Comparative analysis of arterial compliance in mice genetically null for cathepsins K, L, or S.

Cysteine cathepsins are potent proteases implicated in cardiovascular disease for degrading extracellular matrix (ECM) whose structure and integrity determine the mechanical behavior of arteries. Cathepsin knockout mouse models fed atherogenic diets have been used to study their roles in cardiovascular disease, but the impacts of cathepsin knockout on non-atherosclerotic arterial mechanics are scarce. We examine arterial mechanics in several cathepsin knockout mouse lines (CatK-/-, CatL-/-ApoE-/- and CatS-/-ApoE-/-) and controls (C57/Bl6, apolipoprotein E-/-). Common carotid arteries of three month-old mice were isolated and underwent biaxial mechanical testing and opening angle tests. Measured wall thicknesses and pressure-diameter curves were fed into a 4-fiber constitutive model to assess differences in material properties. Pressure-diameter data revealed CatL-/-ApoE-/- arteries were smaller in caliber compared to CatK-/-, CatS-/-ApoE-/- and ApoE-/- controls and were less compliant than ApoE-/- and CatS-/-ApoE-/- arteries at lower pressures, where elastin governs the mechanical response. CatK-/- arteries showed increased in vivo axial stretches compared to CatL-/-ApoE-/- and CatS-/-ApoE-/- arteries. CatL-/-ApoE-/- arteries were less compliant than ApoE-/- and CatS-/-ApoE-/- arteries pressurized to sub-diastolic pressures. 4-fiber and unified fiber distribution models were able to capture arteries' nonlinear mechanical responses; calculated material parameters suggested that ApoE-/- arteries had increased axial parameters compared to CatL-/-ApoE-/- and CatS-/-ApoE-/- arteries. Taken together, the data suggests that loss of the potent collagenase catK increases axial and circumferential arterial compliance, while knockout of the elastase catL decreased circumferential arterial compliance, and knockout of the elastase catS showed no impact on carotid arterial mechanics.

Metabolomics and cytokine profiling of mesenchymal stromal cells identify markers predictive of T-cell suppression.

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) have shown great promise in the field of regenerative medicine, as many studies have shown that MSCs possess immunomodulatory function. Despite this promise, no MSC therapies have been licensed by the Food and Drug Administration. This lack of successful clinical translation is due in part to MSC heterogeneity and a lack of critical quality attributes. Although MSC indoleamine 2,3-dioxygnease (IDO) activity has been shown to correlate with MSC function, multiple predictive markers may be needed to better predict MSC function. METHODS: Three MSC lines (two bone marrow-derived, one induced pluripotent stem cell-derived) were expanded to three passages. At the time of harvest for each passage, cell pellets were collected for nuclear magnetic resonance (NMR) and ultra-performance liquid chromatography mass spectrometry (MS), and media were collected for cytokine profiling. Harvested cells were also cryopreserved for assessing function using T-cell proliferation and IDO activity assays. Linear regression was performed on functional data against NMR, MS and cytokines to reduce the number of important features, and partial least squares regression (PLSR) was used to obtain predictive markers of T-cell suppression based on variable importance in projection scores. RESULTS: Significant functional heterogeneity (in terms of T-cell suppression and IDO activity) was observed between the three MSC lines, as were donor-dependent differences based on passage. Omics characterization revealed distinct differences between cell lines using principal component analysis. Cell lines separated along principal component one based on tissue source (bone marrow-derived versus induced pluripotent stem cell-derived) for NMR, MS and cytokine profiles. PLSR modeling of important features predicted MSC functional capacity with NMR (R2 = 0.86), MS (R2 = 0.83), cytokines (R2 = 0.70) and a combination of all features (R2 = 0.88). CONCLUSIONS: The work described here provides a platform for identifying markers for predicting MSC functional capacity using PLSR modeling that could be used as release criteria and guide future manufacturing strategies for MSCs and other cell therapies.

Correction: mTOR inhibition affects Yap1-ß-catenin-induced hepatoblastoma growth and development.

[This corrects the article DOI: 10.18632/oncotarget.26668.].