Optimization of growth media for obtaining high-cell density cultures of halophilic archaea (family Halobacteriaceae) by response surface methodology

Optimization of media components for the growth and biomass production of Halobacterium salinarum VKMM 013 was carried out using response surface methodology. A second order quadratic model was estimated and media components were determined based on quadratic regression equation generated by model. These were 6.35 g L⁻¹ of KCl, 9.70 g L⁻¹ of MgSO₄, 13.38 g L⁻¹ of gelatin and 12.00 g L⁻¹ of soluble starch in nutrient broth supplemented with artificial seawater with 20% (w/v) of NaCl. In these optimal conditions, the obtained cell concentration of 0.746 g L⁻¹ dry weight was in agreement with the predicted cell concentration. The optimized media significantly shortened the time required for cell culture to reach the stationary phase while providing a nearly 2.4-fold increase in biomass production. Furthermore, in cell cultures of three other halophilic archaea the use of optimized media enhanced growth rate and provided high-cell density.     

Anti-cataractogenic effect of curcumin and aminoguanidine against selenium-induced oxidative stress in the eye lens of Wistar rat pups: An in vitro study using isolated lens

The aim of this study was to investigate whether curcumin and aminoguanidine (AG) prevent selenium-induced cataractogenesis in vitro. On postpartum day 8, transparent isolated lens were incubated in 24 well plates containing Dulbecco's Modified Eagle Medium (DMEM). Isolated lens of group I were incubated with DMEM medium alone. Group II: lenses incubated in DMEM containing 100 μM sodium selenite; group III: lenses incubated in DMEM containing 100 μM sodium selenite and 100 μM curcumin; group IV: lenses incubated in DMEM containing 100 μM sodium selenite and 200 μM curcumin; group V: lenses incubated in DMEM containing 100 μM sodium selenite and 100 μM AG; group V: lenses incubated in DMEM containing 100 μM sodium selenite and 200 μM AG. On day 12, cataract development was graded using an inverted microscope and the lenses were analyzed for enzymic as well as non-enzymic antioxidants, lipid peroxidation (LPO), nitric oxide (NO), superoxide anion (O₂⁻) and hydroxyl radical generation (OH) and inducible nitric oxide synthase (iNOS) activity by Western blotting and RT-PCR. All control lenses in group I were clear (0). In groups II and III, all isolated lenses developed cataract with variation in levels (+++ or ++), whereas isolated lenses from groups IV, V and VI were clear (0). In agreement to this, a decrease in antioxidants and increased free radical generation and also iNOS expression were observed in selenium exposed lenses when compared to other groups. AG (100 μM) was found to be more effective in anti-cataractogenic effect than curcumin (200 μM). Curcumin and AG suppressed selenium-induced oxidative stress and cataract formation in isolated lens from Wistar rat pups, possibly by inhibiting depletion of enzymic as well as non-enzymic antioxidants, and preventing uncontrolled generation of free radicals and also by inhibiting iNOS expression. Our results implicate a major role for curcumin and AG in preventing cataractogenesis in selenite-exposed lenses, wherein AG was found to be more potent.     

Teucrium ramaswamii sp. nov. (Lamiaceae) from India

A new species of Lamiaceae, Teucrium ramaswamii M. B. Viswan. & U. Manik. is described from the Kalakkad-Mundanthurai Tiger Reserve (KMTR) in the Agastyamalai hills of the southwestern Ghats in peninsular India. It is allied to T. tomentosum Heyne ex Benth. but differs by stem, leaves and inflorescence being glandular strigose; leaves being deltoid–ovate, crenate–dentate or doubly crenate–dentate at margin, subcoriaceous, sparsely strigose above, densely strigose beneath; bracts being oblong–deltoid, ca 9.4×2.6 mm; calyx with uppermost teeth being lanceolate, ca 2.8×1.9 mm, lateral teeth being broadly triangular, lower teeth being oblong–lanceolate; corolla being glandular strigose outside below lateral lobes and ovary being glandular strigose. Using the IUCN criteria, conservation status of the species is assigned as Critically Endangered based on the field data (2000–2002). Life history studies, population ecology, genome resource banking and wild population management are recommended for conserving this species.     

Disease associated cellular machinery in anaphylaxis – And the de novo paradigm shift

Anaphylaxis is a sudden immune reaction against an allergen that can potentially lead to Anaphylactic Shock (AS). This immune reaction is characterized by an increase in Immunoglobulin-E (IgE) type of antibodies that bind with FcεRI receptors on mast cells to release inflammatory mediators. Various intracellular signaling molecules downstream of IgE/ FcεRI axis play a potential role in cytokine, chemokine and eicosanoid secretion as well as degranulation of immune cells causing vasodilation, vascular permeability, and reduction of intravascular volume leading to cardiovascular collapse. Here, we discuss the cellular machinery of anaphylaxis and the de novo paradigm shift in the cellular aspects of AS.     

Nuclear GIT2 Is an ATM Substrate and Promotes DNA Repair

Insults to nuclear DNA induce multiple response pathways to mitigate the deleterious effects of damage and mediate effective DNA repair. G-protein-coupled receptor kinase-interacting protein 2 (GIT2) regulates receptor internalization, focal adhesion dynamics, cell migration, and responses to oxidative stress. Here we demonstrate that GIT2 coordinates the levels of proteins in the DNA damage response (DDR). Cellular sensitivity to irradiation-induced DNA damage was highly associated with GIT2 expression levels. GIT2 is phosphorylated by ATM kinase and forms complexes with multiple DDR-associated factors in response to DNA damage. The targeting of GIT2 to DNA double-strand breaks was rapid and, in part, dependent upon the presence of H2AX, ATM, and MRE11 but was independent of MDC1 and RNF8. GIT2 likely promotes DNA repair through multiple mechanisms, including stabilization of BRCA1 in repair complexes; upregulation of repair proteins, including HMGN1 and RFC1; and regulation of poly(ADP-ribose) polymerase activity. Furthermore, GIT2-knockout mice demonstrated a greater susceptibility to DNA damage than their wild-type littermates. These results suggest that GIT2 plays an important role in MRE11/ATM/H2AX-mediated DNA damage responses.     

A network of SMG-8, SMG-9 and SMG-1 C-terminal insertion domain regulates UPF1 substrate recruitment and phosphorylation

Mammalian nonsense-mediated mRNA decay (NMD) is a eukaryotic surveillance mechanism that degrades mRNAs containing premature translation termination codons. Phosphorylation of the essential NMD effector UPF1 by the phosphoinositide-3-kinase-like kinase (PIKK) SMG-1 is a key step in NMD and occurs when SMG-1, its two regulatory factors SMG-8 and SMG-9, and UPF1 form a complex at a terminating ribosome. Electron cryo-microscopy of the SMG-1–8–9-UPF1 complex shows the head and arm architecture characteristic of PIKKs and reveals different states of UPF1 docking. UPF1 is recruited to the SMG-1 kinase domain and C-terminal insertion domain, inducing an opening of the head domain that provides access to the active site. SMG-8 and SMG-9 interact with the SMG-1 C-insertion and promote high-affinity UPF1 binding to SMG-1–8–9, as well as decelerated SMG-1 kinase activity and enhanced stringency of phosphorylation site selection. The presence of UPF2 destabilizes the SMG-1–8–9-UPF1 complex leading to substrate release. Our results suggest an intricate molecular network of SMG-8, SMG-9 and the SMG-1 C-insertion domain that governs UPF1 substrate recruitment and phosphorylation by SMG-1 kinase, an event that is central to trigger mRNA decay.     

Common dysregulation network in the human prefrontal cortex underlies two neurodegenerative diseases

Using expression profiles from postmortem prefrontal cortex samples of 624 dementia patients and non-demented controls, we investigated global disruptions in the co-regulation of genes in two neurodegenerative diseases, late-onset Alzheimer''s disease (AD) and Huntington''s disease (HD). We identified networks of differentially co-expressed (DC) gene pairs that either gained or lost correlation in disease cases relative to the control group, with the former dominant for both AD and HD and both patterns replicating in independent human cohorts of AD and aging. When aligning networks of DC patterns and physical interactions, we identified a 242-gene subnetwork enriched for independent AD/HD signatures. This subnetwork revealed a surprising dichotomy of gained/lost correlations among two inter-connected processes, chromatin organization and neural differentiation, and included DNA methyltransferases, DNMT1 and DNMT3A, of which we predicted the former but not latter as a key regulator. To validate the inter-connection of these two processes and our key regulator prediction, we generated two brain-specific knockout (KO) mice and show that Dnmt1 KO signature significantly overlaps with the subnetwork (P = 3.1 × 10⁻¹²), while Dnmt3a KO signature does not (P = 0.017).     

Proteomic analysis of human placental syncytiotrophoblast microvesicles in preeclampsia

Background

Placental syncytiotrophoblast microvesicles (STBM) are shed into the maternal circulation during normal pregnancy. STBM circulate in significantly increased amounts in preeclampsia (PE) and are considered to be among contributors to the exaggerated proinflammatory, procoagulant state of PE. However, protein composition of STBM in normal pregnancy and PE remains unknown. We therefore sought to determine the protein components of STBM and whether STBM protein expressions differ in preeclamptic and normal pregnancies.Patients with PE (n = 3) and normal pregnant controls (n = 6) were recruited. STBM were prepared from placental explant culture supernatant. STBM proteins were analyzed by a combination of 1D Gel-LC-MS/MS. Protein expressions levels were quantified using spectral counts and validated by immunohistochemistry.

Results

Over 400 proteins were identified in the STBM samples. Among these, 25 proteins were found to be differentially expressed in preeclampsia compared to healthy pregnant controls, including integrins, annexins and histones.

Conclusion

STBM proteins include those that are implicated in immune response, coagulation, oxidative stress, apoptosis as well as lipid metabolism pathways. Differential protein expressions of STBM suggest their pathophysiological relevance in PE.

Electronic supplementary material

The online version of this article (doi:10.1186/1559-0275-11-40) contains supplementary material, which is available to authorized users.     

Structural,Optical and Micro-Raman Scattering Studies of Nanosized Copper Ion (Cu+) Exchanged Soda Lime Glasses

Copper nanoclusters embedded in soda lime glass are prepared by ion exchanged method. The ion exchanged glasses are annealed in air for 1 h at different temperature. These samples exhibit surface plasmon and surface enhancement effect. UV-visible optical absorption spectroscopic analysis shows the signature of the copper nanocluster in the ion exchanged glasses. Surface-enhanced Raman spectroscopy (SERS) technique is used to characterize the copper ion exchanged and annealed glasses. Additional results are obtained by SERS for optimizing the SERS substrate. The highest Raman enhancement is obtained for substrates with high cluster size. The micro-Raman scattering spectroscopic images of ion exchanged and different temperature annealed glasses support the optical absorption spectroscopy results.