Immunohistochemical evidences showing the presence of thymulin containing cells located in involuted thymus and in peripheral lymphoid organs

Thymulin is a well-characterized thymic hormone that exists as a nonapeptide coupled to equimolar amounts of Zn2+. Thymulin is known to have multiple biological roles, including T cell differentiation, immune regulation, and analgesic functions. It has been shown that thymulin is produced by the reticulo-epithelial cells of the thymus, and it circulates in the blood from the moment of birth, maintain its serum level until puberty diminishing thereafter in life. To study the localization of this hormone, we prepared polyclonal and monoclonal antibodies against the commercial peptide and utilized immunocytochemical techniques for visualization. The results indicate that thymulin stains the thymic reticular cells, the outer layers of Hassall's corpuscles and a large round cellular type, which is keratin-negative and does not show affinity for the common leukocyte antigen (CD-45). In mice, this thymulin-positive cell remains in the thymus throughout life and even appears in relatively increased numbers in old involuted thymi. It also appears in thymus-dependent areas of the spleen and lymph nodes, demonstrating that at least one of the thymus cells containing this peptide can be found in peripheral lymphoid tissue.     

Synthesis and biological evaluation of novel (4 or 5-aryl)pyrazolyl-indoles as inhibitors of interleukin-2 inducible T-cell kinase (ITK)

Interleukin-2 inducible T-cell kinase (ITK) is one of five kinases that belong to the Tec kinase family that plays an important role in T-cell and mast cell signaling. Various reports point to a role of ITK in the treatment of allergic asthma. For example, it was shown that mice lacking ITK have reduced airway hyperresponsiveness, inflammation and tracheal responses in an allergic asthma model. In this article, we disclose novel ITK inhibitors based on (4 or 5-aryl)pyrazolyl-indole scaffold that were also found to be selective for ITK over other kinases like IRK, CDK2, GSK3ß and PKA.     

The hydroclimatic and ecophysiological basis of cloud forest distributions under current and projected climates

Background

Tropical montane cloud forests (TMCFs) are characterized by a unique set of biological and hydroclimatic features, including frequent and/or persistent fog, cool temperatures, and high biodiversity and endemism. These forests are one of the most vulnerable ecosystems to climate change given their small geographic range, high endemism and dependence on a rare microclimatic envelope. The frequency of atmospheric water deficits for some TMCFs is likely to increase in the future, but the consequences for the integrity and distribution of these ecosystems are uncertain. In order to investigate plant and ecosystem responses to climate change, we need to know how TMCF species function in response to current climate, which factors shape function and ecology most and how these will change into the future.

Scope

This review focuses on recent advances in ecophysiological research of TMCF plants to establish a link between TMCF hydrometeorological conditions and vegetation distribution, functioning and survival. The hydraulic characteristics of TMCF trees are discussed, together with the prevalence and ecological consequences of foliar uptake of fog water (FWU) in TMCFs, a key process that allows efficient acquisition of water during cloud immersion periods, minimizing water deficits and favouring survival of species prone to drought-induced hydraulic failure.

Conclusions

Fog occurrence is the single most important microclimatic feature affecting the distribution and function of TMCF plants. Plants in TMCFs are very vulnerable to drought (possessing a small hydraulic safety margin), and the presence of fog and FWU minimizes the occurrence of tree water deficits and thus favours the survival of TMCF trees where such deficits may occur. Characterizing the interplay between microclimatic dynamics and plant water relations is key to foster more realistic projections about climate change effects on TMCF functioning and distribution.     

Inherent trait differences explain wheat cultivar responses to climate factor interactions: New insights for more robust crop modelling

Climate change predictions foresee a combination of rising CO₂, temperature and altered precipitation. Effects of single climatic variables are well defined, but the importance of combined variables and genotypic effects is less known, although pivotal for assessing climate change impacts, for example, with crop growth models. This study provides developmental and physiological data from combined climatic factors for two distinct wheat cultivars (Paragon and Gladius), as a basis to improve predictions for climate change scenarios. The two cultivars were grown in controlled climate chambers in a fully factorial setup of atmospheric CO₂ concentration, growth temperature and watering regime. The cultivars differed considerably in their developmental rate, response pattern and the parameters responsible for most of their variation. The growth of Paragon was linked to climatic effects on photosynthesis and mainly affected by temperature. Paragon was overall more negatively affected by all treatment combinations compared to Gladius. Gladius was mostly affected by watering regime. The cultivars' acclimation strategies to climate factors varied significantly. Thus, considering a single factor is an oversimplification very likely impacting the accuracy of crop growth models. Intraspecific crop variation could help understanding genotype by environment variation. Cultivars with high phenotypic plasticity may have greater resilience against climatic variability.     

Casein-Derived Peptides with Antihypertensive Potential: Production,Identification and Assessment of Complex Formation with Angiotensin I-Converting Enzyme (ACE) through Molecular Docking Studies

Hypertension is nowadays one of the major world concerns in public health. Several food proteins, among which caseins, can be substrates for generating peptides with antihypertensive potential. With the increasingly evolution of computational tools, in silico molecular modeling have gained prominence in studies of protein-ligand complexes in different research fields, such as pharmaceutics and biochemical engineering. However, the application of such methodologies in food-related research can be considered still embryonic. Thus, the central aim of the present work was to apply molecular modelling in order to elucidate the molecular bases of the anti-hypertensive potential of milk caseins-derived peptides. Firstly, hydrolysates obtained from a controlled trypsinolysis of caseins were fractioned according to their molecular weight, by ultrafiltration and RP-HPLC. The obtained fractions were evaluated with regard to their in vitro inhibitory angiotensin-converting enzyme activity (%I_ACE). Six chromatographic fractions were identified, and three of them displayed high ACE-inhibition (F₁: 80.68%; F₂: 79.00%; and F₄: 62.44%). Finally, intermolecular interactions networks in complexes formed between ACE and the identified peptides were assessed through in silico molecular docking. At the molecular level, a correlation between in vitro and in silico results was found: the peptides FFVAPFPEVFGK (F₆), FALPQYLK (F₂, F₄) and ALNEINQFYQK (F₁) presented the lowest biding energies and interacted by specific H-bonds, electrostatic and hydrophobic interactions formed within ACE active site S1 residues (Ala354, Glu384, and Tyr 523) and the Zn²⁺ coordinated residues (His383, His387, and Glu411). The fraction F₃, despite its low total peptide concentration, presented a moderate inhibitory activity for ACE (49.2%), likely due to H-bonds between HQGLPQEVLNENLLR and the active site S1 residues.

     

The correlation between crassulacean acid metabolism and water uptake in Senecio medley-woodii

The combination of a chamber for CO₂ gas exchange with a potometric measuring arrangement allowed concomitant investigations into CO₂ gas exchange, transpiration and water uptake by the roots of whole plants of Senecio medley-woodii, a species which exhibits Crassulacean acid metabolism. The water-uptake rate showed the same daily pattern as malate concentration and osmotic potential. The accumulation of organic acids resulting from nocturnal CO₂ fixation enhanced the water-uptake rate from dusk to dawn. During the day the water-uptake rates decreased with decreasing organic-acid concentration. With gradually increasing water stress, CO₂ dark fixation of S. medley-woodii was increased as long as water could be taken up by the roots. It was also shown that a reestablished water supply after drought caused a similar increase which in both cases ameliorated the water uptake in order to conserve a positive water balance for as long as possible. This water-uptake pattern shows that Crassulacean acid metabolism is not only a water-saving adaptation but also enhances water uptake and is directly correlated with the amelioration of the plant water status.Abbreviation CAM Crassulacean acid metabolism     

Continuous cultivation of human hamstring tenocytes on microcarriers in a spinner flask bioreactor system

Tendon healing is a time consuming process leading to the formation of a functionally altered reparative tissue. Tissue engineering‐based tendon reconstruction is attracting more and more interest. The aim of this study was to establish tenocyte expansion on microcarriers in continuous bioreactor cultures and to study tenocyte behavior during this new approach. Human hamstring tendon‐derived tenocytes were expanded in monolayer culture before being seeded at two different seeding densities (2.00 and 4.00 × 10⁶ cells/1000 cm² surface) on Cytodex? type 3 microcarriers. Tenocytes' vitality, growth kinetics and glucose/lactic acid metabolism were determined dependent on the seeding densities and stirring velocities (20 or 40 rpm) in a spinner flask bioreactor over a period of 2 weeks. Gene expression profiles of tendon extracellular matrix (ECM) markers (type I/III collagen, decorin, cartilage oligomeric protein [COMP], aggrecan) and the tendon marker scleraxis were analyzed using real time detection polymerase chain reaction (RTD‐PCR). Type I collagen and decorin deposition was demonstrated applying immunolabeling. Tenocytes adhered on the carriers, remained vital, proliferated and revealed an increasing glucose consumption and lactic acid formation under all culture conditions. “Bead‐to‐bead” transfer of cells from one microcarrier to another, a prerequisite for continuous tenocyte expansion, was demonstrated by scanning electron microscopy. Type I and type III collagen gene expression was mainly unaffected, whereas aggrecan and partly also decorin and COMP expression was significantly downregulated compared to monolayer cultures. Scleraxis gene expression revealed no significant regulation on the carriers. In conclusion, tenocytes could be successfully expanded on microcarriers. Therefore, bioreactors are promising tools for continuous tenocyte expansion. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 30:142–151, 2014     

Anaphylatoxin receptors and complement regulatory proteins in human articular and non-articular chondrocytes: interrelation with cytokines

Tissue trauma induces an inflammatory response associated with a cytokine release that may engage complement pathways. Cytokine-mediated complement expression may contribute to cartilage degradation. Hence, we analysed the complement expression profile in primary articular and non-articular chondrocytes and its interrelation with cytokines. The expression of the anaphylatoxin receptors (C3aR and C5aR) and the complement regulatory proteins (CPRs) CD35, CD46, CD55 and CD59 was studied in cultured articular, auricular and nasoseptal chondrocytes using RTD-PCR and immunofluorescence labelling. The complement profile of peripheral blood mononuclear cells (PBMCs) was opposed to the expression in articular chondrocytes. The time-dependent regulation (6 and 24?h) of these complement factors was assessed in articular chondrocytes in response to the cytokines TNF??, IL-10 or TNF?? combined with IL-10 (each 10?ng/mL). C3aR, C5aR, CD46, CD55 and CD59 but almost no CD35 mRNA was expressed in any of chondrocyte types studied. The anaphylatoxin receptor expression was lower and that of the CRPs was higher in chondrocytes when compared with PBMCs. The majority of the studied complement factors were expressed at a significantly lower level in non-articular chondrocytes compared with the articular chondrocytes. TNF?? significantly increased the C3aR expression in chondrocytes after 6 and 24?h. TNF?? + IL-10 significantly downregulated C5aR and IL-10 significantly inhibited the CD46 and CD55 gene expression after 24?h. C5aR and CD55 could be localised in cartilage in situ. Anaphylatoxin receptors and CRPs are regulated differentially by TNF?? and IL-10. Whether cytokine-induced complement activation occurs in response to cartilage trauma has to be further identified.