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)...     

The E3 ubiquitin ligase RNF121 is a positive regulator of NF-κB activation

Background

The nuclear factor κB (NF-κB) family members regulate several biological processes as cell proliferation and differentiation, inflammation, immunity and tumor progression. Ubiquitination plays a key role in NF-κB activation and the ubiquitylated transmitters of the NF-κB signaling cascade accumulate in close proximity to endomembranes.

Findings

We performed an unbiased siRNA library screen targeting the 46 E3 ubiquitin ligases bearing transmembrane domains to uncover new modulators of NF-κB activation, using tumor necrosis factor–α (TNF-α) receptor (TNFR) stimulation as a model. We report here the identification of a new Golgi Apparatus-resident protein, RNF121, as an enhancer of NF-κB promoter activity through the catalytic function of its RING domain. From a molecular standpoint, while knocking down RNF121 did not alter RIP1 ubiquitination and IKK activation, the proteasomal degradation of IκBα was impaired suggesting that this E3 ubiquitin ligase regulates this process. However, RNF121 did not directly ubiquitinate IκBα While they were found in the same complex. Finally, we discovered that RNF121 acts as a broad regulator of NF-κB signaling since its silencing also dampens NF-κB activation following stimulation of Toll-Like Receptors (TLRs), Nod-Like Receptors (NLRs), RIG-I-Like Receptors (RLRs) or after DNA damages.

Conclusions

These results unveil an unexpected role of Golgi Apparatus and reveal RNF121 as a new player involved in the signaling leading to NF-κB activation.

     

Smoking habits, signs of chronic diseases and survival in inland and coastal regions of Croatia: a follow-up study

Aim of the study was to estimate, the relationship between survival, smoking habits, and the results of medical examinations in inland and coastal regions of Croatia. Age and sex stratified sample of general population (1,571 men and 1,793 women, 37-56 years old in 1972; followed in 1982: N = 1,090 men; 1,325 women and/or 1972-1999 controlling vital status). Relative risks and 95% confidence limits were estimated using Cox regression in the model with time dependent covariates, separately by sex. In all regions, the proportion of male smokers decreased between 1972 and 1982. The proportion of female smokers increased, differently in urban and rural regions. During the follow-up between 1972 and 1999, 568 deaths were recorded among men and 382 among women. In men, in addition to age, significant hazards of death were the number of smoked cigarettes per day, body mass index, sedative intake, vital lung capacity (FVC), 100FEV1/VC, systolic blood pressure, electrocardiogram, history of heart attack, and region. In women, in addition to age, significant predictors were the number of smoked cigarettes per day, systolic blood pressure, electrocardiogram, history of heart disease (excluding coronary diseases), and region. Survival relative risk increased with each additional smoked pack of cigarettes by 2.4% in women and 1.3% in men. Regional differences vs. smoking habit were observed. These data emphasize the need for prevention of smoking.     

IL-12Rβ1 deficiency in two of fifty children with severe tuberculosis from Iran, Morocco, and Turkey

Background and Objectives

In the last decade, autosomal recessive IL-12Rβ1 deficiency has been diagnosed in four children with severe tuberculosis from three unrelated families from Morocco, Spain, and Turkey, providing proof-of-principle that tuberculosis in otherwise healthy children may result from single-gene inborn errors of immunity. We aimed to estimate the fraction of children developing severe tuberculosis due to IL-12Rβ1 deficiency in areas endemic for tuberculosis and where parental consanguinity is common.

Methods and Principal Findings

We searched for IL12RB1 mutations in a series of 50 children from Iran, Morocco, and Turkey. All children had established severe pulmonary and/or disseminated tuberculosis requiring hospitalization and were otherwise normally resistant to weakly virulent BCG vaccines and environmental mycobacteria. In one child from Iran and another from Morocco, homozygosity for loss-of-function IL12RB1 alleles was documented, resulting in complete IL-12Rβ1 deficiency. Despite the small sample studied, our findings suggest that IL-12Rβ1 deficiency is not a very rare cause of pediatric tuberculosis in these countries, where it should be considered in selected children with severe disease.

Significance

This finding may have important medical implications, as recombinant IFN-γ is an effective treatment for mycobacterial infections in IL-12Rβ1-deficient patients. It also provides additional support for the view that severe tuberculosis in childhood may result from a collection of single-gene inborn errors of immunity.     

Inactivation of the ybdD Gene in Lactococcus lactis Increases the Amounts of Exported Proteins

Random insertional mutagenesis performed on a Lactococcus lactis reporter strain led us to identify L. lactis ybdD as a protein-overproducing mutant. In different expression contexts, the ybdD mutant shows increased levels of exported proteins and therefore constitutes a new and attractive heterologous protein production host. This study also highlights the importance of unknown regulatory processes that play a role during protein secretion.     

Dietary effects of harmine,a β-carboline alkaloid,on development,energy reserves and α-amylase activity of Plodia interpunctella Hübner (Lepidoptera: Pyralidae)

The physiological and developmental effects of harmine, a β-carboline alkaloid, on the insect pest Plodia interpunctella have been analyzed. When added at the larval diet, harmine induced a strong reduction of larvae weight, cannibalism between larvae, in addition to significant mortality. On the other hand, it caused a remarkable development disruption, manifested by both delay and reduction of pupation and adult emergence. Using spectrophotometric assays, we have shown that harmine ingestion provoked a severe reduction in protein, glycogen and lipid contents. Beside, when larvae fed harmine, the activity of the digestive enzyme α-amylase was strongly reduced. In conclusion, our experiments clearly show the susceptibility of P. interpunctella to harmine ingestion revealing the potent bioinsecticidal effect of harmine.     

Prolactin administration during early postnatal life decreases hippocampal and olfactory bulb neurogenesis and results in depressive-like behavior in adulthood

Tight regulation of hormone and neurochemical milieu during developmental periods is critical for adequate physiological functions. For instance, activation of peptide systems during early life stress induces morphological changes in the brain resulting in depression and anxiety disorders. Prolactin (PRL) exerts different actions within the brain; it regulates neurogenesis and modulates neuroendocrine functions in the adult. However, PRL effects during early postnatal life are hardly known. Therefore, we examined whether neonatal administration of PRL influences cell survival in the hippocampal dentate gyrus (DG) and in the olfactory bulb (OB) and whether such influence results in behavioral consequences in adulthood. PRL-treated rat pups (13 mg/kg; PND1 to PND14), injected with BrdU at postnatal day 5 (PND5), showed a decrease in the density of DG BrdU/DCX and BrdU/NeuN-positive cells that survive at PND15. Similarly, PRL treatment decreased the density of BrdU + cells in the OB compared with VEH. Fluorojade B analysis showed no significant changes in the amount of cell death in the DG between the groups. Postnatal PRL administration induced a passive coping strategy in the forced swimming test in male and female adult rats when compared with control and vehicle groups. Corticosterone endogenous levels at PND12 were not affected by PRL or VEH treatment. Altogether, these results suggest that opposed to its effects in the adult, postnatal PRL treatment affects neurogenesis and results in psychopathology later in life. High PRL levels, as observed in neonates under several pathological states, might contribute to detrimental effects on the developing brain.     

A missense mutation accelerating the gating of the lysosomal Cl?/H+-exchanger ClC-7/Ostm1 causes osteopetrosis with gingival hamartomas in cattle

Chloride-proton exchange by the lysosomal anion transporter ClC-7/Ostm1 is of pivotal importance for the physiology of lysosomes and bone resorption. Mice lacking either ClC-7 or Ostm1 develop a lysosomal storage disease and mutations in either protein have been found to underlie osteopetrosis in mice and humans. Some human disease-causing CLCN7 mutations accelerate the usually slow voltage-dependent gating of ClC-7/Ostm1. However, it has remained unclear whether the fastened kinetics is indeed causative for the disease. Here we identified and characterized a new deleterious ClC-7 mutation in Belgian Blue cattle with a severe symptomatology including perinatal lethality and in most cases gingival hamartomas. By autozygosity mapping and genome-wide sequencing we found a handful of candidate variants, including a cluster of three private SNPs causing the substitution of a conserved tyrosine in the CBS2 domain of ClC-7 by glutamine. The case for ClC-7 was strengthened by subsequent examination of affected calves that revealed severe osteopetrosis. The Y750Q mutation largely preserved the lysosomal localization and assembly of ClC-7/Ostm1, but drastically accelerated its activation by membrane depolarization. These data provide first evidence that accelerated ClC-7/Ostm1 gating per se is deleterious, highlighting a physiological importance of the slow voltage-activation of ClC-7/Ostm1 in lysosomal function and bone resorption.KEY WORDS: CLCN7, Hamartomas, Osteopetrosis, Lysosomal storage, Ion homeostasis, Belgian Blue cattle     

Electrochemical behavior of the 316L steel type in a marine culture of microalgae (<Emphasis Type="Italic">Porphyridium purpureum</Emphasis>) under the 12/12 h photoperiod and effect of different working electrode exposure conditions on the biofilm–metal interface

The industrial crops of microalgae use processes calling upon the presence of parts of metal nature such as steel 316L type. The goal of this study is to test the electrochemical behavior of this material in a marine culture of microalgae. Porphyridium purpureum was used under a photoperiod of alternation darkness/light 12/12 h, in order to apprehend the problems of biocorrosion involved in the biofouling. The evolution of the free potential of corrosion, according to the position of the samples and for different surface roughness, observations of the surface quality under the electron microscope with sweeping were carried out. The results showed that, overall, the strain P. purpureum does not have a corrosive effect on the 316L. The free potential of corrosion lies between −0.307 and −0.005 V(SCE). The adhesion of the cells seems stronger on the interface air/solid of the half-plunged sample with surface grit polished 1,000, confirmed by the presence of biofilm on the air part. The photoperiod acts on the evolution of the generated free potential of corrosion of the one 24-h period oscillation. Furthermore, the samples plunged horizontally lead to a stabilizing effect on the potential of free corrosion.