Impact of precursors and plant growth regulators on <Emphasis Type="Italic">in vitro</Emphasis> growth,bioactive lignans,and antioxidant content of <Emphasis Type="Italic">Phyllanthus</Emphasis> species

The production of specific secondary metabolites in vitro can be improved through medium supplementation with secondary metabolite precursors, plant growth regulators (PGRs), and abiotic and biotic elicitors. In the present study, node and internode explants of Phyllanthus amarus and P. urinaria collected from Karkala region, Udupi District, Karnataka, India, were inoculated aseptically onto Murashige and Skoog (MS) medium for callus induction. Uniform calluses were inoculated onto MS medium fortified with one of two precursor’s cinnamic acid (CA) or phenylalanine (PA), or with naphthalene acetic acid (NAA). After 30 d of treatment, calluses from treatment and control groups were harvested and quantitatively analyzed for three lignans (phyllanthin, hypophyllanthin and niranthin) and an antioxidant (ellagic acid). Increased amounts of the lignans and ellagic acid were obtained through supplementation with CA, PA, and NAA, and higher ellagic acid was present at higher amounts than the three lignans. These results demonstrated that the Phyllanthus species collected from Karkala region (designated “Accessions3”) show substantial response to CA, PA, and NAA treatment and represent a potential source of donor plants with higher amounts of lignans and antioxidants. These plants can be cultivated on a large scale both in vitro and in vivo for production of important bioactive compounds. Production of these compounds can be further enhanced through induction of somaclonal variant plants with higher amounts of bioactive molecule production and through production of transgenic plants overexpressing genes related to lignan- and phenolic-compound biosynthesis.     

Therapeutic efficacy of anti‐MMP9 antibody in combination with nab‐paclitaxel‐based chemotherapy in pre‐clinical models of pancreatic cancer

Matrix metalloproteinase 9 (MMP9) is involved in the proteolysis of extracellular proteins and plays a critical role in pancreatic ductal adenocarcinoma (PDAC) progression, invasion and metastasis. The therapeutic potential of an anti‐MMP9 antibody (αMMP9) was evaluated in combination with nab‐paclitaxel (NPT)‐based standard cytotoxic therapy in pre‐clinical models of PDAC. Tumour progression and survival studies were performed in NOD/SCID mice. The mechanistic evaluation involved RNA‐Seq, Luminex, IHC and Immunoblot analyses of tumour samples. Median animal survival compared to controls was significantly increased after 2‐week therapy with NPT (59%), Gem (29%) and NPT+Gem (76%). Addition of αMMP9 antibody exhibited further extension in survival: NPT+αMMP9 (76%), Gem+αMMP9 (47%) and NPT+Gem+αMMP9 (94%). Six‐week maintenance therapy revealed that median animal survival was significantly increased after NPT+Gem (186%) and further improved by the addition of αMMP9 antibody (218%). Qualitative assessment of mice exhibited that αMMP9 therapy led to a reduction in jaundice, bloody ascites and metastatic burden. Anti‐MMP9 antibody increased the levels of tumour‐associated IL‐28 (1.5‐fold) and decreased stromal markers (collagen I, αSMA) and the EMT marker vimentin. Subcutaneous tumours revealed low but detectable levels of MMP9 in all therapy groups but no difference in MMP9 expression. Anti‐MMP9 antibody monotherapy resulted in more gene expression changes in the mouse stroma compared to the human tumour compartment. These findings suggest that anti‐MMP9 antibody can exert specific stroma‐directed effects that could be exploited in combination with currently used cytotoxics to improve clinical PDAC therapy.     

Comparative Nuclear Proteomics Analysis Provides Insight into the Mechanism of Signaling and Immune Response to Blast Disease Caused by Magnaporthe oryzae in Rice

Modulation of plant immune system by extrinsic/intrinsic factors and host‐specific determinants fine‐tunes cellular components involving multiple organelles, particularly nucleus to mount resistance against pathogen attack. Rice blast, caused by hemibiotrophic fungus Magnaporthe oryzae, is one of the most devastating diseases that adversely affect rice productivity. However, the role of nuclear proteins and their regulation in response to M. oryzae remains unknown. Here, the nucleus‐associated immune pathways in blast‐resistant rice genotype are elucidated. Temporal analysis of nuclear proteome is carried out using 2‐DE coupled MS/MS analysis. A total of 140 immune responsive proteins are identified associated with nuclear reorganization, cell division, energy production/deprivation, signaling, and gene regulation. The proteome data are interrogated using correlation network analysis that identified significant functional modules pointing toward immune‐related coinciding processes through a common mechanism of remodeling and homeostasis. Novel clues regarding blast resistance include nucleus‐associated redox homeostasis and glycolytic enzyme–mediated chromatin organization which manipulates cell division and immunity. Taken together, the study herein provides evidence that the coordination of nuclear function and reprogramming of host translational machinery regulate resistance mechanism against blast disease.     

Differential seminal plasma proteome signatures of acute lymphoblastic leukemia survivors

With advances in therapeutic methods, there is a high survival rate among leukemia patients, of an extent more than 80%. However, chemotherapeutic drugs used to treat these patients have adverse effects on their overall health profile including fertility. The primary aim of this study was to identify differentially expressed proteins in seminal plasma of acute lymphoblastic leukemia (ALL) survivors compared to age-matched healthy controls, which can provide molecular basis of idiopathic infertility in such survivors. Differential proteome profiling was performed by 2D–differential in-gel electrophoresis, protein spots were identified by mass spectrometry and selective differentially expressed proteins (DEPs) were validated by western blotting and ELISA method. Out of eight DEPs identified, five proteins (isocitrate dehydrogenase 1, semenogelin 1, lactoferrin, prolactin-inducible protein, and human serum albumin) were upregulated and three (pepsinogen, prostate specific antigen and prostatic acid phosphatase) were downregulated. Expression profiles of these proteins are suggestive of reduction in semen quality in ALL survivors and can further be explored to determine their fertility status.     

Substrate specificities and functional characterization of a thermo-tolerant uracil DNA glycosylase (UdgB) from Mycobacterium tuberculosis

Uracil DNA glycosylases (UDGs) excise uracil from DNA and initiate the base (uracil) excision repair pathway. Ung, a highly conserved protein, is the only UDG characterized so far in mycobacteria. Here, we show that Rv1259 from Mycobacterium tuberculosis codes for a double-stranded DNA (dsDNA) specific UDG (MtuUdgB). MtuUdgB is thermo-tolerant, contains Fe-S cluster and, in addition to uracil, it excises ethenocytosine and hypoxanthine from dsDNA. MtuUdgB is product inhibited by AP-site containing dsDNA but not by uracil. While MtuUdgB excises uracil present as a single-nucleotide bulge in dsDNA, it is insensitive to inhibition by dsDNA containing AP-site in the bulge. Interestingly, in the presence of cellular factors, the uracil excision activity of MtuUdgB is enhanced, and when introduced into E. coli (ung(-)), it rescues its mutator phenotype and prevents C to T mutations in DNA. Novel features of the mechanism of action of MtuUdgB and the physiological significance of the family 5 UDG in mycobacteria have been discussed.     

Exploring the therapeutic potential of staphylococcal phage formulations: Current challenges and applications in phage therapy

Unconstrained consumption of antibiotics throughout the expanse of the 21st century has resulted in increased antimicrobial resistance (AMR) among bacterial pathogens, a transpiring predicament affecting the public healthcare sector. The upsurge of multidrug-resistant pathogens, including Staphylococcus aureus, synchronously with the breakdown of the conventional antibiotic pipeline has led to the exploration of alternate strategies. Phage therapy applications have thus gained immense prominence among the scientific community to conquer this notorious pathogen associated with wide-ranging clinical manifestations, especially in immunosuppressed individuals. In this direction, a plethora of phage formulations like topical solutions, medicated dressings impregnated with phages, liposomal entrapments, etc., have been considered as an effective and upcoming strategy. Owing to the synergistic effect of phages with other antibacterial agents, they can be easily exploited for biomedical application. This review primarily focuses on the therapeutic implications of S. aureus phages in the biotechnological and medical arena. Through this review article, we have also discussed the current status and the incurring challenges in phage therapy.