The ABCF gene family facilitates disaggregation during animal development

Protein aggregation, once believed to be a harbinger and/or consequence of stress, age, and pathological conditions, is emerging as a novel concept in cellular regulation. Normal versus pathological aggregation may be distinguished by the capacity of cells to regulate the formation, modification, and dissolution of aggregates. We find that Caenorhabditis elegans aggregates are observed in large cells/blastomeres (oocytes, embryos) and in smaller, further differentiated cells (primordial germ cells), and their analysis using cell biological and genetic tools is straightforward. These observations are consistent with the hypothesis that aggregates are involved in normal development. Using cross-platform analysis in Saccharomyces cerevisiae, C. elegans, and Xenopus laevis, we present studies identifying a novel disaggregase family encoded by animal genomes and expressed embryonically. Our initial analysis of yeast Arb1/Abcf2 in disaggregation and animal ABCF proteins in embryogenesis is consistent with the possibility that members of the ABCF gene family may encode disaggregases needed for aggregate processing during the earliest stages of animal development.

Serum vitamin D concentrations are associated with falling and cognitive function in older adults

OBJECTIVES

To elucidate the mechanism through which vitamin D is associated with decreased falls.

DESIGN

This was a convenience sample from a larger observational study examining correlations between vitamin D and 1) falls, 2) motor function, and 3) cognition (n=159).

SETTING

Falls data were collected via weekly on-line surveys completed in the participants' homes. Yearly evaluations of motor and cognitive function were conducted in an out-patient setting of a large tertiary medical center.

PARTICIPANTS

Participants from the Intelligent Systems for Assessment of Aging Changes Study (ISAAC), a community-based cohort study of independently living older adults over age 70, who had vitamin D concentration within 6 months of clinical evaluations were included in the analysis.

RESULTS

Participants mean age was 85 years and 74% were women. Fallers (n=37) had significantly lower vitamin D concentration (32.9ng/ml) compared to non-fallers (39.2ng/ml) (p<0.01). The relationship between vitamin D and falls remained significant after adjusting for age, health status (via CIRS), and supplement use (p=0.004). Vitamin D concentration were significantly associated with cognitive impairment (Clinical Dementia Rating = 0.5) (p=0.02) and MMSE (p<0.01) after adjusting for age, gender, and education. Vitamin D concentrations did not correlate with any motor measures.

CONCLUSION

Vitamin D concentrations correlated with cognition and falls, but not with motor measures. Further research is needed to demonstrate a causal relationship between vitamin D and cognitive function and determine if cognition plays a role in falls reduction.

Luteolin inhibits myelin basic protein-induced human mast cell activation and mast cell-dependent stimulation of Jurkat T cells

BACKGROUND AND PURPOSE

Allergic inflammation and autoimmune diseases, such as atopic dermatitis, psoriasis and multiple sclerosis (MS), involve both mast cell and T-cell activation. However, possible interactions between the two and the mechanism of such activations are largely unknown.

EXPERIMENTAL APPROACH

Human umbilical cord blood-derived cultured mast cells (hCBMCs) and Jurkat T cells were incubated separately or together, following activation with myelin basic protein (MBP), as well as with or without pretreatment with the flavonoid luteolin for 15 min. The supernatant fluid was assayed for inflammatory mediators released from mast cells and interleukin (IL)-2 release from Jurkat cells.

KEY RESULTS

MBP (10 microM) stimulates hCBMCs to release IL-6, IL-8, transforming growth factor (TGF)-beta1, tumour necrosis factor-alpha (TNF-alpha), vascular endothelial growth factor (VEGF), histamine and tryptase (n=6, P<0.05). Addition of mast cells to Jurkat cells activated by anti-CD3/anti-CD28 increases IL-2 release by 30-fold (n=3, P<0.05). MBP-stimulated mast cells and their supernatant fluid further increase Jurkat cell IL-2 release (n=3, P<0.05). Separation of mast cells and activated Jurkat cells by a Transwell permeable membrane inhibits Jurkat cell stimulation by 60%. Pretreatment of Jurkat cells with a TNF-neutralizing antibody reduces IL-2 release by another 40%. Luteolin pretreatment inhibits mast cell activation (n=3-6, P<0.05), Jurkat cell activation and mast cell-dependent Jurkat cell stimulation (n=3, P<0.05).

CONCLUSIONS AND IMPLICATIONS

Mast cells can stimulate activated Jurkat cells. This interaction is inhibited by luteolin, suggesting that this flavonoid may be useful in the treatment of autoimmune diseases.