On the existence and function of galanin receptor heteromers in the central nervous system

Galanin receptor (GalR) subtypes 1-3 linked to central galanin neurons may form heteromers with each other and other types of G protein-coupled receptors in the central nervous system (CNS). These heteromers may be one molecular mechanism for galanin peptides and their N-terminal fragments (gal 1-15) to modulate the function of different types of glia-neuronal networks in the CNS, especially the emotional and the cardiovascular networks. GalR-5-HT1A heteromers likely exist with antagonistic GalR-5-HT1A receptor-receptor interactions in the ascending midbrain raphe 5-HT neuron systems and their target regions. They represent a novel target for antidepressant drugs. Evidence is given for the existence of GalR1-5-HT1A heteromers in cellular models with trans-inhibition of the protomer signaling. A GalR1-GalR2 heteromer is proposed to be a galanin N-terminal fragment preferring receptor (1-15) in the CNS. Furthermore, a GalR1-GalR2-5-HT1A heterotrimer is postulated to explain why only galanin (1-15) but not galanin (1-29) can antagonistically modulate the 5-HT1A receptors in the dorsal hippocampus rich in gal fragment binding sites. The results underline a putative role of different types of GalR-5-HT1A heteroreceptor complexes in depression. GalR antagonists may also have therapeutic actions in depression by blocking the antagonistic GalR-NPYY1 receptor interactions in putative GalR-NPYY1 receptor heteromers in the CNS resulting in increases in NPYY1 transmission and antidepressant effects. In contrast the galanin fragment receptor (a postulated GalR1-GalR2 heteromer) appears to be linked to the NPYY2 receptor enhancing the affinity of the NPYY2 binding sites in a putative GalR1-GalR2-NPYY2 heterotrimer. Finally, putative GalR-α2-adrenoreceptor heteromers with antagonistic receptor-receptor interactions may be a widespread mechanism in the CNS for integration of galanin and noradrenaline signals also of likely relevance for depression.

Changes in the redox status of chickpea roots in response to infection by Fusarium oxysporum f. sp. ciceris: apoplastic antioxidant enzyme activities and expression of oxidative stress-related genes

Activity levels of oxidative stress-related enzymes in the root apoplast during the interaction of WR315 (resistant) and JG62 (susceptible) chickpeas (Cicer arietinum L.) with the highly virulent race 5 of Fusarium oxysporum f. sp. ciceris were compared. Because this fungus develops asymptomatic infections in the chickpea root cortex in both susceptible and resistant plants, but only intrudes into the root xylem in the susceptible variety, the interactions were compared at three specific stages during disease development in JG62: (i) before symptom development (10 days after inoculation); (ii) at the time of appearance of the first disease symptoms (15-17 days after inoculation) and (iii) when all plants had developed disease symptoms (20-22 days after inoculation). Diamine oxidase (DAO), ascorbate peroxidase (APX), glutathione reductase (GR), guaiacol-dependent peroxidase and superoxide dismutase (SOD), but not catalase (CAT), were found in the apoplast of chickpea roots. In terms of APX activity, infection by the pathogen caused a different response in the incompatible compared to the compatible plant. In the case of GR, SOD and DAO activities, the pathogen caused the same response, but it developed earlier (i.e. GR and SOD) or to higher levels (i.e. DAO) in the incompatible interaction. Expression of apx, cat, sod, lipoxygenase (lox) and actin genes was also analysed in infected roots. Infection by F. oxysporum f. sp. ciceris race 5 only caused a significant change in the root expression of lox and actin genes. This up-regulation was earlier (lox) or higher (actin) in the incompatible than in the compatible interaction. Thus, changes in oxidative metabolism differ in compatible and incompatible interactions in Fusarium wilt of chickpea.

Glial fibrillary acidic protein in brain tumors

Glial fibrillary acidic protein has been widely used in neurobiology and neuropathology as a specific marker for normal and abnormal astrocytes. Here, we report the immunostaining of 107 brain tumors and controls using an antiserum against glial fibrillary acidic protein. Selection of astroglia-derived tumors was easy and of high accuracy. Pattern of staining and usefulness of the method are described.

Systemic acquired resistance in sunflower (Helianthus annuus L.)

Systemic acquired resistance (SAR) to infection by Botrytis cinerea in the leaves of sunflower (Helianthus annuus L.) plants was induced following cotyledon inoculation with B. cinerea or treatment with abiotic inducers. Salicylic acid (SA), benzo-(1,2,3)-thiadiazole-7-carbothioic S-methyl ester (BTH), 2,6-dichloroisonicotinic acid (INA) or EDTA protected sunflower plants against Botrytis infection, that was revealed by a reduction in the number and area of the necrotic lesions in upper leaves after challenge inoculation with the pathogen. SA and BTH were more potent inducers than INA, EDTA or pre-inoculation with the fungus. In addition to resistance to B. cinerea, the upper leaves have also developed resistance to maceration by a mixture of cell wall-degrading enzymes. Calcium nitrate inhibited both the protective effect and the resistance of leaf discs to cell-wall degrading enzymes. All the tested chemicals increased the synthesis and excretion of sunflower phytoalexins--coumarins scopoletin and ayapin and induced the PR-proteins chitinase and 1,3-beta-glucanase, being the inducer effect of each activator correlated with the level of protection against B. cinerea (BTH > SA > INA > EDTA). Thus, SAR induction is mediated by general increase of plant defence responses. This is the first report on SAR in sunflower.

Kinetic properties of phenylalanine ammonia-lyase from sunflower (Helianthus annuus L.) hypocotyls

Phenylalanine ammonia-lyase (PAL) from sunflower hypocotyls has been partially purified by selective precipitation with ammonium sulfate and molecular gel filtration on Sephacryl S-300. Kinetic assays carried out with this partially purified PAL preparation revealed that the enzyme did not show a homogeneous kinetic behaviour. The observed kinetic pattern and parameters (Km and Vmax) depended on the assay conditions used and the protein concentration added to the assay mixture. PAL displayed Michaelian or negative cooperativity kinetics. Such behaviour can be explained by the existence of an association-dissociation process of PAL-protein subunits. The presence of mono-, tri- and tetrameric forms of PAL has been assessed by molecular gel filtration on Sephacryl S-200, using different elution conditions.

A real-life ImmunoCAT study: impact of molecular diagnosis through ImmunoCAPTM ISAC 112 on immunotherapy prescription in pollen-polysensitized patients in Catalonia, Spain

BACKGROUND

Molecular diagnosis in allergology helps to identify multiple allergenic molecules simultaneously. The use of purified and/or recombinant allergens increases the accuracy of individual sensitization profiles in allergic patients.

OBJECTIVE

To assess the impact of molecular diagnosis through the ImmunoCAPTM ISAC 112 microarray on etiological diagnosis and specific immunotherapy (SIT) prescription. This was compared to the use of conventional diagnoses in pediatric, adolescent, and young adult patients with rhinitis or rhinoconjunctivitis and/or allergic asthma, sensitized to three or more pollen allergens of different botanical species.

METHODS

A multicenter, prospective, observational study was conducted in patients aged 3-25 years who received care at the Allergology service of 14 hospitals in Catalonia from 2017 to 2020. Allergology diagnosis was established based on the patient's clinical assessment and the results of the skin prick test and specific immunoglobulin E assays. Subsequently, molecular diagnosis was conducted using ImmunoCAPTM ISAC® 112 to recombinant and/or purified allergen components.

RESULTS

A total of 109 patients were included; 35 (32.1%) were pediatric patients and 74 (67.9%) were adolescents or young adults (mean age: 18 years), with 58.0% being females. A change of 51.0% was observed in SIT prescription following molecular etiological diagnosis by means of a multi-parameter microarray.

CONCLUSIONS

Molecular diagnosis by means of multi-parameter tests increases the accuracy of etiological diagnosis and helps to define an accurate composition of SIT.

Sunflower (Helianthus annuus) variability in antioxidant enzyme defenses

In order to investigate the existence of genetic variability in antioxidant enzyme defenses in sunflower, twelve inbred lines, six cytoplasmic male-sterile and six restorer lines, commonly used in breeding programs have been compared with respect to (a) their levels of constitutive superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), glutathione reductase (GR, EC 1.6.4.2) and guaiacol-dependent peroxidase (GPX, EC 1.11.1.7), and (b) their isoenzyme polymorphism in SOD, CAT, and GPX activities. Constitutive levels of antioxidant enzymes in the 2nd leaf pair of 15-20-day-old sunflower plants showed significant differences between lines. The ranges of variation in enzyme activities of the different lines were equivalent to 34.3% (CAT), 38.2% (SOD), 59.5% (APX), 60.0% (GR), and 62.9% (GPX) of the respective maximal values. Isoenzyme profiles of CAT, GPX and SOD revealed the existence in sunflower of at least three, six and four isoforms of these enzymes, respectively. Further characterization of SOD isoenzymes revealed that no isoenzyme corresponded to a Mn-SOD, the faster moving isoform being a Cu/Zn-SOD and the remainder three Fe-SODs. Among the twelve inbred sunflower lines studied there were ample qualitative, and sometimes quantitative too, differences in isoenzyme dotation of CAT, GPX and Fe-SOD.