Antioxidants Maintain Cellular Redox Homeostasis by Elimination of Reactive Oxygen Species

Reactive oxygen species (ROS) are produced by living cells as normal cellular metabolic byproduct. Under excessive stress conditions, cells will produce numerous ROS, and the living organisms eventually evolve series of response mechanisms to adapt to the ROS exposure as well as utilize it as the signaling molecules. ROS molecules would trigger oxidative stress in a feedback mechanism involving many biological processes, such as apoptosis, necrosis and autophagy. Growing evidences have suggested that ROS play a critical role as the signaling molecules throughout the entire cell death pathway. Overwhelming production of ROS can destroy organelles structure and bio-molecules, which lead to inflammatory response that is a known underpinning mechanism for the development of diabetes and cancer. Cytochrome P450 enzymes (CYP) are regarded as the markers of oxidative stress, can transform toxic metabolites into ROS, such as superoxide anion, hydrogen peroxide and hydroxyl radical which might cause injury of cells. Accordingly, cells have evolved a balanced system to neutralize the extra ROS, namely antioxidant systems that consist of enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidases (GPxs), thioredoxin (Trx) as well as the non-enzymatic antioxidants which collectively reduce oxidative state. Herein, we review the recent novel findings of cellular processes induced by ROS, and summarize the roles of cellular endogenous antioxidant systems as well as natural anti-oxidative compounds in several human diseases caused by ROS in order to illustrate the vital role of antioxidants in prevention against oxidative stress.

Interleukin 10 (IL-10) inhibits human lymphocyte interferon gamma-production by suppressing natural killer cell stimulatory factor/IL-12 synthesis in accessory cells

Natural killer cell stimulatory factor or interleukin 12 (NKSF/IL-12) is a heterodimeric cytokine produced by monocytes/macrophages, B cells, and possibly other accessory cell types primarily in response to bacteria or bacterial products. NKSF/IL-12 mediates pleiomorphic biological activity on T and NK cells and, alone or in synergy with other inducers, is a powerful stimulator of interferon gamma (IFN-gamma) production. IL-10 is a potent inhibitor of monocyte-macrophage activation, that inhibits production of tumor necrosis factor alpha (TNF-alpha), IL-1 and also IFN-gamma from lymphocytes acting at the level of accessory cells. Because TNF-alpha and IL-1 are not efficient inducers of IFN-gamma, the mechanism by which IL-10 inhibits IFN-gamma production is not clear. In this paper, we show that IL-10 is a potent inhibitor of NKSF/IL-12 production from human peripheral blood mononuclear cells activated with Staphylococcus aureus or lipopolysaccharide (LPS). Both the production of the free NKSF/IL-12 p40 chain and the biologically active p70 heterodimer are blocked by IL-10. NKSF/IL-12 p40 chain mRNA accumulation is strongly induced by S. aureus or LPS and downregulated by IL-10, whereas the p35 mRNA is constitutively expressed and only minimally regulated by S. aureus, LPS, or IL-10. Although IL-10 is able to block the production of NKSF/IL-12, a powerful inducer of IFN-gamma both in vitro and in vivo, the mechanism of inhibition of IFN-gamma by IL-10 cannot be explained only on the basis of inhibition of NKSF/IL-12 because IL-10 can partially inhibit IFN-gamma production induced by NKSF/IL-12, and also, the IFN-gamma production in response to various stimuli in the presence of neutralizing antibodies to NKSF/IL-12. Our findings that antibodies against NKSF/IL-12, TNF-alpha, or IL-1 beta can significantly inhibit IFN-gamma production in response to various stimuli and that NKSF/IL-12 and IL-1 beta can overcome the IL-10-mediated inhibition of IFN-gamma, suggest that IL-10 inhibition of IFN-gamma production is primarily due to its blocking production from accessory cells of the IFN-gamma-inducer NKSF/IL-12, as well as the costimulating molecule IL-1 beta.

Butyrate: A Double-Edged Sword for Health?

Butyrate, a four-carbon short-chain fatty acid, is produced through microbial fermentation of dietary fibers in the lower intestinal tract. Endogenous butyrate production, delivery, and absorption by colonocytes have been well documented. Butyrate exerts its functions by acting as a histone deacetylase (HDAC) inhibitor or signaling through several G protein-coupled receptors (GPCRs). Recently, butyrate has received particular attention for its beneficial effects on intestinal homeostasis and energy metabolism. With anti-inflammatory properties, butyrate enhances intestinal barrier function and mucosal immunity. However, the role of butyrate in obesity remains controversial. Growing evidence has highlighted the impact of butyrate on the gut-brain axis. In this review, we summarize the present knowledge on the properties of butyrate, especially its potential effects and mechanisms involved in intestinal health and obesity.

The interleukin 12 p40 gene promoter is primed by interferon gamma in monocytic cells

Interleukin (IL) 12 is a proinflammatory cytokine produced by phagocytic cells, B cells, and other antigen-presenting cells that modulates adaptive immune responses by favoring the generation of T helper type 1 cells. IL-12 mediates some of its physiological activities by acting as a potent inducer of interferon (IFN) gamma production by T and natural killer cells. IFN-gamma enhances the ability of the phagocytic cells to produce IL-12 and other proinflammatory cytokines. Thus, IL-12-induced IFN-gamma acts in a positive feedback loop that represents an important amplifying mechanism in the inflammatory response to infections. We show here that IFN-gamma enhances IL-12 production mostly by priming phagocytic cells for lipopolysaccharide (LPS)-induced transcription of the IL-12 p40 gene, which encodes the heavy chain of the IL-12 heterodimer; furthermore, IFN-gamma directly induces transcription of the IL-12 p35 gene, which encodes the light chain of IL-12, and has at least an additive effect with LPS stimulation in inducing its transcription. The priming effect of IFN-gamma on the LPS-induced p40 gene transcription requires preincubation of the cells with IFN-gamma for at least 8 h to obtain a maximal effect. The priming effect of IFN-gamma for IL-12 production is predominantly at the transcriptional level for both the p40 and the p35 gene, and no evidence for a major role of posttranscriptional or translational mechanisms was found. A 3.3-kb human IL-12 p40 promoter construct transfected into cell lines recapitulated the tissue specificity of the endogenous gene, being silent in two human T cell lines, constitutively active in two human Epstein-Barr virus-positive B lymphoblastoid cell lines, and LPS inducible in the human THP-1 and mouse RAW264.7 monocytic cell lines. Because the RAW264.7 cell line is easily transfectable and regulates the endogenous IL-12 p40 gene in response to IFN-gamma or LPS similarly to human monocytes, it was used for analysis of the regulation of the cloned human IL-12 p40 promoter. A requirement for the region between -222 and -204 in both LPS responsiveness and IFN-gamma priming was established. This region contains an ets consensus sequence that was shown to mediate activation of the promoter by IFN-gamma and LPS, as well as by a cotransfected ets-2. The -222 construct was also regulated in a tissue-specific manner. Two other elements, IRF-1 located at -730 to -719, and NF-IL6 at -520 to -512, were also studied by deletion analysis, which did not result in decreased response to IFN-gamma and LPS stimulation.

Branched Chain Amino Acids: Beyond Nutrition Metabolism

Branched chain amino acids (BCAAs), including leucine (Leu), isoleucine (Ile), and valine (Val), play critical roles in the regulation of energy homeostasis, nutrition metabolism, gut health, immunity and disease in humans and animals. As the most abundant of essential amino acids (EAAs), BCAAs are not only the substrates for synthesis of nitrogenous compounds, they also serve as signaling molecules regulating metabolism of glucose, lipid, and protein synthesis, intestinal health, and immunity via special signaling network, especially phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signal pathway. Current evidence supports BCAAs and their derivatives as the potential biomarkers of diseases such as insulin resistance (IR), type 2 diabetes mellitus (T2DM), cancer, and cardiovascular diseases (CVDs). These diseases are closely associated with catabolism and balance of BCAAs. Hence, optimizing dietary BCAA levels should have a positive effect on the parameters associated with health and diseases. This review focuses on recent findings of BCAAs in metabolic pathways and regulation, and underlying the relationship of BCAAs to related disease processes.

Colocalization of cell division proteins FtsZ and FtsA to cytoskeletal structures in living Escherichia coli cells by using green fluorescent protein

In the current model for bacterial cell division, FtsZ protein forms a ring that marks the division plane, creating a cytoskeletal framework for the subsequent action of other proteins such as FtsA. This putative protein complex ultimately generates the division septum. Herein we report that FtsZ and FtsA proteins tagged with green fluorescent protein (GEP) colocalize to division-site ring-like structures in living bacterial cells in a visible space between the segregated nucleoids. Cells with higher levels of FtsZ-GFP or with FtsA-GFP plus excess wild-type FtsZ were inhibited for cell division and often exhibited bright fluorescent spiral tubules that spanned the length of the filamentous cells. This suggests that FtsZ may switch from a septation-competent localized ring to an unlocalized spiral under some conditions and that FtsA can bind to FtsZ in both conformations. FtsZ-GFP also formed nonproductive but localized aggregates at a higher concentration that could represent FtsZ nucleation sites. The general domain structure of FtsZ-GFP resembles that of tubulin, since the C terminus of FtsZ is not required for polymerization but may regulate polymerization state. The N-terminal portion of Rhizobium FtsZ polymerized in Escherichia coli and appeared to copolymerize with E. coli FtsZ, suggesting a degree of interspecies functional conservation. Analysis of several deletions of FtsA-GFP suggests that multiple segments of FtsA are important for its localization to the FtsZ ring.

A novel role for ursodeoxycholic acid in inhibiting apoptosis by modulating mitochondrial membrane perturbation

The hydrophilic bile salt ursodeoxycholic acid (UDCA) protects against the membrane-damaging effects associated with hydrophobic bile acids. This study was undertaken to (a) determine if UDCA inhibits apoptosis from deoxycholic acid (DCA), as well as from ethanol, TGF-beta1, Fas ligand, and okadaic acid; and to (b) determine whether mitochondrial membrane perturbation is modulated by UDCA. DCA induced significant hepatocyte apoptosis in vivo and in isolated hepatocytes determined by terminal transferase-mediated dUTP-digoxigenin nick end-labeling assay and nuclear staining, respectively (P < 0.001). Apoptosis in isolated rat hepatocytes increased 12-fold after incubation with 0.5% ethanol (P < 0.001). HuH-7 cells exhibited increased apoptosis with 1 nM TGF-beta1 (P < 0. 001) or DCA at >/= 100 microM (P < 0.001), as did Hep G2 cells after incubation with anti-Fas antibody (P < 0.001). Finally, incubation with okadaic acid induced significant apoptosis in HuH-7, Saos-2, Cos-7, and HeLa cells. Coadministration of UDCA with each of the apoptosis-inducing agents was associated with a 50-100% inhibition of apoptotic changes (P < 0.001) in all the cell types. Also, UDCA reduced the mitochondrial membrane permeability transition (MPT) in isolated mitochondria associated with both DCA and phenylarsine oxide by > 40 and 50%, respectively (P < 0.001). FACS(R) analysis revealed that the apoptosis-inducing agents decreased the mitochondrial transmembrane potential and increased reactive oxygen species production (P < 0.05). Coadministration of UDCA was associated with significant prevention of mitochondrial membrane alterations in all cell types. The results suggest that UDCA plays a central role in modulating the apoptotic threshold in both hepatocytes and nonliver cells, and inhibition of MPT is at least one pathway by which UDCA protects against apoptosis.

Suppression of transforming growth factor-beta isoforms, TGF-beta receptor type II, and myofibroblast differentiation in cultured human corneal and limbal fibroblasts by amniotic membrane matrix

Down-regulation of the transforming growth factor-beta (TGF-beta) signaling system is a strategy for preventing scarring during wound healing. Human corneal and limbal fibroblasts were cultured on the stromal matrix side of preserved human amniotic membrane. The levels of TGF-beta1, beta2, and beta3 and TGF-beta type II receptor transcripts and TGF-beta1 and beta2 proteins were suppressed as early as 8 hr and more dramatically at 24 hr after contact with an amniotic membrane. This suppressive effect was accompanied by down-regulation of alpha-smooth muscle actin, EDA spliced form of fibronectin, and integrin alpha5. It persisted even when challenged by 10 ng/ml TGF-beta1. In contrast with their counterparts grown on plastic or in collagen gel, such suppression in amniotic membrane cultures remained complete after 1 week of culturing. Cells cultured on amniotic membrane showed significantly reduced [3H]-thymidine incorporation compared to cells cultured on plastic and displayed no DNA fragmentation. These results reveal a novel mechanism by which the TGF-beta signaling system, DNA synthesis, and subsequent myofibroblast differentiation can be suppressed by an amnionic membrane matrix. This action explains in part the antiscarring results of amniotic membrane transplantation used for ocular surface reconstruction, a surgical technique applicable to other subspecialties. It may also explain in part why fetal wound healing is scarless.

Impaired interleukin 12 production in human immunodeficiency virus-infected patients

Peripheral blood mononuclear cells (PBMC) from human immunodeficiency virus (HIV)-infected patients, asymptomatic or with acquired immunodeficiency virus, produced 10-fold less interleukin 12 (IL-12) free heavy chain and fivefold less biologically active IL-12 heterodimer than PBMC from uninfected healthy donors when challenged in vitro with the common human pathogen Staphylococcus aureus. In contrast, PBMC from HIV-infected individuals and uninfected control donors produced similar levels of tumor necrosis factor alpha, IL-1 beta, and IL-10, and PBMC from HIV-infected individuals produced three- to fourfold more IL-6 compared with PBMC from uninfected control donors. The defect in IL-12 production is not due to hyperproduction of IL-10, a cytokine exerting an autocrine-negative feedback on IL-12 production, but was directly related to HIV infection, as suggested by the reduced ability of monocytes infected in vitro with HIV to produce IL-12. IL-12 deficiency may be an important component of the immunodeficiency associated with HIV infection.

Clinical and computed tomographic imaging features of novel coronavirus pneumonia caused by SARS-CoV-2

Purpose

To investigate the clinical and imaging characteristics of computed tomography (CT) in novel coronavirus pneumonia (NCP) caused by SARS-CoV-2.

Materials and methods

A retrospective analysis was performed on the imaging findings of patients confirmed with COVID-19 pneumonia who had chest CT scanning and treatment after disease onset. The clinical and imaging data were analyzed.

Results

Fifty patients were enrolled, including mild type in nine, common in 28, severe in 10 and critically severe in the rest three. Mild patients (29 years) were significantly (P<0.03) younger than either common (44.5 years) or severe (54.7) and critically severe (65.7 years) patients, and common patients were also significantly (P<0.03) younger than severe and critically severe patients. Mild patients had low to moderate fever (<39.1 °C), 49 (98%) patients had normal or slightly reduced leukocyte count, 14 (28%) had decreased counts of lymphocytes, and 26 (52%) patients had increased C-reactive protein. Nine mild patients were negative in CT imaging. For all the other types of NCP, the lesion was in the right upper lobe in 30 cases, right middle lobe in 22, right lower lobe in 39, left upper lobe in 33 and left lower lobe in 36. The lesion was primarily located in the peripheral area under the pleura with possible extension towards the pulmonary hilum. Symmetrical lesions were seen in 26 cases and asymmetrical in 15. The density of lesion was mostly uneven with ground glass opacity as the primary presentation accompanied by partial consolidation and fibrosis.

Conclusion

CT imaging presentations of NCP are mostly patchy ground glass opacities in the peripheral areas under the pleura with partial consolidation which will be absorbed with formation of fibrotic stripes if improved. CT scanning provides important bases for early diagnosis and treatment of NCP.

Cloning and pharmacological characterization of a fourth histamine receptor (H(4)) expressed in bone marrow

Histamine is a multifunctional hormone that regulates smooth muscle contraction in the airways, acid secretion in the gut, and neurotransmitter release in the central nervous system through three well characterized receptor subtypes, H(1), H(2), H(3), respectively. As part of a directed effort to discover novel G-protein-coupled receptors through homology searching of genomic databases, we identified a partial clone (GPCR105) that had significant homology to the recently identified histamine H(3) receptor cDNA. Expression of the full-length human GPCR105 in cells confers the ability to bind [(3)H]histamine with high affinity (K(D) = 5 nM). GPCR105 is pharmacologically similar to the histamine H(3) receptor in that it binds many of the known H(3) agonists and antagonists, albeit with a different rank order of affinity/potency. GPCR105 does not bind (i.e., K(D) > 10 microM) all tested H(1) and H(2) receptor antagonists such as diphenhydramine, loratadine, ranitidine, and cimetidine, but has modest affinity for the H(2) receptor agonist, dimaprit (377 nM). Whereas the H(3) receptor is expressed almost exclusively in nervous tissues, GPRC105 is expressed primarily in bone marrow and eosinophils. Together, these data demonstrate that GPCR105 is a novel histamine receptor structurally and pharmacologically related to the H(3) receptor. However, its unique expression profile and physiological role suggest that GPCR105 is a fourth histamine receptor subtype (H(4)) and may be a therapeutic target for the regulation of immune function, particularly with respect to allergy and asthma.

Normalization of diabetes in spontaneously diabetic cynomologus monkeys by xenografts of microencapsulated porcine islets without immunosuppression

Porcine pancreatic islets were microencapsulated in alginate-polylysine-alginate capsules and transplanted intraperitoneally into nine spontaneously diabetic monkeys. After one, two, or three transplants of 3-7 x 10(4) islets per recipient, seven of the monkeys became insulin independent for periods ranging from 120 to 804 d with fasting blood glucose levels in the normoglycemic range. Glucose clearance rates in the transplant recipients were significantly higher than before the graft administration and the insulin secretion during glucose tolerance tests was significantly higher compared with pretransplant tests. Porcine C-peptide was detected in all transplant recipients throughout their period of normoglycemia while none was found before the graft administration. Hemoglobin A1C levels dropped significantly within 2 mo after transplantation. While ketones were detected in the urine of all recipients before the graft administration, all experimental animals became ketone free 2 wk after transplantation. Capsules recovered from two recipients 3 mo after the restoration of normoglycemia were found physically intact with enclosed islets clearly visible. The capsules were free of cellular overgrowth. Examination of internal organs of two of the animals involved in our transplantation studies for the duration of 2 yr revealed no untoward effect of the extended presence of the microcapsules.

Clostridium species as probiotics: potentials and challenges

Clostridium species, as a predominant cluster of commensal bacteria in our gut, exert lots of salutary effects on our intestinal homeostasis. Up to now, Clostridium species have been reported to attenuate inflammation and allergic diseases effectively owing to their distinctive biological activities. Their cellular components and metabolites, like butyrate, secondary bile acids and indolepropionic acid, play a probiotic role primarily through energizing intestinal epithelial cells, strengthening intestinal barrier and interacting with immune system. In turn, our diets and physical state of body can shape unique pattern of Clostridium species in gut. In view of their salutary performances, Clostridium species have a huge potential as probiotics. However, there are still some nonnegligible risks and challenges in approaching application of them. Given this, this review summarized the researches involved in benefits and potential risks of Clostridium species to our health, in order to develop Clostridium species as novel probiotics for human health and animal production.

Frequent activation of AKT2 and induction of apoptosis by inhibition of phosphoinositide-3-OH kinase/Akt pathway in human ovarian cancer

We previously demonstrated that AKT2, a member of protein kinase B family, is activated by a number of growth factors via Ras and PI 3-kinase signaling pathways. Here, we report the frequent activation of AKT2 in human primary ovarian cancer and induction of apoptosis by inhibition of phosphoinositide-3-OH kinase (PI 3-kinase)/Akt pathway. In vitro AKT2 kinase assay analyses in 91 ovarian cancer specimens revealed elevated levels of AKT2 activity (>3-fold) in 33 cases (36.3%). The majority of tumors displaying activated AKT2 were high grade and stages III and IV. Immunostaining and Western blot analyses using a phospho-ser-473 Akt antibody that detects the activated form of AKT2 (AKT2 phosphorylated at serine-474) confirmed the frequent activation of AKT2 in ovarian cancer specimens. Phosphorylated AKT2 in tumor specimens localized to the cell membrane and cytoplasm but not the nucleus. To address the mechanism of AKT2 activation, we measured in vitro PI 3-kinase activity in 43 ovarian cancer specimens, including the 33 cases displaying elevated AKT2 activation. High levels of PI 3-kinase activity were observed in 20 cases, 15 of which also exhibited AKT2 activation. The remaining five cases displayed elevated AKT1 activation. Among the cases with elevated AKT2, but not PI 3-kinase activity (18 cases), three showed down-regulation of PTEN protein expression. Inhibition of PI 3-kinase/AKT2 by wortmannin or LY294002 induces apoptosis in ovarian cancer cells exhibiting activation of the PI 3-kinase/AKT2 pathway. These findings demonstrate for the first time that activation of AKT2 is a common occurrence in human ovarian cancer and that PI 3-kinase/Akt pathway may be an important target for ovarian cancer intervention.

Stimulatory and inhibitory effects of interleukin (IL)-4 and IL-13 on the production of cytokines by human peripheral blood mononuclear cells: priming for IL-12 and tumor necrosis factor alpha production

The production of cytokines in monocytes/macrophages is regulated by several different cytokines that have activating or inhibitory effects. Interleukin (IL)-10, IL-4, IL-13, and transforming growth factor (TGF)-beta are usually considered to be the most important macrophage-deactivating factors, with inhibitory effects on cytokine production. Unlike IL-10 and TGF-beta, which appear to act as downmodulators of many phagocytic cell functions, the mode of action of IL-4 and IL-13 is more complex. Addition of IL-4 and IL-13 to peripheral blood mononuclear cell (PBMC) cultures inhibited production of IL-12, tumor necrosis factor (TNF)-alpha, IL-10, and IL-1 beta induced by lipopolysaccharide (LPS) or Staphylococcus aureus added simultaneously with the cytokines. However, pretreatment of PBMC with IL-4 or IL-13 for > or = 20 h enhanced the production of IL-12 and TNF-alpha in response to LPS or S. aureus several fold in these cells; this IL-4-induced priming for the two cytokines was inhibited by anti-IL-4 neutralizing antibodies. IL-4 priming also enhanced the accumulation of IL-12 and TNF-alpha mRNA induced by LPS and S. aureus. The enhanced accumulation of transcripts for the IL-12 p35 and p40 chains by IL-4 priming was reflected in enhanced secretion of both the IL-12 free p40 chain and the p70 heterodimer. These results suggest an unexpected complexity in the regulatory role of IL-4 and IL-13 in immune responses.

Distinctive microRNA profiles relating to patient survival in esophageal squamous cell carcinoma

Esophageal cancer is the sixth leading cause of death from cancer and one of the least studied cancers worldwide. The global microRNA expression profile of esophageal cancer has not been reported previously. Here, for the first time, we have investigated expressed microRNAs in cryopreserved esophageal cancer tissues using advanced microRNA microarray techniques. Our microarray analyses identified seven microRNAs that could distinguish malignant esophageal cancer lesions from adjacent normal tissues. Some microRNAs could be correlated with the different clinicopathologic classifications. High expression of hsa-miR-103/107 correlated with poor survival by univariate analysis as well as by multivariate analysis. These results indicate that microRNA expression profiles are important diagnostic and prognostic markers of esophageal cancer, which might be analyzed simply using economical approaches such as reverse transcription-PCR.

A phase I trial of andrographolide in HIV positive patients and normal volunteers

A phase I dose-escalating clinical trial of andrographolide from Andrographis paniculata was conducted in 13 HIV positive patients and five HIV uninfected, healthy volunteers. The objectives were primarily to assess safety and tolerability and secondarily to assess effects on plasma virion HIV-1 RNA levels and CD4(+) lymphocyte levels. No subjects used antiretroviral medications during the trial. Those with liver or renal abnormalities were excluded. The planned regimen was 5 mg/kg bodyweight for 3 weeks, escalating to 10 mg/kg bodyweight for 3 weeks, and to 20 mg/kg bodyweight for a final 3 weeks. The trial was interrupted at 6 weeks due to adverse events including an anaphylactic reaction in one patient. All adverse events had resolved by the end of observation. A significant rise in the mean CD4(+) lymphocyte level of HIV subjects occurred after administration of 10 mg/kg andrographolide (from a baseline of 405 cells/mm(3) to 501 cells/mm(3); p = 0.002). There were no statistically significant changes in mean plasma HIV-1 RNA levels throughout the trial. Andrographolide may inhibit HIV-induced cell cycle dysregulation, leading to a rise in CD4(+) lymphocyte levels in HIV-1 infected individuals.

Tumor cell responses to IFNgamma affect tumorigenicity and response to IL-12 therapy and antiangiogenesis

Expression of a dominant negative mutant IFNgammaR1 in murine SCK and K1735 tumor cells rendered them relatively unresponsive to IFNgamma in vitro and more tumorigenic and less responsive to IL-12 therapy in vivo. IL-12 induced histologic evidence of ischemic damage only in IFNgamma-responsive tumors, and in vivo Matrigel vascularization assays revealed that while IFNgamma-responsive and -unresponsive tumor cells induced angiogenesis equally well, IL-12 and its downstream mediator IFNgamma only inhibited angiogenesis induced by the responsive cells. IL-12 induced angiogenesis inhibitory activity in the responsive cells, which may be attributable to production of the chemokine IP-10. Thus, IL-12 and IFNgamma inhibit tumor growth by inducing tumor cells to generate antiangiogenic activity.

Moderate dietary protein restriction alters the composition of gut microbiota and improves ileal barrier function in adult pig model

This study was conducted to investigate impacts of dietary protein levels on gut bacterial community and gut barrier. The intestinal microbiota of finishing pigs, fed with 16%, 13% and 10% crude protein (CP) in diets, respectively, were investigated using Illumina MiSeq sequencing. The ileal bacterial richness tended to decrease when the dietary protein concentration reduced from 16% to 10%. The proportion of Clostridium_sensu_stricto_1 in ileum significantly decreased, whereas Escherichia-Shigella increased with reduction of protein concentration. In colon, the proportion of Clostridium_sensu_stricto_1 and Turicibacter increased, while the proportion of RC9_gut_group significantly decreased with the dietary protein reduction. Notably, the proportion of Peptostreptococcaceae was higher in both ileum and colon of 13% CP group. As for metabolites, the intestinal concentrations of SCFAs and biogenic amines decreased with the dietary protein reduction. The 10% CP dietary treatment damaged ileal mucosal morphology, and decreased the expression of biomarks of intestinal cells (Lgr5 and Bmi1), whereas the expression of tight junction proteins (occludin and claudin) in 13% CP group were higher than the other two groups. In conclusion, moderate dietary protein restriction (13% CP) could alter the bacterial community and metabolites, promote colonization of beneficial bacteria in both ileum and colon, and improve gut barrier function.

Diagnostic and prognostic implications of microRNAs in human hepatocellular carcinoma

MicroRNAs (miRNAs) are important gene regulators, which are often deregulated in cancers. In this study, the authors analyzed the microRNAs profiles of 78 matched cancer/noncanerous liver tissues from HCC patients and 10 normal liver tissues and found that 69 miRNAs were differentially expressed between hepatocellular carcinoma (HCC) and corresponding noncancerous liver tissues (N). Then the expressions of 8 differentially expressed miRNAs were validated by real time RT PCR. The set of differentially expressed miRNAs could distinctly classify HCC, N and normal liver tissues (NL). Moreover, some of these differentially expressed miRNAs were related to the clinical factors of HCC patients. Most importantly, Kaplan-Meier estimates and the log-rank test showed that high expression of hsa-miR-125b was correlated with good survival of HCC patients (hazard ratio, 1.787, 95% confidence interval, 1.020-3.133, p = 0.043). The transfection assay showed that overexpression of miR-125b in HCC cell line could obviously suppress the cell growth and phosporylation of Akt. In conclusion, the authors have demonstrated the diagnostic miRNA profile for HCC, and for the first time, identified the miR-125b with predictive significance for HCC prognosis.

Interleukin-17 exacerbates hepatic steatosis and inflammation in non-alcoholic fatty liver disease

Mechanisms associated with the progression of simple steatosis to non-alcoholic fatty liver disease (NAFLD) remain undefined. Regulatory T cells (T(regs)) play a critical role in regulating inflammatory processes in non-alcoholic steatohepatitis (NASH) and because T helper type 17 (Th17) functionally oppose T(reg)-mediated responses, this study focused on characterizing the role of Th17 cells using a NAFLD mouse model. C57BL/6 mice were fed either a normal diet (ND) or high fat (HF) diet for 8 weeks. Mice in the HF group had a significantly higher frequency of liver Th17 cells compared to ND-fed mice. Neutralization of interleukin (IL)-17 in HF mice ameliorated lipopolysaccharide (LPS)-induced liver injury reflected by decreased serum alanine aminotransferase (ALT) levels and reduced inflammatory cell infiltrates in the liver. In vitro, HepG2 cells cultured in the presence of free fatty acids (FFA; oleic acid and palmitic acid) for 24 h and IL-17 developed steatosis via insulin-signalling pathway interference. IL-17 and FFAs synergized to induce IL-6 production by HepG2 cells and murine primary hepatocytes which, in combination with transforming growth factor (TGF-β), expanded Th17 cells. It is likely that a similar process occurs in NASH patients, as there were significant levels of IL-17(+) cell infiltrates in NASH patient livers. The hepatic expression of Th17 cell-related genes [retinoid-related orphan receptor gamma (ROR)γt, IL-17, IL-21 and IL-23] was also increased significantly in NASH patients compared to healthy controls. Th17 cells and IL-17 were associated with hepatic steatosis and proinflammatory response in NAFLD and facilitated the transition from simple steatosis to steatohepatitis. Strategies designed to alter the balance between Th17 cells and T(regs) should be explored as a means of preventing progression to NASH and advanced liver diseases in NAFLD patients.

Genetic and functional analyses of the conserved C-terminal core domain of Escherichia coli FtsZ

In Escherichia coli, FtsZ is required for the recruitment of the essential cell division proteins FtsA and ZipA to the septal ring. Several C-terminal deletions of E. coli FtsZ, including one of only 12 amino acids that removes the highly conserved C-terminal core domain, failed to complement chromosomal ftsZ mutants when expressed on a plasmid. To identify key individual residues within the core domain, six highly conserved residues were replaced with alanines. All but one of these mutants (D373A) failed to complement an ftsZ chromosomal mutant. Immunoblot analysis demonstrated that whereas I374A and F377A proteins were unstable in the cell, L372A, D373A, P375A, and L378A proteins were synthesized at normal levels, suggesting that they were specifically defective in some aspect of FtsZ function. In addition, all four of the stable mutant proteins were able to localize and form rings at potential division sites in chromosomal ftsZ mutants, implying a defect in a function other than localization and multimerization. Because another proposed function of FtsZ is the recruitment of FtsA and ZipA, we tested whether the C-terminal core domain was important for interactions with these proteins. Using two different in vivo assays, we found that the 12-amino-acid truncation of FtsZ was defective in binding to FtsA. Furthermore, two point mutants in this region (L372A and P375A) showed weakened binding to FtsA. In contrast, ZipA was capable of binding to all four stable point mutants in the FtsZ C-terminal core but not to the 12-amino-acid deletion.

Interleukin-12 production by human polymorphonuclear leukocytes

Human polymorphonuclear leukocytes (PMN) stimulated by lipopolysaccharide (LPS) produce interleukin-12 (IL-12). Both the free IL-12 p40 chain and minute amounts of the biologically active IL-12 p70 heterodimers are produced by PMN. Interferon-gamma (IFN-gamma) enhanced the LPS-induced secretion of both the free IL-12 p40 chain and the p70 heterodimer by approximately fivefold. As observed for other IL-12-producing cell types, the ratio of free p40 chain to p70 heterodimer secreted by LPS-stimulated PMN was approximately 20:1. LPS induced a 100-fold increase of IL-12 p40 mRNA, but had minimal effect on p35 mRNA accumulation. IFN-gamma enhanced the LPS-induced accumulation of p40 mRNA and directly induced a several-fold increase in the accumulation of p35 mRNA. Therefore, the combined effect of LPS and IFN-gamma induced sufficient expression of both p40 and p35 to attain production of the biologically active p70 heterodimer at physiologically relevant concentrations. The ratio between p40 and p35 mRNA abundance in PMN stimulated with both LPS and IFN-gamma was approximately 200:1, explaining the secretion of the free p40 chain in much higher concentrations than the p70 heterodimer. IL-10, an inhibitor of the production of various cytokines in PMN, also suppressed IL-12 mRNA accumulation and secretion by PMN. Because of the important immunoregulatory function of IL-12, in particular induction of IFN-gamma production and facilitation of T helper cell type 1 response, the ability of PMN to produce IL-12 suggests that neutrophils may play an active role in the regulatory interaction between innate resistance and adaptive immunity.

Urinary catecholamine excretion and severity of PTSD symptoms in Vietnam combat veterans

In the present study, we replicated and extended our previous findings of increased 24-hour urinary catecholamine excretion in posttraumatic stress disorder (PTSD). Dopamine, norepinephrine, and epinephrine concentrations were measured in 22 male patients with PTSD (14 inpatients and eight outpatients) and in 16 nonpsychiatric normal males. The PTSD inpatients showed significantly higher excretion of all three catecholamines compared with both outpatients with PTSD and normal controls. Dopamine and norepinephrine, but not epinephrine, levels were significantly correlated with severity of PTSD symptoms in the PTSD group as a whole. In particular, these catecholamines seemed related to intrusive symptoms. None of the catecholamines were correlated with severity of depression. The findings support the hypothesis of an enhanced sympathetic nervous system activation in PTSD, and suggest that increased sympathetic arousal may be closely linked to severity of certain PTSD symptom clusters.