Real-life treatment persistence and treatment outcomes of Finnish patients with inflammatory bowel disease receiving vedolizumab as first-line biological treatment.

Purpose: To analyze treatment persistence and treatment outcomes of vedolizumab as first-line biological treatment in Crohn's disease (CD) and ulcerative colitis (UC) patients in a Finnish real-world setting. Methods: Observational, retrospective, multi-center chart review study that included adult CD and UC patients initiating vedolizumab as first-line biological treatment between 2014 and 2020. Results: The cohort consisted of 54 CD and 69 UC patients. At month 12, treatment persistence was 84.9 % in CD and 64.7 % in UC. Most vedolizumab discontinuations (CD, n = 11; UC, n = 26) were due to inefficacy. Discontinuations due to adverse events were rare (n < 5). Efficacy improvements were observed in treatment persistent patients at 12 months vs. baseline in the Harvey-Bradshaw Index (CD, 1.8 vs. 3.9, p = 0.001), Partial Mayo Score (UC, 1.0 vs. 4.9, p < 0.001), Physician's Global Assessment (CD, 0.9 vs. 1.8, p < 0.001; UC, 0.4 vs. 2.1, p < 0.001), along with positive endoscopic and biochemical outcomes. Clinical remission was 90.9 % vs. 63.0 % for CD, and 81.6 % vs. 12.3 % for UC, while corticosteroid use was 15.9 % vs. 53.7 % for CD, and 14.6 % vs. 92.8 % for UC at 12 months and baseline, respectively. Conclusion: Vedolizumab was associated with improvements in efficacy, endoscopic activity, biochemical parameters, and decreased corticosteroid burden when used as a first-line biological treatment.

Novel function for blood platelets and podoplanin in developmental separation of blood and lymphatic circulation.

During embryonic development, lymph sacs form from the cardinal vein, and sprout centrifugally to form mature lymphatic networks. Separation of the lymphatic from the blood circulation by a hitherto unknown mechanism is essential for the homeostatic function of the lymphatic system. O-glycans on the lymphatic endothelium have recently been suggested to be required for establishment and maintenance of distinct blood and lymphatic systems, primarily by mediating proper function of podoplanin. Here, we show that this separation process critically involves platelet activation by podoplanin. We found that platelet aggregates build up in wild-type embryos at the separation zone of podoplanin(+) lymph sacs and cardinal veins, but not in podoplanin(-/-) embryos. Thus, podoplanin(-/-) mice develop a "nonseparation" phenotype, characterized by a blood-filled lymphatic network after approximately embryonic day 13.5, which, however, partially resolves in postnatal mice. The same embryonic phenotype is also induced by treatment of pregnant mice with acetyl salicylic acid, podoplanin-blocking antibodies, or by inactivation of the kindlin-3 gene required for platelet aggregation. Therefore, interaction of endothelial podoplanin of the developing lymph sac with circulating platelets from the cardinal vein is critical for separating the lymphatic from the blood vascular system.

Therapeutic management and outcomes in inflammatory bowel diseases, 2010 to 2017 in cohorts from Denmark, Sweden and Norway.

BACKGROUND: Despite the increasing use of biologics in patients with inflammatory bowel disease (IBD), real-world data about outcomes in the era of biologics remain inconclusive. AIMS: To investigate trends in surgeries, hospitalisations and medication use in patients with IBD in a multinational, population-based cohort METHODS: We included 42,894 patients with ulcerative colitis (UC) and 24,864 with Crohn's disease (CD) who were diagnosed between 2010 and 2017 in Denmark, Norway and Sweden. We extracted data about surgeries, hospitalisations and medications from national registries and compared across countries and diagnosis years. RESULTS: Between 2010 and 2017, 2-year surgery rates were 4-7% in UC and 10-15% in CD and were stable over time. Two-year hospitalisation rates increased in Denmark (UC: 20% to 35%; CD: 27% to 32%) but were stable in Norway and Sweden (fluctuating between 33% and 37% in UC, and 46% and 52% in CD). Two-year rates of biologic use increased in both UC (7% to 16% in Denmark, 8% to 18% in Norway) and CD (22% to 26% in Denmark; 21% to 35% in Norway). Two-year rates of immunomodulator use increased in Norway (from 14% to 23% in UC; 37% to 45% in CD) and Sweden (from 41% to 52% in CD), but were stable in Denmark (between 17% and 21% in UC; 39% to 46% in CD). CONCLUSION: Between 2010 and 2017, surgery rates among Scandinavian patients with IBD remained stable, with no clear changes in hospitalisation rates despite the increasing use of immunomodulators and biologics.

VEGF-C is a trophic factor for neural progenitors in the vertebrate embryonic brain.

Vascular endothelial growth factor C (VEGF-C) was first identified as a regulator of the vascular system, where it is required for the development of lymphatic vessels. Here we report actions of VEGF-C in the central nervous system. We detected the expression of the VEGF-C receptor VEGFR-3 in neural progenitor cells in Xenopus laevis and mouse embryos. In Xenopus tadpole VEGF-C knockdowns and in mice lacking Vegfc, the proliferation of neural progenitors expressing VEGFR-3 was severely reduced, in the absence of intracerebral blood vessel defects. In addition, Vegfc-deficient mouse embryos showed a selective loss of oligodendrocyte precursor cells (OPCs) in the embryonic optic nerve. In vitro, VEGF-C stimulated the proliferation of OPCs expressing VEGFR-3 and nestin-positive ventricular neural cells. VEGF-C thus has a new, evolutionary conserved function as a growth factor selectively required by neural progenitor cells expressing its receptor VEGFR-3.

Transgenic induction of vascular endothelial growth factor-C is strongly angiogenic in mouse embryos but leads to persistent lymphatic hyperplasia in adult tissues.

Vascular endothelial growth factor-C (VEGF-C) is the quintessential lymphangiogenic growth factor that is required for the development of the lymphatic system and is capable of stimulating lymphangiogenesis in adults by activating its receptor, VEGFR-3. Although VEGF-C is a major candidate molecule for the development of prolymphangiogenic therapy for defective lymphatic vessels in lymphedema, the stability of lymph vessels generated by exogenous VEGF-C administration is not currently known. We studied VEGF-C-stimulated lymphangiogenesis in inducible transgenic mouse models in which growth factor expression can be spatially and temporally controlled without side effects, such as inflammation. VEGF-C induction in adult mouse skin for 1 to 2 weeks caused robust lymphatic hyperplasia that persisted for at least 6 months. VEGF-C induced lymphangiogenesis in numerous tissues and organs when expressed in the vascular endothelium in either neonates or adult mice. Very few or no effects were observed in either blood vessels or collecting lymph vessels. Additionally, VEGF-C stimulated lymphangiogenesis in embryos after the onset of lymphatic vessel development. Strikingly, a strong angiogenic effect was observed after VEGF-C induction in vascular endothelium at any point before embryonic day 16.5. Our results indicate that blood vessels can undergo VEGF-C-induced angiogenesis even after down-regulation of VEGFR-3 in embryos; however, transient VEGF-C expression in adults can induce long-lasting lymphatic hyperplasia with no obvious side effects on the blood vasculature.

Preexisting lymphatic endothelium but not endothelial progenitor cells are essential for tumor lymphangiogenesis and lymphatic metastasis.

Endothelial progenitor cells have been shown to contribute to angiogenesis in various tumor models. Here, we have studied the relative contributions of bone marrow (BM)-derived endothelial progenitors and pre-existing lymphatic vessels to tumor lymphangiogenesis. We did not find significant incorporation of genetically marked BM-derived cells in lymphatic vessels during tumor- or vascular endothelial growth factor C-induced lymphangiogenesis. The degree of tumor lymphangiogenesis correlated with lymphatic vessel density in the peritumoral area, and despite tumor lymphangiogenesis, lymphatic metastasis failed to occur in gene-targeted vascular endothelial growth factor C(+/-) mice that have hypoplasia of the lymphatic network. Our data demonstrate that during tumor lymphangiogenesis and cancer cell dissemination via the lymphatics, the newly formed lymphatic vessels sprout from the pre-existing local lymphatic network with little if any incorporation of BM-derived endothelial progenitor cells.

Essential role of the coxsackie- and adenovirus receptor (CAR) in development of the lymphatic system in mice.

The coxsackie- and adenovirus receptor (CAR) is a cell adhesion molecule predominantly associated with epithelial tight junctions in adult tissues. CAR is also expressed in cardiomyocytes and essential for heart development up to embryonic day 11.5, but not thereafter. CAR is not expressed in vascular endothelial cells but was recently detected in neonatal lymphatic vessels, suggesting that CAR could play a role in the development of the lymphatic system. To address this, we generated mice carrying a conditional deletion of the CAR gene (Cxadr) and knocked out CAR in the mouse embryo at different time points during post-cardiac development. Deletion of Cxadr from E12.5, but not from E13.5, resulted in subcutaneous edema, hemorrhage and embryonic death. Subcutaneous lymphatic vessels were dilated and structurally abnormal with gaps and holes present at lymphatic endothelial cell-cell junctions. Furthermore, lymphatic vessels were filled with erythrocytes showing a defect in the separation between the blood and lymphatic systems. Regionally, erythrocytes leaked out into the interstitium from leaky lymphatic vessels explaining the hemorrhage detected in CAR-deficient mouse embryos. The results show that CAR plays an essential role in development of the lymphatic vasculature in the mouse embryo by promoting appropriate formation of lymphatic endothelial cell-cell junctions.

Deletion of vascular endothelial growth factor C (VEGF-C) and VEGF-D is not equivalent to VEGF receptor 3 deletion in mouse embryos.

Lymphatic vessels play an important role in the regulation of tissue fluid balance, immune responses, and fat adsorption and are involved in diseases including lymphedema and tumor metastasis. Vascular endothelial growth factor (VEGF) receptor 3 (VEGFR-3) is necessary for development of the blood vasculature during early embryogenesis, but later, VEGFR-3 expression becomes restricted to the lymphatic vasculature. We analyzed mice deficient in both of the known VEGFR-3 ligands, VEGF-C and VEGF-D. Unlike the Vegfr3(-/-) embryos, the Vegfc(-/-); Vegfd(-/-) embryos displayed normal blood vasculature after embryonic day 9.5. Deletion of Vegfr3 in the epiblast, using keratin 19 (K19) Cre, resulted in a phenotype identical to that of the Vegfr3(-/-) embryos, suggesting that this phenotype is due to defects in the embryo proper and not in placental development. Interestingly, the Vegfr3(neo) hypomorphic mutant mice carrying the neomycin cassette between exons 1 and 2 showed defective lymphatic development. Overexpression of human or mouse VEGF-D in the skin, under the K14 promoter, rescued the lymphatic hypoplasia of the Vegfc(+/-) mice in the K14-VEGF-D; Vegfc(+/-) compound mice, suggesting that VEGF-D is functionally redundant with VEGF-C in the stimulation of developmental lymphangiogenesis. Our results suggest VEGF-C- and VEGF-D-independent functions for VEGFR-3 in the early embryo.

Binding of ras to phosphoinositide 3-kinase p110alpha is required for ras-driven tumorigenesis in mice.

Ras proteins signal through direct interaction with a number of effector enzymes, including type I phosphoinositide (PI) 3-kinases. Although the ability of Ras to control PI 3-kinase has been well established in manipulated cell culture models, evidence for a role of the interaction of endogenous Ras with PI 3-kinase in normal and malignant cell growth in vivo has been lacking. Here we generate mice with mutations in the Pi3kca gene encoding the catalytic p110alpha isoform that block its interaction with Ras. Cells from these mice show proliferative defects and selective disruption of signaling from growth factors to PI 3-kinase. The mice display defective development of the lymphatic vasculature, resulting in perinatal appearance of chylous ascites. Most importantly, they are highly resistant to endogenous Ras oncogene-induced tumorigenesis. The interaction of Ras with p110alpha is thus required in vivo for certain normal growth factor signaling and for Ras-driven tumor formation.

Vascular endothelial growth factor C is required for sprouting of the first lymphatic vessels from embryonic veins.

Lymphatic vessels are essential for immune surveillance, tissue fluid homeostasis and fat absorption. Defects in lymphatic vessel formation or function cause lymphedema. Here we show that the vascular endothelial growth factor C (VEGF-C) is required for the initial steps in lymphatic development. In Vegfc-/- mice, endothelial cells commit to the lymphatic lineage but do not sprout to form lymph vessels. Sprouting was rescued by VEGF-C and VEGF-D but not by VEGF, indicating VEGF receptor 3 specificity. The lack of lymphatic vessels resulted in prenatal death due to fluid accumulation in tissues, and Vegfc+/- mice developed cutaneous lymphatic hypoplasia and lymphedema. Our results indicate that VEGF-C is the paracrine factor essential for lymphangiogenesis, and show that both Vegfc alleles are required for normal lymphatic development.