Mammalian milk glycomes: Connecting the dots between evolutionary conservation and biosynthetic pathways

Milk oligosaccharides (MOs) are among the most abundant constituents of breast milk and are essential for health and development. Biosynthesized from monosaccharides into complex sequences, MOs differ considerably between taxonomic groups. Even human MO biosynthesis is insufficiently understood, hampering evolutionary and functional analyses. Using a comprehensive resource of all published MOs from >100 mammals, we develop a pipeline for generating and analyzing MO biosynthetic networks. We then use evolutionary relationships and inferred intermediates of these networks to discover (1) systematic glycome biases, (2) biosynthetic restrictions, such as reaction path preference, and (3) conserved biosynthetic modules. This allows us to prune and pinpoint biosynthetic pathways despite missing information. Machine learning and network analysis cluster species by their milk glycome, identifying characteristic sequence relationships and evolutionary gains/losses of motifs, MOs, and biosynthetic modules. These resources and analyses will advance our understanding of glycan biosynthesis and the evolution of breast milk.

Regulatory T cells reduce endothelial neutral sphingomyelinase 2 to prevent T-cell migration into tumors

Endothelial cells are key regulators of transendothelial migration and their secretion of chemokines and expression of adhesion molecules facilitates lymphocyte entry into tissues. Previously, we demonstrated that Tregs can reduce transendothelial migration of T cells into tumors by decreasing endothelial CXCL10 secretion, but the mechanism by which this occurs is still not known. In this study, we aimed to define how Tregs decrease transendothelial migration into tumors. mRNA sequencing of intestinal tumor endothelial cells from Treg depleted mice identified neutral sphingomyelinase 2 (nSMase2) as a gene downregulated in the presence of Tregs. nSMase2 is expressed in human umbilical vein endothelial cells (HUVECs) and was decreased after coculture with Tregs. Furthermore, blocking of nSMase2 activity in vitro decreased VCAM1, CX3CL1, and CXCL10 expression in HUVECs, mirroring the same decrease found in Treg cocultures. In the APC^min/+ mouse model of intestinal cancer, nSMase2 is lower in tumor endothelial cells than in unaffected small intestine and chronic treatment with a nSMase2 inhibitor suppressed the increased migration that is otherwise seen in the absence of Tregs. We conclude that nSMase2 is an important mediator in endothelial cells supporting transendothelial migration, which may be targeted by Tregs to reduce T-cell migration into tumors.

Older patients' recovery following intensive care: A follow-up study with the RAIN questionnaire

The aim was to investigate older patient recovery (65 years+) up to two years following discharge from an intensive care unit (ICU) using the Recovery After Intensive Care (RAIN) instrument and to correlate RAIN with the Hospital Anxiety and Depression Scale (HAD).

METHODS

An explorative and descriptive longitudinal design was used. Eighty-two patients answered RAIN and HAD at least twice following discharge. Demographic and clinical data were collected from patient records.

RESULTS

Recovery after the ICU was relatively stable and good for older patients at the four data collection points. There was little variation on the RAIN subscales over time. The greatest recovery improvement was found in existential ruminations from 2 to 24 months. A patient that could look forward and those with supportive relatives had the highest scores at all four measurements. Having lower financial situation was correlated to poorer recovery and was significant at 24 months. The RAIN and HAD instruments showed significant correlations, except for the revaluation of life subscale, which is not an aspect in HAD.

CONCLUSION

The RAIN instrument shows to be a good measurement for all dimensions of recovery, including existential dimensions, which are not covered by any other instrument.