Effect of bone morphogenetic protein-7 on folliculogenesis and ovulation in the rat

We have previously established the presence of a functional bone morphogenetic protein (BMP) system in the ovary by demonstrating the expression of BMP ligands and receptors as well as novel cellular functions. Specifically, BMP-4 and BMP-7 are expressed in theca cells, and their receptors by granulosa cells. These BMPs enhanced and attenuated the stimulatory action of FSH on estradiol and progesterone production, respectively. To investigate the underlying mechanism of the differential regulation, we analyzed mRNA levels for key regulators in the steroid biosynthetic pathways by RNase protection assay. BMP-7 enhanced P450 aromatase (P450(arom)) but suppressed steroidogenic acute regulatory protein (StAR) mRNAs induced by FSH, whereas mRNAs encoding further-downstream steroidogenic enzymes, including P450 side-chain cleavage enzyme and 3beta-hydroxysteroid dehydrogenase, were not significantly altered. These findings suggest that BMP-7 stimulation and inhibition of P450(arom) and StAR mRNA expression, respectively, may play a role in the mechanisms underlying the differential regulation of estradiol and progesterone production. To establish the physiological relevance of BMP functions, we investigated the in vivo effects of injections of recombinant BMP-7 into the ovarian bursa of rats. Ovaries treated with BMP-7 had decreased numbers of primordial follicles, yet had increased numbers of primary, preantral, and antral follicles, suggesting that BMP-7 may act to facilitate the transition of follicles from the primordial stage to the pool of primary, preantral, and antral follicles. In this regard, we have also found that BMP-7 caused an increase in DNA synthesis and proliferation of granulosa cells from small antral follicles in vitro. In contrast to the stimulatory activity, BMP-7 exhibited pronounced inhibitory effects on ovulation rate and serum progesterone levels. These findings establish important new biological activities of BMP-7 in the context of ovarian physiology, including folliculogenesis and ovulation.     

Aurine tricarboxylic acid, a potent metal-chelating inhibitor of NFkappaB-DNA binding

The metal-interaction of aurine tricarboxylic acid (ATA) and its inhibitory effect on the DNA binding of NFkappaB were studied. Chemical speciation and spectroscopic studies have shown the strong interaction of ATA with metal ions present in the biological systems. EPR, FTIR and electronic spectral studies indicated the square planar structure of the metal-binding carboxylic and hydroxyl groups of ATA indicating the ground state 2B1g. Electrophoretic mobility shift assay using NFkappaB and 32P labeled DNA has shown that ATA was inhibitory against the DNA-NFkappaB binding at 30 microM. This activity was the strongest among the metal-chelating inhibitors of NFkappaB-DNA binding reported so far.     

AMP-activated protein kinase regulates PDGF-BB-stimulated interleukin-6 synthesis in osteoblasts: involvement of mitogen-activated protein kinases

AimWe have previously reported that platelet-derived growth factor (PDGF)-BB stimulates synthesis of interleukin-6 (IL-6), a potent bone resorptive agent, in osteoblast-like MC3T3-E1 cells, and that the activation of p44/p42 mitogen-activated protein (MAP) kinase, p38MAP kinase and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) is implicated in the IL-6 synthesis. In the present study,we investigated the involvement of AMP-activated protein kinase (AMPK), a regulator of energy metabolism, in the PDGF-BB-stimulated IL-6 synthesis in MC3T3-E1 cells.Main methodsThe levels of IL-6 were measured by ELISA. The phosphorylation of each protein kinases was analyzed by Western blotting. The mRNA levels of IL-6 were determined by real-time RT-PCR.Key findingsPDGF-BB time-dependently induced the phosphorylation of AMPK. Compound C, an inhibitor of AMPK, which reduced PDGF-BB-induced acetyl-CoA carboxylase phosphorylation, dose-dependently suppressed the PDGF-BB-stimulated IL-6 release. In addition, the PDGF-BB-stimulated IL-6 release in human osteoblasts was also inhibited by compound C. The mRNA expression of IL-6 induced by PDGF-BB was markedly reduced by compound C. The PDGF-BB-induced phosphorylation of p44/p42 MAP kinase, p38 MAP kinase and SAPK/JNK was inhibited by compound C.SignificanceThese results strongly suggest that AMPK positively regulates PDGF-BB-stimulated IL-6 synthesis via the MAP kinases in osteoblasts.     

Infant feeding practices and breastfeeding duration in Japan: A review

The Japanese health system places great emphasis on healthy development. However, the prevalence of Exclusive Breastfeeding at one month postpartum between 1980 and 2005 has remained unchanged, fluctuating between 42% and 49%. At the same time, the Any Breastfeeding prevalence has gradually increased from about 80% to 95%. In 2010, the latest national breastfeeding report showed that ‘exclusive’ and ‘any’ breastfeeding rates have improved. However, as the World Health Organization (WHO) definition of breastfeeding practices was not used in this study or in other national surveys, it is difficult to interpret these latest results. While the Japanese government has launched several promotion projects, there have been few studies and reviews of risk factors that influence breastfeeding duration. The objectives of this review were to summarise the factors that have influenced the duration of breastfeeding in Japan to provide information relevant to breastfeeding promotion programs. A search of electronic databases in Japanese and English was undertaken up to 2011. The inclusion criteria for this review were studies that focused on infant feeding practices and targeted Japanese mothers, fathers, or health professionals, but excluded mothers’ friends and peer groups. In total, 12 articles were selected for the final analysis. Smoking status, low birth weight of infants and maternal perceptions of insufficient breast milk supply were negative influences on breastfeeding duration, while support from husbands/partners is associated with continued breastfeeding. Some factors that have been found to be associated with breastfeeding in other countries, including maternal age, family income, maternal educational levels, and living with grandparents of infants have not been confirmed in Japan. While the national breastfeeding rates were higher than other countries of similar health status, inconsistent knowledge of breastfeeding benefits and inappropriate hospital practices remain in Japan may be associated with increased the use of infant formula and reduced breastfeeding duration. Most of the studies reviewed were cross-sectional in design, with only a limited number of cohort studies. Also many published studies used small sample sizes. Cohort studies of infant feeding practices with larger sample sizes are required to monitor trends in rates and risk factors for breastfeeding outcomes.     

Derlin-1 and UBXD8 are engaged in dislocation and degradation of lipidated ApoB-100 at lipid droplets

Apolipoprotein B-100 (ApoB) is the principal component of very low density lipoprotein. Poorly lipidated nascent ApoB is extracted from the Sec61 translocon and degraded by proteasomes. ApoB lipidated in the endoplasmic reticulum (ER) lumen is also subjected to proteasomal degradation, but where and how it dislocates to the cytoplasm remain unknown. In the present study, we demonstrate that ApoB after lipidation is dislocated to the cytoplasmic surface of lipid droplets (LDs) and accumulates as ubiquitinated ApoB in Huh7 cells. Depletion of UBXD8, which is almost confined to LDs in this cell type, decreases recruitment of p97 to LDs and causes an increase of both ubiquitinated ApoB on the LD surface and lipidated ApoB in the ER lumen. In contrast, abrogation of Derlin-1 function induces an accumulation of lipidated ApoB in the ER lumen but does not increase ubiquitinated ApoB on the LD surface. UBXD8 and Derlin-1 bind with each other and with lipidated ApoB and show colocalization around LDs. These results indicate that ApoB after lipidation is dislocated from the ER lumen to the LD surface for proteasomal degradation and that Derlin-1 and UBXD8 are engaged in the predislocation and postdislocation steps, respectively.     

Altered Plasma Apolipoprotein Modifications in Patients with Pancreatic Cancer: Protein Characterization and Multi-Institutional Validation

Background

Among the more common human malignancies, invasive ductal carcinoma of the pancreas has the worst prognosis. The poor outcome seems to be attributable to difficulty in early detection.

Methods

We compared the plasma protein profiles of 112 pancreatic cancer patients with those of 103 sex- and age-matched healthy controls (Cohort 1) using a newly developed matrix-assisted laser desorption/ionization (oMALDI) QqTOF (quadrupole time-of-flight) mass spectrometry (MS) system.

Results

We found that hemi-truncated apolipoprotein AII dimer (ApoAII-2; 17252 m/z), unglycosylated apolipoprotein CIII (ApoCIII-0; 8766 m/z), and their summed value were significantly decreased in the pancreatic cancer patients [P = 1.36×10⁻²¹, P = 4.35×10⁻¹⁴, and P = 1.83×10⁻²⁴ (Mann-Whitney U-test); area-under-curve values of 0.877, 0.798, and 0.903, respectively]. The significance was further validated in a total of 1099 plasma/serum samples, consisting of 2 retrospective cohorts [Cohort 2 (n = 103) and Cohort 3 (n = 163)] and a prospective cohort [Cohort 4 (n = 833)] collected from 8 medical institutions in Japan and Germany.

Conclusions

We have constructed a robust quantitative MS profiling system and used it to validate alterations of modified apolipoproteins in multiple cohorts of patients with pancreatic cancer.