Role of antigen presentation in the production of pro-inflammatory cytokines in obese adipose tissue

Type II diabetes regroups different physiological anomalies that ultimately lead to low-grade chronic inflammation, insulin resistance and loss of pancreatic β-cells. Obesity is one of the best examples of such a condition that can develop into Metabolic Syndrome, causing serious health problems of great socio-economic consequences. The pathological outcome of obesity has a genetic basis and depends on the delicate balance between pro- and anti-inflammatory effectors of the immune system. The causal link between obesity and inflammation is well established. While innate immunity plays a key role in the development of a pro-inflammatory state in obese adipose tissues, it has now become clear that adaptive immune cells are also involved and participate in the cascade of events that lead to metabolic perturbations. The efficacy of some immunotherapeutic protocols in reducing the symptoms of obesity-driven metabolic syndrome in mice implicated all arms of the immune response. Recently, the production of pathogenic immunoglobulins and pro-inflammatory cytokines by B and T lymphocytes suggested an auto-immune basis for the establishment of a non-healthy obese state. Understanding the cellular landscape of obese adipose tissues and how immune cells sustain chronic inflammation holds the key to the development of targeted therapies. In this review, we emphasize the role of antigen-presenting cells and MHC molecules in obese adipose tissue and the general contribution of the adaptive arm of the immune system in inflammation-induced insulin resistance.     

Insulin-like growth factor (IGF)-like peptide and 20-hydroxyecdysone regulate the growth and development of the male genital disk through different mechanisms in the silkmoth,Bombyx mori

It is well established that ecdysteroids play pivotal roles in the regulation of insect molting and metamorphosis. However, the mechanisms by which ecdysteroids regulate the growth and development of adult organs after pupation are poorly understood. Recently, we have identified insulin-like growth factor (IGF)-like peptides (IGFLPs), which are secreted after pupation under the control of 20-hydroxyecdysone (20E). In the silkmoth, Bombyx mori, massive amounts of Bombyx-IGFLP (BIGFLP) are present in the hemolymph during pupal-adult development, suggesting its importance in the regulation of adult tissue growth. Thus, we hypothesized that the growth and development of adult tissues including imaginal disks are regulated by the combined effects of BIGFLP and 20E. In this study, we investigated the growth-promoting effects of BIGFLP and 20E using the male genital disks of B. mori cultured ex vivo, and further analyzed the cell signaling pathways mediating hormone actions. We demonstrate that 20E induces the elongation of genital disks, that both hormones stimulate protein synthesis in an additive manner, and that BIGFLP and 20E exert their effects through the insulin/IGF signaling pathway and mitogen-activated protein kinase pathway, respectively. These results show that the growth and development of the genital disk are coordinately regulated by both BIGFLP and 20E.     

Role of interleukin-6 to differentiate sepsis from non-infectious systemic inflammatory response syndrome

Differentiating between sepsis and non-infectious systemic inflammatory response syndrome (SIRS) poses a great challenge. Several potential bloodstream biomarkers including Interleukin 6 (IL-6) have been investigated for their ability to diagnose sepsis. We conducted the present meta-analysis to evaluate the diagnostic quality of IL-6 in differentiating sepsis from non-infectious SIRS in adults. We also compared its accuracy with procalcitonin (PCT) and C-reactive protein (CRP). PubMed and EMBASE were systematically searched for studies published up to January 18, 2016. Twenty articles containing 22 studies and 2680 critically ill patients were included, of which, 21 studies also involved PCT and 14 involved CRP. Quantitative synthesis of studies showed that the pooled sensitivity/specificity of IL-6 and PCT were 0.68/0.73 and 0.78/0.67. The area under the curve (AUC) of IL-6, PCT and CPR for diagnosis of sepsis was 0.80, 0.83, and 0.71, respectively. This meta-analysis provides evidence that the IL-6 test has moderate diagnostic performance in differentiating sepsis from non-infectious SIRS in adults. IL-6 and PCT test has similar diagnostic value but higher than CRP. Considering its relatively high specificity, we recommend the use of IL-6 as a diagnostic aid to confirm infection rather than exclude infection in patients with SIRS.     

Effect of cryopreservation on viability and growth efficiency of stromal-epithelial cells derived from neonatal human thymus

The thymus is the major site of T lymphocyte generation and so is critical for a functional adaptive immune system. Since, thymectomy is a component of neonatal surgery for congenital heart diseases, it provides great potential for collection and storage of thymic tissue for autologous transplantation. However, specific investigation into the optimum parameters for thymic tissue cryopreservation have not been conducted. In this research, we evaluated the effect of different cryoprotective media compositions, which included penetrating (Me₂SO, glycerol) and non-penetrating (dextran-40, sucrose, hydroxyethyl starch) components, on the viability and functionality of frozen-thawed human thymic samples to select an optimal cryoprotective medium suitable for long-term storage of thymic tissue and a stromal-epithelial enriched population. Our primary focus was on receiving, low-temperature storage, culturing and evaluation of thymic tissue samples from newborns and infants with congenital heart diseases, who had undergone thymectomy as a part of standard surgical procedure. Thus, this work builds the platform for autologous clinical intervention into the thymus-deficient patients with congenital heart diseases. From our data, we conclude that although there were no significant differences in efficiency of tested cryoprotective media compositions, the combination of Me₂SO and dextran-40 compounds was the most suitable for long-term storage both thymic cell suspensions and thymic fragments based on the viability of CD326⁺ epithelial cells and stromal-epithelial cell monolayer formation.     

Potential chemical transformation of phosphinic acid derivatives and their applications in the synthesis of drugs

The chemical transformation of phosphinic acid is a well-considered mature area of research on account of the historical significant reactions such as Kabachnik–Fields, Mannich, Arbuzov, Michaelis–Becker, etc. Considerable advances have been made over last years especially in metal-catalyzed, free-radical processes and asymmetric synthesis using catalytic enantioselective. As a result, the aim of this synopsis is to make the reader familiar with advances in the approaches of phosphinic acids toward the synthesis of highly functionalized and valuable buildings blocks. Another purpose of this survey is to provide the current status of the applications of phosphinic acids in the synthesis of drugs.     

Proteome variation of the rat liver after static cold storage assayed in an ex vivo model

Cold storage is a common procedure for liver preservation in a transplant setting. However, during cold ischemia, the liver suffers molecular alterations that can affect its performance. Also, deleterious mechanisms set forth in the storage phase are exacerbated during reperfusion. This study aimed to identify liver proteins associated with injury during cold storage and/or normothermic reperfusion using the isolated perfused rat liver model. Livers from male rats were subjected to either (1) cold storage for 24 h, (2) ex vivo normothermic reperfusion for 90 min or (3) cold storage for 24 h followed by ex vivo normothermic reperfusion for 90 min. Then, the livers were homogenized and proteins were extracted. Protein expression between each experimental group and the control (freshly resected livers) was compared by two-dimensional (2D) gel electrophoresis. Protein identification was carried out by matrix‐assisted laser desorption/ionization time‐of‐flight spectrometry (MALDI‐TOF/TOF) using MASCOT as the search engine. 23 proteins were detected with significantly altered levels of expression among the different treatments, including molecular chaperones, antioxidant enzymes, and proteins involved in energy metabolism. Some of them have been postulated as biomarkers for liver damage while others had been identified in other organs subjected to ischemia and reperfusion injury. The whole data set will be a useful resource for studying deleterious molecular mechanisms that result in diminished liver function during storage and subsequent reperfusion.     

Know your ABCs: Characterization and gene expression dynamics of ABC transporters in the polyphagous herbivore Helicoverpa armigera

Polyphagous insect herbivores are adapted to many different secondary metabolites of their host plants. However, little is known about the role of ATP-binding cassette (ABC) transporters, a multigene family involved in detoxification processes. To study the larval response of the generalist Helicoverpa armigera (Lepidoptera) and the putative role of ABC transporters, we performed developmental assays on artificial diet supplemented with secondary metabolites from host plants (atropine-scopolamine, nicotine and tomatine) and non-host plants (taxol) in combination with a replicated RNAseq experiment. A maximum likelihood phylogeny identified the subfamily affiliations of the ABC transporter sequences. Larval performance was equal on the atropine-scopolamine diet and the tomatine diet. For the latter we could identify a treatment-specific upregulation of five ABC transporters in the gut. No significant developmental difference was detected between larvae fed on nicotine or taxol. This was also mirrored in the upregulation of five ABC transporters when fed on either of the two diets. The highest number of differentially expressed genes was recorded in the gut samples in response to feeding on secondary metabolites. Our results are consistent with the expectation of a general detoxification response in a polyphagous herbivore. This is the first study to characterize the multigene family of ABC transporters and identify gene expression changes across different developmental stages and tissues, as well as the impact of secondary metabolites in the agricultural pest H. armigera.     

Ontogenetic trajectory and allometry of Diplonychus rusticus (Fabricius), an Oriental aquatic bug (Hemiptera: Belostomatidae) from the Western Ghats of India

Despite being one of the dominant groups in freshwater ecosystems, morphological and ontogenetic studies on aquatic Hemiptera have received little attention in the Oriental region. We present the ontogenetic trajectory and allometry of the widespread Oriental belostomatid species, Diplonychus rusticus (Fabricius) for the first time. We have measured nine different morphological variables throughout the growth of the bug using both field captured and laboratory reared specimens. Our results suggest that the developmental instars can be distinguished by the size variables, as seen in the Principal Component Analysis. On the basis of a CHAID (Chi-squared Automatic Interaction Detection) based regression tree, we also show that the characters – total length without head and maximum width – prove to be adequate for effective instar identification. The multivariate allometric growth pattern shows that different body parts exhibit different types of allometry. This is apparent in the allometry exhibited by forelegs and mid and hind legs, which show allometry of opposite polarities. This may be due to the different functions attributed to these body parts. Our results show that the growth pattern in D. rusticus is comparable with the New World genus Belostoma, suggesting a conserved growth pattern in the family Belostomatidae.     

Transposition burst of mariner-like elements in the sequenced genome of Rhodnius prolixus

Transposable elements (TEs) are widespread in insect's genomes. However, there are wide differences in the proportion of the total DNA content occupied by these repetitive sequences in different species. We have analyzed the TEs present in R. prolixus (vector of the Chagas disease) and showed that 3.0% of this genome is occupied by Class II TEs, belonging mainly to the Tc1-mariner superfamily (1.65%) and MITEs (1.84%). Interestingly, most of this genomic content is due to the expansion of two subfamilies belonging to: irritans himar, a well characterized subfamily of mariners, and prolixus1, one of the two novel subfamilies here described. The high amount of sequences in these subfamilies suggests that bursts of transposition occurred during the life cycle of this family. In an attempt to characterize these elements, we performed an in silico analysis of the sequences corresponding to the DDD/E domain of the transposase gene. We performed an evolutionary analysis including network and Bayesian coalescent-based methods in order to infer the dynamics of the amplification, as well as to estimate the time of the bursts identified in these subfamilies. Given our data, we hypothesized that the TE expansions occurred around the time of speciation of R. prolixus around 1.4 mya. This suggestion lays on the “Transposon Model” of TE evolution, in which the members of a TE population that are replicative active are present at multiple loci in the genome, but their replicative potential varies, and of the “Life Cycle Model” that states that when present-day TEs have been involved in amplification bursts, they share an ancestral copy that dates back to this initial amplification.     

Defects in mitochondrial DNA replication and oxidative damage in muscle of mtDNA mutator mice

A causal role for mitochondrial dysfunction in mammalian aging is supported by recent studies of the mtDNA mutator mouse (“PolG” mouse), which harbors a defect in the proofreading-exonuclease activity of mitochondrial DNA polymerase gamma. These mice exhibit accelerated aging phenotypes characteristic of human aging, including systemic mitochondrial dysfunction, exercise intolerance, alopecia and graying of hair, curvature of the spine, and premature mortality. While mitochondrial dysfunction has been shown to cause increased oxidative stress in many systems, several groups have suggested that PolG mutator mice show no markers of oxidative damage. These mice have been presented as proof that mitochondrial dysfunction is sufficient to accelerate aging without oxidative stress. In this study, by normalizing to mitochondrial content in enriched fractions we detected increased oxidative modification of protein and DNA in PolG skeletal muscle mitochondria. We separately developed novel methods that allow simultaneous direct measurement of mtDNA replication defects and oxidative damage. Using this approach, we find evidence that suggests PolG muscle mtDNA is indeed oxidatively damaged. We also observed a significant decrease in antioxidants and expression of mitochondrial biogenesis pathway components and DNA repair enzymes in these mice, indicating an association of maladaptive gene expression with the phenotypes observed in PolG mice. Together, these findings demonstrate the presence of oxidative damage associated with the premature aging-like phenotypes induced by mitochondrial dysfunction.     

Localization of the ultraviolet-sensor Opn5m and its effect on myopia-related gene expression in the late-embryonic chick eye

Recent studies show that exposure to ultraviolet (UV) light suppresses ocular elongation, which causes myopia development. However, the specific mechanisms of this process have not been elucidated. A UV-sensor, Opsin 5 (Opn5) mRNA was shown to be present in extraretinal tissues. To test the possibility that UV-signals mediated by Opn5 would have a direct effect on the outer connective tissues of the eye, we first examined the expression patterns of a mammalian type Opn5 (Opn5m) in the late-embryonic chicken eye. Quantitative PCR showed Opn5m mRNA expression in the cornea and sclera. The anti-Opn5m antibody stained a small subset of cells in the corneal stroma and fibrous sclera. We next assessed the effect of UV-A (375 nm) irradiation on the chicken fibroblast cell line DF-1 overexpressing chicken Opn5m. UV-A irradiation for 30 min significantly increased the expression of Early growth response 1 (Egr1), known as an immediate early responsive gene, and of Matrix metalloproteinase 2 (Mmp2) in the presence of retinal chromophore 11-cis-retinal. In contrast, expression of Transforming growth factor beta 2 and Tissue inhibitor of metalloproteinase 2 was not significantly altered. These results indicate that UV-A absorption by Opn5m can upregulate the expression levels of Egr1 and Mmp2 in non-neuronal, fibroblasts. Taken together with the presence of Opn5m in the cornea and sclera, it is suggested that UV-A signaling mediated by Opn5 in the extraretinal ocular tissues could influence directly the outer connective tissues of the chicken late-embryonic eye.     

Home environment and cord blood levels of lead,arsenic, and zinc on neurodevelopment of 24 months children living in Chitwan Valley,Nepal

In a birth cohort living in Chitwan Valley, lowland Nepal, we have previously reported inverse associations between in utero levels of lead (Pb), arsenic (As) and neurodevelopment at birth measured by the Brazelton Neonatal Behavioral Assessment Scale, third edition (NBAS III). In the present paper, a follow-up of the same cohort was made on 24-month-old infants regarding the neurodevelopmental effects of these metals, taking the postnatal environment into account. In total, the same100 mother-infant pairs as the previous study, whose Pb, As, and Zn concentrations in cord blood were known, were recruited. Postnatal raising environment was evaluated using the Home Observation for Measurement of Environment (HOME) scale. Neurodevelopment of children at 24 months of age (n = 74) was assessed using the Bayley Scale of Infant Development, Second Edition (BSID II). Multivariable regression adjusting for covariates was performed to determine the associations of in utero levels of toxic and essential elements and the home environment with neurodevelopment scores. Unlike the NBAS III conducted for newborns, none of the BSID II cluster scores in 24-month-old infants were associated with cord blood levels of Pb, As, and Zn. The total HOME score was positively associated with the mental development scale (MDI) score (coefficient = 0.67, at 95% CI = 0.03 to 1.31). In this cohort, a detrimental effect of in utero Pb and As on neurodevelopmental indicators observed at birth disappeared at 24 months, while an association between neurodevelopment and home environment continued.     

Role of labile iron in the toxicity of pharmacological ascorbate

Pharmacological ascorbate has been shown to induce toxicity in a wide range of cancer cell lines. Pharmacological ascorbate in animal models has shown promise for use in cancer treatment. At pharmacological concentrations the oxidation of ascorbate produces a high flux of H₂O₂ via the formation of ascorbate radical (Asc^•-). The rate of oxidation of ascorbate is principally a function of the level of catalytically active metals. Iron in cell culture media contributes significantly to the rate of H₂O₂ generation. We hypothesized that increasing intracellular iron would enhance ascorbate-induced cytotoxicity and that iron chelators could modulate the catalytic efficiency with respect to ascorbate oxidation. Treatment of cells with the iron-chelators deferoxamine (DFO) or dipyridyl (DPD) in the presence of 2 mM ascorbate decreased the flux of H₂O₂ generated by pharmacological ascorbate and reversed ascorbate-induced toxicity. Conversely, increasing the level of intracellular iron by preincubating cells with Fe-hydroxyquinoline (HQ) increased ascorbate toxicity and decreased clonogenic survival. These findings indicate that redox metal metals, e.g., Fe³⁺/Fe²⁺, have an important role in ascorbate-induced cytotoxicity. Approaches that increase catalytic iron could potentially enhance the cytotoxicity of pharmacological ascorbate in vivo.     

Post rapid freezing growth of Antarctic strain of Heterococcus sp. monitored by cell viability and chlorophyll fluorescence

The soil microalgae of the genus Heterococcus are found in cold environments and have been reported for the terrestrial ecosystems of several Sub-Antarctic and Antarctic Islands. This study focused on resistance of Heterococcus sp. to sub-zero temperature. Heterococcus sp. was isolated from soil samples from James Ross Island, Antarctica. Culture of Heterococcus sp. grown in liquid medium were used to study ribitol effects at sub-zero temperatures on the species resistance to rapid freezing (RF, immersion of a sample into liquid nitrogen) and consequent cultivation on agar. Before the experiment, Heterococcus sp. was cultured in liquid medium for 11 months and then treated in ribitol concentrations of 32 or 50 mM for 2 h. Then, 1 ml samples were frozen to −196 °C in liquid nitrogen (day 0) and inoculated on BBM agar after thawing. Number of living and dead cells was evaluated and the cell viability (P_ν) was calculated repeatedly using the optical microscopy approach. The addition of ribitol caused a noticable increase in P_ν on days 9, 12, 14 (with a P_ν of 25–45% in ribitol-treated samples compared to 10% in the untreated control). In the following period (d 16–19), the positive effect of ribitol on P_ν was less pronounced but still statistically significant. To evaluate the negative effects of RF on chlorophyll fluorescence parameters, the potential yield of photochemical reactions in PS II (F_V/F_M), and the effective quantum yield of photochemical reactions in PS II (Ф_PSII) were measured immediately before and after RF. Consequently, F_V/F_M and Ф_PSII of agar inoculates were measured repeatedly for 30 d cultivation in 3 d interval. Both the 32 and the 50 mM addition of ribitol caused earlier detection of the parameters (d 16) compared to the control measurements (d 23) as well as reaching the maximum values of the chlorophyll fluorescence parameters earlier (d 23 in ribitol-treated samples compared to d 25 in control samples). Heterococcus sp. proved to be a species resistant to rapid freezing. The ability may help the species to survive in harsh Antarctic environments typified by rapid fluctuations in temperature that may bring a rapid freezing of the alga.     

Probing the chemical mechanism and critical regulatory amino acid residues of Drosophila melanogaster arylalkylamine N-acyltransferase like 2

Arylalkylamine N-acyltransferase like 2 (AANATL2) catalyzes the formation of N-acylarylalkylamides from the corresponding acyl-CoA and arylalkylamine. The N-acylation of biogenic amines in Drosophila melanogaster is a critical step for the inactivation of neurotransmitters, cuticle sclerotization, and melatonin biosynthesis. In addition, D. melanogaster has been used as a model system to evaluate the biosynthesis of fatty acid amides: a family of potent cell signaling lipids. We have previously showed that AANATL2 catalyzes the formation of N-acylarylakylamides, including long-chain N-acylserotonins and N-acyldopamines. Herein, we define the kinetic mechanism for AANATL2 as an ordered sequential mechanism with acetyl-CoA binding first followed by tyramine to generate the ternary complex prior to catalysis. Bell shaped k_{cat,app – acetyl-CoA} and (k_cat/K_m)_{app – acetyl-CoA} pH-rate profiles identified two apparent pK_a,app values of ∼7.4 and ∼8.9 that are critical to catalysis, suggesting the AANATL2-catalyzed formation of N-acetyltyramine occurs through an acid/base chemical mechanism. Site-directed mutagenesis of a conserved glutamate that corresponds to the catalytic base for other D. melanogaster AANATL enzymes did not produce a substantial depression in the k_cat,app value nor did it abolish the pK_a,app value attributed to the general base in catalysis (pK_a ∼7.4). These data suggest that AANATL2 catalyzes the formation of N-acylarylalkylamides using either different catalytic residues or a different chemical mechanism relative to other D. melanogaster AANATL enzymes. In addition, we constructed other site-directed mutants of AANATL2 to help define the role of targeted amino acids in substrate binding and/or enzyme catalysis.     

Therapeutic utility of the newly discovered properties of interleukin-21

Since its discovery in 2000, interleukin-21 (IL-21) has been shown to display a broad spectrum of pleiotropic actions including the regulation of development, differentiation and function of lymphoid-myeloid cells. More specifically, IL-21 modulates the effector functions of T, B and NK cells, which not only have key roles in antitumoral and antiviral immunity but also in exerting major effects on inflammatory responses promoting the development of autoimmune diseases. Recent studies have unveiled an unexpected role for IL-21 in immune regulation and de novo T-cell development. While highlighting its critical role in immunity, this review will mainly focus on recent advances in IL-21 biology and how such newly discovered properties could potentially be exploited therapeutically in the establishment of future clinical trials.