Development of a PCR-based SNP marker system for effective selection of kernel length and kernel elongation in rice

Kernel length in rice (Oryza sativa L.) is controlled by various quantitative trait loci of which GS3 is the most important, being responsible for 80–90% of the variation in kernel length. A mutation in the second exon of this gene has been reported to be associated with maximum variations in the kernel length. We have developed a simple PCR-based marker system named DRR-GL which targets the functional nucleotide polymorphism at GS3. This marker system has the advantages that it is easy to use, saves time and cost, and is amenable for large-scale marker-assisted selection for the trait of kernel length. Validation of this marker in a segregating population and 152 rice varieties, which includes 30 elite basmati varieties, reveals its effective co-segregation and association with the traits of kernel length as well as kernel elongation after cooking. We recommend utilization of this simple, low-cost marker system in breeding programs targeted at improvement of key rice grain quality traits, kernel length and kernel elongation.     

Discovery of morpholine-based aryl sulfonamides as Nav1.7 inhibitors

Replacement of the piperidine ring in the lead benzenesulfonamide Na_v1.7 inhibitor 1 with a weakly basic morpholine core resulted in a significant reduction in Na_v1.7 inhibitory activity, but the activity was restored by shortening the linkage from methyleneoxy to oxygen. These efforts led to a series of morpholine-based aryl sulfonamides as isoform-selective Na_v1.7 inhibitors. This report describes the synthesis and SAR of these analogs.     

Alterations in mRNA levels, expression, and function of GTP-binding regulatory proteins in adipocytes from obese mice (C57BL/6J-ob/ob)

Messenger RNA levels for the alpha subunit of G-proteins expressed in adipocytes of lean and obese (ob/ob) mice were compared with relative levels of the encoded proteins. Using both toxin labeling and Western blots, expression of Gs alpha, Gi alpha-1, and Gi alpha-3 was decreased by approximately 2-fold in adipocytes of obese mice, while levels of Gi alpha-2 did not differ between the phenotypes. The decreases in Gi alpha-1 and Gs alpha in the obese mouse were attributed to decreased mRNA levels for these proteins. Similar mRNA levels for Gi alpha-3 were noted in both phenotypes, but Gi alpha-2 message was increased 2-fold in the obese mouse. Inhibitory regulation of adipocyte adenylylcyclase through G-proteins was evaluated by comparing the ability of R-PIA to inhibit isoproterenol-stimulated responses between the phenotypes. In spite of the decrease in Gi alpha-1 and Gi alpha-3 in adipocytes from obese mice, R-PIA inhibited adenylylcyclase, cAMP-dependent protein kinase, and lipolysis in similar fashion in both phenotypes. The GTP analog, Gpp(NH)p also inhibited forskolin-stimulated adenylylcyclase in a comparable manner, but the magnitude of the inhibition was slightly less in adipocyte membranes from obese mice. In contrast, the decrease in expression of Gs alpha was translated into substantially poorer activation of isoproterenol-stimulated responses in the obese mouse. The concentration of isoproterenol producing half-maximal activation of adenylylcyclase, protein kinase, and lipolysis did not differ between the phenotypes, but the maximal responses were much lower in cells from obese mice. Similar lipolytic potential in isolated adipocytes from each phenotype and similar total forskolin-stimulated cyclase activity in adipocyte membranes from each phenotype suggest that decreased expression of Gs alpha may contribute to the characteristic alteration in mobilization of triglycerides noted in adipocytes from obese mice.     

Epithelial to mesenchymal transition (EMT) of feto-maternal reproductive tissues generates inflammation: a detrimental factor for preterm birth

Human pregnancy is a delicate and complex process where multiorgan interactions between two independent systems, the mother, and her fetus, maintain pregnancy. Intercellular interactions that can define homeostasis at the various cellular level between the two systems allow uninterrupted fetal growth and development until delivery. Interactions are needed for tissue remodeling during pregnancy at both fetal and maternal tissue layers. One of the mechanisms that help tissue remodeling is via cellular transitions where epithelial cells undergo a cyclic transition from epithelial to mesenchymal (EMT) and back from mesenchymal to epithelial (MET). Two major pregnancy-associated tissue systems that use EMT, and MET are the fetal membrane (amniochorion) amnion epithelial layer and cervical epithelial cells and will be reviewed here. EMT is often associated with localized inflammation, and it is a well-balanced process to facilitate tissue remodeling. Cyclic transition processes are important because a terminal state or the static state of EMT can cause accumulation of proinflammatory mesenchymal cells in the matrix regions of these tissues and increase localized inflammation that can cause tissue damage. Interactions that determine homeostasis are often controlled by both endocrine and paracrine mediators. Pregnancy maintenance hormone progesterone and its receptors are critical for maintaining the balance between EMT and MET. Increased intrauterine oxidative stress at term can force a static (terminal) EMT and increase inflammation that are physiologic processes that destabilize homeostasis that maintain pregnancy to promote labor and delivery of the fetus. However, conditions that can produce an untimely increase in EMT and inflammation can be pathologic. These tissue damages are often associated with adverse pregnancy complications such as preterm prelabor rupture of the membranes (pPROM) and spontaneous preterm birth (PTB). Therefore, an understanding of the biomolecular processes that maintain cyclic EMT-MET is critical to reducing the risk of pPROM and PTB. Extracellular vesicles (exosomes of 40-160 nm) that can carry various cargo are involved in cellular transitions as paracrine mediators. Exosomes can carry a variety of biomolecules as cargo. Studies specifically using exosomes from cells undergone EMT can carry a pro-inflammatory cargo and in a paracrine fashion can modify the neighboring tissue environment to cause enhancement of uterine inflammation.     

DNA methylation provides insight into intergenerational risk for preterm birth in African Americans

African Americans are at increased risk for spontaneous preterm birth (PTB). Though PTB is heritable, genetic studies have not identified variants that account for its intergenerational risk, prompting the hypothesis that epigenetic factors may also contribute. The objective of this study was to evaluate DNA methylation from maternal leukocytes to identify patterns specific to PTB and its intergenerational risk. DNA from peripheral leukocytes from African American women that delivered preterm (24–34 weeks; N = 16) or at term (39–41 weeks; N = 24) was assessed for DNA methylation using the HumanMethylation450 BeadChip. In maternal samples, 17,829 CpG sites associated with PTB, but no CpG site remained associated after correction for multiple comparisons. Examination of paired maternal-fetal samples identified 5,171 CpG sites in which methylation of maternal samples correlated with methylation of her respective fetus (FDR < 0.05). These correlated sites were enriched for association with PTB in maternal leukocytes. The majority of correlated CpG sites could be attributed to one or more genetic variants. They were also significantly more likely to be in genes involved in metabolic, cardiovascular, and immune pathways, suggesting a role for genetic and environmental contributions to PTB risk and chronic disease. The results of this study may provide insight into the factors underlying intergenerational risk for PTB and its consequences.     

Alteration of DMBA-induced oxidative stress by additive action of a modified indigenous preparation--Kalpaamruthaa

The present study investigated the protective efficacy of the novel preparation named as Kalpaamruthaa (KA, includes Semecarpus anacardium Linn nut milk extract (SA), dried powder of Phyllanthus emblica fruit and honey) on the peroxidative damage and abnormal antioxidant levels in the hepatic mitochondrial fraction of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma rats. Female Sprague-Dawley rats of weight 180+/-10 g were categorized into six groups. Three groups were administered DMBA (25 mg/rat dissolved in olive oil, orally) to induce mammary carcinoma. One of these groups received KA treatment (300 mg/kg b.wt., orally) and other group received SA (200 mg/kg b.wt., orally) for 14 days after 90 days of DMBA induction. Vehicle-treated control and drug control groups were also included. The hepatic mitochondrial fraction of untreated DMBA rats showed 2.96-fold increase in MDA content when compared to control rats and abnormal changes in the activities/levels of mitochondrial enzymic (superoxide dismutase, glutathione peroxidase and glutathione reductase) and non-enzymic (glutathione, vitamin C and vitamin E) antioxidants were observed. DMBA-treated rats also showed decline in the activities of mitochondrial enzymes such as succinate dehydrogenase, alpha-ketoglutarate dehydrogenase, malate dehydrogenase and isocitrate dehydrogenase. In contrast, rats treated with SA and KA showed normal lipid peroxidation antioxidant defenses and mitochondrial enzymes, thereby showing the protection rendered by SA and KA. Although, KA treatment exhibited more profound effect in inhibiting DMBA-induced oxidative stress than sole SA treatment. Results of the study indicate that the anticarcinogenic activity of KA during DMBA-initiated mammary carcinogenesis is mediated through alteration of hepatic antioxidant status as well as modulation of TCA cycle enzymes. On the basis of the observed results, KA can be considered as a readily accessible, promising and novel cancer chemopreventive agent.