The Brucella Effector BspI Suppresses Inflammation via Inhibition of IRE1 Kinase Activity during Brucella Infection.

Mammalian GTPase-activating proteins (GAPs) can inhibit innate immunity signaling in a spatiotemporal fashion; however, the role of bacterial GAPs in mediating innate immunity remains unknown. In this study, we show that BspI, a Brucella type IV secretion system (T4SS) effector protein, containing a GAP domain at the C terminus, negatively regulates proinflammatory responses and host protection to Brucella abotus infection in a mouse model. In macrophages, BspI inhibits the activation of inositol-requiring enzyme 1 (IRE1) kinase, but it does not inhibit activation of ATF6 and PERK. BspI suppresses induction of proinflammatory cytokines via inhibiting the activity of IRE1 kinase caused by VceC, a type IV secretion system effector protein that localizes to the endoplasmic reticulum. Ectopically expressed BspI interacts with IRE1 in HeLa cells. The inhibitory function of BspI depends on its GAP domain but not on interaction with small GTPase Ras-associated binding protein 1B (RAB1B). Collectively, these data support a model where BspI, in a GAP domain-dependent manner, inhibits activation of IRE1 to prevent proinflammatory cytokine responses.

Sec-O-Glucosylhamaudol Inhibits RANKL-Induced Osteoclastogenesis by Repressing 5-LO and AKT/GSK3ß Signaling.

Sec-O-glucosylhamaudol (SOG), an active flavonoid compound derived from the root of Saposhnikovia divaricata (Turcz. ex Ledeb.) Schischk., exhibits analgesic, anti-inflammatory, and high 5-lipoxygenase (5-LO) inhibitory effects. However, its effect on osteoclastogenesis was unclear. We demonstrated that SOG markedly attenuated RANKL-induced osteoclast formation, F-actin ring formation, and mineral resorption by reducing the induction of key transcription factors NFATc1, c-Fos, and their target genes such as TRAP, CTSK, and DC-STAMP during osteoclastogenesis. Western blotting showed that SOG significantly inhibited the phosphorylation of AKT and GSK3ß at the middle-late stage of osteoclastogenesis without altering calcineurin catalytic subunit protein phosphatase-2ß-Aα expression. Moreover, GSK3ß inhibitor SB415286 partially reversed SOG-induced inhibition of osteoclastogenesis, suggesting that SOG inhibits RANKL-induced osteoclastogenesis by activating GSK3ß, at least in part. 5-LO gene silencing by small interfering RNA in mouse bone marrow macrophages markedly reduced RANKL-induced osteoclastogenesis by inhibiting NFATc1. However, it did not affect the phosphorylation of AKT or GSK3ß, indicating that SOG exerts its inhibitory effects on osteoclastogenesis by suppressing both the independent 5-LO pathway and AKT-mediated GSK3ß inactivation. In support of this, SOG significantly improved bone destruction in a lipopolysaccharide-induced mouse model of bone loss. Taken together, these results suggest a potential therapeutic effect for SOG on osteoclast-related bone lysis disease.

A Brief Review of Diagnosis of Small Ruminants Brucellosis.

Brucellosis caused by bacteria of the genus of Brucella remains a major zoonosis in the wide world, which is an infectious disease with a severe economic impact on animal husbandry and public health. The genus of Brucella includes ten species and the most prevalent is Brucella melitensis. The diagnosis of Brucella melitensis ruminant brucellosis is based on bacteriological and immunological tests. The use of vaccines and the false-positive serological reactions (FPSR) caused by other cross-reacting bacteria represent the immunological contexts. This complex context results in the development of the large number of diagnosis of Brucella melitensis brucellosis. The aim of this article is to briefly review the detection methods and compare the superiorities of different tests.

Proteomics in Influenza Research: The Emerging Role of Posttranslational Modifications.

Influenza viruses continue evolving and have the ability to cause a global pandemic, so it is very important to elucidate its pathogenesis and find new treatment methods. In recent years, proteomics has made important contributions to describing the dynamic interaction between influenza viruses and their hosts, especially in posttranslational regulation of a variety of key biological processes. Protein posttranslational modifications (PTMs) increase the diversity of functionality of the organismal proteome and affect almost all aspects of pathogen biology, primarily by regulating the structure, function, and localization of the modified proteins. Considerable technical achievements in mass spectrometry-based proteomics have been made in a large number of proteome-wide surveys of PTMs in many different organisms. Herein we specifically focus on the proteomic studies regarding a variety of PTMs that occur in both the influenza viruses, mainly influenza A viruses (IAVs), and their hosts, including phosphorylation, ubiquitination and ubiquitin-like modification, glycosylation, methylation, acetylation, and some types of acylation. Integration of these data sets provides a unique scenery of the global regulation and interplay of different PTMs during the interaction between IAVs and their hosts. Various techniques used to globally profiling these PTMs, mostly MS-based approaches, are discussed regarding their increasing roles in mechanical regulation of interaction between influenza viruses and their hosts.

Administration of Exogenous Progesterone Protects Against Brucella abortus Infection-Induced Inflammation in Pregnant Mice.

Progesterone has been recognized as essential for the establishment and maintenance of pregnancy, and is typically known as an immunosuppressive agent. However, its effects on mediating Brucella infection-induced inflammation have not been evaluated. Here we demonstrated that Brucella abortus infection inhibits progesterone levels in the pregnant mouse by suppressing the production of progesterone by placenta. Progesterone treatment significantly reduced the secretion of inflammatory cytokines in serum, macrophages, and trophoblasts of B. abortus-infected mice, leading to decreased placentitis and enhancing the pup viability. Mechanistically, this decreased inflammatory response results from inhibition of NF-kB activation by progesterone. Moreover, progesterone treatment suppresses B. abortus growth within trophoblasts associated with an inability of bacteria to escape the late endosome compartment in vitro. Collectively, our data illustrate that progesterone treatment might be useful therapeutically in protection against placentitis or abortion caused by B. abortus infection.

HMGB1 release from trophoblasts contributes to inflammation during Brucella melitensis infection.

Brucella melitensis infection causes acute necrotizing inflammation in pregnant animals; however, the pathophysiological mechanisms leading to placentitis are unknown. Here, we demonstrate that high-mobility group box 1 (HMGB1) acts as a mediator of placenta inflammation in B. melitensis-infected pregnant mice model. HMGB1 levels were increased in trophoblasts or placental explant during B. melitensis infection. Inhibition of HMGB1 activity with neutralising antibody significantly reduced the secretion of inflammatory cytokines in B. melitensis-infected trophoblasts or placenta, whereas administration of recombinant HMGB1 (rHMGB1) increased the inflammatory response. Mechanistically, this decreased inflammatory response results from inhibition of HMGB1 activity, which cause the suppression of both mitogen-activated protein kinases and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. Moreover, neutralising antibody to HMGB1 prevented B. melitensis infection-induced activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in trophoblasts. In contrast, in vitro stimulation of trophoblasts with rHMGB1 caused activation of NADPH oxidase and increased the production of ROS, which contributes to high bacterial burden within trophoblasts or placenta. In vivo, treatment with anti-HMGB1 antibody increases the number of Brucella survival within placenta in B. melitensis-infected pregnant mice but successfully reduced the severity of placentitis and abortion.

The advances in brucellosis vaccines.

Brucellosis is a worldwide zoonosis affecting animal and human health. Till now, there is no effective vaccine licensed for brucellosis in humans. Although M5, H38 and 45/20 vaccines were used to prevent animal brucellosis in the early stages, the currently used animal vaccines are S19, Rev.1, S2, RB51 and SR82. However, these vaccines still have several drawbacks such as residual virulence and interfering conventional serological tests. With the development of DNA recombination technologies and the completion of the sequence of Brucella genome, much research focuses on the search for potential safer and more effective vaccines. Preliminary studies have demonstrated that new vaccines, including genetically engineered attenuated vaccines, subunit vaccines and other potential vaccines, have higher levels of protection, but there are still some problems. In this paper, we briefly review the main vaccines that have been used in controlling the brucellosis for decades and the progress in the development of new brucellosis vaccines.

Inhibition of nucleolar stress response by Sirt1: A potential mechanism of acetylation-independent regulation of p53 accumulation.

The mammalian Sirt1 deacetylase is generally thought to be a nuclear protein, but some pilot studies have suggested that Sirt1 may also be involved in orchestrating nucleolar functions. Here, we show that nucleolar stress response is a ubiquitous cellular reaction that can be induced by different types of stress conditions, and Sirt1 is an endogenous suppressor of nucleolar stress response. Using stable isotope labeling by amino acids in cell culture approach, we have identified a physical interaction of between Sirt1 and the nucleolar protein nucleophosmin, and this protein-protein interaction appears to be necessary for Sirt1 inhibition on nucleolar stress, whereas the deacetylase activity of Sirt1 is not strictly required. Based on the reported prerequisite role of nucleolar stress response in stress-induced p53 protein accumulation, we have also provided evidence suggesting that Sirt1-mediated inhibition on nucleolar stress response may represent a novel mechanism by which Sirt1 can modulate intracellular p53 accumulation independent of lysine deacetylation. This process may represent an alternative mechanism by which Sirt1 regulates functions of the p53 pathway.

Anemonin Attenuates RANKL-Induced Osteoclastogenesis and Ameliorates LPS-Induced Inflammatory Bone Loss in Mice via Modulation of NFATc1.

Osteoporosis is a metabolic bone disease characterized by insufficient osteoblastic function and/or excessive osteoclastic activity. One promising strategy for treating osteoporosis is inhibiting excessive osteoclast resorbing activity. Previous studies have revealed that anemonin (ANE), isolated from various types of Chinese natural herbs, has anti-inflammatory and anti-oxidative properties. However, whether ANE regulates osteoclastogenesis is unknown. This study aimed to investigate the potential effect of ANE on osteoclastogenesis and inflammatory bone loss in mice. In in vitro studies, ANE suppressed RANKL-stimulated osteoclast differentiation and function by downregulating the expression of osteoclast master transcriptor NFATc1, as well as its upstream transcriptor c-Fos, by decreasing NF-κB and ERK1/2 signaling. Interestingly, ANE did not change the phosphorylation and degradation of IκB-α and activation of JNK and p38 MAPKs. However, ANE repressed the phosphorylation of MSK-1 which is the downstream target of ERK1/2 and p38 MAPK and can phosphorylate NF-κB p65 subunit. These results implicated that ANE might suppress NF-κB activity via modulation of ERK1/2 mediated NF-κB phosphorylation. In addition, ANE directly suppressed NFATc1 transcription by inhibiting Blimp-1 expression, and the subsequent enhancement of the expression of NFATc1 negative regulators, Bcl-6 and IRF-8. Moreover, in vivo studies were conducted using an LPS-induced inflammatory bone loss mice model. Micro-CT and histology analysis showed that ANE treatment significantly improved trabecular bone parameters and bone destruction. These data indicate that ANE can attenuate RANKL-induced osteoclastogenesis and ameliorate LPS-induced inflammatory bone loss in mice through modulation of NFATc1 via ERK1/2-mediated NF-κB phosphorylation and Blimp1 signal pathways. ANE may provide new treatment options for osteoclast-related diseases.

Research Progress on Brucellosis.

Brucellosis is a debilitating febrile illness caused by an intracellular Brucella. The disease is distributed in humans and animals widely, especially in developing countries. Ten species are included in the genus Brucella nowadays; four species of them are pathogenic to humans, which make brucellosis a zoonosis with more than 500,000 new cases reported annually. For human brucellosis, the most pathogenic species is B. melitensis followed by B. suis, while B. abortus is the mildest type of brucellosis. The infection mechanism of Brucella is complicated and mostly relies on its virulence factors. The therapy of the disease contains vaccination and antibiotic. However, there are some defects in currently available vaccines such as the lower protective level and safety. Thus, safe and efficient vaccines for brucellosis are still awaited. The dual therapy of antibacterial is effective in the treatment of brucellosis if a rapid and exact detection method is found.

Tatarinan N inhibits osteoclast differentiation through attenuating NF-κB, MAPKs and Ca2+-dependent signaling.

Osteoclasts are multinucleated cells that originate from hemopoietic stem cells. Targeting over activated osteoclasts is thought to be an effective therapeutic approach to osteoporosis. In a previous study, we reported that Tatarinan O, a lignin-like compound, suppressed RANKL-induced osteoclastogenesis. In this study, we further examined the effects on osteoclast formation of three lignin-like compounds including Tatarinan N (TN), Tatarinan U (TU) and Tatarinan V (TV), all containing a common structure of asarone. We found that only TN suppressed RANKL-induced osteoclast differentiation, bone resorption pit formation and F-acting ring formation. TU and TV did not influence RANKL-induced osteoclastogenesis. We also found that TN dose-dependently inhibited the expression of osteoclastogenesis-associated genes, including TRAP, cathepsin K and MMP-9. Furthermore, we found that TN down-regulated the key transcription factor NFATc1 and c-Fos by preventing the activation of NF-κB and phosphorylation of MAPKs including ERK1/2 and p38 but not JNK. TN attenuated calcineurin expression via suppression of the Btk-PLCγ2 cascade and reduction of intracellular Ca2+, modulating NFATc1 activation. Taking together, our results indicated that TN might have therapeutic potential for osteoporosis.

Overexpression of Cu-Zn SOD in Brucella abortus suppresses bacterial intracellular replication via down-regulation of Sar1 activity.

Brucella Cu-Zn superoxide dismutase (Cu-Zn SOD) is a periplasmic protein, and immunization of mice with recombinant Cu-Zn SOD protein confers protection against Brucella abortus infection. However, the role of Cu-Zn SOD during the process of Brucella infection remains unknown. Here, we report that Cu-Zn SOD is secreted into culture medium and is translocated into host cells independent of type IV secretion systems (T4SS). Furthermore, co-immunoprecipitation and immunofluorescence studies reveal that Brucella abortus Cu-Zn SOD interacts with the small GTPase Sar1. Overexpression of Cu-Zn SOD in Brucella abortus inhibits bacterial intracellular growth by abolishing Sar1 activity in a manner independent of reactive oxygen species (ROS) production.

DOK3 Modulates Bone Remodeling by Negatively Regulating Osteoclastogenesis and Positively Regulating Osteoblastogenesis.

Osteoclastogenesis is essential for bone remodeling and normal skeletal maintenance. Receptor activator of NF-κB ligand (RANKL) promotes osteoclast differentiation and function but requires costimulation of immunoreceptor tyrosine-based activation motif (ITAM)-coupled immunoreceptors. Triggering receptor expressed on myeloid cells-2 (TREM2) coupled to ITAM-adaptor protein DNAX activation protein 12kDA (DAP12) provides costimulation of intracellular calcium signaling during osteoclastogenesis. Previously, we found that downstream of kinase-3 (DOK3) physically associates with DAP12 to inhibit toll-like receptor (TLR)-induced inflammatory signaling in macrophages. However, whether and how DOK3 modulates DAP12-dependent osteoclastogenesis is unknown and the focus of this study. Bone microarchitecture and histology of sex- and age-matched wild-type (WT) and DOK3-deficient (DOK3-/- ) mice were evaluated. Male and female DOK3-/- mice have significantly reduced trabecular bone mass compared with WT mice with increased TRAP+ osteoclasts in vivo. In vitro, DOK3-/- bone marrow-derived macrophages (BMMs) have increased macrophage colony-stimulating factor (M-CSF)-induced proliferation and increased sensitivity to RANKL-induced osteoclastogenesis. Compared with WT, DOK3-/- osteoclasts are significantly larger with more nuclei and have increased resorptive capacity. Mechanistically, DOK3 limits osteoclastogenesis by inhibiting activation of Syk and ERK in response to RANKL and M-CSF. DOK3 is phosphorylated in a DAP12-dependent manner and associates with Grb2 and Cbl. Compared with DAP12-/- mice with high bone mass, DOK3- and DAP12- doubly deficient mice (DKO) have normalized bone mass, indicating that DOK3 also limits DAP12-independent osteoclastogenesis in vivo. In vitro osteoclasts derived from DKO mice are mononuclear with poor resorptive capacity similar to DAP12-/- osteoclasts. Histomorphometry reveals that DOK3-/- mice also have reduced osteoblast parameters. DOK3-/- osteoblasts have reduced in vitro osteoblastogenesis and increased osteoprotegerin (OPG) to RANKL expression ratio compared with WT osteoblasts. Co-culture of WT and DOK3-/- osteoblasts with pre-osteoclasts reveals a reduced capacity of DOK3-/- osteoblasts to support osteoclastogenesis. These data indicate that DOK3 regulates bone remodeling by negatively regulating M-CSF- and RANKL-mediated osteoclastogenesis and positively regulating osteoblastogenesis. © 2017 American Society for Bone and Mineral Research.

Tert-butylhydroquinone promotes angiogenesis and improves heart functions in rats after myocardial infarction.

BACKGROUND: Hypertension is an increased risk of heart failure and acute myocardial infarction (MI). Tert-butylhydroquinone (tBHQ), as an antioxidant, shows multiple cardioprotective actions including the reduction in blood pressure. The aim of this study was to investigate whether and how tBHQ improves heart functions in rats. METHODS: The MI model was established in WKY and spontaneously hypertensive rats (SHRs) by ligation of left anterior descending coronary artery. Akt phosphorylation was examined by western blot in human umbilical vein endothelial cells (HUVECs) or in rats. Angiogenesis was assessed by immunohistochemistry and immunofluorescence. Heart function was determined by echocardiography. RESULTS: tBHQ increased Akt phosphorylation, promoted cell proliferations and migrations in HUVECs, which were abolished by Akt inhibitor wortmannin. In SHRs following MI, administration of tBHQ significantly increased Akt phosphorylation, promoted angiogenesis, reduced infarct size, and improved heart functions after 14 postoperative days. Importantly, these in vivo effects of tBHQ were ablated by wortmannin in SHRs. CONCLUSION: tBHQ via Akt activation promotes ischemia-induced angiogenesis and improves heart functions in hypertensive rats. In perspectives, the application of tBHQ should be considered in patients with ischemic diseases such as MI and stroke.

Lovastatin upregulates microRNA-29b to reduce oxidative stress in rats with multiple cardiovascular risk factors.

AIMS: Proteasome-linked oxidative stress is believed to cause endothelial dysfunction, an early event in cardiovascular diseases (CVD). Statin, as HMG-CoA reductase inhibitor, prevents endothelial dysfunction in CVD. However, the molecular mechanism of statin-mediated normalization of endothelial function is not completely elucidated. METHODS AND RESULTS: Lovastatin time/dose-dependently increased miR-29b expression and decreased proteasome activity in cultured human umbilical vein endothelial cells (HUVECs). Anti-miR-29b or overexpression of PA200 abolished lovastatin-induced inhibition of proteasome activity in HUVECs. In contrast, pre-miR-29b or PA200 siRNA mimics these effects of lovastatin on proteasome activity. Lovastatin inhibited oxidative stress induced by multiple oxidants including ox-LDL, H2O2, TNFα, homocysteine thiolactone (HTL), and high glucose (HG), which were reversed by inhibition of miR-29b in HUVECs. Ex vivo analysis indicated that lovastatin normalized the acetylcholine-induced endothelium-dependent relaxation and the redox status in isolated rat aortic arteries exposure to multiple cardiovascular risk factors. In vivo analysis revealed that administration of lovastatin remarkably suppressed oxidative stress and prevented endothelial dysfunction in rats with hyperglycemia, dyslipidemia, and hyperhomocysteinemia, as well as increased miR-29b expressions, reduced PA200 protein levels, and suppression of proteasome activity in aortic tissues. CONCLUSION: Upregulation of miR-29b expression is a common mechanism contributing to endothelial dysfunction induced by multiple cardiovascular risk factors through PA200-dependent proteasome-mediated oxidative stress, which is prevented by lovastatin.

Inhibition of Aberrant MicroRNA-133a Expression in Endothelial Cells by Statin Prevents Endothelial Dysfunction by Targeting GTP Cyclohydrolase 1 in Vivo.

BACKGROUND: GTP cyclohydrolase 1 (GCH1) deficiency is critical for endothelial nitric oxide synthase uncoupling in endothelial dysfunction. MicroRNAs (miRs) are a class of regulatory RNAs that negatively regulate gene expression. We investigated whether statins prevent endothelial dysfunction via miR-dependent GCH1 upregulation. METHODS: Endothelial function was assessed by measuring acetylcholine-induced vasorelaxation in the organ chamber. MiR-133a expression was assessed by quantitative reverse transcription polymerase chain reaction and fluorescence in situ hybridization. RESULTS: We first demonstrated that GCH1 mRNA is a target of miR-133a. In endothelial cells, miR-133a was robustly induced by cytokines/oxidants and inhibited by lovastatin. Furthermore, lovastatin upregulated GCH1 and tetrahydrobiopterin, and recoupled endothelial nitric oxide synthase in stressed endothelial cells. These actions of lovastatin were abolished by enforced miR-133a expression and were mirrored by a miR-133a antagomir. In mice, hyperlipidemia- or hyperglycemia-induced ectopic miR-133a expression in the vascular endothelium, reduced GCH1 protein and tetrahydrobiopterin levels, and impaired endothelial function, which were reversed by lovastatin or miR-133a antagomir. These beneficial effects of lovastatin in mice were abrogated by in vivo miR-133a overexpression or GCH1 knockdown. In rats, multiple cardiovascular risk factors including hyperglycemia, dyslipidemia, and hyperhomocysteinemia resulted in increased miR-133a vascular expression, reduced GCH1 expression, uncoupled endothelial nitric oxide synthase function, and induced endothelial dysfunction, which were prevented by lovastatin. CONCLUSIONS: Statin inhibits aberrant miR-133a expression in the vascular endothelium to prevent endothelial dysfunction by targeting GCH1. Therefore, miR-133a represents an important therapeutic target for preventing cardiovascular diseases.

Identification of single amino acid substitutions (SAAS) in neuraminidase from influenza a virus (H1N1) via mass spectrometry analysis coupled with de novo peptide sequencing.

RATIONALE: Amino acid substitutions in the neuraminidase of the influenza virus are the main cause of the emergence of resistance to zanamivir or oseltamivir during seasonal influenza treatment; they are the result of non-synonymous mutations in the viral genome that can be successfully detected by polymer chain reaction (PCR)-based approaches. There is always an urgent need to detect variation in amino acid sequences directly at the protein level. Mass spectrometry coupled with de novo sequencing has been explored as an alternative and straightforward strategy for detecting amino acid substitutions, as well - this approach is the primary focus of the present study. METHODS: Influenza virus (A/Puerto Rico/8/1934 H1N1) propagated in embryonated chicken eggs was purified by ultracentrifugation, followed by PNGase F treatment. The deglycosylated virion was lysed and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The gel band corresponding to neuraminidase was picked up and subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. RESULTS: LC-MS/MS analyses, coupled with manual de novo sequencing, allowed the determination of three amino acid substitutions: R346K, S349 N, and S370I/L, in the neuraminidase from the influenza virus (A/Puerto Rico/8/1934 H1N1), which were located in three mutated peptides of the neuraminidase: YGNGVWIGK, TKNHSSR, and PNGWTETDI/LK, respectively. CONCLUSIONS: We found that the amino acid substitutions in the proteins of RNA viruses (including influenza A virus) resulting from non-synonymous gene mutations can indeed be directly analyzed via mass spectrometry, and that manual interpretation of the MS/MS data may be beneficial. Copyright © 2016 John Wiley & Sons, Ltd.

Activation of activator protein 2 alpha by aspirin alleviates atherosclerotic plaque growth and instability in vivo.

AIMS: Aspirin has been used for the secondary prevention and treatment of cardiovascular disease for several decades. We investigated the roles of transcriptional factor activator protein 2α (AP-2α) in the beneficial effects of aspirin in the growth and vulnerability of atherosclerotic plaque. METHODS AND RESULTS: In mice deficient of apolipoprotein E (Apoe-/-), aspirin (20, 50 mg/kg/day) suppressed the progression of atherosclerosis in aortic roots and increased the plaque stability in carotid atherosclerotic plaques induced by collar-placement. In vivo lentivirus-mediated RNA interference of AP-2α reversed the inhibitory effects of aspirin on atherosclerosis in Apoe-/- mice. Mechanically, aspirin increased AP-2α phosphorylation and its activity, upregulated IkBα mRNA and protein levels, and reduced oxidative stress in cultured vascular smooth muscle cells. Furthermore, deficiency of AP-2α completely abolished aspirin-induced upregulation of IkBα levels and inhibition of oxidative stress in Apoe-/- mice. Clinically, conventional doses of aspirin increased AP-2α phosphorylation and IkBα protein expression in humans subjects. CONCLUSION: Aspirin activates AP-2α to upregulate IkBα gene expression, resulting in attenuations of plaque development and instability in atherosclerosis.

MicroRNA-125b-5p suppresses Brucella abortus intracellular survival via control of A20 expression.

BACKGROUND: Brucella may establish chronic infection by regulating the expression of miRNAs. However, the role of miRNAs in modulating the intracellular growth of Brucella remains unclear. RESULTS: In this study, we show that Brucella. abortus infection leads to downregulation of miR-125b-5p in macrophages. We establish that miR-125b-5p targets A20, an inhibitor of the NF-kB activation. Additionally, expression of miR-125b-5p decreases A20 expression in B. abortus-infected macrophages and leads to NF-kB activation and increased production of TNFα. Furthermore, B. abortus survival is attenuated in the presence of miR-125b-5p. CONCLUSIONS: These results uncover a role for miR-125b-5p in the regulation of B. abortus intracellular survival via the control of A20 expression.

The Rab1 in host cells modulates Brucella intracellular survival and binds to Brucella DnaK protein.

The intracellular pathogen Brucella abortus (B. abortus) survives and replicates inside host cells within the Brucella-containing vacuole, in which membrane contains a small GTPase Rab1. Here, we reported that Rab1 mediates B. abortus intracellular growth. Furthermore, B. abortus DnaK was identified to interact with Rab1 using GST pull-down and mass spectrometry analysis. This interaction was confirmed by co-immunoprecipitation and immunofluorescence. Through DnaK-CyaA fusion protein translocation assay and immunofluorescence confocal microscopy, the B. abortus DnaK was proved to be a virB-dependent translocated substrate.