In vivo role of p38 mitogen-activated protein kinase in mediating the anti-inflammatory effects of CpG oligodeoxynucleotide in murine asthma

DNA containing unmethylated CpG motifs is intrinsically immunostimulatory, inducing the production of a variety of cytokines and chemokines by immune cells. The strong Th1 response triggered by CpG oligodeoxynucleotide (ODN) inhibits the development of Th2-mediated allergic asthma in mice. This work documents that CpG ODN-induced IL-12 production plays a critical role in this process, because intrapulmonary CpG ODN inhibits allergic inflammation in wild-type but not IL-12(-/-) mice. CpG ODN rapidly localized to alveolar macrophages (AM), thereby triggering the phosphorylation of p38 mitogen-activated protein kinase (MAP kinase). AM cultured with CpG but not control ODN up-regulated IL-12 p40 expression and release, and these effects were blocked by the highly specific p38 MAP kinase inhibitor SB202190. Intrapulmonary administration of this inhibitor blocked the ability of CpG ODN to produce IL-12 in the lungs and reversed the anti-inflammatory effects of CpG ODN on allergic lung inflammation. These findings indicate that IL-12 production by AM is stimulated by intrapulmonary CpG ODN administration through a p38 MAP kinase-dependent process, and IL-12 is a key cytokine that mediates CpG ODN-induced protection against allergic lung inflammation.     

Characterization of cross-bridge elasticity and kinetics of cross-bridge cycling during force development in single smooth muscle cells

Force development in smooth muscle, as in skeletal muscle, is believed to reflect recruitment of force-generating myosin cross-bridges. However, little is known about the events underlying cross-bridge recruitment as the muscle cell approaches peak isometric force and then enters a period of tension maintenance. In the present studies on single smooth muscle cells isolated from the toad (Bufo marinus) stomach muscularis, active muscle stiffness, calculated from the force response to small sinusoidal length changes (0.5% cell length, 250 Hz), was utilized to estimate the relative number of attached cross-bridges. By comparing stiffness during initial force development to stiffness during force redevelopment immediately after a quick release imposed at peak force, we propose that the instantaneous active stiffness of the cell reflects both a linearly elastic cross-bridge element having 1.5 times the compliance of the cross-bridge in frog skeletal muscle and a series elastic component having an exponential length-force relationship. At the onset of force development, the ratio of stiffness to force was 2.5 times greater than at peak isometric force. These data suggest that, upon activation, cross-bridges attach in at least two states (i.e., low-force-producing and high-force-producing) and redistribute to a steady state distribution at peak isometric force. The possibility that the cross-bridge cycling rate was modulated with time was also investigated by analyzing the time course of tension recovery to small, rapid step length changes (0.5% cell length in 2.5 ms) imposed during initial force development, at peak force, and after 15 s of tension maintenance. The rate of tension recovery slowed continuously throughout force development following activation and slowed further as force was maintained. Our results suggest that the kinetics of force production in smooth muscle may involve a redistribution of cross-bridge populations between two attached states and that the average cycling rate of these cross-bridges becomes slower with time during contraction.     

Length–weight relationships of Barilius bendelisis (Hamilton, 1807), Barilius shacra (Hamilton, 1822) and Barilius barna (Hamilton, 1822) from Manas River in Assam,India

The present study describes the length–weight relationships (LWRs) for three ornamental hill stream fish species from the Manas River in Assam, India, namely, Barilius bendelisis (Hamilton, 1807), Barilius shacra (Hamilton, 1822), and Barilius barna (Hamilton, 1822). Fishes were collected on a monthly basis from March 2015 to February 2016 with cast nets (270 cm, 1.2 cm) and gillnets (7,500 × 130 cm, 5 cm). This is the first information on LWR data for two of the species.     

Analysis of Genetic Diversity of Persea bombycina “Som” Using RAPD-Based Molecular Markers

The utility of RAPD markers in assessing genetic diversity and phenetic relationships in Persea bombycina, a major tree species for golden silk (muga) production, was investigated using 48 genotypes from northeast India. Thirteen RAPD primer combinations generated 93 bands. On average, seven RAPD fragments were amplified per reaction. In a UPGMA phenetic dendrogram based on Jaccard’s coefficient, the P. bombycina accessions showed a high level of genetic variation, as indicated by genetic similarity. The grouping in the phenogram was highly consistent, as indicated by high values of cophenetic correlation and high bootstrap values at the key nodes. The accessions were scattered on a plot derived from principal correspondence analysis. The study concluded that the high level of genetic diversity in the P. bombycina accessions may be attributed to the species’ outcrossing nature. This study may be useful in identifying diverse genetic stocks of P. bombycina, which may then be conserved on a priority basis.     

Freeze preservation of platelets using hydroxyethyl starch (HES); a preliminary report.

A comparative study has been made of platelets stored by freeze preservation following treatment with dimethyl sulfoxide (DMSO) or hydroxyethyl starch (HES) with fresh platelets and platelets stored at 4 °C for 48 hr. The indices studied were platelet recovery, pH, light microscope morphology, platelet Factor 3 (PF₃) availability and the hypotonic stress response. The DMSO preserved platelets gave a better response to hypotonic stress and incurred lesser degrees of membrane damage as demonstrated by PF₃ availability. There was however a significantly higher recovery of platelets treated with HES; with DMSO the osmotic damage inflicted during removal caused considerable lysis. Platelets frozen by DMSO or HES gave consistently better in vitro results than platelets stored at 4 °C for 48 hr. A preliminary clinical trial of HES preserved platelets has confirmed haemostatic effectiveness in vivo. HES being relatively nontoxic, platelets can be infused immediately after thawing and with minimal post thaw manipulation, thus maintaining a relatively closed system. It is concluded that cryopreservation with HES is a practical and effective means for long term platelet storage.     

Bacterial cellulases and saccharification of lignocellulosic materials

Five locally isolated bacterial strains produced extracellular cellulase enzymes, primarily CMCase, when grown on different natural and commercial cellulosic substrates. Extracellular CMCase and avicelase activity was higher with the strain CLS-32, a Cytophaga sp., compared to four other strains. The whole-cell preparations of these isolates were found to saccharify cellulosic substrates to reducing sugars. Maximum release of reducing sugar (5.75 mg ml⁻¹) was obtained with CLS-32 using sugar cane bagasse as growth and hydrolysis substrates.     

CCAAT/enhancer-binding protein beta (C/EBPβ) knockdown reduces inflammation,ER stress,and apoptosis,and promotes autophagy in oxLDL-treated RAW264.7 macrophage cells

Molecular and Cellular Biochemistry - Atherosclerosis is associated with deregulated cholesterol metabolism and formation of macrophage foam cells. CCAAT/enhancer-binding protein beta (C/EBPβ)...     

Fragile DNA Motifs Trigger Mutagenesis at Distant Chromosomal Loci in Saccharomyces cerevisiae

DNA sequences capable of adopting non-canonical secondary structures have been associated with gross-chromosomal rearrangements in humans and model organisms. Previously, we have shown that long inverted repeats that form hairpin and cruciform structures and triplex-forming GAA/TTC repeats induce the formation of double-strand breaks which trigger genome instability in yeast. In this study, we demonstrate that breakage at both inverted repeats and GAA/TTC repeats is augmented by defects in DNA replication. Increased fragility is associated with increased mutation levels in the reporter genes located as far as 8 kb from both sides of the repeats. The increase in mutations was dependent on the presence of inverted or GAA/TTC repeats and activity of the translesion polymerase Polζ. Mutagenesis induced by inverted repeats also required Sae2 which opens hairpin-capped breaks and initiates end resection. The amount of breakage at the repeats is an important determinant of mutations as a perfect palindromic sequence with inherently increased fragility was also found to elevate mutation rates even in replication-proficient strains. We hypothesize that the underlying mechanism for mutagenesis induced by fragile motifs involves the formation of long single-stranded regions in the broken chromosome, invasion of the undamaged sister chromatid for repair, and faulty DNA synthesis employing Polζ. These data demonstrate that repeat-mediated breaks pose a dual threat to eukaryotic genome integrity by inducing chromosomal aberrations as well as mutations in flanking genes.