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Inflammatory bowel disease (IBD) affects 0.3% of the global population, yet the etiology remains poorly understood. Anti-inflammation therapy has shown great success, but only 60% of patients with IBD benefit from it, indicating that new targets are needed. Here, we report the discovery of an intrinsic counter regulatory mechanism in colitis pathogenesis that may be targeted for IBD treatment. In response to microbial invasion, resident Vimentin+ stromal cells, connective tissue cells genetically marked by Twist2, are activated during the propagation phase of the disease, but not during initiation and resolution phases, and become a primary source of prostaglandin E2 (PGE2). PGE2 induction requires a nuclear factor κB-independent, TLR4-p38MAPK-Cox2 pathway activation. Ablation of each of the pathway genes, but not Rela or Tgfb1, in Twist2 cells enhanced M1 macrophage polarization and granulocyte/T helper 1 (TH1)/TH17 infiltration and aggravated colitis development. PGE2 administration ameliorated colitis in mouse models with defective PGE2 production but not in animals with normal PGE2 induction. Analysis of clinical samples and public domain data revealed increased expression of Cox2, the rate-limiting enzyme of PGE2 biosynthesis, in inflamed tissues, and especially in colon Vimentin+Twist2+ stromal cells, in about 60% of patients with active Crohn's disease or ulcerative colitis. Moreover, Cox2 protein expression was negatively correlated with disease severity, suggesting an involvement of stromal cells in IBD pathogenesis. Thus, the study uncovers an active immune pathway in colitic inflammation that may be targeted to treat patients with IBD with defects in PGE2 production.Abdominal aortic aneurysm (AAA) is a potentially fatal vascular disease, but the underlying mechanisms remain unknown. Here, we tested the hypothesis that erythropoietin (EPO) may promote the formation of AAA. We found that EPO dose-dependently promoted the formation of AAA in both Apoe -/- (66.7%) and wild-type (WT) (60%) mice receiving a high dose of EPO. read more EPO monoclonal antibodies given to Apoe -/- mice receiving angiotensin II (AngII) stimulation resulted in a markedly lower incidence of AAA (from 86.7 to 20%, P less then 0.001), and EPO receptor (EPOR) knockdown in Epor +/- Apoe -/- mice substantially reduced the incidence of AAA compared to Apoe -/- mice after AngII stimulation (from 86.7 to 45.5%, P less then 0.05), further supporting the finding that EPO is a contributor to AAA formation. EPO-induced AAA resulted in increased microvessels, phagocyte infiltration, and matrix metalloproteinase secretion, as well as reduced collagen and smooth muscle cells (SMCs). Experiments in vitro and ex vivo demonstrated that EPO induced proliferation, migration, and tube formation of endothelial cells via the JAK2/STAT5 signaling pathway. In humans, serum EPO concentrations were higher in patients with AAA than in healthy individuals and correlated with the size of the AAA, suggesting a potential link between EPO and the severity of AAA in humans. In conclusion, we found that EPO promotes the formation of AAA in both Apoe -/- and WT mice by enhancing angiogenesis, inflammation, collagen degradation, and apoptosis of SMCs and that EPO/EPOR signaling is essential for AngII-induced AAA. The association between EPO and AAA in humans warrants further study.Pharmacogenomics is a key component of personalized medicine that promises safer and more effective drug treatment by individualizing drug choice and dose based on genetic profiles. In clinical practice, genetic biomarkers are used to categorize patients into *-alleles to predict CYP450 enzyme activity and adjust drug dosages accordingly. However, this approach leaves a large part of variability in drug response unexplained. Here, we present a proof-of-concept approach that uses continuous-scale (instead of categorical) assignments to predict enzyme activity. We used full CYP2D6 gene sequences obtained with long-read amplicon-based sequencing and cytochrome P450 (CYP) 2D6-mediated tamoxifen metabolism data from a prospective study of 561 patients with breast cancer to train a neural network. The model explained 79% of interindividual variability in CYP2D6 activity compared to 54% with the conventional *-allele approach, assigned enzyme activities to known alleles with previously reported effects, and predicted the activity of previously uncharacterized combinations of variants. The results were replicated in an independent cohort of tamoxifen-treated patients (model R 2 adjusted = 0.66 versus *-allele R 2 adjusted = 0.35) and a cohort of patients treated with the CYP2D6 substrate venlafaxine (model R 2 adjusted = 0.64 versus *-allele R 2 adjusted = 0.55). Human embryonic kidney cells were used to confirm the effect of five genetic variants on metabolism of the CYP2D6 substrate bufuralol in vitro. These results demonstrate the advantage of a continuous scale and a completely phased genotype for prediction of CYP2D6 enzyme activity and could potentially enable more accurate prediction of individual drug response.The role that mechanical forces play in shaping the structure and function of the heart is critical to understanding heart formation and the etiology of disease but is challenging to study in patients. Engineered heart tissues (EHTs) incorporating human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes have the potential to provide insight into these adaptive and maladaptive changes. However, most EHT systems cannot model both preload (stretch during chamber filling) and afterload (pressure the heart must work against to eject blood). Here, we have developed a new dynamic EHT (dyn-EHT) model that enables us to tune preload and have unconstrained contractile shortening of >10%. To do this, three-dimensional (3D) EHTs were integrated with an elastic polydimethylsiloxane strip providing mechanical preload and afterload in addition to enabling contractile force measurements based on strip bending. Our results demonstrated that dynamic loading improves the function of wild-type EHTs on the basis of the magnitude of the applied force, leading to improved alignment, conduction velocity, and contractility.

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