Mechanistic understanding of the stabilisation of vitamin A in oil by wheat bran: The interplay between vitamin A degradation, lipid oxidation, and lipase activity

Wheat bran stabilises vitamin A (retinyl palmitate, RP) in oil during storage, but the stabilisation mechanism remains unknown. We here studied the effect of the concentration of RP in oil (0.1-2%) and of RP-enriched oil in the system (5-50%) on the RP retention during accelerated storage of systems with native and toasted wheat bran. Generally, toasted bran showed better RP stabilisation than native bran. After four weeks of storage, up to 65% RP was retained in toasted bran systems, whereas the RP retention for native bran was below 10%. For native bran, a higher oil-to-bran ratio and, thus, a lower wheat lipase level resulted in better RP retention. For toasted bran, combined high oil and high RP concentrations resulted in the lowest RP retention. We, therefore, conclude that wheat bran protects RP and lipids from oxidation. This protection is reduced by the pro-oxidative effect of RP, lipid oxidation and lipase.

A novel phosphoglucomutase-deficient mouse model reveals aberrant glycosylation and early embryonic lethality

Patients with phosphoglucomutase (PGM1) deficiency, a congenital disorder of glycosylation (CDG) suffer from multiple disease phenotypes. Midline cleft defects are present at birth. Overtime, additional clinical phenotypes, which include severe hypoglycemia, hepatopathy, growth retardation, hormonal deficiencies, hemostatic anomalies, frequently lethal, early-onset of dilated cardiomyopathy and myopathy emerge, reflecting the central roles of the enzyme in (glycogen) metabolism and glycosylation. To delineate the pathophysiology of the tissue-specific disease phenotypes, we constructed a constitutive Pgm2 (mouse ortholog of human PGM1)-knockout (KO) mouse model using CRISPR-Cas9 technology. After multiple crosses between heterozygous parents, we were unable to identify homozygous life births in 78 newborn pups (P = 1.59897E-06), suggesting an embryonic lethality phenotype in the homozygotes. Ultrasound studies of the course of pregnancy confirmed Pgm2-deficient pups succumb before E9.5. Oral galactose supplementation (9 mg/mL drinking water) did not rescue the lethality. Biochemical studies of tissues and skin fibroblasts harvested from heterozygous animals confirmed reduced Pgm2 enzyme activity and abundance, but no change in glycogen content. However, glycomics analyses in serum revealed an abnormal glycosylation pattern in the Pgm2^+/- animals, similar to that seen in PGM1-CDG.

Lack of effect of doxycycline on disease activity and joint damage in patients with rheumatoid arthritis. A double blind, placebo controlled trial

OBJECTIVE

To investigate the effects of doxycycline on disease activity and joint destruction in patients with rheumatoid arthritis (RA).

METHODS

A 36 week double blind, placebo controlled crossover trial was conducted. Patients (n = 66) received 50 mg doxycycline or placebo twice a day during 12, 24, or 36 weeks. Patient assessments were performed before the treatment was administered, at 6, 12, 24 and 36 weeks of treatment, and finally at 4 weeks after cessation of treatment. Patient assessments, swollen and tender joint counts, duration of morning stiffness, erythrocyte sedimentation rate, and Modified Disease Activity Score were used as measures of disease activity. Effects on joint destruction were assessed by urinary excretion of the pyridinolines hydroxylysylpyridinoline and lysylpyridinoline and by scoring radiographic damage of hands and feet before and after treatment.

RESULTS

The changes of clinical or laboratory disease activity measures, pyridinoline excretion, or progression of radiographic joint damage during doxycycline or placebo treatment did not differ significantly.

CONCLUSION

The results indicate that 50 mg doxycycline twice a day provided no therapeutic benefit for patients with RA.

Urokinase-receptor/integrin complexes are functionally involved in adhesion and progression of human breast cancer in vivo

Interactions between specific cell-surface molecules, which include the urokinase receptor (uPAR) and integrins, are crucial to processes of tumor invasion and metastasis. Here we demonstrate that uPAR and beta1-integrins may cluster at distinct sites at the cell surface of metastatic MDA-MB-231 breast cancer cells and form functional complexes. Attachment assays performed in the presence of a synthetic peptide (p25), which interferes with the formation of uPAR-integrin complexes, reveal that uPAR is able to regulate the adhesive function of integrins in breast cancer cells. On dissociation of the uPAR-integrin complexes by p25, tumor cell attachment to the extracellular matrix was either decreased (vitronectin) or increased (fibronectin). Moreover, the tumor cells display remarkable morphological changes when cultured on fibronectin in the continuous presence of p25, leading to increased cell spreading and attachment. In marked contrast to control conditions, increased cellular adhesion to fibronectin after p25 treatment was entirely beta1-integrin-mediated. The role of uPAR-integrin complexes in tumor progression was studied in an in vivo bone xenograft model. Stably transfected MDA-MB-231 cells that overexpress p25 showed a significant reduction in tumor progression in bone (P < or = 0.0001 versus mock-control). In line with these observations, continuous administration of p25 (25 microg/mouse/day, osmotic minipumps) for 28 days resulted in significantly reduced tumor progression of MDA-MB-231 cells in bone (P < or = 0.005) when compared to scrambled control peptide. In conclusion, our data demonstrate that uPAR can act as an adhesion receptor in breast cancer and is capable of regulating integrin function. Our findings strongly suggest that adhesive and proteolytic events are tightly associated in metastatic breast cancer cells and that functional integrin-uPAR complexes are involved in tumor progression in vivo.

A short phosphodiester window is sufficient to direct RNase H-dependent RNA cleavage by antisense peptide nucleic acid

The potential pharmacologic benefits of using peptide nucleic acid (PNA) as an antisense agent are tempered by its incapacity to activate RNase H. The mixed backbone oligonucleotide (ON) (or gapmer) approach, in which a short internal window of RNAse H-competent residues is embedded within an RNase H-incompetent ON has not been applied previously to PNA because PNA and DNA hybridize to RNA with very different helical structures, creating structural perturbations at the two PNA-DNA junctions. It is demonstrated here for the first time that a short internal phosphodiester window within a PNA is sufficient to evoke the RNase H-dependent cleavage of a targeted RNA and to abrogate translation elongation in a well-characterized in vitro assay.

Differential regulation of plasminogen activation in normal keratinocytes and SCC-4 cells by fibroblasts

The plasminogen activator (PA)/plasmin system is thought to be involved in processes such as tumor invasion and wound healing, during which epithelial and mesenchymal cells come close together. However, information on regulation of the PA/plasmin system during epithelial-mesenchymal interactions is scarce. Therefore, we examined the in vitro modulation of the production and activity of the components of the PA/plasmin system in squamous carcinoma cells (SCC-4) and normal human keratinocytes in relation to cell density and the presence or absence of fibroblasts (3T3 cells). There was an inverse relation between cell density and mRNA expression for urokinase-type plasminogen activator (u-PA) and u-PA receptor in both SCC-4 cells and keratinocytes. In addition, such a relation was found for plasminogen activator inhibitor types 1 (PAI-1) and 2 (PAI-2) in SCC-4 monocultures, but not in keratinocyte monocultures. In contrast to monocultures, variation of cell density did not affect the mRNA expression of the components of the PA/plasmin system in cocultures of SCC-4 cells or keratinocytes with 3T3 cells. However, the relative expression of mRNAs in co-cultures was clearly different from that in monocultures, especially at low cell density. For most of the components of the PA/plasmin system, a decrease in mRNA expression and u-PA receptor protein was observed at most cell densities, whereas for PAI-1 only in keratinocytes a marked increase was documented. Zymography of supernatants revealed that the levels of both free u-PA and PA-PAI were increased in SCC-4/3T3 co-cultures, whereas in keratinocytes/3T3 co-cultures, only levels of the PA-PAI complex were increased, while the amount of free u-PA activity decreased. This occurred despite the increase u-PA immunoreactivity and was probably caused by the markedly elevated levels of immunoreactive PAI-1. The results of the present study reveal that the production and synthesis of various components of the PA/plasmin system in keratinocytes and SCC-4 cells depend on the density of epithelial cells and are modulated by fibroblasts, probably through a direct cell-cell or cell-matrix contact. Fibroblast-induced modulations are similar in keratinocytes and SCC-4 cells except for the regulation of PAI-1, which is markedly enhanced only in keratinocytes. This suggests that the modulation of PA activity in the direct microenvironment may be different under physiologic and pathologic conditions.

Canine intervertebral disc disease: a review of etiologic and predisposing factors

In this report the literature on etiologic and predisposing factors of disc disease in the dog is reviewed and discussed. Hypochondroplasia is considered to be important in the etiology of disc disease. After some consideration on nomenclature and morphology, the genetic background of hypochondroplasia is described. The histochemical morphological and developmental similarities and differences between and within various dog breeds are discussed. Macroscopically visible features that predispose to disc disease are outlined. The biomechanical bow-string model of the vertebral column is reviewed. In the discussion the various literature data are interrelated to show how disc disease might be reduced by breeding measures without implicating the breed characteristics. Literature recommendations to help the individual dog are included.