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Oxidized phospholipids (OxPLs), including 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC) and 1-palmitoyl-2-oxovaleroyl-sn-glycero-3-phosphocholine (POVPC) are among several biologically active derivatives that are generated during oxidation of low-density lipoproteins (LDLs). These OxPLs are factors contributing to pro-atherogenic effects of oxidized LDLs (OxLDLs), including inflammation, proliferation and death of vascular cells. OxLDL also elicits formation of the lipid messenger ceramide (Cer) which plays a pivotal role in apoptotic signaling pathways. Here we report that both PGPC and POVPC are cytotoxic to cultured macrophages and induce apoptosis in these cells which is associated with increased cellular ceramide levels after several hours. In addition, exposure of RAW 264.7 cells to POVPC and PGPC under the same conditions resulted in a significant increase in ceramide synthase activity, whereas, acid or neutral sphingomyelinase activities were not affected. PGPC is not only more toxic than POVPC, but also a more potent inducer of ceramide formation by activating a limited subset of CerS isoforms. The stimulated CerS activities are in line with the C16-, C22-, and C24:0-Cer species that are generated under the influence of the OxPL. Fumonisin B1, a specific inhibitor of CerS, suppressed OxPL-induced ceramide generation, demonstrating that OxPL-induced CerS activity in macrophages is responsible for the accumulation of ceramide. OxLDL elicits the same cellular ceramide and CerS effects. Thus, it is concluded that PGPC and POVPC are active components that contribute to the capacity of this lipoprotein to elevate ceramide levels in macrophages.

The article presents a study which investigates on the progress of fertility transition in Karnataka, India for three decades ending 2012 and its comparison to the progress in southern states. The study explored the role of major demographic indicators in population change in the area such as mortality, fertility, and migration. The study showed that the replacement of fertility level in northern part of the region remains lagging behind due to socio-economic and cultural factors.

In mammalian cells, spurious transcription results in a vast repertoire of unproductive non-coding RNAs, whose deleterious accumulation is prevented by rapid decay. The nuclear exosome targeting (NEXT) complex plays a central role in directing non-functional transcripts to exosome-mediated degradation, but the structural and molecular mechanisms remain enigmatic. Here, we elucidated the architecture of the human NEXT complex, showing that it exists as a dimer of MTR4-ZCCHC8-RBM7 heterotrimers. Dimerization preconfigures the major MTR4-binding region of ZCCHC8 and arranges the two MTR4 helicases opposite to each other, with each protomer able to function on many types of RNAs. In the inactive state of the complex, the 3' end of an RNA substrate is enclosed in the MTR4 helicase channel by a ZCCHC8 C-terminal gatekeeping domain. The architecture of a NEXT-exosome assembly points to the molecular and regulatory mechanisms with which the NEXT complex guides RNA substrates to the exosome., Competing Interests: Declaration of interests E.C. is a member of the Molecular Cell advisory board., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

We report the 3.45-Å resolution cryo-EM structure of human SMG1-SMG8-SMG9, a phosphatidylinositol-3-kinase (PI(3)K)-related protein kinase (PIKK) complex central to messenger RNA surveillance. Structural and MS analyses reveal the presence of inositol hexaphosphate (InsP 6 ) in the SMG1 kinase. We show that the InsP 6 -binding site is conserved in mammalian target of rapamycin (mTOR) and potentially other PIKK members, and that it is required for optimal in vitro phosphorylation of both SMG1 and mTOR substrates.

The nuclear exosome and its essential co-factor, the RNA helicase MTR4, play crucial roles in several RNA degradation pathways. Besides unwinding RNA substrates for exosome-mediated degradation, MTR4 associates with RNA-binding proteins that function as adaptors in different RNA processing and decay pathways. Here, we identify and characterize the interactions of human MTR4 with a ribosome processing adaptor, NVL, and with ZCCHC8, an adaptor involved in the decay of small nuclear RNAs. We show that the unstructured regions of NVL and ZCCHC8 contain short linear motifs that bind the MTR4 arch domain in a mutually exclusive manner. These short sequences diverged from the arch-interacting motif (AIM) of yeast rRNA processing factors. Our results suggest that nuclear exosome adaptors have evolved canonical and non-canonical AIM sequences to target human MTR4 and demonstrate the versatility and specificity with which the MTR4 arch domain can recruit a repertoire of different RNA-binding proteins.

The RNA exosome was originally discovered in yeast as an RNA-processing complex required for the maturation of 5.8S ribosomal RNA (rRNA), one of the constituents of the large ribosomal subunit. The exosome is now known in eukaryotes as the major 3'-5' RNA degradation machine involved in numerous processing, turnover, and surveillance pathways, both in the nucleus and the cytoplasm. Yet its role in maturing the 5.8S rRNA in the pre-60S ribosomal particle remains probably the most intricate and emblematic among its functions, as it involves all the RNA unwinding, degradation, and trimming activities embedded in this macromolecular complex. Here, we propose a comprehensive mechanistic model, based on current biochemical and structural data, explaining the dual functions of the nuclear exosome-the constructive versus the destructive mode., (© 2019 Lingaraju et al.; Published by Cold Spring Harbor Laboratory Press.)

The present investigation was undertaken to assess the result of pretreatment of luteolin in sepsis-induced acute lung injury in mice and its mechanism of action. Luteolin was administered intraperitoneally one hour before caecal ligation and puncture (CLP) surgery in mice. Acute lung injury was assessed by estimation of different parameters like lung edema, protein content, cytokines level, oxidative stress, inducible nitric oxide synthase (iNOS), intercellular adhesion molecule (ICAM)-1 expression and histopathology. Pretreatment of mice with luteolin showed decrease lung edema and protein content in tissue and bronchoalveolar lavage fluid (BALF). However, mice pretreated with luteolin showed reduction (p = 0.92) in blood and lung tissue bacterial counts however it was non significant. Further, luteolin showed significant reduction in interleukin (IL)-6 and IL-1β in lung tissue which are the proinflammatory cytokines. However, plasma IL-1β and tissue tumor necrosis factor (TNF)-α level decrease (p = 0.24; p = 0.19) with this pretreatment. Further, ICAM-1 mRNA expression and nuclear factor (NF)-kappa B protein expression were significantly (p < 0.01) decreased in luteolin pretreated septic mice. The lung iNOS level, iNOS mRNA and protein expressions were markedly (p = 0.25; p = 0.50; p = 0.06) altered with luteolin pretreatment, respectively. Also, significant reduction in lipid peroxidation and increase in the activity of antioxidant enzymes like superoxide dismutase (SOD) and catalase was noted with luteolin pretreatment. However, luteolin did not alter (p = 0.36) the non enzymatic antioxidant GSH activity in septic mice. Histopathology of lung tissue showed reduction in lung injury with the luteolin pretreatment in septic mice. The study suggests that luteolin showed attenuation in sepsis-induced acute lung injury in mice through suppression in ICAM-1, NF-kappa B, oxidative stress and partially iNOS pathways., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Nonsense-mediated mRNA decay (NMD) is a eukaryotic mRNA degradation pathway involved in surveillance and post-transcriptional regulation, and executed by the concerted action of several trans -acting factors. The SMG1 kinase is an essential NMD factor in metazoans and is associated with two recently identified and yet poorly characterized proteins, SMG8 and SMG9. We determined the 2.5 Å resolution crystal structure of a SMG8-SMG9 core complex from C. elegans We found that SMG8-SMG9 is a G-domain heterodimer with architectural similarities to the dynamin-like family of GTPases such as Atlastin and GBP1. The SMG8-SMG9 heterodimer forms in the absence of nucleotides, with interactions conserved from worms to humans. Nucleotide binding occurs at the G domain of SMG9 but not of SMG8. Fitting the GDP-bound SMG8-SMG9 structure in EM densities of the human SMG1-SMG8-SMG9 complex raises the possibility that the nucleotide site of SMG9 faces SMG1 and could impact the kinase conformation and/or regulation., (© 2017 Li et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.)

Traditionally, the Indian Blackberry or locally called Jamun, Eugenia jambolana Lam. (Syn.: Syzygium cumini), is well known for its pharmacological potential, particularly anti-inflammatory. Here, we studied kaempferol-7-O-α-L-rhamnopyranoside]-4'-O-4'- [kaempferol-7-O-α-L-rhamnopyranoside (EJ-01) isolated from the E. jambolana leaves for possible anti-inflammatory activity. EJ-01 (3, 10 and 30 mg/kg, p.o.) was assessed for anti-inflammatory activity using carrageenan-induced paw edema model in mice by determining edema volume, myeloperoxidase (MPO), nitrite plus nitrate (NOx) and cytokine levels in paw edema tissue. EJ-01 significantly attenuated the edema, MPO levels, tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) levels in the edema of paw at the 5th hour after carrageenan injection at all doses. EJ-01 (30 mg/kg) decreased the nitric oxide (NO) levels of the edema of paw at the 5th hour after carrageenan injection. The anti-inflammatory mechanisms of EJ-01 might be related to the decrease in the level of edema paw by reduced activities of NO and MPO. It probably exerts anti-inflammatory effects through the suppression of TNF-α and IL-1β. Therefore, we conclude that EJ-01 could be positively exploited for itspotential benefits against inflammatory diseases and support the pharmacological basis of E. jambolana as traditional herbal medicine for the treatment of inflammatory diseases.

The founding members of the HD-domain protein superfamily are phosphohydrolases, and newly discovered members are generally annotated as such. However, myo-inositol oxygenase (MIOX) exemplifies a second, very different function that has evolved within the common scaffold of this superfamily. A recently discovered HD protein, PhnZ, catalyzes conversion of 2-amino-1-hydroxyethylphosphonate to glycine and phosphate, culminating a bacterial pathway for the utilization of environmentally abundant 2-aminoethylphosphonate. Using Mössbauer and EPR spectroscopies, X-ray crystallography, and activity measurements, we show here that, like MIOX, PhnZ employs a mixed-valent Fe(II)/Fe(III) cofactor for the O2-dependent oxidative cleavage of its substrate. Phylogenetic analysis suggests that many more HD proteins may catalyze yet-unknown oxygenation reactions using this hitherto exceptional Fe(II)/Fe(III) cofactor. The results demonstrate that the catalytic repertoire of the HD superfamily extends well beyond phosphohydrolysis and suggest that the mechanism used by MIOX and PhnZ may be a common strategy for oxidative C-X bond cleavage.

Sword bean (Entada scandens) is a tree climber that belongs to Mimosoideae, a subfamily of Leguminosae. A potent Kunitz type trypsin inhibitor (ESTI) was purified to homogeneity from Entada scandens seeds by sequential ammonium sulfate precipitation, affinity chromatography on trypsin-Sepharose and DEAE-Sephacel ion-exchange chromatography. ESTI is a single polypeptide chain of 19,766 Da. Both native PAGE as well as isoelectric focusing showed a single inhibitor species with a pI of 7.43. MALDI-TOF analysis also confirmed the monomeric nature. The amino-terminal sequence of ESTI reveals significant homology to the Kunitz-type protease inhibitors of legume plants. ESTI is unique in that it contains a single disulfide bridge, and unlike other inhibitors from Mimosoideae species is a single chain polypeptide. ESTI inhibited bovine trypsin with a stoichiometry of 1:1 and the apparent K(i) was 4.9 x 10(-9) M. In vitro assay showed that ESTI inhibited the midgut proteinase of the fifth instar larvae of Rice moth (Corcyra cephalonica) with an IC(50) of 26.4+/-0.01 nM. ESTI exhibits a mixed type competitive inhibition at lower concentration and pure competitive at higher inhibitor concentrations. Phylogenetic analyses depicted a clear divergence of single disulfide containing inhibitors from other tree legume Kunitz inhibitors. The homology of ESTI to Kunitz inhibitors together with the absence of Bowman-Birk type inhibitors in sword bean further supports the theory that there exists an evolutionary relationship between the families of inhibitors found in Leguminosae.