Project description:ObjectivePathological angiogenesis is a hallmark of various diseases characterized by local hypoxia and inflammation. These disorders can be treated with inhibitors of angiogenesis, but current compounds display a variety of side effects and lose efficacy over time. This makes the identification of novel signaling pathways and pharmacological targets involved in angiogenesis a top priority. Approach and Results: Here, we show that inactivation of FAAH (fatty acid amide hydrolase), the enzyme responsible for degradation of the endocannabinoid anandamide, strongly impairs angiogenesis in vitro and in vivo. Both, the pharmacological FAAH inhibitor URB597 and anandamide induce downregulation of gene sets for cell cycle progression and DNA replication in endothelial cells. This is underscored by cell biological experiments, in which both compounds inhibit proliferation and migration and evoke cell cycle exit of endothelial cells. This prominent antiangiogenic effect is also of pathophysiological relevance in vivo, as laser-induced choroidal neovascularization in the eye of FAAH-/- mice is strongly reduced.ConclusionsThus, elevation of endogenous anandamide levels by FAAH inhibition represents a novel antiangiogenic mechanism.
Project description:Background & Aims: Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer deaths in the United States. Tyrosine sulfation, catalyzed by the tyrosylprotein sulfotransferase 2 (TPST2), is a post-translational modification essential for protein-protein interactions and cellular functions. SLC35B2 is a key transporter that transports the universal sulfate donor 3’-phosphoadenosine 5’-phosphosulfate (PAPS) into the Golgi apparatus where the protein sulfation occurs. The goal of this study is to determine whether and how SLC35B2-TPST2 axis of tyrosine sulfation plays a role in PDAC. Methods: Gene expression was analyzed in PDAC patients and mice. Human PDAC MIA PaCa-2 and PANC-1 cells were used for in vitro studies. TPST2 deficient MIA PaCa-2 cells were generated to assess xenograft tumor growth in vivo. Mouse PDAC cells derived from the KrasLSL-G12D/+;Tp53L/+;Pdx1-Cre (KPC) mice were used to generate Tpst2 KO KPC cells to evaluate tumor growth and metastasis in vivo. Results: High expressions of SLC35B2 and TPST2 were correlated with poor PDAC patient survival. Knockdown of SLC35B2 or TPST2, or pharmacological inhibition of sulfation inhibited PDAC cell proliferation and migration in vitro. TPST2 deficient MIA PaCa-2 cells exhibited inhibited xenograft tumor growth. Orthotopic inoculation of Tpst2 KO KPC cells in mice showed inhibition of primary tumor growth, local invasion, and metastasis. Mechanistically, the integrin ITGB4 was found to be a novel substrate of TPST2. Inhibition of sulfation destabilizes ITGB4 protein, which may have accounted for the suppression of metastasis. Conclusions: Targeting the SLC35B2-TPST2 axis of tyrosine sulfation may represent a novel approach for therapeutic intervention of PDAC.
Project description:Age-induced decline in osteogenic potential of bone marrow mesenchymal stem cells (BMSCs) potentiates osteoporosis and increases risk for bone fractures. Despite epidemiology studies reporting concurrent development of vascular- and bone diseases in the elderly, the underlying mechanisms for the vascular-bone cross-talk in aging are largely unknown. In this study, we show that accelerated endothelial aging deteriorates bone tissue through paracrine repression of Wnt-driven-axis in BMSCs. Here, we utilize physiologically aged mice in conjunction with our transgenic endothelial progeria mouse model (Hutchinson-Gilford progeria syndrome; HGPS) that displays hallmarks of an aged bone marrow vascular niche. We find bone defects associated with diminished BMSC osteogenic differentiation that implicate the existence of angiocrine factors with long-term inhibitory effects. microRNA-transcriptomics of HGPS-patient plasma combined with aged-vascular niche analyses in progeria mice reveal abundant secretion of Wnt-repressive microRNA-31-5p. Moreover, we show that inhibition of microRNA-31-5p as well as selective Wnt-activator CHIR99021 boost the osteogenic potential of BMSCs through de-repression and activation of the Wnt-signalling, respectively. Our results demonstrate that the vascular niche significantly contributes to osteogenesis defects in aging and pave ground for microRNA-based therapies of bone loss in elderly.
Project description:Obesity is associated with impairments of wound healing and tissue regeneration. Angiogenesis, the formation of new blood capillaries, plays a key role in organ regeneration and repair. Inhibition of lung angiogenesis impairs regenerative lung growth after unilateral pneumonectomy (PNX). However, the effects of obesity on post-PNX lung vascular and alveolar morphogenesis remain unclear. In this report, we have demonstrated that regenerative lung growth and angiogenic factor VEGFA expression induced by PNX are inhibited in Lepob/ob obese mice compared to Lepob/- mice. The levels of adiponectin, one of the adipokines that exhibits pro-angiogenic and vascular protective properties, increase in endothelial cells (ECs) isolated from remaining mouse lungs after unilateral PNX, while these effects are attenuated in Lepob/ob obese mice. Post-PNX lung growth, vascular and alveolar morphogenesis, and VEGFA levels in the lungs are inhibited in adiponectin knockout mice. Adiponectin agonist, AdipoRon stimulates post-PNX lung growth and vascular and alveolar morphogenesis in Lepob/ob obese mice. These findings suggest that obesity impairs lung vascular and alveolar regeneration and adiponectin may be one of the key molecules to improve lung regeneration in obese people.