Symposium Report: International Symposium on Ciliate Biology,India Habitat Centre,New Delhi,India, 04–06 April 2018

Ciliated protists have attracted wide interest among researchers from the Indian subcontinent in the last few years. An International Symposium on Ciliate Biology (ISCB) 2018 was held on 04–06 April 2018 at the India Habitat Centre, New Delhi, India. The symposium represented a synergy with International Research Coordination Network for Biodiversity of Ciliates (IRCN‐BC), an affiliate society of International Society of Protistologists (ISOP). The symposium provided a platform for Indian and International delegates to exchange knowledge, present their latest research findings, and establish collaborations as well as creating a networking opportunity for undergraduate and postgraduate students. Nine foreign delegates from 5 countries and 300 Indian delegates actively participated in the event which included 22 oral and 57 poster presentations.     

(+)-Episesamin inhibits adipogenesis and exerts anti-inflammatory effects in 3T3-L1 (pre)adipocytes by sustained Wnt signaling,down-regulation of PPARγ and induction of iNOS

Obesity and its associated health risks still demand for effective therapeutic strategies. Drugs and compositions derived from Oriental medicine such as green tea polyphenols attract growing attention. Previously, an extract from the Japanese spice bush Lindera obtusiloba (L. obtusiloba) traditionally used for treatment of inflammation and prevention of liver damage was shown to inhibit adipogenesis. Aiming for the active principle of this extract (+)-episesamin was identified, isolated and applied in adipogenic research using 3T3-L1 (pre)adipocytes, an established cell line for studying adipogenesis. With an IC₅₀ of 10 μM (+)-episesamin effectively reduced the growth of 3T3-L1 preadipocytes and decreased hormone-induced 3T3-L1 differentiation as shown by reduced accumulation of intracellular lipid droplets and diminished protein expression of GLUT-4 and vascular endothelial growth factor. Mechanistically, the presence of (+)-episesamin during hormone-induced differentiation provoked a reduced phosphorylation of ERK1/2 and β-catenin along with a reduced protein expression of peroxisome proliferator-activated receptor γ and a strongly increased protein expression of iNOS. Treatment of mature adipocytes with (+)-episesamin resulted in a reduction of intracellular stored lipid droplets and induced the proapoptotic enzymes caspases-3/-7. Besides interfering with adipogenesis, (+)-episesamin showed anti-inflammatory activity by counteracting the lipopolysaccharide- and tumor necrosis factor α-induced secretion of interleukin 6 by 3T3-L1 preadipocytes. In conclusion, (+)-episesamin seems to be the active drug in the L. obtusiloba extract being responsible for the inhibition of adipogenesis and, thus, should be evaluated as a novel potential complementary treatment for obesity.     

Multifarious Pharmacological Applications of Green Routed Eco-Friendly Iron Nanoparticles Synthesized by Streptomyces Sp. (SRT12)

Biological Trace Element Research - A simple, eco-friendly, green routine co-precipitation method was experimented to synthesize iron nanoparticles (Fe-NPs) using the cell-free supernatant of...     

The structure of lombricine kinase: implications for phosphagen kinase conformational changes

Lombricine kinase is a member of the phosphagen kinase family and a homolog of creatine and arginine kinases, enzymes responsible for buffering cellular ATP levels. Structures of lombricine kinase from the marine worm Urechis caupo were determined by x-ray crystallography. One form was crystallized as a nucleotide complex, and the other was substrate-free. The two structures are similar to each other and more similar to the substrate-free forms of homologs than to the substrate-bound forms of the other phosphagen kinases. Active site specificity loop 309-317, which is disordered in substrate-free structures of homologs and is known from the NMR of arginine kinase to be inherently dynamic, is resolved in both lombricine kinase structures, providing an improved basis for understanding the loop dynamics. Phosphagen kinases undergo a segmented closing on substrate binding, but the lombricine kinase ADP complex is in the open form more typical of substrate-free homologs. Through a comparison with prior complexes of intermediate structure, a correlation was revealed between the overall enzyme conformation and the substrate interactions of His(178). Comparative modeling provides a rationale for the more relaxed specificity of these kinases, of which the natural substrates are among the largest of the phosphagen substrates.     

Epstein-Barr virus nuclear antigen 1 replication and segregation functions in nasopharyngeal carcinoma cell lines

Nasopharyngeal carcinomas (NPC) are usually Epstein-Barr virus (EBV) positive, but, with the exception of C666-1 cells, these cells lose the EBV genomes when grown in culture. Maintenance of EBV requires the viral EBV nuclear antigen 1 (EBNA1) protein, which ensures the replication and mitotic segregation of the genomes through interactions with OriP. Here we compare the abilities of C666-1 and NPC cells that have lost EBV genomes to replicate and segregate OriP plasmids. We found that either cell line can replicate and maintain OriP plasmids for extended periods under conditions where low levels of EBNA1 are expressed but that high EBNA1 levels selectively interfered with mitotic segregation.     

Nitrite infusion increases cerebral blood flow and decreases mean arterial blood pressure in rats: A role for red cell NO

It has been proposed that the reduction of nitrite by red cells producing NO plays a role in the regulation of vascular tone. This hypothesis was investigated in rats by measuring the effect of nitrite infusion on mean arterial blood pressure (MAP), cerebral blood flow (CBF) and cerebrovascular resistance (CVR) in conjunction with the accumulation of red cell NO. The relative magnitude of the effects on MAP and CBF as well as the time dependent changes during nitrite infusion are used to distinguish between the effects on the peripheral circulation and the effects on the cerebral circulation undergoing cerebral autoregulation. The nitrite infusion was found to reverse the 96% increase in MAP and the 13% decrease in CBF produced by L-NAME inhibition of e-NOS. At the same time there was a 20-fold increase in oxygen stable red cell NO. Correlations of the red cell NO for individual rats support a role for red cell nitrite reduction in regulating vascular tone in both the peripheral and the cerebral circulation. Furthermore, data obtained prior to treatment is consistent with a contribution of red cell reduced nitrite in regulating vascular tone even under normal conditions.     

Melanoma-derived conditioned media efficiently induce the differentiation of monocytes to macrophages that display a highly invasive gene signature

The presence of tumor-associated macrophages (TAMs) in melanomas is correlated with a poor clinical prognosis. However, there is limited information on the characteristics and biological activities of human TAMs in melanomas. In this study, we developed an in vitro method to differentiate human monocytes to macrophages using modified melanoma-conditioned medium (MCM). We demonstrate that factors from MCM-induced macrophages (MCMI-Mφ) express both M1-Mφ and M2-Mφ markers and inhibit melanoma-specific T-cell proliferation. Furthermore, microarray analyses reveal that the majority of genes up-regulated in MCMI-Mφ are associated with tumor invasion. The most strikingly up-regulated genes are CCL2 and MMP-9. Consistent with this, blockade of both CCL-2 and MMPs diminish MCMI-Mφ-induced melanoma invasion. Finally, we demonstrated that both MCMI-Mφ and in vivo TAMs express the pro-invasive, melanoma-associated gene, glycoprotein non-metastatic melanoma protein B. Our study provides a framework for understanding the mechanisms of cross-talk between TAMs and melanoma cells within the tumor microenvironment.     

A simple flow cytometry-based assay to study global methylation levels in onion,a non-model species

DNA methylation is an important epigenetic mark and global methylation dynamics regulate plant developmental processes. Even though genome sequencing technologies have made DNA methylation studies easier, it is difficult in non-model species where genome information is not available. Therefore in this study, we developed a simple assay for analysing global methylation levels in plants by washless immunolabelling of unfixed nuclei using flow cytometry. Onion leaf tissue was used as a model system, and mean fluorescence intensity due to anti-5- methyl cytosine (5-mC) antibodies were used as a measure of global methylation levels. Among three nuclear isolation buffers evaluated, the highest nuclear yield with the low background was obtained with LB01. To maintain a balance between high DNA fluorescence value and low coefficient of variation of DNA peaks, 45 min of hydrolysis with 0.2 N hydrochloric acid was used for chromatin denaturation resulting in six-fold increase in 5-mC fluorescence compared to control. This method was used successfully to detect 5-Azacytidine induced DNA hypomethylation in onion leaf tissues.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-01047-6.     

Interstitial collagens I, III, and VI sequester and modulate the multifunctional cytokine oncostatin M.

The binding of certain growth factors and cytokines to components of the extracellular matrix can regulate their local availability and modulate their biological activities. We show that oncostatin M (OSM), a profibrogenic cytokine and modulator of cancer cell proliferation, specifically binds to collagen types I, III, IV, and VI, immobilized on polystyrene or nitrocellulose. Single collagen chains inhibit these interactions in a dose-dependent manner. Cross-inhibition experiments of collagen-derived peptides point to a limited set of OSM-binding collagenous consensus sequences. Furthermore, this interaction is found for OSM but not for other interleukin-6 type cytokines. OSM binding to collagens is saturable, with dissociation constants around 10(-8) m and estimated molar ratios of 1-3 molecules of OSM bound to one molecule of triple helical collagen. Furthermore, collagen-bound OSM is biologically active and able to inhibit proliferation of A375 melanoma cells. We conclude that abundant interstitial collagens dictate the spatial pattern of bioavailable OSM. This interaction could be exploited for devising collagenous peptide-antagonists that modulate OSM bioactivity in tumor growth and fibrotic disorders like rheumatoid arthritis and hepatic fibrosis.     

Safety and physiologic effects of intranasal midazolam and nitrous oxide inhalation based sedation in children visiting Saveetha Dental College and Hospitals,India

A large number of patients avoid dental care due to anxiety. Various techniques are available for behaviour related management. Therefore, safety and physiologic effects of intranasal midazolam and nitrous oxide inhalation based sedation in children aged 4 to 8 years visiting Saveetha Dental College and Hospitals, India is of interest. 35 anxious patients aged 4 to 8 years were included in the study. The patient received either intranasal midazolam/nitrous oxide in the first visit and vice versa at the second visit. The onset of sedation, recovery time and procedure duration were recorded using a timer. Physiological parameters were recorded using a monitor. Safety scale was used for assessing prevalence of adverse reactions. There was no significant difference between the groups in safety scale scores, recovery time and procedure duration. Midazolam group showed a statistically significant faster onset of sedation and a statistically significant increase in heart rate at four recorded time-points. All the vitals were within the physiological limits. Thus, intranasal midazolamis a safe alternative to nitrous-oxide sedation in completing the intended dental treatment while managing the anxious children in dental clinic.