Ammonium and proline accumulation in senescing cut leaves of <Emphasis Type="Italic">Zantedeschia</Emphasis>

Accumulation of ammonium and proline were reported as phenomena associated with plant response to stress and/or senescence. The effects of a preservative (8HQC + sucrose) and 24 hrs pulse conditioning with GA₃ on the ammonium and proline contents were studied in senescing cut leaves of Zantedeschia aethiopica Spr. and Z. elliottiana Engl., grown for the florists green. Generally, accumulation of both compounds was observed in senescing leaves, however, the final ammonium and proline levels depended upon the species and the treatment applied. Conditioning with GA₃, a treatment known to delay leaf senescence in Zantedeschia sp., prevented the increases in the ammonium and proline contents. Standard preservative solution used to prolong the longevity of cut flowers enhanced the ammonium accumulation in senescing leaves of both species, and the proline accumulation in the leaves of Z. aethiopica, but not in Z. elliottiana. These observations suggest that neither ammonium nor proline accumulation would be fully reliable predictors of cut leaf freshness during their entire market life. However, proline accumulation could serve as a quick test of freshness in the first half of the useful market life of cut leaves of Zantedeschia.     

POLYPRENOL REDUCTASE2 Deficiency Is Lethal in Arabidopsis Due to Male Sterility

Dolichol is a required cofactor for protein glycosylation, the most common posttranslational modification modulating the stability and biological activity of proteins in all eukaryotic cells. We have identified and characterized two genes, PPRD1 and -2, which are orthologous to human SRD5A3 (steroid 5α reductase type 3) and encode polyprenol reductases responsible for conversion of polyprenol to dolichol in Arabidopsis thaliana. PPRD1 and -2 play dedicated roles in plant metabolism. PPRD2 is essential for plant viability; its deficiency results in aberrant development of the male gametophyte and sporophyte. Impaired protein glycosylation seems to be the major factor underlying these defects although disturbances in other cellular dolichol-dependent processes could also contribute. Shortage of dolichol in PPRD2-deficient cells is partially rescued by PPRD1 overexpression or by supplementation with dolichol. The latter has been discussed as a method to compensate for deficiency in protein glycosylation. Supplementation of the human diet with dolichol-enriched plant tissues could allow new therapeutic interventions in glycosylation disorders. This identification of PPRD1 and -2 elucidates the factors mediating the key step of the dolichol cycle in plant cells which makes manipulation of dolichol content in plant tissues feasible.     

Differential Induction of Ly6G and Ly6C Positive Myeloid Derived Suppressor Cells in Chronic Kidney and Liver Inflammation and Fibrosis

CD11b⁺Gr1⁺ myeloid derived suppressor cells (MDSC) are known to be very potent suppressors of T cell immunity and can be further stratified into granulocytic MDSC and monocytic MDSC in mice based on expression of Ly6G or Ly6C, respectively. Here, using these markers and functional assays, we aimed to identify whether MDSC are induced during chronic inflammation leading to fibrosis in both kidney and liver and whether additional markers could more specifically identify these MDSC subsets. In an adenine-induced model of kidney inflammation/fibrosis suppressive Ly6G^pos MDSC were induced. The suppressive function within the Ly6G⁺ MDSC population was exclusively present in IFNγRβ expressing cells. In contrast, in chronic inflammation in the liver induced by bile duct ligation, suppressive capacity was exclusively present in the Ly6C^pos MDSC subset. Gene expression analyses confirmed the differential origins and regulation of those MDSC subsets. Additionally, depletion of MDSC in either kidney or liver fibrosis enhanced fibrosis markers, indicating a protective role for MDSC in organ fibrosis. Thus, our data demonstrate that during liver inflammation and kidney fibrosis MDSC with similar function arise bearing a distinct marker profile and arising from different cell populations.     

Inducible cell labeling and lineage tracking during fracture repair

Mouse models incorporating inducible Cre‐ER^T2/LoxP recombination coupled with sensitive fluorescent reporter lines are being increasingly used to track cell lineages in vivo. In this study we use two inducible reporter strains, Ai9_iCol2a1 (Ai9 × Col2a1‐creER^T2) to track contribution of chondrogenic progenitors during bone regeneration in a closed fracture model and Ai9_iUBC (Ai9 × UBC–creER^T2) to examine methods for inducing localized recombination. By comparing with Ai9 littermate controls as well as inducible reporter mice not dosed with tamoxifen, we revealed significant leakiness of the CreER^T2 system, particularly in the bone marrow of both lines. These studies highlight the challenges associated with highly sensitive reporters that may be activated without induction in tissues where the CreER^T2 fusion is expressed. Examination of the growth plate in the Ai9_iCol2a1 strain showed cells of the osteochondral lineage (cell co‐staining with chondrocyte and osteoblast markers) labeled with the tdTom reporter. However, no such labeling was noted in healing fractures of Ai9_iCol2a1 mice. Attempts to label a single limb using intramuscular injection of 4‐hydroxytamoxifen in the Ai9_iUBC strain resulted in complete labeling of the entire animal, comparable to intraperitoneal injection. While a challenge to interpret, these data are nonetheless informative regarding the limitations of these inducible reporter models, and justify caution and expansive controls in future studies using such models.     

Thermodynamic fingerprints of ligand binding to human telomeric G-quadruplexes

Thermodynamic studies of ligand binding to human telomere (ht) DNA quadruplexes, as a rule, neglect the involvement of various ht-DNA conformations in the binding process. Therefore, the thermodynamic driving forces and the mechanisms of ht-DNA G-quadruplex-ligand recognition remain poorly understood. In this work we characterize thermodynamically and structurally binding of netropsin (Net), dibenzotetraaza[14]annulene derivatives (DP77, DP78), cationic porphyrin (TMPyP4) and two bisquinolinium ligands (Phen-DC3, 360A-Br) to the ht-DNA fragment (Tel22) AGGG(TTAGGG)₃ using isothermal titration calorimetry, CD and fluorescence spectroscopy, gel electrophoresis and molecular modeling. By global thermodynamic analysis of experimental data we show that the driving forces characterized by contributions of specific interactions, changes in solvation and conformation differ significantly for binding of ligands with low quadruplex selectivity over duplexes (Net, DP77, DP78, TMPyP4; K_Tel22 ≈ <K_dsDNA) and for highly selective quadruplex-specific ligands (Phen-DC3, 360A-Br; K_Tel22 > K_dsDNA). These contributions are in accordance with the observed structural features (changes) and suggest that upon binding Net, DP77, DP78 and TMPyP4 select hybrid-1 and/or hybrid-2 conformation while Phen-DC3 and 360A-Br induce the transition of hybrid-1 and hybrid-2 to the structure with characteristics of antiparallel or hybrid-3 type conformation.     

Impact of Vitamin D Supplementation during Lactation on Vitamin D Status and Body Composition of Mother-Infant Pairs: A MAVID Randomized Controlled Trial

Objective

The optimal vitamin D intake for nursing women is controversial. Deterioration, at least in bone mass, is reported during lactation. This study evaluated whether vitamin D supplementation during lactation enhances the maternal and infant’s vitamin D status, bone mass and body composition.

Design and Methods

After term delivery, 174 healthy mothers were randomized to receive 1200 IU/d (800 IU/d+400 IU/d from multivitamins) or 400 IU/d (placebo+400 IU/d from multivitamins) of cholecalciferol for 6 months while breastfeeding. All infants received 400 IU/d of cholecalciferol. Serum 25-hydroxyvitamin D [25(OH)D], iPTH, calcium, urinary calcium, and densitometry were performed in mother-offspring pairs after delivery, and at 3 and 6 months later.

Results

A total of 137 (79%) (n = 70; 1200 IU/d, n = 67; 400 IU/d) completed the study. 25(OH)D was similar in both groups at baseline (13.7 ng/ml vs. 16.1 ng/ml; P = 0.09) and at 3 months (25.7 ng/ml vs. 24.5 ng/ml; P = 0.09), but appeared higher in the 1200 IU/d group at 6 months of supplementation (25.6 ng/ml vs. 23.1 ng/ml; P = 0.009). The prevalence of 25(OH)D <20 ng/ml was comparable between groups at baseline (71% vs. 64%, P = 0.36) but lower in the 1200 IU/d group after 3 months (9% vs. 25%, P = 0.009) and 6 months (14% vs. 30%, P = 0.03). Maternal and infants’ iPTH, calciuria, bone mass and body composition as well as infants’ 25(OH)D levels were not significantly different between groups during the study. Significant negative correlations were noted between maternal 25(OH)D and fat mass (R = −0.49, P = 0.00001), android fat mass (R = −0.53, P = 0.00001), and gynoid fat mass (R = −0.43, P = 0.00001) after 6 months of supplementation.

Conclusions

Vitamin D supplementation at a dose of 400 IU/d was not sufficient to maintain 25(OH)D >20 ng/ml in nursing women, while 1200 IU/d appeared more effective, but had no effect on breastfed offspring vitamin D status, or changes in the bone mass and the body composition observed in both during breastfeeding.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01506557","term_id":"NCT01506557"}}NCT01506557     

Hematology and serum biochemistry of European mouflon (<Emphasis Type="Italic">Ovis orientalis musimon</Emphasis>) in Croatia

The aim of the present study was to determine the reference intervals for the most commonly used hematological and biochemical parameters of European mouflon from a closed hunting ground in the eastern part of the Republic of Croatia. Blood samples were collected from 39 live, physically restrained, clinically normal European mouflon, as well as from 50 domestic sheep. The distribution of values within each parameter was determined and statistical differences in values between sexes were also determined. For each sample, 14 hematological and 18 biochemical parameters were analyzed. Hematology and biochemistry values of the European mouflon were also compared with the values of domestic sheep. In further studies, the established values might be useful for the health assessment of mouflon.     

Thermostability and esterification activity ofMucor javanicus lipase entrapped in silica aerogel matrix and in organic solvents

The lipase ofMucor javanicus (nowM. circinelloides) entrapped in silica matrix by the sol-gel method esterified primary and secondary alcohols with conversions ranging from 30 to 35% and 10 to 15%, respectively. Loss in activity of the preparations after incubation at 100°C for 1 h with petroleum ether, dodecane, 1-heptanol or oleyl alcohol was about half of that observed for the native lipase.