Response of antioxidant enzymes to high NaCl concentration in different salt-tolerant plants

The effects of NaCl on the H₂O₂ content and the activities of catalase (CAT) and superoxide dismutase (SOD) were studied in diverse group of plants, such as a unicellular alga, Chlorella sp., an aquatic macrophyte, Najas graminea, and a mangrove plant, Suaeda maritima, all showing high tolerance to NaCl. Significant accumulation of H₂O₂ was observed in all the tested plants upon their exposure to 255 mM NaCl. The activity of both CAT and SOD increased significantly in response to the NaCl treatment. Growing the plants in presence of 255 mM NaCl also resulted in the synthesis of new isoforms of both CAT and SOD.     

Inhibiting the Growth of Pancreatic Adenocarcinoma In Vitro and In Vivo through Targeted Treatment with Designer Gold Nanotherapeutics

Background

Pancreatic cancer is one of the deadliest of all human malignancies with limited options for therapy. Here, we report the development of an optimized targeted drug delivery system to inhibit advanced stage pancreatic tumor growth in an orthotopic mouse model.

Method/Principal Findings

Targeting specificity in vitro was confirmed by preincubation of the pancreatic cancer cells with C225 as well as Nitrobenzylthioinosine (NBMPR - nucleoside transporter (NT) inhibitor). Upon nanoconjugation functional activity of gemcitabine was retained as tested using a thymidine incorporation assay. Significant stability of the nanoconjugates was maintained, with only 12% release of gemcitabine over a 24-hour period in mouse plasma. Finally, an in vivo study demonstrated the inhibition of tumor growth through targeted delivery of a low dose of gemcitabine in an orthotopic model of pancreatic cancer, mimicking an advanced stage of the disease.

Conclusion

We demonstrated in this study that the gold nanoparticle-based therapeutic containing gemcitabine inhibited tumor growth in an advanced stage of the disease in an orthotopic model of pancreatic cancer. Future work would focus on understanding the pharmacokinetics and combining active targeting with passive targeting to further improve the therapeutic efficacy and increase survival.     

Regulatory mechanisms across networks of the circadian clock and senescence pathways

Journal of Plant Biochemistry and Biotechnology - The circadian clock serves the fitness of higher plants by controlling various aspects of plant growth and development ranging from photosynthesis...     

Cross-genera amplification of Cajanus spp. specific SSR markers in Clitoria ternatea (L.) and their application in genetic diversity studies

Clitoria ternatea (L.) is a medicinal leguminous plant and is cultivated to cater the need of herbal industries and asthetic purposes. The unavailability of steady molecular marker impedes the genetic improvement of C. ternatea. In the present study, transferability of 98 pairs of Cajanus spp. specific SSR primers were assessed among 14 genotypes of C. ternatea, varied for their flower color, floral architecture and bio-metabolite (taraxerol and delphinidin) content, and out of them 43 had successfully amplified the fragments. Among them, 36 pairs of primers showed 100% transferability, whereas rest seven varied from 42.86 to 92.85% transferability. The transferable 43 pairs of SSR primers generated 196 alleles across the 14 genotypes and the AMOVA analysis showed moderate genetic variation (55.1%) among the genotypes of C. ternatea, which was also reinforced by Nei’s genetic distance and gene identity estimates derived haplotype matrix. Similarly, both the principal coordinate analysis and dendrogram grouped these 14 genotypes of C. ternatea into two major clusters based on SSR allele distribution and frequency, and the clustering pattern is in accordance with petal color but in contrast to floral architecture. MCheza based outlier analysis revealed 16 alleles for balancing selection, which are putatively involved in the maintenance of genetic polymorphism in C. ternatea. Moreover, the estimates of molecular diversity and bio-metabolite content revealed the possible use of these genotypes in future breeding programme of this species.Electronic supplementary materialThe online version of this article (10.1007/s12298-020-00907-x) contains supplementary material, which is available to authorized users.     

Structure and energy of non-canonical basepairs: comparison of various computational chemistry methods with crystallographic ensembles

Different types of non-canonical basepairs, in addition to the Watson-Crick ones, are observed quite frequently in RNA. Their importance in the three dimensional structure is not fully understood, but their various roles have been proposed by different groups. We have analyzed the energetics and geometry of 32 most frequently observed basepairs in the functional RNA crystal structures using different popular empirical, semi-empirical and ab initio quantum chemical methods and compared their optimized geometry with the crystal data. These basepairs are classified into three categories: polar, non-polar and sugar-mediated, depending on the types of atoms involved in hydrogen bonding. In case of polar basepairs, most of the methods give rise to optimized structures close to their initial geometry. The interaction energies also follow similar trends, with the polar ones having more attractive interaction energies. Some of the C-H...O/N hydrogen bond mediated non-polar basepairs are also found to be significantly stable in terms of their interaction energy values. Few polar basepairs, having amino or carboxyl groups not hydrogen bonded to anything, such as G:G H:W C, show large flexibility. Most of the non-polar basepairs, except A:G s:s T and A:G w:s C, are found to be stable; indicating C-H...O/N interaction also plays a prominent role in stabilizing the basepairs. The sugar mediated basepairs show variability in their structures, due to the involvement of flexible ribose sugar. These presumably indicate that the most of the polar basepairs along with few non-polar ones act as seed for RNA folding while few may act as some conformational switch in the RNA.     

Impaired Expression of Type I and Type II Interferon Receptors in HCV-Associated Chronic Liver Disease and Liver Cirrhosis

Purpose

Chronic Hepatitis C Virus (HCV)-infected patients with liver cirrhosis (LC) respond poorly to interferon-alpha (IFN-α) and ribavirin (RBV) combination therapy, but the reason for this is unclear. We previously reported that HCV-infection induces endoplasmic reticulum (ER) stress and autophagy response that selectively down regulates the type I IFN-α receptor-1 (IFNAR1) and RBV transporters (CNT1 and ENT1), leading to IFN-α/RBV resistance. The goal of this study is to verify whether an increase in ER stress and autophagy response is also associated with the reduced expression of IFNAR1 and RBV transporters in chronic HCV-infected patients.

Methods

Primary human hepatocytes (PHH) were infected with cell culture grown HCV particles (JFH-ΔV3-Rluc). HCV replication was confirmed by the detection of viral RNA by RT-qPCR and HCV-core protein by Western blotting. The ER stress and autophagy response and expression of IFN receptors and RBV transporters in HCV infected PHH and liver tissues derived from patients were measured by Western blotting.

Result

HCV infection of PHH showed impaired expression of IFNAR1, IFNγR1 (Type II IFN receptor) and RBV transporters but not IL10Rβ (Type III IFN-λ receptor). ER stress markers (BiP, IRE1α and peIF2α) and autophagy response (LC3II, Beclin 1 and ATG5) were induced in HCV infected chronic liver disease (CLD) and LC patients. Liver biopsies (CLD) show a 50% reduced expression of IFNAR1 and RBV transporters. Furthermore, the expression of IFNAR1 and RBV transporters was impaired in almost all LC patients.

Conclusion

HCV infection induces ER stress and autophagy response in infected PHH and chronically infected liver tissues. The expression of IFNAR1, IFNγR1 and RBV transporters were significantly impaired in CLD and cirrhotic livers. Our study provides a potential explanation for the reduced response rate of IFN-α and RBV combination therapy in HCV infected patients with liver cirrhosis.     

Increased β-Catenin/Tcf Signaling in Pilocytic Astrocytomas: A Comparative Study to Distinguish Pilocytic Astrocytomas from Low-Grade Diffuse Astrocytomas

Although pilocytic and diffuse grade II astrocytomas considered as low-grade tumors, the distinction between them is still a major clinical problem. Previously we reported the activation of Wnt/β-catenin/Tcf signaling pathway in diffuse astrocytomas, however its role in pilocytic astrocytomas is not well understood. In this study, we investigated the Wnt/β-catenin/Tcf pathway in pilocytic astrocytomas and compared with diffuse astrocytomas. We observed the differential expression of β-catenin, Tcf4, Lef1 and c-Myc in astrocytomas particularly higher levels were observed in pilocytic astrocytomas and GBM while very little expression was documented in grade II tumors. Further, immunohistochemical analysis revealed the strong positivity of β-catenin, Tcf4, Lef1 and c-Myc in pilocytic astrocytomas than that of grade II tumors and also exhibited the strong positivity in vascular endothelial cells of pilocytic astrocytomas and GBM. Hence, Wnt/β-catenin/Tcf signaling pathway is differentially expressed in astrocytomas, activation of this pathway might be helpful in separating pilocytic astrocytomas from low-grade diffuse astrocytomas.     

Modeling of molecular interaction between apoptin, BCR-Abl and CrkL--an alternative approach to conventional rational drug design

In this study we have calculated a 3D structure of apoptin and through modeling and docking approaches, we show its interaction with Bcr-Abl oncoprotein and its downstream signaling components, following which we confirm some of the newly-found interactions by biochemical methods. Bcr-Abl oncoprotein is aberrantly expressed in chronic myelogenous leukaemia (CML). It has several distinct functional domains in addition to the Abl kinase domain. The SH3 and SH2 domains cooperatively play important roles in autoinhibiting its kinase activity. Adapter molecules such as Grb2 and CrkL interact with proline-rich region and activate multiple Bcr-Abl downstream signaling pathways that contribute to growth and survival. Therefore, the oncogenic effect of Bcr-Abl could be inhibited by the interaction of small molecules with these domains. Apoptin is a viral protein with well-documented cancer-selective cytotoxicity. Apoptin attributes such as SH2-like sequence similarity with CrkL SH2 domain, unique SH3 domain binding sequence, presence of proline-rich segments, and its nuclear affinity render the molecule capable of interaction with Bcr-Abl. Despite almost two decades of research, the mode of apoptin's action remains elusive because 3D structure of apoptin is unavailable. We performed in silico three-dimensional modeling of apoptin, molecular docking experiments between apoptin model and the known structure of Bcr-Abl, and the 3D structures of SH2 domains of CrkL and Bcr-Abl. We also biochemically validated some of the interactions that were first predicted in silico. This structure-property relationship of apoptin may help in unlocking its cancer-selective toxic properties. Moreover, such models will guide us in developing of a new class of potent apoptin-like molecules with greater selectivity and potency.