Developmental Programming Mediated by Complementary Roles of Imprinted Grb10 in Mother and Pup

Developmental programming links growth in early life with health status in adulthood. Although environmental factors such as maternal diet can influence the growth and adult health status of offspring, the genetic influences on this process are poorly understood. Using the mouse as a model, we identify the imprinted gene Grb10 as a mediator of nutrient supply and demand in the postnatal period. The combined actions of Grb10 expressed in the mother, controlling supply, and Grb10 expressed in the offspring, controlling demand, jointly regulate offspring growth. Furthermore, Grb10 determines the proportions of lean and fat tissue during development, thereby influencing energy homeostasis in the adult. Most strikingly, we show that the development of normal lean/fat proportions depends on the combined effects of Grb10 expressed in the mother, which has the greater effect on offspring adiposity, and Grb10 expressed in the offspring, which influences lean mass. These distinct functions of Grb10 in mother and pup act complementarily, which is consistent with a coadaptation model of imprinting evolution, a model predicted but for which there is limited experimental evidence. In addition, our findings identify Grb10 as a key genetic component of developmental programming, and highlight the need for a better understanding of mother-offspring interactions at the genetic level in predicting adult disease risk.     

Both Carboplatin and Bevacizumab Improve Pathological Complete Remission Rate in Neoadjuvant Treatment of Triple Negative Breast Cancer: A Meta-Analysis

Triple negative breast cancer (TNBC) is associated with high pathological complete remission (pCR) rate in neoadjuvant treatment (NAT). TNBC patients who achieve pCR have superior outcome than those without pCR. A meta-analysis was done to evaluate whether integrating novel approaches into NAT can improve the pCR rate in TNBC. Medical subject heading terms (Breast Neoplasm) and key words (triple negative OR estrogen receptor (ER) negative OR HER2 negative) AND (primary systemic OR neoadjuvant OR preoperative) were used to select eligible studies. Experimental arm in each study was considered as the testing regimen, and control arm was defined as the standard regimen in this meta-analysis. A total of 11 studies with 14 paired regimens were included in the final analysis. Aggregate pCR rate was 37.3% and 44.6% in the standard and testing group, respectively. Novel approaches in the testing regimen significantly improved the pCR rate in NAT of TNBC patients compared with the standard regimen, with an odds ratio (OR) of 1.34 (95% confidence interval (CI) 1.11–1.62, P = 0.002). Considering specific regimens, we demonstrated the pCR rate to be much higher in the carboplatin-containing (OR = 1.80, 95% CI 1.39–2.32, P<0.001) or bevacizumab-containing regimens (OR = 1.36, 95% CI 1.11–1.66, P = 0.003) than in the control regimens. The addition of carboplatin in NAT had a pCR rate as high as 51.2% in TNBC patients, with an absolute pCR difference of 13.8% as compared with control regimens. No significant heterogeneity was identified among studies evaluating the addition of carboplatin or bevacizumab efficacy in NAT. This meta-analysis indicates that these novel NAT regimens have achieved a significant pCR improvement in TNBC patients, especially among patients treated with carboplatin-containing or bevacizumab-containing regimen. This can help us design appropriate trials in the adjuvant setting and guide clinical practice.     

3-Hydroxyl-3-methylglutaryl Coenzyme A (HMG-CoA) Reductase Inhibitor (Statin)-induced 28-kDa Interleukin-1β Interferes with Mature IL-1β Signaling

Multiple clinical trials have shown that the 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors known as statins have anti-inflammatory effects. However, the underlying molecular mechanism remains unclear. The proinflammatory cytokine interleukin-1β (IL-1β) is synthesized as a non-active precursor. The 31-kDa pro-IL-1β is processed into the 17-kDa active form by caspase-1-activating inflammasomes. Here, we report a novel signaling pathway induced by statins, which leads to processing of pro-IL-1β into an intermediate 28-kDa form. This statin-induced IL-1β processing is independent of caspase-1- activating inflammasomes. The 28-kDa form of IL-1β cannot activate interleukin-1 receptor-1 (IL1R1) to signal inflammatory responses. Instead, it interferes with mature IL-1β signaling through IL-1R1 and therefore may dampen inflammatory responses initiated by mature IL-1β. These results may provide new clues to explain the anti-inflammatory effects of statins.     

Fermentation of protopanaxadiol type ginsenosides (PD) with probiotic Bifidobacterium lactis and Lactobacillus rhamnosus

Applied Microbiology and Biotechnology - Ginsenosides are believed to be the principal components behind the pharmacological actions of ginseng, and their bioactive properties are closely related...     

Conception and pharmacodynamic profile of drospirenone

Progesterone is more than a progestin. Beyond functions in cycle and pregnancy, progesterone binds with high affinity to the mineralocorticoid receptor (MR) acting as an antagonist, with obvious significance for electrolyte homeostasis, an array of MR-related functions in the circulation as well as in the CNS. Progesterone induces natriuresis at physiological concentrations. Lack of antimineralocorticoid activity with conventional progestins may account for sodium and water retention, minor elevation of blood pressure and "pill hypertension" in susceptible women on oral contraceptives. Ethinylestradiol (EE) contributes to this problem by distinct activation of the renin-angiotensin-aldosterone (RAAS) system. Drospirenone (DRSP: 6beta,7beta,15beta,16beta-dimethylene-3-oxo 17alpha-pregn-4-ene-21,17 carbolactone) is the first synthetic progestin with antialdosterone activity. DRSP and progesterone bind to PR in uterine (affinity of both is about 30% of R5020) and MR in kidney cytosol (affinity about 230 and 100% of aldosterone, respectively). Intrauterine administration of DRSP in silastic tubes induced maximum local progestational effects in rabbits. At systemic subcutaneous (s.c.) administration (McPhail-assay) full endometrial transformation was obtained at 1mg per animal per day. At 1-3mg DRSP per animal per day subcutaneously, pregnancy maintenance after ovariectomy, antiovulatory activity, and antimineralocorticoid activity were seen in the respective assays in rats. The latter activity indicates about eight-fold higher potency than spironolactone. DRSP decreased blood pressure in male hypertensive rats, whereas an increase was noted under conventional progestins. DRSP also prevented hypertension and fetal growth retardation in pregnant rats after L-NAME, an inhibitor of nitric oxide synthase. DRSP has antiandrogenic activity. Feminizing effects were recorded during sexual differentiation in male fetuses at high doses. Powerful antiandrogenic effects were also seen in gonad intact and testosterone substituted castrated male rats. The antiandrogenic potency of DRSP is superior to that of spironolactone but below that of cyproterone acetate. Endometrial transformation, inhibition of ovulation, and antimineralocorticoid, i.e. natriuretic effects and mild antiandrogenic effects were recorded at the same range of oral doses (0.5-4 mg per day) in humans. Combined with EE (3 mg DRSP+30 microg EE), DRSP provides effective inhibition of ovulation and cycle control. Body weight compared to conventional oral contraceptives was reduced. DRSP (3 mg per day+15, 20, or 30 microg ethinyl estradiol per day) prevented the mild increase of blood pressure seen under a conventional levonorgestrel-containing contraceptive and even tended to reduce pretreatment blood pressure. Studies on modulation (i.e. inhibition) of glucocorticoid effects at the MR in the CNS remain an unexplored and interesting area for research.     

Characterization of a lysyl aminopeptidase activity associated with phosphoglucose isomerase of Vibrio vulnificus

Phosphoglucose isomerase (PGI) is a multifunctional enzyme involved in glycolysis and gluconeogenesis and, in mammalian cells, functions as neuroleukin, autocrine motility factor (AMF), and differentiation and maturation factor (MF). We isolated and characterized PGI with a novel lysyl aminopeptidase (LysAP) activity (PGI-LysAP) from Vibrio vulnificus. Mass spectrometry revealed that PGI-LysAP is a heterodimer consisting of 23.4- and 60.8-kDa subunits. Only the heterodimer displayed LysAP activity. PGI-LysAP has a pI around 6.0 and high specificity toward the synthetic, fluorogenic substrate l-lysyl-7-amino-4-methylcoumarin. LysAP activity is optimal at pH 8.0, is 64% higher at 37 degrees C than at 21 degrees C, does not directly correlate with virulence, and is strongly inhibited by serine protease and metalloprotease inhibitors. PGI-LysAP was also identified in Vibrio parahaemolyticus and V. cholerae, but was absent from non-Vibrio human pathogens. Sequencing of the pgi gene revealed 1653 bp coding for a 550-amino-acid protein. Cloned and expressed PGI formed a homodimer with isomerase activity, but not LysAP activity. The finding of LysAP activity associated with heterodimeric PGI should foster a broad search for putative substrates in an effort to elucidate the role of PGI-LysAP in bacteria and its roles in the pathophysiology of diseases.     

Cyclic hydrostatic compression stimulates chondroinduction of C3H/10T1/2 cells

While the potential for intermittent hydrostatic pressure to promote cartilaginous matrix synthesis is well established, its potential to influence chondroinduction remains poorly understood. This study examined the effects of relatively short- and long-duration cyclic hydrostatic compression on the chondroinduction of C3H/10T1/2 murine embryonic fibroblasts by recombinant human bone morphogenetic protein-2 (rhBMP-2). Cells were seeded at high density into round bottom wells of a 96-well plate and supplemented with 25 ng/ml rhBMP-2. Experimental cultures were subjected to either 1,800 cycles/day or 7,200 cycles/day of 1 Hz sinusoidal hydrostatic compression to 5 MPa (applied 10 min on/10 min off) for 3 days. Non-pressurized control and experimental cultures were maintained in static culture for an additional 5 days. Cultures were then analyzed for alcian blue staining intensity, DNA and sulfated glycosaminoglycan (sGAG) content, and for the rate of collagen synthesis. Whereas cultures subjected to 1,800 pressure cycles exhibited no significant differences (statistical or qualitative) compared to controls, those subjected to 7,200 cycles stained more intensely with alcian blue, contained nearly twice as much sGAG, and displayed twice the rate of collagen synthesis as non-pressurized controls. This study demonstrates the potential for cyclic hydrostatic compression to stimulate chondrogenic differentiation of the C3H/10T1/2 cell line in a duration-dependent manner.     

Exploring the sialome of the blood-sucking bug Rhodnius prolixus

Rhodnius prolixus is a Hemiptera that feeds exclusively on vertebrate blood in all life stages. Its salivary glands produce potent pharmacological substances that counteract host hemostasis, including anti-clotting, anti-platelet, and vasodilatory substances. To obtain a further insight into the salivary biochemical and pharmacological complexity of this insect, a cDNA library was randomly sequenced, and salivary gland homogenates were fractionated by HPLC to obtain aminoterminal sequences of abundantly expressed proteins. Results indicate a remarkable expansion of the lipocalin family in Rhodnius salivary glands, among other protein sequences described. A summary of 31 new full length proteins deducted from their mRNA sequence is described, including several new members of the nitrophorin, triabin, and pallidipin families. The electronic version of the complete tables is available at http://www.ncbi.nlm.nih.gov/projects/vectors/rhodnius_prolixus.     

Human ABCB6 localizes to both the outer mitochondrial membrane and the plasma membrane

Expression of the ATP-binding cassette transporter ABCB6 has been associated with multiple cellular functions, including resistance to several cytotoxic agents, iron homeostasis, and porphyrin transport. To further elucidate its physiological function and/or role in drug resistance, we determined the subcellular location of ABCB6. Using three novel ABCB6-specific antibodies, Western blot analysis of cells expressing cDNA-derived or endogenous ABCB6 revealed two distinct molecular weight forms. Confocal microscopy indicates that the protein localizes to both mitochondria and the plasma membrane. Differential centrifugation revealed that the lower molecular weight form predominantly resides in the mitochondria, while the larger protein form is more abundant in the plasma membrane. Preliminary studies indicate that ABCB6 is functionally relevant in the plasma membrane, where its expression prevents the accumulation of specific porphyrins in the cell. Digitonin solubilization of mitochondria demonstrated that ABCB6 is present in the outer mitochondrial membrane, while back-titration assays with the ABCB6-specific antibodies reveal that the nucleotide binding domain of ABCB6 is cytoplasmic. These studies are the first to demonstrate that ABCB6 exists in two molecular weight forms, is localized to both the outer mitochondrial membrane and the plasma membrane, and plays a functional role in the plasma membrane.     

Effects on ligand interaction and membrane translocation of the positively charged arginine residues situated along the C1 domain binding cleft in the atypical protein kinase C isoforms

The C1 domain zinc finger structure is highly conserved among the protein kinase C (PKC) superfamily members. As the interaction site for the second messenger sn-1,2-diacylglycerol (DAG) and for the phorbol esters, the C1 domain has been an important target for developing selective ligands for different PKC isoforms. However, the C1 domains of the atypical PKC members are DAG/phorbol ester-insensitive. Compared with the DAG/phorbol ester-sensitive C1 domains, the rim of the binding cleft of the atypical PKC C1 domains possesses four additional positively charged arginine residues (at positions 7, 10, 11, and 20). In this study, we showed that mutation to arginines of the four corresponding sites in the C1b domain of PKCdelta abolished its high potency for phorbol 12,13-dibutyrate in vitro, with only marginal remaining activity for phorbol 12-myristate 13-acetate in vivo. We also demonstrated both in vitro and in vivo that the loss of potency to ligands was cumulative with the introduction of the arginine residues along the rim of the binding cavity rather than the consequence of loss of a single, specific residue. Computer modeling reveals that these arginine residues reduce access of ligands to the binding cleft and change the electrostatic profile of the C1 domain surface, whereas the basic structure of the binding cleft is still maintained. Finally, mutation of the four arginine residues of the atypical PKC C1 domains to the corresponding residues in the deltaC1b domain conferred response to phorbol ester. We speculate that the arginine residues of the C1 domain of atypical PKCs may provide an opportunity for the design of ligands selective for the atypical PKCs.