Minor salivary gland mesenchymal stromal cells derived from patients with Sjӧgren's syndrome deploy intact immune plasticity

Background aimsMesenchymal stromal cells (MSCs) provide minor salivary glands (MSGs) with support and niche cells for epithelial glandular tissue. Little is known about resident MSG-derived MSCs (MSG-MSCs) in primary Sj?gren's syndrome (PSS). The authors’ objective is to define the immunobiology of endogenous PSS MSG-MSCs.MethodsUsing culture-adapted MSG-MSCs isolated from consenting PSS subjects (n = 13), the authors performed in vitro interrogation of PSS MSG-MSC immunobiology and global gene expression compared with controls. To this end, the authors performed phenotypic and immune functional analysis of indoleamine 2,3-dioxygenase (IDO), programmed death ligand 1 (PD-L1) and intercellular adhesion marker 1 (ICAM-1) before and after interferon γ (IFNγ) licensing as well as the effect of MSG-MSCs on T-cell proliferation. Considering the female predominance of PSS, the authors also addressed the influence of 17-β-estradiol on estrogen receptor α-positive-related MSC function.ResultsThe authors found that MSG-MSCs deployed normal immune regulatory functionality after IFNγ stimulation, as demonstrated by increased protein-level expression of IDO, PD-L1 and ICAM-1. The authors also found that MSG-MSCs suppressed T-cell proliferation in a dose-dependent manner independent of 17-β-estradiol exposure. Gene ontology and pathway analysis highlighted extracellular matrix deposition as a possible difference between PSS and control MSG-MSCs. MSG-MSCs demonstrated increased α-smooth muscle actin expression in PSS, indicating a partial myofibroblast-like adaptation.ConclusionsThese findings establish similar immune regulatory function of MSG-MSCs in both PSS and control patients, precluding intrinsic MSC immune regulatory defects in PSS. PSS MSG-MSCs show a partial imprinted myofibroblast-like phenotype that may arise in the setting of chronic inflammation, providing a plausible etiology for PSS-related glandular fibrosis.     

Synthesis of 2′-C-α-Methyl-2′,3′-dideoxynucleosides

Abstract

A general method for the synthesis of 2′-C-α-methyl-2′,3′-dideoxynucleosides is presented. Stereofacial selectivity of the 2-C-methylation reaction of γ-lactone has been investigated, in which the presence of a bulky group at the 5-hydroxymethyl produced the α-isomer as a major product. During glycosylation, the α-methyl group directed the formation of nucleosides in favor of the ß-isomer. This methodology is applied to the synthesis of some new pyrimidine and purine nucleosides.

     

The molecular mechanism of vernalization in Arabidopsis and cereals: role of Flowering Locus C and its homologs

Winter varieties of plants can flower only after exposure to prolonged cold. This phenomenon is known as vernalization and has been widely studied in the model plant Arabidopsis thaliana as well as in monocots. Through the repression of floral activator genes, vernalization prevents flowering in winter. In Arabidopsis, FLOWERING LOCUS C or FLC is the key repressor during vernalization, while in monocots vernalization is regulated through VRN1, VRN2 and VRN3 (or FLOWERING LOCUS T). Interestingly, VRN genes are not homologous to FLC but FLC homologs are found to have a significant role in vernalization response in cereals. The presence of FLC homologs in monocots opens new dimensions to understand, compare and retrace the evolution of vernalization pathways between monocots and dicots. In this review, we discuss the molecular mechanism of vernalization-induced flowering along with epigenetic regulations in Arabidopsis and temperate cereals. A better understanding of cold-induced flowering will be helpful in crop breeding strategies to modify the vernalization requirement of economically important temperate cereals.     

Structural–functional insights of single and multi-domain Capsicum annuum protease inhibitors

Pin-II protease inhibitors (PIs) are the focus of research interest because of their large structural–functional diversity and relevance in plant defense. Two representative Capsicum annuum PI genes (CanPI-15 and -7) comprising one and four inhibitory repeat domains, respectively, were expressed and recombinant proteins were characterized. β-Sheet and unordered structure was found predominant in CanPI-15 while -7 also displayed the signatures of polyproline fold, as revealed by circular dichroism studies. Inhibition kinetics against bovine trypsin indicated three times higher potency of CanPI-7 (K_i ～ 57 μM) than -15 (～184 μM). Activity and structural stability of these CanPIs were revealed under various conditions of pH, temperature and denaturing agent. Structure prediction, docking studies with proteases and mass spectroscopy revealed the organization of multiple reactive site loops of multi domain PIs in space as well as the steric hindrances imposed while binding to proteases due to their close proximity.     

Spatial variability of chlorophyll-a and abiotic variables in a river–floodplain system during different hydrological phases

Chlorophyll-a (Chl-a) and abiotic variables were measured in the main channel and floodplain waterbodies of the Middle Paraná River to analyse the system dynamics and to assess their spatial variability during different hydrological phases, including an extreme flood. We wanted to test that the flood does not always have a homogenising effect in a river–floodplain system. An explanatory model for Chl-a was performed according to Akaike’s Information Criterion (AIC), and the relation of water level with the coefficient of variation (CV) among sites for each variable was explored. The model explained 64% of Chl-a variability. Water level, depth:euphotic zone ratio (Z _d:Z _eu) (inverse correlation) and conductivity (direct correlation) were the significant explicative variables. The CV of Chl-a decreased with flood from the main channel to the floodplain, but for turbidity, Z _d:Z _eu, pH, dissolved oxygen, soluble reactive phosphorus and Chl-a:pheophytin-a ratio, it increased. However, within the floodplain, CV of turbidity, Z _d:Z _eu and pH decreased during flood. These suggest that the homogenising effect frequently observed during inundation cannot be generalised and that the floodplain may maintain its identity even during flood. The extreme flood and its overlap with the warm season and sedimentological pulse probably contributed to the heterogeneity in the spatial gradient.     

Plant proteomics in India and Nepal: current status and challenges ahead

Plant proteomics has made tremendous contributions in understanding the complex processes of plant biology. Here, its current status in India and Nepal is discussed. Gel-based proteomics is predominantly utilized on crops and non-crops to analyze majorly abiotic (49 %) and biotic (18 %) stress, development (11 %) and post-translational modifications (7 %). Rice is the most explored system (36 %) with major focus on abiotic mainly dehydration (36 %) stress. In spite of expensive proteomics setup and scarcity of trained workforce, output in form of publications is encouraging. To boost plant proteomics in India and Nepal, researchers have discussed ground level issues among themselves and with the International Plant Proteomics Organization (INPPO) to act in priority on concerns like food security. Active collaboration may help in translating this knowledge to fruitful applications.     

Substrate utilization of stress tolerant methylotrophs isolated from revegetated heavy metal polluted coalmine spoil

We analyzed methylotrophs in Bina natural vegetation (BNV), and revegetated overburden dump of four (ROBD4) and 12 years (ROBD12), at Bina coal mine in Sonbhadra district. The cultured strains identified as Pseudomonas, Acinetobacter, Stenotrophomonas and Cellvibrio (γ-Proteobacteria), Methylophilus, Ralstonia, Burkholderia (α-Proteobacteria) Methylobacterium and Inquilinus (β-Proteobacteria), Bacillus (Firmicutes) and Flexibacter (Sphingobacteria) in their 16s rRNA gene sequence similarity. The strains differed in citrate, lactose, formate, urea and xylose utilization. Methanol utilization by Stenotrophomonas, Inquilinus, Cellvibrio and Flexibacter is for first time. The preferred N- sources were proline, glutamate and nitrate for most of the strains. All strains tolerated (2.5 % NaCl) and SDS (0.2 %); 16 strains survived in crystal violet (0.01 %) and nine strains in sodium azide (0.02 %. Methylotrophic population trend was BNV > ROBD12 > ROBD4. The presence of majority of strain of BNV at ROBD12 and ROBD4 indicated restoration of soil methylotrophic functional diversity in revegetated dumps.     

Synthesis of Some O-Alkyl O-(2-Methoxycarbonylphenyl) N-Substituted Phosphoramidates as Fungicides

The reaction between the amino group and the carbonyl group is important in food quality control. Furthermore, advanced glycation end products from foods are considered to relate to aging and diabetes. Thus, it is important to control this reaction. In this study, we investigated the effects of salt concentration on the rates of browning reaction of amino acid, peptides, and proteins. A high concentration of sodium chloride retarded the reaction rate of Glc with amino acids as measured with the absorbance at 470 nm, but did not change the browning rate of Glc with peptides. On the other hand, sodium chloride retarded the browning reaction rate of proteins as measured with polymerization degree or by the loss of Lys. It is hoped that the results of this study will be applied in the control of amino-carbonyl reaction rates in the food industry.