Molecular docking approaches in identification of High affinity inhibitors of Human SMO receptor

Inappropriate activation of the Hh signaling pathway has been implicated in the development of several types of cancers including prostate, lung, pancreas, breast, brain and skin. Present study identified the binding affinities of eight established inhibitors viz., Cyclopamine, Saridegib, Itraconazole, LDE-225, TAK-441, BMS-833923 (XL139), PF-04449913 and Vismodegib targeting SMO receptor - a candidate protein involved in hedgehog pathway and sought to identify the best amongst the established inhibitors through by molecular docking. Exelxis® BMS 833923 (XL 139) demonstrated superior binding affinity aided by MolDock scoring docking algorithm. Further BMS 833923 (XL 139) was evaluated for pharmacophoric features which revealed appreciable ligand receptor interactions.     

PTEN-mediated ERK1/2 inhibition and paradoxical cellular proliferation following Pnck overexpression

Pregnancy upregulated non-ubiquitous calmodulin kinase (Pnck), a novel calmodulin kinase, is significantly overexpressed in breast and renal cancers. We present evidence that at high cell density, overexpression of Pnck in HEK 293 cells inhibits serum-induced extracellular signal-regulated kinase (ERK1/ERK2) activation. ERK1/2 inhibition is calcium-dependent and Pnck kinase activity is required for ERK1/2 inhibition, since expression of a kinase-dead (K44A) and a catalytic loop phosphorylation mutant (T171A) Pnck protein is unable to inhibit ERK 1/2 activity. Ras is constitutively active at high cell density, and Pnck does not alter Ras activation, suggesting that Pnck inhibition of ERK1/2 activity is independent of Ras activity. Pnck inhibition of serum-induced ERK1/2 activity is lost in cells in which phosphatase and tensin homolog (PTEN) is suppressed, suggesting that Pnck inhibition of ERK1/2 activity is mediated by PTEN. Overexpression of protein phosphatase-active but lipid phosphatase-dead PTEN protein inhibits ERK1/2 activity in control cells and enhances Pnck-mediated ERK1/2 inhibition, suggesting that Pnck increases availability of protein phosphatase active PTEN for ERK1/2 inhibition. Pnck is a stress-responsive kinase; however, serum-induced p38 MAP kinase activity is also downregulated by Pnck in a Pnck kinase- and PTEN-dependent manner, similar to ERK1/2 inhibition. Pnck overexpression increases proliferation, which is inhibited by PTEN knockdown, implying that PTEN acts as a paradoxical promoter of proliferation in ERK1/2 and p38 MAP kinase phosphorylation-inhibited, Pnck-overexpressing cells. Overall, these data reveal a novel function of Pnck in the regulation of ERK1/2 and p38 MAP kinase activity and cell proliferation, which is mediated by paradoxical PTEN functions. The possible biological implications of these data are discussed.     

Ligation of cell surface-associated glucose-regulated protein 78 by receptor-recognized forms of alpha 2-macroglobulin: activation of p21-activated protein kinase-2-dependent signaling in murine peritoneal macrophages

Previous studies of the plasma proteinase inhibitor alpha2-macroglobulin (alpha2M) demonstrated that alpha2M-proteinase complexes (alpha2M*) modulate immune responses and promotes macrophage locomotion and chemotaxis. Alpha2M* binds to cell surface-associated glucose-regulated protein 78 (GRP78), which activates downstream signaling events. The role of p21-activated protein kinase-1 and -2 (PAK-1 and -2) in promoting cellular motility is well documented. In the current study, we examined the ability of alpha2M* to activate PAK-1 and PAK-2. Upon macrophage stimulation with alpha2M*, PAK-2 is autophosphorylated, resulting in increased kinase activity; however, PAK-1 is negligibly affected. Alpha2M*-stimulated macrophages showed a marked elevation in the levels of Rac x GTP. Receptor tyrosine phosphorylation upon binding of alpha2M* to GRP78, recruits PAK-2 to the plasma membrane via the adaptor protein NCK. Consistent with this hypothesis, silencing of GRP78 gene expression greatly attenuated the levels of membrane-associated PAK-2 and NCK. PAK-2 activity was markedly decreased by inhibition of tyrosine kinases and PI3K before alpha2M* stimulation. We further demonstrate that phosphorylation of Lin-11, Isl-1, Mec-3 (LIM) kinase and cofilin is promoted by treating macrophages with alpha2M*. Thus, alpha2M* regulates activation of the PAK-2-dependent motility mechanism in these cells.     

Redescription of the Male and Female of <Emphasis Type="Italic">Caliris keralensis</Emphasis> (Vyjayandi et al., 2006) (Mantodea: Caliridinae)

The holotype of Caliris keralensis (Vyjayandi et al. 2006) (Mantodea: Caliridinae) is reviewed along with another paratype female not listed by the authors. The male of this species is re-described in details and is assigned paratype male. Photographs of the specimens are given. Male genital complex is described for better understanding the species.     

Design, synthesis and evaluation of naphthalene-2-carboxamides as reversal agents in MDR cancer

A novel class of molecules with structure N-[3-(4-substituted-1-piperazinyl) propyl]-6-methoxy naphthalene-2-carboxamides were designed by generating a pharmacophore for potent MDR reversal activity, using Elacridar (GF 120918) as a query molecule and using MOE software. They were synthesized by condensing 6-methoxynaphthalene-2-carboxylic acid with N-[3-(4-substituted-1-piperazinyl) propyl] amines in the presence of DCC in DMF. They were evaluated in P388 murine lymphocytic leukemia cell line (P388) in vitro using SRB assay for cytotoxicity and in adriamycin-resistant P388 murine lymphocytic leukemia cell line (P388/ADR) using MTT assay for resistant reversal activity. Test compounds were non-toxic at the doses studied (upto 80 microg/ml). They effectively reversed adriamycin resistance at the doses studied (40 and 80 microg/ml). The percentage enhancement in adriamycin activity was in the range 33.58 -90.67 (at 40 microg/ml) and 8.80-46.04 (at 80 microg/ml) and the corresponding reversal potency values were in the range 1.33-1.90 and 1.08-1.46, respectively. Test compounds 2, 3, and 5 exhibited better activity as compared to the standard resistant reversal agent (Verapamil), at same concentration.     

Demonstration of an endogenous activator for the Na+, K+-ATPase system

A heat-labile, non-dialysable and protease-sensitive endogenous activator (NaAF) capable of stimulating the Na⁺, K⁺-ATPase system has been demonstrated. The activator (NaAF) activity was partially enriched (about 10 fold) by dialysis (30 kDa cutoff) under negative pressure and pH 4.8 precipitation. The NaAF has been found to occur in the cytosolic fractions of tissues such as the kidney and brain from two different species (rabbit and pig) tested so far. Also, the factor from one tissue stimulates with equal efficacy the Na⁺, K⁺-ATPase systems of other tissues regardless of the species; thus demonstrating universal nature of the activator. Some degree of cross-reactivity was noted between the activating effects of this activator (for the Na⁺,K⁺-ATPase) and that for the H⁺,K⁺-ATPase recently described (J. Biol. Chem. 262:5664–5670, 1987). The purified NaAF obtained from sephacryl S-300 column chromatography activates the pure renal medullary Na⁺,K⁺-ATPase in a dose dependent manner.A preliminary account of this work was published in Fed. Proc. 46(4): 4466, 1987     

Rosuvastatin alleviates high-salt and cholesterol diet-induced cognitive impairment in rats via Nrf2–ARE pathway

Objective: The objectives of our study were to investigate the possible effect of rosuvastatin in ameliorating high salt and cholesterol diet (HSCD)-induced cognitive impairment and to also investigate its possible action via the Nrf2-ARE pathway.

Methods: In silico studies were performed to check the theoretical binding of rosuvastatin to the Nrf2 target. HSCD was used to induce cognitive impairment in rats and neurobehavioral studies were performed to evaluate the efficacy of rosuvastatin in enhancing cognition. Biochemical analyses were used to estimate changes in oxidative markers. Western blot and immunohistochemical analyses were done to check Nrf2 translocation. TUNEL and caspase 3 tests were performed to evaluate reversal of apoptosis by rosuvastatin.

Results: Rosuvastatin showed good theoretical affinity to Nrf2, significantly reversed changes in oxidative biomarkers which were induced by HSCD, and also improved the performance of rats in the neurobehavioral test. A rise in nuclear translocation of Nrf2 was revealed through immunohistochemical analysis and western blot. TUNEL staining and caspase 3 activity showed attenuation of apoptosis.

Discussion: We have investigated a novel mechanism of action for rosuvastatin (via the Nrf2–ARE pathway) and demonstrated that it has the potential to be used in the treatment of cognitive impairment.     

Methyl salicylate and trans‐anethole affect the pheromonal activity of homofarnesal,the female sex pheromone of azuki bean beetle

Plant essential oils (EOs) exhibit an array of biological activities against insect pests. However, their negative influences on the pheromonal activity of azuki bean beetle (ABB), Callosobruchus chinensis L. have not received research attentions. ABB is a field‐to‐storage pest of legumes, and its female produces the sex pheromone known as homofarnesal with two isomeric components: 2E‐ and 2Z–homofarnesal, (2E,6E)‐7‐ethyl‐3,11‐dimethyl‐2,6,10‐dodecatrienals and (2Z,6E)‐7‐ethyl‐3,11‐dimethyl‐2,6,10‐dodecatrienals. We evaluated the effects of three EOs and their two major components on the attractiveness of male ABBs to synthetic homofarnesal (2E‐:2Z–homofarnesal = 6:4) using Y‐tube olfactometry in laboratory and rocket traps in the semi‐open polyhouse. Y‐tube olfactometry showed the significant negative effect of EOs of Illicium verum, Croton anisatum at 10 and 100 ng, and Gaultheria fragrantissima at 100 ng against homofarnesal (100 ng) in attracting male ABBs. Similarly trans‐anethole (at 10 and 100 ng) and methyl salicylate (at 100 ng) also ascertained significant negative effect against homofarnesal (100 ng) in Y‐tube olfactometry. When 10 mg of each of trans‐anethole and methyl salicylate was released at the downstream of 30 mg homofarnesal lure in rocket traps, highly significant effect was achieved against attractiveness of homofarnesal to ABB males. This study ascertained significant level of negative effect of the tested EOs and their major components to homofarnesal, tracing out a new opportunity of integrating them in ABB management programs both in field and storage.     

Cushing disease with pregnancy

Pregnancy occurs rarely in patients with Cushing syndrome (CS) due to hypercortisolism. So far, about 150 cases of CS in pregnancy have been reported in the literature. We describe a 22-year-old female who presented in pregnancy with clinical features of CS. She delivered at 34 weeks of gestation and baby had transient adrenal insufficiency in the neonatal period. Mother underwent transsphenoidal surgery 1 year postpartum and on follow up she is under remission. Neonatal hypoadrenalism should be anticipated in maternal CS.