonstrated that glucose concentration in both HF females and their offspring was normalized by LF ingestion, which further standardized the concentration of insulin, but not leptin. LF ingestion was unable to reverse female infertility in ob/ob mice, although their obesity and uterine function were partially improved. Our results indicate that LF upregulates female fertility by reinforcing ovarian and uterine functions in females that are overweight due to caloric surplus.

Albumin fusion at the N-terminus or C-terminus of human lactoferrin leads to improved pharmacokinetics and anti-proliferative effects on cancer cell lines.

Human lactoferrin (hLF), a soluble factor of the innate immune system, exhibits various biological functions and therefore has potential as a therapeutic protein. However, the clinical applications of hLF are limited by its low stability in blood. We therefore attempted to resolve this by producing recombinant hLF fused to human serum albumin (HSA). Two HSA-fused hLFs with different fusion orientations (hLF-HSA and HSA-hLF) were produced in Chinese hamster ovary (CHO) DG44 cells. hLF-HSA revealed higher thermal stability, resistance to peptic degradation, and stability during the process of cellular uptake and release in an intestinal enterocyte model (Caco-2 cells) than HSA-hLF. The lower stability of HSA-hLF is presumably due to the steric hindrance imposed by HSA fusion to the N-terminus of hLF. Both HSA fusion proteins, especially HSA-hLF, displayed improved pharmacokinetic properties despite the lower protein stability of HSA-hLF. hLF-HSA and HSA-hLF exhibited approximately 3.3- and 20.7-fold longer half-lives (64.0 and 403.6 min), respectively, than holo-rhLF (19.5 min). Both HSA fusion proteins were found to exert enhanced growth inhibition effects on cancer cells in vitro, but not normal cells. Their enhanced growth inhibitory activities were considered to be due to the synergetic effects of hLF and HSA because hLF alone or HSA alone failed to exert such an effect. Altogether, Fusion of HSA to hLF yielded superior pharmacokinetics and anti-proliferative activities against cancer cells. HSA-fused hLF is a novel candidate for further application of hLF as biopharmaceuticals for intravenous administration.

Lactobacillus rhamnosus GG and Lactobacillus casei suppress Escherichia coli-induced chemokine expression in intestinal epithelial cells.

BACKGROUND: Recently, some strains of lactic acid bacteria (LAB) have been reported to prevent the development of atopic dermatitis and to improve allergic symptoms, especially in young children. However, the mechanisms involved in these effects are not fully understood. Intestinal microbiota play critical roles in the development of host immune development and are recognized and regulated by the host through intestinal epithelial cells (IECs). We thus hypothesized that LAB influence the host immune system through the activation of IECs. To begin testing this hypothesis, chemokine expression in IECs exposed to intestinal bacteria was investigated. METHODS: Caco-2 cell monolayers were stimulated with different concentrations of various live or heat-killed intestinal bacteria or bacterial components for up to 3 h. Changes in the gene expressions of various chemokines were measured using quantitative real-time PCR. RESULTS: The expressions of CCL20, CXCL8, CXCL10 and CX3CL1 were strongly induced by nonpathogenic Escherichia coli in a dose-dependent manner and were partially induced by some commensal LAB. In contrast, Lactobacillus rhamnosus GG (LGG) and Lactobacillus casei did not induce these chemokine expressions. In addition, LGG significantly suppressed the expressions of CCL20 and CXCL10 induced by E. coli, peptidoglycan or flagellin when cultured simultaneously. CONCLUSIONS: LGG and L. casei markedly suppressed E. coli-induced chemokine expression, presumably through the suppression of the Toll-like receptor-mediated signal transduction pathway, at least in part. The clinical importance of this suppressive effect and the mechanisms involved require further investigation; however, such effects can be used as a marker to identify clinically useful LAB.

Prostaglandin A2 acts as a transactivator for NOR1 (NR4A3) within the nuclear receptor superfamily.

Within the nuclear receptor superfamily, Nur77, Nurr1, and NOR1 constitute the nuclear receptor subfamily 4 group A. Modulation of NOR1 function would be therapeutic potential for diseases related to dysfunction of NOR1, including extraskeletal myxoid chondrosarcoma and autoimmune diseases. By screening arachidonate metabolites for their capacity of transcriptional activation, we have identified prostaglandin (PG) A2 as a transactivator for NOR1. PGA2 acted as a potent activator of NOR1-dependent transcription through the GAL4-based reporter system. The putative ligand-binding domain (LBD) of the receptor directly bound PGA2, and LBD-deleted receptor showed little transcriptional activation by PGA2. Primary cultured spleen cells derived from transgenic mice overexpressing NOR1, showed higher sensitivity to PGA2 compared to those from wild-type mice. These observations suggest that PGA2 can serve as a transactivator of NOR1, and thus suggest a possibility of pharmacological modulation of the NOR1 pathways by PGA2-related compounds.

NR4A orphan nuclear receptor family in peripheral blood eosinophils from patients with atopic dermatitis and apoptotic eosinophils in vitro.

To identify novel genes related to the clinical signs of atopic dermatitis (AD), differentially expressed genes were sought in peripheral blood eosinophils from both AD patients and healthy volunteers. RNA was prepared from eosinophils, expression of various genes was monitored using the Affymetrix GeneChip, and expression was quantified by real-time RT-PCR. Two genes, Nur77 and NOR1, members of NR4A orphan nuclear receptor family, were expressed at a significantly higher level in AD patients than in healthy volunteers. Expression of another gene in the NR4A receptor family, Nurr1, was also higher in AD patients than in healthy volunteers. When peripheral blood leukocytes from healthy volunteers were fractionated, NOR1 expression was highest in eosinophils, but expression of Nur77 and Nurr1 genes was not eosinophil-specific. Extremely intense apoptosis was induced in both eosinophils and an eosinophil cell line, AML14.3D10, by treatment with antibody (Ab) to both CD30 and Fas. Rapid expression of the genes for the NR4A receptor family was observed with anti-CD30 Ab treatment but not with anti-Fas Ab. The NR4A orphan nuclear receptor family gene expression and the subsequent eosinophil apoptosis were downregulated by the MAPK inhibitor, U0126. These results suggest that the expression of the NR4A receptor family genes through CD30 signaling may regulate eosinophil apoptosis in allergic conditions such as AD.