Biology of amphibian granulocytes - From evolutionary pressures to functional consequences.

Granulocyte-lineage cells are important innate immune effectors across all vertebrates. Named for conspicuous secretory granules, granulocytes have historically been studied for their antimicrobial roles. Although versions of these cells are found in all vertebrate species examined to date, disparate environmental and physiological pressures acting on distinct vertebrate classes have shaped many of the facets dictating granulocyte biology. Immune pressures further determine granulopoietic constraints, ultimately governing granulocyte functions. For amphibians that inhabit pathogen-rich aquatic environments for some or all their lives, their unique granulocyte biologies satisfy many of their antimicrobial needs. Amphibians also occupy an intermediate position in the evolution of vertebrate immune systems, using combinations of primitive (e.g., subcapsular liver) and more recently evolved (e.g., bone marrow) tissue sites for hematopoiesis and specifically, granulopoiesis. The last decade of research has revealed vertebrate granulocytes in general, and amphibian granulocytes in particular, are more complex than originally assumed. With dynamic leukocyte phenotypes, granulocyte-lineage cells are being acknowledged for their multifaceted roles beyond immunity in other physiological processes. Here we provide an overview of granulopoiesis in amphibians, highlight key differences in these processes compared to higher vertebrates, and identify open questions.

Mitochondrial energy metabolism in baby hamster kidney (BHK-21/C13) cells treated with karnozin extra® / Metabolismo energético mitocondrial en células de riñón de hámster bebé (BHK-21 / C13) tratadas con karnozin extra®

SUMMARY: Carnosine is known as a natural dipeptide, which inhibits the proliferation of tumor cells throughout its action on mitochondrial respiration and cell glycolysis. However, not much is known about its effects on the metabolism of healthy cells. We explored the effects of Karnozin EXTRA® capsule with different concentrations of L-carnosine, on the cell viability and the expressions of intermediate filament vimentin (VIM) and superoxide dismutase (SOD2) in normal fibroblasts BHK-21/C13. Furthermore, we investigated its action on the energy production of these cells. Cell viability was quantified by the MTT assay. The Clark oxygen electrode (Oxygraph, Hansatech Instruments, England) was used to measure the "intact cell respiration rate", state 3 of ADP-stimulated oxidation, maximum oxidation capacity and the activities of complexes I, II and IV. Results showed that Karnozin EXTRA® capsule in concentrations of 2 and 5 mM of L-carnosine did not induce toxic effects and morphological changes in treated cells. Our data revealed a dose-dependent immunofluorescent signal amplification of VIM and SOD2 in the BHK-21/C13 cell line. This supplement substantially increased the recorded mitochondrial respiration rates in the examined cell line. Due to the stimulation of mitochondrial energy production in normal fibroblasts, our results suggested that Karnozin EXTRA® is a potentially protective dietary supplement in the prevention of diseases with altered mitochondrial function.

RESUMEN: La carnosina se conoce como dipéptido natural, que inhibe la proliferación de células tumorales a través de su acción sobre la respiración mitocondrial y la glucólisis celular. Sin embargo, no se sabe mucho de sus efectos sobre el metabolismo de las células sanas. Exploramos los efectos de la cápsula Karnozin EXTRA® con diferentes concentraciones de L-carnosina, sobre la viabilidad celular y las expresiones de vimentina de filamento intermedio (VIM) y superóxido dismutasa (SOD2) en fibroblastos normales BHK-21 / C13. Además, estudiamos su acción sobre la producción de energía de estas células. La viabilidad celular se cuantificó mediante el ensayo MTT. Se utilizó el electrodo de oxígeno Clark (Oxygraph, Hansatech Instruments, Inglaterra) para medir la "tasa de respiración de células intactas", el estado 3 de oxidación estimulada por ADP, la capacidad máxima de oxidación y las actividades de los complejos I, II y IV. Los resultados mostraron que la cápsula de Karnozin EXTRA® en concentraciones de 2 y 5 mM de L- carnosina no indujo efectos tóxicos ni cambios morfológicos en las células tratadas. Nuestros datos revelaron una amplificación de señal inmunofluorescente dependiente de la dosis de VIM y SOD2 en la línea celular BHK-21 / C13. Este suplemento aumentó sustancialmente las tasas de respiración mitocondrial registradas en la línea celular examinada. Debido a la estimulación de la producción de energía mitocondrial en fibroblastos normales, nuestros resultados sugirieron que Karnozin EXTRA® es un suplemento dietético potencialmente protector en la prevención de enfermedades con función mitocondrial alterada.

JUVENILE POLYP IN ADULTS.

Colorectal juvenile polyp as a pathologic entity was first described by Verse. These non-neoplastic lesions are most commonly found in children and infants, while in older children after the age of 14 and adults are a rare phenomenon. A 75-year-old female underwent colonoscopy. There was a pedunculated polyp in the transverse colon. Complete endoscopic electroresection of this polyp was performed and the polyp was sent for histopathologic analysis. Macroscopically, the polyp was described as a fragment of irregular round shape, size of about 2.5x2x1 cm, with fine-grained, reddish surface, showing dark red color on serial sections. Histologic examination of the polyp showed some irregularly distributed glands, some of which were cystically dilated. All glandular formations were coated with normal intestinal epithelium. The surface of the polyp was partially eroded and replaced by non-specific cellular granulation tissue. There were some signs of hemorrhagic infarction in the stroma of the polyp. Histopathologic examination indicated that histopathologic characteristics of this polyp corresponded to juvenile polyp. Juvenile polyps are very rarely found in adults. Therefore, we describe a case of this patient in her eighties with juvenile polyp localized in the transverse colon.

An unusual finding of tumorlet carcinoid and endobronchial hamartoma in the lobar bronchus / Hallazgo inusual de tumorlet carcinoide y hamartoma endobronquial en el bronquio lobar

SUMMARY: Neuroendocrine lung tumours are a group of different tumours that have similar morphological, immunohistochemical and molecular characteristics, and represents 1-2 % of all malignant lung tumours. Tumorlet carcinoids represent the nodular proliferation of hyperplastic neuroendocrine cells that is smaller than 5 mm in size. In this study, we reported the unusual finding of tumour carcinoid and endobronchial hamartoma in the same bronchus. A 49-year-old male patient with symptoms of prolonged severe cough and fever, and was treated for pneumonia. Since he did not adequately respond to antibiotic therapy lung CT scan was performed which showed middle lobe bronchus obstruction. Bronchoscopy revealed a lobulated whitish tumour which was biopsied and histopathological diagnosis was hamartoma. Tumour could not be completely removed during bronchoscopy, it was decided to surgically remove it. On serial section, during gross examination in the same bronchus, an oval yellowish area with a diameter of 3 mm was found along the bronchial wall. According to gross and histomorphological characteristics and immunophenotype of tumour cells, the diagnosis of tumour carcinoid was set. Diagnosis of carcinoids of the tumorlet type is usually an accidental finding and it can be seen on CT in the form of subcentimeter, single or multiple, nodular changes. Considering that the clinical picture is nonspecific, they should always be kept in mind as a possible differential diagnosis.

RESUMEN: Los tumores neuroendocrinos de pulmón son un grupo de tumores de diferentes características morfológicas, inmunohistoquímicas y moleculares similares, y representan el 1- 2 % de todos los tumores malignos de pulmón. Los carcinoides tumorales representan la proliferación nodular de células neuroendocrinas hiperplásicas de tamaño inferior a 5 mm. En este estudio reportamos el hallazgo inusual de tumor carcinoide y hamartoma endobronquial en el mismo bronquio. Un paciente varón de 49 años con síntomas de tos severa prolongada y fiebre fue tratado por neumonía. Al no responder adecuadamente a la terapia con antibióticos, se realizó una tomografía computarizada de pulmón que mostró obstrucción del bronquio del lóbulo medio. La broncoscopia reveló una tumoración blanquecina lobulada de la cual se tomó biopsia y el diagnóstico histopatológico fue hamartoma. No fue posible extirpar el tumor por completo durante la broncoscopia y se decidió extirparlo quirúrgicamente. En la sección seriada, durante el examen macroscópico en el mismo bronquio, se encontró un área amarillenta ovalada de 3 mm de diámetro a lo largo de la pared bronquial. De acuerdo a las características macroscópicas e histomorfológicas y de inmunofenotipo de las células tumorales, se estableció el diagnóstico de tumor carcinoide. El diagnóstico de carcinoides de tipo tumorlet suele ser un hallazgo accidental y se observan en la TC en forma de cambios nodulares subcentimétricos, únicos o múltiples. En consideración de que el cuadro clínico es inespecífico, siempre debe tenerse en cuenta como posible diagnóstico diferencial.

Molecular genetic analysis of primary renal epithelial tumours with granular oncocytic cytoplasms / Análisis genético molecular de tumores epiteliales renales primarios con citoplasma oncocítico granular

SUMMARY: The group of primary renal tumours with granular-oncocytic cytoplasm is a very heterogeneous group, in its histological origin and biological behavior resulting in many diagnostic problems. In this study 57 renal epithelial tumours with granular oncocytic cells were analyzed using fluorescence in situ hybridisation (FISH), array comparative genomic hybridisation (aCGH) and polymerase chain reaction (PCR). The results of analysis in renal oncocytoma (RO) did not indicate the presence of the gene mutations or chromosomal abnormalities. Sporadic renal hybrid oncocytic/chromophobe tumours (HOCT) had multiple numerical aberrations of chromosomes 1, 2, 6, 9, 10, 13, 17, 20, 21 and 22. This type of tumour had no mutations in the VHL, c-kit, PDGFRA, and FLCN genes. Oncocytic papillary renal cell carcinoma (O-PRCC) had numerical abnormalities of chromosomes 7 and 17 and the loss of the Y chromosome. Cytogenetic analysis of 20 pigmented microcystic chromophobe renal cell carcinomas (PMChRCC) showed monosomy as the most frequent aberration in all analyzed chromosomes 1, 2, 5, 10, 13, 17 and 21. One case of chromophobe renal cell carcinoma (ChRCC) with hyaline globules had a mutation in the distal part of exon 3 of the VHL gene. Absence of genetic disorders in usual RO is common result, but we have established absence of genetic disorders even in rare variants. Variety of genetic alterations detected in sporadic renal HOCT proves it to be a separate entity, not a variant of ChRCC, while PMChRCC is an uncommon variant of ChRCC. O-PRCC is a subtype of papillary renal cell carcinoma.

RESUMEN: El grupo de tumores renales primarios con citoplasma granular-oncocítico es un grupo muy heterogéneo, en su origen histológico y comportamiento biológico, resultando en problemas de diagnóstico. En el estudio se analizaron 57 tumores epiteliales renales con citoplasma oncocítico granular mediante hibridación fluorescente in situ (FISH), hibridación genómica comparativa de matriz (aCGH) y reacción en cadena de la polimerasa (PCR). Los resultados del análisis en oncocitoma renal (RO) no indicaron la presencia de mutaciones genéticas ni anomalías cromosómicas. Los tumores oncocíticos / cromófobos híbridos renales esporádicos (HOCT) tenían múltiples aberraciones numéricas de los cromosomas 1, 2, 6, 9, 10, 13, 17, 20, 21 y 22. No se observaron mutaciones en este tipo de tumor en el VHL, c-kit, PDGFRA y genes FLCN. El carcinoma de células renales papilar oncocítico (O-PRCC) tenía anomalías numéricas de los cromosomas 7 y 17 y la pérdida del cromosoma Y. El análisis citogenético de 20 carcinomas de células renales cromófobos microquísticos pigmentados (PMChRCC) mostró que la monosomía era la aberración más frecuente en todos los cromosomas analizados 1, 2, 5, 10, 13, 17 y 21. Un caso de carcinoma de células renales cromófobo (CCRc) hialino tenía una mutación en la parte distal del exón 3 del gen VHL. La ausencia de trastornos genéticos en la OI habitual es un resultado común, pero hemos establecido la ausencia de trastornos genéticos incluso en variantes raras. Varias alteraciones genéticas detectadas en esporádica HOCT renal demuestran que es una entidad separada, no una variante de ChRCC, mientras que PMChRCC es una variante poco común de ChRCC. O-PRCC es un subtipo de carcinoma papilar de células renales.

Sulfatase 2 Is Associated with Steroid Resistance in Childhood Nephrotic Syndrome.

Glucocorticoid (GC) resistance complicates the treatment of ~10-20% of children with nephrotic syndrome (NS), yet the molecular basis for resistance remains unclear. We used RNAseq analysis and in silico algorithm-based approaches on peripheral blood leukocytes from 12 children both at initial NS presentation and after ~7 weeks of GC therapy to identify a 12-gene panel able to differentiate steroid resistant NS (SRNS) from steroid-sensitive NS (SSNS). Among this panel, subsequent validation and analyses of one biologically relevant candidate, sulfatase 2 (SULF2), in up to a total of 66 children, revealed that both SULF2 leukocyte expression and plasma arylsulfatase activity Post/Pre therapy ratios were greater in SSNS vs. SRNS. However, neither plasma SULF2 endosulfatase activity (measured by VEGF binding activity) nor plasma VEGF levels, distinguished SSNS from SRNS, despite VEGF's reported role as a downstream mediator of SULF2's effects in glomeruli. Experimental studies of NS-related injury in both rat glomeruli and cultured podocytes also revealed decreased SULF2 expression, which were partially reversible by GC treatment of podocytes. These findings together suggest that SULF2 levels and activity are associated with GC resistance in NS, and that SULF2 may play a protective role in NS via the modulation of downstream mediators distinct from VEGF.

Using histological staining techniques to improve visualization and interpretability of tooth cementum annulation analysis / Uso de técnicas de tinción histológica para mejorar la visualización y la interpretación del análisis de la anulación del cemento dental

SUMMARY: The aim of the present study was to evaluate the effect of different staining techniques on applicability and accuracy of tooth cementum annulation (TCA) method. Nine decalcination techniques, 8 dehydration protocols and 8 different techniques were applied in 3 teeth from the persons of a known age. Black and white, and color images of histological sections were captured. An x- ray was taken of each tooth and they were photographed. Researchers were asked to observe both black/white and color images of histological sections. Researchers were divided into two groups. The first group analyzed histological images only, and the second group had photos of teeth and X-rays. In the first group of observers (without X ray) the differences in age estimation between real and observed age were significant for 2 younger patients, but not for the oldest patient, where the observed and real values matched. Of the 6 raters, the assesments of the last 3 (that used x-ray images together with histological sections) did not differ significantly from the real values. Extensive analysis and multiple repetitions performed in the present investigation revealed that the most optimal method of decalcification for TCA method was EDTA II for a period longer than 14 days at a section thickness of 2-3mm, while the most optimal protocol for dehydration was number IV. When it comes to staining, the most optimal staining protocol used for the cemental lines visualization and counting was Crocein Scarlet/Acid Fuchsin staining and Toluidine blue staining used at semithin section. Additional use of preexperimental evaluation employing x-ray of analyzed teeth decreased the errors of age estimation.

RESUMEN: El objetivo del presente estudio fue evaluar el efecto de diferentes técnicas de tinción sobre la aplicación y precisión del método de anulación de cemento dental (TCA). Se usaron nueve técnicas de descalcinación, 8 protocolos de deshidratación y 8 técnicas diferentes en 3 dientes de personas de edad conocida. Se capturaron imágenes en blanco y negro y en color de cortes histológicos. Se tomó una radiografía de cada diente y se fotografiaron. Los investigadores observaron las imágenes en blanco y negro y en color de las secciones histológicas. Los investigadores se dividieron en dos grupos; el primer grupo analizó solo imágenes histológicas y el segundo grupo tenía fotografías de los dientes y las radiografías. En el primer grupo de observadores (sin rayos X) las diferencias en la estimación de la edad entre la edad real y la edad observada fueron significativas para 2 pacientes más jóvenes, pero no para el paciente de mayor edad, donde los valores observados y reales coincidieron. De los 6 evaluadores, las valoraciones de los 3 últimos (que utilizaron imágenes de rayos X junto con cortes histológicos) no difirieron significativamente de los valores reales. El análisis exhaustivo y las múltiples repeticiones realizadas en la presente investigación revelaron que el método de descalcificación más óptimo para el método TCA fue EDTA II durante un período superior a 14 días con un grosor de sección de 2-3 mm, mientras que el protocolo óptimo para la deshidratación fue el número IV. En lo que respecta a la tinción, el protocolo de tinción más óptimo utilizado para la visualización y el recuento de las líneas de cemento fue la tinción con croceína escarlata / fucsina ácida y la tinción con azul de toluidina utilizada en la sección semifina. El uso adicional de la evaluación pre-experimental que emplea los rayos X de los dientes analizados disminuyó los errores de estimación de la edad.

Exploring the relationships between amphibian (Xenopus laevis) myeloid cell subsets.

The differentiation of distinct leukocyte subsets is governed by lineage-specific growth factors that elicit disparate expression of transcription factors and markers by the developing cell populations. For example, macrophages (Mφs) and granulocytes (Grns) arise from common granulocyte-macrophage progenitors in response to distinct myeloid growth factors. In turn, myelopoiesis of the Xenopus laevis anuran amphibian appears to be unique to other studied vertebrates in several respects while the functional differentiation of amphibian Mφs and Grns from their progenitor cells remains poorly understood. Notably, the expression of colony stimulating factor-1 receptor (CSF-1R) or CSF-3R on granulocyte-macrophage progenitors marks their commitment to Mφ- or Grn-lineages, respectively. CSF-1R is activated by the colony stimulating factor-1 (CSF-1) and interleukin (IL-34) cytokines, resulting in morphologically and functionally distinct Mφ cell types. Conversely, CSF-3R is ligated by CSF-3 in a process indispensable for granulopoiesis. Presently, we explore the relationships between X. laevis CSF-1-Mφs, IL-34-Mφs and CSF-3-Grns by examining their expression of key lineage-specific transcription factor and myeloid marker genes as well as their enzymology. Our findings suggest that while the CSF-1- and IL-34-Mφs share some commonalities, the IL-34-Mφs possess transcriptional patterns more akin to the CSF-3-Grns. IL-34-Mφs also possess robust expression of dendritic cell-associated transcription factors and surface marker genes, further underlining the difference between this cell type and the CSF-1-derived frog Mφ subset. Moreover, the three myeloid populations differ in their respective tartrate-resistant acid phosphatase, specific- and non-specific esterase activity. Together, this work grants new insights into the developmental relatedness of these three frog myeloid subsets.

Colony-stimulating factor-1- and interleukin-34-derived macrophages differ in their susceptibility to Mycobacterium marinum.

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), remains the leading global cause of death from an infectious agent. Mycobacteria thrive within their host Mϕs and presently, there is no animal model that permits combined in vitro and in vivo study of mycobacteria-host Mϕ interactions. Mycobacterium marinum (Mm), which causes TB in aquatic vertebrates, has become a promising model for TB research, owing to its close genetic relatedness to Mtb and the availability of alternative, natural host aquatic animal models. Here, we adopted the Xenopus laevis frog-Mm surrogate infection model to study host Mϕ susceptibility and resistance to mycobacteria. Mϕ differentiation is regulated though the CSF-1 receptor (CSF-1R), which is activated by CSF-1 and the unrelated IL-34 cytokines. Using combined in vitro and in vivo approaches, we demonstrated that CSF-1-Mϕs exacerbate Mm infections, are more susceptible to mycobacterial entry and are less effective at killing this pathogen. By contrast, IL-34-Mϕs confer anti-Mm resistance in vivo, are less susceptible to Mm entry and more effectively eliminate internalized mycobacteria. Moreover, we showed that the human CSF-1- and IL-34-Mϕs are likewise, respectively, susceptible and resistant to mycobacteria, and that both frog and human CSF-1-Mϕs are more prone to the spread of mycobacteria and to being infected by Mm-laden Mϕs than the respective IL-34-Mϕ subsets. This work marks the first report describing the roles of these Mϕ subsets in mycobacterial disease and may well lead to the development of more targeted anti-Mtb approaches.

Programming of Distinct Chemokine-Dependent and -Independent Search Strategies for Th1 and Th2 Cells Optimizes Function at Inflamed Sites.

T-helper (Th) cell differentiation drives specialized gene programs that dictate effector T cell function at sites of infection. Here, we have shown Th cell differentiation also imposes discrete motility gene programs that shape Th1 and Th2 cell navigation of the inflamed dermis. Th1 cells scanned a smaller tissue area in a G protein-coupled receptor (GPCR) and chemokine-dependent fashion, while Th2 cells scanned a larger tissue area independent of GPCR signals. Differential chemokine reliance for interstitial migration was linked to STAT6 transcription-factor-dependent programming of integrin αVß3 expression: Th2 cell differentiation led to high αVß3 expression relative to Th1 cells. Th1 and Th2 cell modes of motility could be switched simply by manipulating the amount of αVß3 on the cell surface. Deviating motility modes from those established during differentiation impaired effector function. Thus, programmed expression of αVß3 tunes effector T cell reliance on environmental cues for optimal exploration of inflamed tissues.

Amylopectin Chain Length Dynamics and Activity Signatures of Key Carbon Metabolic Enzymes Highlight Early Maturation as Culprit for Yield Reduction of Barley Endosperm Starch after Heat Stress.

Abiotic environmental stresses have a negative impact on the yield and quality of crops. Understanding these stresses is an essential enabler for mitigating breeding strategies and it becomes more important as the frequency of extreme weather conditions increases due to climate change. This study analyses the response of barley (Hordeum vulgare L.) to a heat wave during grain filling in three distinct stages: the heat wave itself, the return to a normal temperature regime, and the process of maturation and desiccation. The properties and structure of the starch produced were followed throughout the maturational stages. Furthermore, the key enzymes involved in the carbohydrate supply to the grain were monitored. We observed differences in starch structure with well-separated effects because of heat stress and during senescence. Heat stress produced marked effects on sucrolytic enzymes in source and sink tissues. Early cessation of plant development as an indirect consequence of the heat wave was identified as the major contributor to final yield loss from the stress, highlighting the importance for functional stay-green traits for the development of heat-resistant cereals.

Amphibian (Xenopus laevis) Interleukin-8 (CXCL8): A Perspective on the Evolutionary Divergence of Granulocyte Chemotaxis.

The glutamic acid-leucine-arginine (ELR) motif is a hallmark feature shared by mammalian inflammatory CXC chemokines such the granulocyte chemo-attractant CXCL8 (interleukin-8, IL-8). By contrast, most teleost fish inflammatory chemokines lack this motif. Interestingly, the amphibian Xenopus laevis encodes multiple isoforms of CXCL8, one of which (CXCL8a) possesses an ELR motif, while another (CXCL8b) does not. These CXCL8 isoforms exhibit distinct expression patterns during frog development and following immune challenge of animals and primary myeloid cultures. To define potential functional differences between these X. laevis CXCL8 chemokines, we produced them in recombinant form (rCXCL8a and rCXCL8b) and performed dose-response chemotaxis assays. Our results indicate that compared to rCXCL8b, rCXCL8a is a significantly more potent chemo-attractant of in vivo-derived tadpole granulocytes and of in vitro-differentiated frog bone marrow granulocytes. The mammalian CXCL8 mediates its effects through two distinct chemokine receptors, CXCR1 and CXCR2 and our pharmacological inhibition of these receptors in frog granulocytes indicates that the X. laevis CXCL8a and CXCL8b both chemoattract tadpole and adult frog granulocytes by engaging CXCR1 and CXCR2. To delineate which frog cells are recruited by CXCL8a and CXCL8b in vivo, we injected tadpoles and adult frogs intraperitoneally with rCXCL8a or rCXCL8b and recovered the accumulated cells by lavage. Our transcriptional and cytological analyses of these tadpole and adult frog peritoneal exudates indicate that they are comprised predominantly of granulocytes. Interestingly, the granulocytes recruited into the tadpole, but not adult frog peritonea by rCXCL8b, express significantly greater levels of several pan immunosuppressive genes.

Changes of the peripheral blood mononuclear cells membrane fluidity from type 1 Gaucher disease patients: an electron paramagnetic resonance study.

Gaucher disease (GD) is a lysosomal storage disorder, caused by an impaired function of ß-glucocerebrosidase, which results in accumulation of glucocerebroside in cells, and altered membrane ordering. Using electron paramagnetic resonance spin labeling, a statistically significant difference in the order parameter between the peripheral blood mononuclear cell membranes of GD patients and healthy controls was observed. Moreover, the results show that the introduction of the enzyme replacement therapy leads to the restoration of the physiological membrane fluidity. Accordingly, this simple method could serve as a preliminary test for GD diagnosis and therapy efficiency.

Differentiation-dependent antiviral capacities of amphibian (Xenopus laevis) macrophages.

Infections by ranaviruses such as Frog virus 3 (Fv3), are significantly contributing to worldwide amphibian population declines. Notably, amphibian macrophages (Mφs) are important to both the Fv3 infection strategies and the immune defense against this pathogen. However, the mechanisms underlying amphibian Mφ Fv3 susceptibility and resistance remain unknown. Mφ differentiation is mediated by signaling through the colony-stimulating factor-1 receptor (CSF-1R) which is now known to be bound not only by CSF-1, but also by the unrelated interleukin-34 (IL-34) cytokine. Pertinently, amphibian (Xenopus laevis) Mφs differentiated by CSF-1 and IL-34 are highly susceptible and resistant to Fv3, respectively. Accordingly, in the present work, we elucidate the facets of this Mφ Fv3 susceptibility and resistance. Because cellular resistance to viral replication is marked by expression of antiviral restriction factors, it was intuitive to find that IL-34-Mφs possess significantly greater mRNA levels of select restriction factor genes than CSF-1-Mφs. Xenopodinae amphibians have highly expanded repertoires of antiviral interferon (IFN) cytokine gene families, and our results indicated that in comparison with the X. laevis CSF-1-Mφs, the IL-34-Mφs express substantially greater transcripts of representative IFN genes, belonging to distinct gene family clades, as well as their cognate receptor genes. Finally, we demonstrate that IL-34-Mφ-conditioned supernatants confer IFN-mediated anti-Fv3 protection to the virally susceptible X. laevis kidney (A6) cell line. Together, this work underlines the differentiation pathways leading to Fv3-susceptible and -resistant amphibian Mφ populations and defines the molecular mechanisms responsible for these differences.

CXCL16 in Vascular Pathology Research: from Macro Effects to microRNAs.

Chemokines and their receptors have become significant factors in atherosclerosis research. CXCL16 is a multifunctional agent located on a separate locus to all other known chemokines and binds only to its "unique" receptor named CXCR6. As a scavenger receptor, adhesion molecule, and chemokine, it quickly became an interesting target in atherosclerosis research as all its functions have a role in vascular pathology. The investigation of the role of CXCL16 in atherosclerosis, although shown in in vitro studies, animal knockout models, and CXCL16 gene polymorphisms, haplotypes, and circulating levels, still shows puzzling results. Genetic and epigenetic studies have just scratched the surface of research necessary for a better assessment of the significance and perspective of this marker in plaque development and progression. In this review, we will summarize current knowledge about CXCL16 in atherosclerosis. Additionally, we will point out the importance of bioinformatics tools for the detection of potentially new CXCL16 regulatory networks through microRNA activity. This review aims to provide a better understanding of the underlying mechanisms, define more specific biomarkers, and discover new therapeutic targets.

Kinetic and stoichiometric characterization of organoautotrophic growth of Ralstonia eutropha on formic acid in fed-batch and continuous cultures.

Formic acid, acting as both carbon and energy source, is a safe alternative to a carbon dioxide, hydrogen and dioxygen mix for studying the conversion of carbon through the Calvin-Benson-Bassham (CBB) cycle into value-added chemical compounds by non-photosynthetic microorganisms. In this work, organoautotrophic growth of Ralstonia eutropha on formic acid was studied using an approach combining stoichiometric modeling and controlled cultures in bioreactors. A strain deleted of its polyhydroxyalkanoate production pathway was used in order to carry out a physiological characterization. The maximal growth yield was determined at 0.16 Cmole Cmole(-1) in a formate-limited continuous culture. The measured yield corresponded to 76% to 85% of the theoretical yield (later confirmed in pH-controlled fed-batch cultures). The stoichiometric study highlighted the imbalance between carbon and energy provided by formic acid and explained the low growth yields measured. Fed-batch cultures were also used to determine the maximum specific growth rate (µmax = 0.18 h(-1) ) and to study the impact of increasing formic acid concentrations on growth yields. High formic acid sensitivity was found in R eutropha since a linear decrease in the biomass yield with increasing residual formic acid concentrations was observed between 0 and 1.5 g l(-1) .

Regulation of T cell motility in vitro and in vivo by LPA and LPA2.

Lysophosphatidic acid (LPA) and the LPA-generating enzyme autotaxin (ATX) have been implicated in lymphocyte trafficking and the regulation of lymphocyte entry into lymph nodes. High local concentrations of LPA are thought to be present in lymph node high endothelial venules, suggesting a direct influence of LPA on cell migration. However, little is known about the mechanism of action of LPA, and more work is needed to define the expression and function of the six known G protein-coupled receptors (LPA 1-6) in T cells. We studied the effects of 18∶1 and 16∶0 LPA on naïve CD4+ T cell migration and show that LPA induces CD4+ T cell chemorepulsion in a Transwell system, and also improves the quality of non-directed migration on ICAM-1 and CCL21 coated plates. Using intravital two-photon microscopy, lpa2-/- CD4+ T cells display a striking defect in early migratory behavior at HEVs and in lymph nodes. However, later homeostatic recirculation and LPA-directed migration in vitro were unaffected by loss of lpa2. Taken together, these data highlight a previously unsuspected and non-redundant role for LPA2 in intranodal T cell motility, and suggest that specific functions of LPA may be manipulated by targeting T cell LPA receptors.

Does oestradiol attenuate the damaging effects of a fructose-rich diet on cardiac Akt/endothelial nitric oxide synthase signalling?

Fructose-rich diets (FRD) cause cardiac insulin resistance manifested by impairment of Akt/endothelial NO synthase (eNOS) signalling. In contrast, oestradiol (E2) activates this signalling pathway in the heart. To study the ability of E2 to revert the detrimental effect of fructose on cardiac Akt/eNOS, female rats were subjected to a FRD and ovariectomy followed with or without E2 replacement. We also analysed the effects of the FRD and E2 on cardiac extracellular signal-regulated kinase (Erk 1/2) signalling related to their role in cardiac hypertrophy development. Expression of Akt, eNOS and Erk 1/2, as well as regulatory phosphorylations of these molecules were determined. The protein expression of cardiac Akt and eNOS was not affected by the diet or E2 treatment. However, the FRD was accompanied by a decrease in Akt phosphorylation at Ser(473) and Thr(308), and eNOS at Ser(1177), while the phosphorylation of eNOS at Thr(495) was increased. E2 replacement in ovariectomised fructose-fed rats caused a reversion of the diet effect on Akt and eNOS serine phosphorylation, but mostly had no effect on threonine phosphorylation of the molecules. The FRD and E2 treatment did not influence Erk 1/2 expression and phosphorylation and heart mass as well. The data show that E2 selectively suppress the negative effects of a FRD on Akt/eNOS signalling and probably point to the different effects of E2 on kinase/phosphatase pathways responsible for phosphorylation/dephosphorylation of Akt and eNOS. Furthermore, the results suggest that the heart of females in the reproductive period is partially protected against the damaging effects of increasedfructose intake.

Thrombin and vascular inflammation.

Vascular endothelium is a key regulator of homeostasis. In physiological conditions it mediates vascular dilatation, prevents platelet adhesion, and inhibits thrombin generation. However, endothelial dysfunction caused by physical injury of the vascular wall, for example during balloon angioplasty, acute or chronic inflammation, such as in atherothrombosis, creates a proinflammatory environment which supports leukocyte transmigration toward inflammatory sites. At the same time, the dysfunction promotes thrombin generation, fibrin deposition, and coagulation. The serine protease thrombin plays a pivotal role in the coagulation cascade. However, thrombin is not only the key effector of coagulation cascade; it also plays a significant role in inflammatory diseases. It shows an array of effects on endothelial cells, vascular smooth muscle cells, monocytes, and platelets, all of which participate in the vascular pathophysiology such as atherothrombosis. Therefore, thrombin can be considered as an important modulatory molecule of vascular homeostasis. This review summarizes the existing evidence on the role of thrombin in vascular inflammation.