Accelerated aging as evidenced by increased telomere shortening and mitochondrial DNA depletion in patients with type 2 diabetes

Although shortened telomeres were shown associated with several risk factors of diabetes, there is lack of data on their relationship with mitochondrial dysfunction. Therefore, we compared the relationship between telomere length and mitochondrial DNA (mtDNA) content in patients with type 2 diabetes mellitus (T2DM; n = 145) and in subjects with normal glucose tolerance (NGT; n = 145). Subjects were randomly recruited from the Chennai Urban Rural Epidemiology Study. mtDNA content and telomere length were assessed by Real-Time PCR. Malonodialdehyde, a marker of lipid peroxidation was measured by thiobarbituric acid reactive substances (TBARS) using fluorescence methodology. Adiponectin levels were measured by radioimmunoassay. Oxidative stress as determined by lipid peroxidation (TBARS) was significantly (p < 0.001) higher in patients with T2DM compared to NGT subjects. In contrast, the mean telomere length, adiponectin and mtDNA content were significantly (p < 0.001) lower in patients with T2DM compared to NGT subjects. Telomere length was positively correlated with adiponectin, HDL, mtDNA content and good glycemic/lipid control and negatively correlated with adiposity and insulin resistance. On regression analysis, shortened telomeres showed significant association with T2DM even after adjusting for waist circumference, insulin resistance, triglyceride, HDL, adiponectin, mtDNA & TBARS. mtDNA depletion showed significant association with T2DM after adjusting for waist circumference and adiponectin but lost its significance when further adjusted for telomere length, TBARS and insulin resistance. Our study emphasizes the clustering of accelerated aging features viz., shortened telomeres, decreased mtDNA content, hypoadiponectinemia, low HDL, and increased oxidative stress in Asian Indian type 2 diabetes patients.     

Brassica juncea chitinase BjCHI1 inhibits growth of fungal phytopathogens and agglutinates Gram-negative bacteria

Brassica juncea BjCHI1 is a plant chitinase with two chitin-binding domains. Its expression, induced in response to wounding, methyl jasmonate treatment, Aspergillus niger infection, and caterpillar Pieris rapae feeding, suggests that it plays a role in defence. In this study, to investigate the potential of using BjCHI1 in agriculture, Pichia-expressed BjCHI1 and its deletion derivatives that lack one or both chitin-binding domains were tested against phytopathogenic fungi and bacteria. Transplastomic tobacco expressing BjCHI1 was also generated and its extracts assessed. In radial growth-inhibition assays, BjCHI1 and its derivative with one chitin-binding domain showed anti-fungal activities against phytopathogens, Colletotrichum truncatum, C. acutatum, Botrytis cinerea, and Ascochyta rabiei. BjCHI1 also inhibited spore germination of C. truncatum. Furthermore, BjCHI1, but not its derivatives lacking one or both domains, inhibited the growth of Gram-negative bacteria (Escherichia coli, Ralstonia solanacearum, Pseudomonas aeruginosa) more effectively than Gram-positive bacteria (Micrococcus luteus and Bacillus megaterium), indicating that the duplicated chitin-binding domain, uncommon in chitinases, is essential for bacterial agglutination. Galactose, glucose, and lactose relieved agglutination, suggesting that BjCHI1 interacts with the carbohydrate components of the Gram-negative bacterial cell wall. Retention of chitinase and bacterial agglutination activities in transplastomic tobacco extracts implicates that BjCHI1 is potentially useful against both fungal and bacterial phytopathogens in agriculture.     

High-affinity selective inhibitor against phospholipase A2 (PLA2): a computational study

Phospholipase A₂ (PLA₂) is the most abundant protein found in snake venom. PLA₂ induces a variety of pharmacological effects such as neurotoxicity, myotoxicity and cardiotoxicity as well as anticoagulant, hemolytic, anti-platelet, hypertensive, hemorrhagic and edema inducing effects. In this study, the three dimensional structure of PLA₂ of Naja sputatrix (Malayan spitting cobra) was modeled by I-TASSER, SWISS-MODEL, PRIME and MODELLER programs. The best model was selected based on overall stereo-chemical quality. Further, molecular dynamics simulation was performed to know the stability of the modeled protein using Gromacs software. Average structure was generated during the simulation period of 10?ns. High throughput virtual screening was employed through different databases (Asinex, Hit finder, Maybridge, TOSLab and ZINC databases) against PLA₂. The top seven compounds were selected based on the docking score and free energy binding calculations. These compounds were analyzed by quantum polarized ligand docking, induced fit docking and density functional theory calculation. Furthermore, the stability of lead molecules in the active site of PLA₂ was employed by MD simulation. The results show that selected lead molecules were highly stable in the active site of PLA₂.     

Isolation and characterization of anticancer flavone chrysin (5,7-dihydroxy flavone)-producing endophytic fungi from <Emphasis Type="Italic">Passiflora incarnata</Emphasis> L. leaves

Chrysin (5,7-dihydroxy flavone, ChR) is a flavone of plant origin, possessing numerous biomedical properties, such as antimicrobial, anti-inflammatory, anti-diabetic, anxiolytic, hepatoprotective, anti-aging and anticonvulsant activities. In this study, chrysin-producing fungal endophytes (A. alternata KT380662, C. capsici KT373967, and C. taiwanense PI-3 KX580307) were isolated from the leaves of Passiflora incarnata L. and characterised via morphology and internal transcribed spacer (ITS) sequences. Thin layer chromatography and high-performance liquid chromatography profiles of fungal extracts showed Rf values and retention times that closely match those of standard chrysin (ChR). Further, the production of fungal chrysin (FChR) was confirmed through UV-vis spectroscopy, FT-IR, LC-ESI-MS, and ¹H₁ NMR analysis. Among the isolated strains, A. alternata KT380662 was identified as having a high-level of ChR production, with rates measuring approximately 846 mg L^?1. On the other hand, in vitro anticancer and radical scavenging studies proved that FChR has significant cytotoxic activity against human liver carcinoma cells (HepG2). These results clearly imply that the isolated A. alternata KT380662 could serve as an alternative source for the commercial production of ChR, which holds anticancer and radical scavenging activities, and the fungal-derived ChR can be used in chemotherapy or in prodrug development.     

Arsenic removal from groundwater by pretreated waste tea fungal biomass

Arsenic contamination in ground water poses a serious threat on human health. The tea fungus, a waste produced during black tea fermentation has been examined for its capacity to sequester the metal ions from ground water samples. Autoclaved tea fungal mat and autoclaving followed by FeCl3 pretreated tea fungal mat were exploited for removal of As(III), As(V) and Fe(II) from ground water sample collected from Kolkata, West Bengal, India. The biosorption rate tends to increase with the increase in contact time and adsorbent dosage. FeCl3 pretreated and autoclaved fungal mats removed 100% of As(III) and Fe(II) after 30 min contact time and 77% of As(V) after 90 min contact time. The optimum adsorbent dosage was 1.0 g/50 mL of water sample. The results revealed that the FeCl3 pretreated fungal mat could be used as an effective biosorbent for As(III) and As(V); autoclaved fungal mat for Fe(II) removal from ground water sample.     

Genome-wide characterization and stress-responsive expression profiling of <Emphasis Type="Italic">MCM</Emphasis> genes in <Emphasis Type="Italic">Brassica oleracea</Emphasis> and <Emphasis Type="Italic">Brassica rapa</Emphasis>

The Minichromosome maintenance protein [MCM (2-7)] complex is associated with helicase activity for replication fork formation during DNA replication. We identified and characterized each 12 putative MCM genes from Brassica oleracea and Brassica rapa. MCM genes were classified into nine groups according to their evolutionary relationships. A high number of syntenic regions were present on chromosomes C03 and A03 in B. oleracea and B. rapa, respectively, compared to the other chromosomes. Expression analysis showed that most of the MCM(2-7) helicase-subunit genes and their coregulating MCM genes were upregulated during hydroxyurea (HU) induced stress in B. oleracea. In B. rapa, MCM(2-7) helicase genes BrMCM2_2, BrMCM7_1, BrMCM7_2 and their co-regulating genes were upregulated during replication stress. During cold stress, BoMCM6 in B. oleracea and BrMCM5 in B. rapa were remarkably upregulated. During salt stress, BoMCM6_2, BoMCM7_1, BoMCM8, BoMCM9, and BoMCM10 were markedly upregulated in B. oleracea. Hence, our study identified the candidate MCM family genes those possess abiotic stress-responsive behavior and DNA replication stress tolerance. As the first genome-wide analysis of MCM genes in B. oleracea and B. rapa, this work provides a foundation to develop stress responsive plants. Further functional and molecular studies on MCM genes will be helpful to enhance stress tolerance in plants.