2-{N-[(2,4,5-trichlorophenoxy) acetyl]-N-methylamino}-3-pyrrolidinepropanamide analogs as potential antagonists of Urotensin II receptor.

THE PURPOSE OF THE ARTICLE: To identify novel small molecule antagonists of Urotensin II receptor with acceptable pharmacological profile. MATERIALS AND METHODS: Structure-activity-relationship (SAR) studies on 2-{N-[(2,4,5-trichlorophenoxy) acetyl]-N-methylamino}-3-pyrrolidinepropanamide series were conducted and shortlisted compounds were synthesized and evaluated in in vitro cell-based assays. Human and mouse Urotensin II receptor overexpressing CHO cells were used for calcium release and radioligand binding assays. Initial molecules in this series had solubility and inter-species variability issue in the calcium release assay. We, therefore, conducted SAR to overcome these 2 issues and molecules with accepted in vitro profile were evaluated further in mouse pressor response model to generate the in vivo proof of concept for UII receptor antagonization. RESULTS AND CONCLUSIONS: We report herewith identification of 2-{N-[(2,4,5-trichlorophenoxy)acetyl]-N-methylamino}-3-pyrrolidinepropanamides series to obtain novel small molecule antagonists of Urotensin II receptor with acceptable pharmacological profile.

ACR11 modulates levels of reactive oxygen species and salicylic acid-associated defense response in Arabidopsis.

The ACT domain (aspartate kinase, chorismate mutase and TyrA), an allosteric effector binding domain, is commonly found in amino acid metabolic enzymes. In addition to ACT domain-containing enzymes, plants have a novel family of ACT domain repeat (ACR) proteins, which do not contain any recognizable catalytic domain. Arabidopsis has 12 ACR proteins, whose functions are largely unknown. To study the functions of Arabidopsis ACR11, we have characterized two independent T-DNA insertion mutants, acr11-2 and acr11-3. RNA gel-blot analysis revealed that the expression of wild-type ACR11 transcripts was not detectable in the acr11 mutants. Interestingly, a lesion-mimic phenotype occurs in some rosette leaves of the acr11 mutants. In addition, high levels of reactive oxygen species (ROS), salicylic acid (SA), and callose accumulate in the mutant leaves when grown under normal conditions. The expression of several SA marker genes and the key SA biosynthetic gene ISOCHORISMATE SYNTHASE1 is up-regulated in the acr11 mutants. Furthermore, the acr11 mutants are more resistant to the infection of bacterial pathogen Pseudomonas syringae pathovar tomato DC3000. These results suggest that ACR11 may be directly or indirectly involved in the regulation of ROS and SA accumulation, which in turn modulates SA-associated defense responses and disease resistance in Arabidopsis.

The Arabidopsis glutamate receptor-like gene GLR3.6 controls root development by repressing the Kip-related protein gene KRP4.

In Arabidopsis, 20 genes encode putative glutamate receptor-like proteins (AtGLRs). However, the functions of most genes are unknown. In this study, our results revealed that loss of function of AtGLR3.6 (atglr3.6-1) leads to reduced primary root growth and fewer lateral roots, whereas AtGLR3.6 overexpression induced both primary and lateral root growth. The glr3.6-1 mutant exhibited a smaller root meristem size compared with the wild type, indicating that AtGLR3.6 controls root meristem size. In addition, atglr3.6-1 roots show a decreased mitotic activity accounting for the reduced root meristem size. Furthermore, expression of a gene encoding a cell cycle inhibitor, the cyclin-dependent kinase (CDK) inhibitor Kip-related protein 4 (KRP4), was significantly up-regulated in the mutant and down-regulated in AtGLR3.6-overexpressing roots, suggesting a role for KRP4 in AtGLR3.6-mediated root meristem maintenance. Importantly, the atglr3.6-1 mutant recovered most of its root growth when KRP4 expression is down-regulated, whereas elevated KRP4 expression in AtGLR3.6-overexpressing plants phenocopied the wild-type root growth, implying an underlying relationship between AtGLR3.6 and KRP4 genes. Cytosolic Ca(2+) elevation is reduced in atglr3.6-1 roots, suggesting impaired calcium signaling. Moreover, calcium treatment reduced the level of KRP4 and hence induced root growth. Collectively, we reveal that AtGLR3.6 is required for primary and lateral root development, and KRP4 functions as a downstream signaling element in Arabidopsis thaliana.

The encapsulation technology in fruit plants--a review.

Encapsulation technology is an exciting and rapidly growing area of biotechnological research. This has drawn tremendous attention in recent years because of its wide use in conservation and delivery of tissue cultured plants of commercial and economic importance. Production of synthetic seeds by encapsulating somatic embryos, shoot buds or any other meristmatic tissue helps in minimizing the cost of micropropagated plantlets for commercialization and final delivery. In most of fruit crops, seed propagation has not been successful because of heterozygosity of seeds, minute seed size, presence of reduced endosperm, low germination rate, and also some are having seedless varieties. Many species have desiccation-sensitive intermediate or recalcitrant seeds and can be stored for only a few weeks or months. Under these circumstances, increasing interest has been shown recently to use encapsulation technology for propagation and conservation. Many fruit plants are studied worldwide for breeding, genetic engineering, propagation, and pharmaceutical purposes. In this context, synthetic seeds would be more applicable in exchange of elite and axenic plant material between laboratories and extension centers due to small bead size and ease in handling. Due to these advantages, interest in using encapsulation technology has continuously been increasing in several fruit plant species. The purpose of this review is to focus upon current information on development of synthetic seeds in several fruit crops.

Inhaled carbenoxolone prevents allergic airway inflammation and airway hyperreactivity in a mouse model of asthma.

BACKGROUND: Asthma is a chronic respiratory disease, which needs a safer medication preferably in inhalation form. In view of this, we have evaluated the effect of inhaled carbenoxolone (CBX), a herbal-derived compound, on asthma in a mouse model. METHODS: Mice were sensitized and challenged with ovalbumin (OVA) to develop certain characteristic features of asthma such as airway hyperreactivity (AHR), airway eosinophilia, lung inflammation and mucus hypersecretion. To evaluate the effect of CBX on the above asthmatic features, CBX (2.5, 5 and 10 mg/ml, 3 ml) or vehicle (water) was given by inhalation. AHR was determined using whole-body plethysmography. Infiltration of eosinophils was estimated by microscopy. Lung inflammation and mucus hypersecretion were assessed using hematoxylin and eosin, and periodic acid-Schiff staining, respectively. Th-2 cytokines, IL-4 and IL-5 were measured in bronchoalveolar lavage (BAL) fluid and IgE in sera. To identify the possible mode of CBX action, we measured corticosterone levels in the BAL fluid and 5-lipoxygenase (5-LO) expression in the lungs. RESULTS: CBX (5 mg/ml) inhalation markedly alleviated AHR (p = 0.0032) and reduced lung inflammation and mucus hypersecretion. Also, it prevented the increase in IL-4 (p = 0.0192), IL-5 (p = 0.0116) and eosinophils (p < 0.0005) in the BAL fluid, and OVA-specific IgE levels (p = 0.00061) in sera. 5-LO expression was also markedly reduced. However, corticosterone levels were not affected. CONCLUSIONS: Inhaled CBX alleviates the asthmatic features in mice and could be a potent nebulized therapy in clinical asthma.

Partitioning of nasal and pulmonary resistance changes during noninvasive plethysmography in mice.

Double-chamber plethysmography is a well established noninvasive method of assessing airflow obstruction in small lab animals. It allows measurement of the specific airway resistance (sRaw), which unlike enhanced pause (Penh), is a meaningful airway mechanics parameter. Since sRaw is measured in spontaneously breathing mice, a limitation of the method is the inability to exclude nasal resistance changes. We recently showed that mice are not truly obligate nasal breathers and that after nasal occlusion, nasally breathing mice can transition to an oral mode of breathing. We now show that it is experimentally possible to algebraically separate the average nasal and pulmonary (including laryngeal) components of total airway resistance change by a series of measurements made across groups of mice breathing nasally or orally, assuming that oral resistance remains constant. Using this approach, we show that nasal resistance change comprises one-half or more of the total resistance change during methacholine challenge. Inhibition of mucin secretion from airway goblet cells attenuates pulmonary but not nasal airway hyperresponsiveness (AHR), and nasal AHR in a murine model of rhinitis may be related to edema.

Mepacrine alleviates airway hyperresponsiveness and airway inflammation in a mouse model of asthma.

Asthma is a multifactorial respiratory disease. Though its incidence is increasing rapidly all over the world, the available therapeutic strategies are neither sufficient nor safe for long term use. Mepacrine, a known antimalarial drug, has been shown to possess antioxidant, anti-inflammatory, platelet anti-aggregant, and PLA2 inhibitory activities. However, its possible use in asthma has not been studied yet. The objective of this study was to investigate the anti-asthmatic property of mepacrine using a mouse model of asthma. To accomplish this, male BALB/c mice were sensitized and challenged with ovalbumin and treated with increasing concentrations of mepacrine. Airway hyperresponsiveness (AHR) to methacholine was assessed using unrestrained whole body plethysmography. Mepacrine (1 mg/kg) has shown marked attenuation of AHR. Cytokines such as IL-4, IL-5, IL-13 and IFN-gamma and OVA-specific IgE levels were measured in BAL (bronchoalveloar lavage) fluid and sera, respectively. Mepacrine effectively reduced the rise in IL-4, IL-5, IL-13, and OVA-specific IgE and restored IFN-gamma levels. Mepacrine also significantly prevented the increase of sPLA2 (secretory phospholipase A2) activity in BAL fluid supernatant and Cys-LT (cysteinyl leukotrienes) in lung tissue homogenates of asthmatic mice. In addition, mepacrine treatment reduced BAL fluid eosinophilia and signs of allergic airway inflammation such as perivascular and peribronchial distribution of inflammatory cells. These findings indicate that mepacrine reduces the asthmatic features in ovalbumin induced asthma by acting on PLA2-Cys-LT axis. Thus, it could be useful for the development of better asthma therapy.