Human blood vessel organoids as a model of diabetic vasculopathy.

The increasing prevalence of diabetes has resulted in a global epidemic1. Diabetes is a major cause of blindness, kidney failure, heart attacks, stroke and amputation of lower limbs. These are often caused by changes in blood vessels, such as the expansion of the basement membrane and a loss of vascular cells2-4. Diabetes also impairs the functions of endothelial cells5 and disturbs the communication between endothelial cells and pericytes6. How dysfunction of endothelial cells and/or pericytes leads to diabetic vasculopathy remains largely unknown. Here we report the development of self-organizing three-dimensional human blood vessel organoids from pluripotent stem cells. These human blood vessel organoids contain endothelial cells and pericytes that self-assemble into capillary networks that are enveloped by a basement membrane. Human blood vessel organoids transplanted into mice form a stable, perfused vascular tree, including arteries, arterioles and venules. Exposure of blood vessel organoids to hyperglycaemia and inflammatory cytokines in vitro induces thickening of the vascular basement membrane. Human blood vessels, exposed in vivo to a diabetic milieu in mice, also mimic the microvascular changes found in patients with diabetes. DLL4 and NOTCH3 were identified as key drivers of diabetic vasculopathy in human blood vessels. Therefore, organoids derived from human stem cells faithfully recapitulate the structure and function of human blood vessels and are amenable systems for modelling and identifying the regulators of diabetic vasculopathy, a disease that affects hundreds of millions of patients worldwide.

Sulfated glycans engage the Ang-Tie pathway to regulate vascular development.

The angiopoietin (Ang)-Tie pathway is essential for the proper maturation and remodeling of the vasculature. Despite its importance in disease, the mechanisms that control signal transduction through this pathway are poorly understood. Here, we demonstrate that heparan sulfate glycosaminoglycans (HS GAGs) regulate Ang-Tie signaling through direct interactions with both Ang ligands and Tie1 receptors. HS GAGs formed ternary complexes with Ang1 or Ang4 and Tie2 receptors, resulting in potentiation of endothelial survival signaling. In addition, HS GAGs served as ligands for the orphan receptor Tie1. The HS-Tie1 interaction promoted Tie1-Tie2 heterodimerization and enhanced Tie1 stability within the mature vasculature. Loss of HS-Tie1 binding using CRISPR-Cas9-mediated mutagenesis in vivo led to decreased Tie protein levels, pathway suppression and aberrant retinal vascularization. Together, these results reveal that sulfated glycans use dual mechanisms to regulate Ang-Tie signaling and are important for the development and maintenance of the vasculature.

Genetic Basis and Therapies for Vascular Anomalies.

Vascular and lymphatic malformations represent a challenge for clinicians. The identification of inherited and somatic mutations in important signaling pathways, including the PI3K (phosphoinositide 3-kinase)/AKT (protein kinase B)/mTOR (mammalian target of rapamycin), RAS (rat sarcoma)/RAF (rapidly accelerated fibrosarcoma)/MEK (mitogen-activated protein kinase kinase)/ERK (extracellular signal-regulated kinases), HGF (hepatocyte growth factor)/c-Met (hepatocyte growth factor receptor), and VEGF (vascular endothelial growth factor) A/VEGFR (vascular endothelial growth factor receptor) 2 cascades has led to the evaluation of tailored strategies with preexisting cancer drugs that interfere with these signaling pathways. The era of theranostics has started for the treatment of vascular anomalies. Registration: URL: https://www.clinicaltrialsregister.eu; Unique identifier: 2015-001703-32.

Bioglass promotes wound healing by inhibiting endothelial cell pyroptosis through regulation of the connexin 43/reactive oxygen species (ROS) signaling pathway.

Bioactive glass (BG) has recently shown great promise in soft tissue repair, especially in wound healing; however, the underlying mechanism remains unclear. Pyroptosis is a novel type of programmed cell death that is involved in various traumatic injury diseases. Here, we hypothesized that BG may promote wound healing through suppression of pyroptosis. To test this scenario, we investigated the possible effect of BG on pyroptosis in wound healing both in vivo and in vitro. This study showed that BG can accelerate wound closure, granulation formation, collagen deposition, and angiogenesis. Moreover, western blot analysis and immunofluorescence staining revealed that BG inhibited the expression of pyroptosis-related proteins in vivo and in vitro. In addition, while BG regulated the expression of connexin43 (Cx43), it inhibited reactive oxygen species (ROS) production. Cx43 activation and inhibition experiments further indicate that BG inhibited pyroptosis in endothelial cells by decreasing Cx43 expression and ROS levels. Taken together, these studies suggest that BG promotes wound healing by inhibiting pyroptosis via Cx43/ROS signaling pathway.

Preserved ß-adrenergic-mediated vasodilation in skeletal muscle of young adults with obesity despite shifts in cyclooxygenase and nitric oxide synthase.

Central adiposity is associated with greater sympathetic support of blood pressure. ß-adrenergic receptors (ß-AR) buffer sympathetically mediated vasoconstriction and ß-AR-mediated vasodilation is attenuated in preclinical models of obesity. With this information, we hypothesized ß-AR vasodilation would be lower in obese compared with normal weight adults. Because ß-AR vasodilation in normal weight adults is limited by cyclooxygenase (COX) restraint of nitric oxide synthase (NOS), we further explored the contributions of COX and NOS to ß-AR vasodilation in this cohort. Forearm blood flow (FBF, Doppler ultrasound) and mean arterial blood pressure (MAP, brachial arterial catheter) were measured and forearm vascular conductance (FVC) was calculated (FVC = FBF/MAP). The rise in FVC from baseline (ΔFVC) was quantified during graded brachial artery infusion of isoproterenol (Iso, 1-12 ng/100 g/min) in normal weight (n = 36) and adults with obesity (n = 22) (18-40 yr old). In a subset of participants, Iso-mediated vasodilation was examined before and during inhibition of NOS [NG-monomethyl-l-arginine (l-NMMA)], COX (ketorolac), and NOS + COX (l-NMMA + ketorolac). Iso-mediated increases in FVC did not differ between groups (P = 0.57). l-NMMA attenuated Iso-mediated ΔFVC in normal weight (P = 0.03) but not adults with obesity (P = 0.27). In normal weight adults, ketorolac increased Iso-mediated ΔFVC (P < 0.01) and this response was lost with concurrent l-NMMA (P = 0.67). In contrast, neither ketorolac (P = 0.81) nor ketorolac + l-NMMA (P = 0.40) altered Iso-mediated ΔFVC in adults with obesity. Despite shifts in COX and NOS, ß-AR vasodilation is preserved in young adults with obesity. These data highlight the presence of a compensatory shift in microvascular control mechanisms in younger humans with obesity.NEW & NOTEWORTHY We examined ß-adrenergic receptor-mediated vasodilation in skeletal muscle of humans with obesity and normal weight. Results show that despite shifts in the contribution of cyclooxygenase and nitric oxide synthase, ß-adrenergic-mediated vasodilation is relatively preserved in young, otherwise healthy adults with obesity. These data highlight the presence of subclinical changes in microvascular control mechanisms early in the obesity process and suggest duration of obesity and/or the addition of primary aging may be necessary for overt dysfunction.

The orphan receptor GPRC5B activates pro-inflammatory signaling in the vascular wall via Fyn and NFκB.

BACKGROUND AND AIMS: Atherosclerosis is driven by an inflammatory process of the vascular wall. The novel orphan G-protein coupled receptor 5B of family C (GPRC5B) is involved in drosophila sugar and lipid metabolism as well as mice adipose tissue inflammation. Here, we investigated the role of GPRC5B in the pro-atherogenic mechanisms of hyperglycemia and vascular inflammation. METHODS: Immortalized and primary endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) were used for stimulation with high glucose or different cytokines. Adenoviral- or plasmid-driven GPRC5B overexpression and siRNA-mediated knockdown were performed in these cells to analyze functional and mechanistic pathways of GPRC5B. RESULTS: In ECs and VSMCs, stimulation with high glucose, TNFα or LPS induced a significant upregulation of endogenous GPRC5B mRNA and protein levels. GPRC5B overexpression and knockdown increased and attenuated, respectively, the expression of the pro-inflammatory cytokines TNFα, IL-1ß, IL-6 as well as the pro-atherogenic vascular adhesion molecules ICAM-1 and VCAM-1. Furthermore, the expression and activity of the metalloproteinase MMP-9, a component of atherosclerotic plaque stabilization, were significantly enhanced by GPRC5B overexpression. Mechanistically, GPRC5B increased the phosphorylation of ERK1/2 and activated NFκB through a direct interaction with the tyrosine kinase Fyn. CONCLUSIONS: Our findings demonstrate that GPRC5B is upregulated in response to high glucose and pro-inflammatory signaling. GPRC5B functionally modulates the inflammatory activity in cells of the vascular wall, suggesting a pro-atherogenic GPRC5B-dependent positive feedback loop via Fyn and NFκB. Thus, GPRC5B warrants further attention as a novel pharmacological target for the treatment of vascular inflammation and possibly atherogenesis.

Selective and Marked Blockade of Endothelial Sprouting Behavior Using Paclitaxel and Related Pharmacologic Agents.

Whether alterations in the microtubule cytoskeleton affect the ability of endothelial cells (ECs) to sprout and form branching networks of tubes was investigated in this study. Bioassays of human EC tubulogenesis, where both sprouting behavior and lumen formation can be rigorously evaluated, were used to demonstrate that addition of the microtubule-stabilizing drugs, paclitaxel, docetaxel, ixabepilone, and epothilone B, completely interferes with EC tip cells and sprouting behavior, while allowing for EC lumen formation. In bioassays mimicking vasculogenesis using single or aggregated ECs, these drugs induce ring-like lumens from single cells or cyst-like spherical lumens from multicellular aggregates with no evidence of EC sprouting behavior. Remarkably, treatment of these cultures with a low dose of the microtubule-destabilizing drug, vinblastine, led to an identical result, with complete blockade of EC sprouting, but allowing for EC lumen formation. Administration of paclitaxel in vivo markedly interfered with angiogenic sprouting behavior in developing mouse retina, providing corroboration. These findings reveal novel biological activities for pharmacologic agents that are widely utilized in multidrug chemotherapeutic regimens for the treatment of human malignant cancers. Overall, this work demonstrates that manipulation of microtubule stability selectively interferes with the ability of ECs to sprout, a necessary step to initiate and form branched capillary tube networks.

3D printing of self-standing and vascular supportive multimaterial hydrogel structures for organ engineering.

Three dimensional printable formulation of self-standing and vascular-supportive structures using multi-materials suitable for organ engineering is of great importance and highly challengeable, but, it could advance the 3D printing scenario from printable shape to functional unit of human body. In this study, the authors report a 3D printable formulation of such self-standing and vascular-supportive structures using an in-house formulated multi-material combination of albumen/alginate/gelatin-based hydrogel. The rheological properties and relaxation behavior of hydrogels were analyzed before the printing process. The suitability of the hydrogel in 3D printing of various customizable and self-standing structures, including a human ear model, was examined by extrusion-based 3D printing. The structural, mechanical, and physicochemical properties of the printed scaffolds were studied systematically. Results supported the 3D printability of the formulated hydrogel with self-standing structures, which are customizable to a specific need. In vitro cell experiment showed that the formulated hydrogel has excellent biocompatibility and vascular supportive behavior with the extent of endothelial sprout formation when tested with human umbilical vein endothelial cells. In conclusion, the present study demonstrated the suitability of the extrusion-based 3D printing technique for manufacturing complex shapes and structures using multi-materials with high fidelity, which have great potential in organ engineering.

Global Reach 2018 Heightened α-Adrenergic Signaling Impairs Endothelial Function During Chronic Exposure to Hypobaric Hypoxia.

RATIONALE: Chronic exposure to hypoxia is associated with elevated sympathetic nervous activity and reduced vascular function in lowlanders, and Andean highlanders suffering from excessive erythrocytosis (EE); however, the mechanistic link between chronically elevated sympathetic nervous activity and hypoxia-induced vascular dysfunction has not been determined. OBJECTIVE: To determine the impact of heightened sympathetic nervous activity on resistance artery endothelial-dependent dilation (EDD), and endothelial-independent dilation, in lowlanders and Andean highlanders with and without EE. METHODS AND RESULTS: We tested healthy lowlanders (n=9) at sea level (344 m) and following 14 to 21 days at high altitude (4300 m), and permanent Andean highlanders with (n=6) and without (n=9) EE at high altitude. Vascular function was assessed using intraarterial infusions (3 progressive doses) of acetylcholine (ACh; EDD) and sodium nitroprusside (endothelial-independent dilation) before and after local α+ß adrenergic receptor blockade (phentolamine and propranolol). Intraarterial blood pressure, heart rate, and simultaneous brachial artery diameter and blood velocity were recorded at rest and during drug infusion. Changes in forearm vascular conductance were calculated. The main findings were (1) chronic hypoxia reduced EDD in lowlanders (changes in forearm vascular conductance from sea level: ACh1: -52.7±19.6%, ACh2: -25.4±38.7%, ACh3: -35.1±34.7%, all P≤0.02); and in Andeans with EE compared with non-EE (changes in forearm vascular conductance at ACh3: -36.4%, P=0.007). Adrenergic blockade fully restored EDD in lowlanders at high altitude, and normalized EDD between EE and non-EE Andeans. (2) Chronic hypoxia had no effect on endothelial-independent dilation in lowlanders, and no differences were detected between EE and non-EE Andeans; however, EID was increased in the non-EE Andeans after adrenergic blockade (P=0.012), but this effect was not observed in the EE Andeans. CONCLUSIONS: These data indicate that chronic hypoxia reduces EDD via heightened α-adrenergic signaling in lowlanders and in Andeans with EE. These vascular mechanisms have important implications for understanding the physiological consequences of acute and chronic high altitude adaptation.

The Noonan Syndrome Gene Lztr1 Controls Cardiovascular Function by Regulating Vesicular Trafficking.

RATIONALE: Noonan syndrome (NS) is one of the most frequent genetic disorders. Bleeding problems are among the most common, yet poorly defined complications associated with NS. A lack of consensus on the management of bleeding complications in patients with NS indicates an urgent need for new therapeutic approaches. OBJECTIVE: Bleeding disorders have recently been described in patients with NS harboring mutations of LZTR1 (leucine zipper-like transcription regulator 1), an adaptor for CUL3 (CULLIN3) ubiquitin ligase complex. Here, we assessed the pathobiology of LZTR1-mediated bleeding disorders. METHODS AND RESULTS: Whole-body and vascular specific knockout of Lztr1 results in perinatal lethality due to cardiovascular dysfunction. Lztr1 deletion in blood vessels of adult mice leads to abnormal vascular leakage. We found that defective adherent and tight junctions in Lztr1-depleted endothelial cells are caused by dysregulation of vesicular trafficking. LZTR1 affects the dynamics of fusion and fission of recycling endosomes by controlling ubiquitination of the ESCRT-III (endosomal sorting complex required for transport III) component CHMP1B (charged multivesicular protein 1B), whereas NS-associated LZTR1 mutations diminish CHMP1B ubiquitination. LZTR1-mediated dysregulation of CHMP1B ubiquitination triggers endosomal accumulation and subsequent activation of VEGFR2 (vascular endothelial growth factor receptor 2) and decreases blood levels of soluble VEGFR2 in Lztr1 haploinsufficient mice. Inhibition of VEGFR2 activity by cediranib rescues vascular abnormalities observed in Lztr1 knockout mice Conclusions: Lztr1 deletion phenotypically overlaps with bleeding diathesis observed in patients with NS. ELISA screening of soluble VEGFR2 in the blood of LZTR1-mutated patients with NS may predict both the severity of NS phenotypes and potential responders to anti-VEGF therapy. VEGFR inhibitors could be beneficial for the treatment of bleeding disorders in patients with NS.

Inhibition of Vascular Growth by Modulation of the Anandamide/Fatty Acid Amide Hydrolase Axis.

OBJECTIVE: Pathological 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. CONCLUSIONS: Thus, elevation of endogenous anandamide levels by FAAH inhibition represents a novel antiangiogenic mechanism.

FGF primes angioblast formation by inducing ETV2 and LMO2 via FGFR1/BRAF/MEK/ERK.

It is critical to specify a signal that directly drives the transition that occurs between cell states. However, such inferences are often confounded by indirect intercellular communications or secondary transcriptomic changes due to primary transcription factors. Although FGF is known for its importance during mesoderm-to-endothelium differentiation, its specific role and signaling mechanisms are still unclear due to the confounding factors referenced above. Here, we attempted to minimize the secondary artifacts by manipulating FGF and its downstream mediators with a short incubation time before sampling and protein-synthesis blockage in a low-density angioblastic/endothelial differentiation system. In less than 8 h, FGF started the conversion of KDRlow/PDGFRAlow nascent mesoderm into KDRhigh/PDGFRAlow angioblasts, and the priming by FGF was necessary to endow endothelial formation 72 h later. Further, the angioblastic conversion was mediated by the FGFR1/BRAF/MEK/ERK pathway in mesodermal cells. Finally, two transcription factors, ETV2 and LMO2, were the early direct functional responders downstream of the FGF pathway, and ETV2 alone was enough to complement the absence of FGF. FGF's selective role in mediating the first-step, angioblastic conversion from mesoderm-to-endothelium thus allows for refined control over acquiring and manipulating angioblasts. The noise-minimized differentiation/analysis platform presented here is well-suited for studies on the signaling switches of other mesodermal-lineage fates as well.

Inflammation as A Precursor of Atherothrombosis, Diabetes and Early Vascular Aging.

Vascular disease was for a long time considered a disease of the old age, but it is becoming increasingly clear that a cumulus of factors can cause early vascular aging (EVA). Inflammation plays a key role in vascular stiffening and also in other pathologies that induce vascular damage. There is a known and confirmed connection between inflammation and atherosclerosis. However, it has taken a long time to prove the beneficial effects of anti-inflammatory drugs on cardiovascular events. Diabetes can be both a product of inflammation and a cofactor implicated in the progression of vascular disease. When diabetes and inflammation are accompanied by obesity, this ominous trifecta leads to an increased incidence of atherothrombotic events. Research into earlier stages of vascular disease, and documentation of vulnerability to premature vascular disease, might be the key to success in preventing clinical events. Modulation of inflammation, combined with strict control of classical cardiovascular risk factors, seems to be the winning recipe. Identification of population subsets with a successful vascular aging (supernormal vascular aging-SUPERNOVA) pattern could also bring forth novel therapeutic interventions.

Blood Vessels: The Pathway Used by Schwann Cells to Colonize Nerve Conduits.

The repair of severe nerve injuries requires an autograft or conduit to bridge the gap and avoid axon dispersion. Several conduits are used routinely, but their effectiveness is comparable to that of an autograft only for short gaps. Understanding nerve regeneration within short conduits could help improve their efficacy for longer gaps. Since Schwann cells are known to migrate on endothelial cells to colonize the "nerve bridge", the new tissue spontaneously forming to connect the injured nerve stumps, here we aimed to investigate whether this migratory mechanism drives Schwann cells to also proceed within the nerve conduits used to repair large nerve gaps. Injured median nerves of adult female rats were repaired with 10 mm chitosan conduits and the regenerated nerves within conduits were analyzed at different time points using confocal imaging of sequential thick sections. Our data showed that the endothelial cells formed a dense capillary network used by Schwann cells to migrate from the two nerve stumps into the conduit. We concluded that angiogenesis played a key role in the nerve conduits, not only by supporting cell survival but also by providing a pathway for the migration of newly formed Schwann cells.

Novel Evidence-Based Combination of Plant Extracts with Multitarget Mechanisms of Action for the Elimination of Hot Flashes during Menopause.

Hot flashes are considered the most bothersome complaint during menopause. Although hormone therapy is an effective option to relieve hot flashes, it has been associated with significant side effects. The aim of our study is to suggest a novel combination of different plant extracts with distinct mechanisms of action against hot flashes. We selected the rhizome of Glycyrrhiza glabra L. (Fabaceae), the rhizome of Actaea racemosa L. (Ranunculaceae), the aerial parts of Hypericum perforatum L. (Hypericaceae) to produce extracts rich in bioactive phytochemicals and the seed oil of Oenothera biennis L. (Onagraceae). We investigated their estrogenic and antioxidant potential and their inhibitory effect against prostaglandin D2 receptor 1 (DP1) as a novel mechanistic pathway for vasodilation in hot flashes, alone or in combination. The phytochemical footprint of the extracts was analyzed using HPLC-PDA and UPLC-HRMS. We observed that the tested extracts possess different mechanisms of action. A. racemosa exerts a beneficial activation of the estrogen receptor, H. perforatum possesses the highest antioxidant capacity and the seed oil of O. biennis inhibits the DP1 receptor. The triple combination in the optimal doses pertains to efficacy against all three mechanisms of action, serves as a multitarget plant-based therapy and could serve as a novel strategy for the alleviation of hot flashes in postmenopausal women.

tPA Deficiency Underlies Neurovascular Coupling Dysfunction by Amyloid-ß.

The amyloid-ß (Aß) peptide, a key pathogenic factor in Alzheimer's disease, attenuates the increase in cerebral blood flow (CBF) evoked by neural activity (functional hyperemia), a vital homeostatic response in which NMDA receptors (NMDARs) play a role through nitric oxide, and the CBF increase produced by endothelial factors. Tissue plasminogen activator (tPA), which is reduced in Alzheimer's disease and in mouse models of Aß accumulation, is required for the full expression of the NMDAR-dependent component of functional hyperemia. Therefore, we investigated whether tPA is involved in the neurovascular dysfunction of Aß. tPA activity was reduced, and the tPA inhibitor plasminogen inhibitor-1 (PAI-1) was increased in male mice expressing the Swedish mutation of the amyloid precursor protein (tg2576). Counteracting the tPA reduction with exogenous tPA or with pharmacological inhibition or genetic deletion of PAI-1 completely reversed the attenuation of the CBF increase evoked by whisker stimulation but did not ameliorate the response to the endothelium-dependent vasodilator acetylcholine. The tPA deficit attenuated functional hyperemia by suppressing NMDAR-dependent nitric oxide production during neural activity. Pharmacological inhibition of PAI-1 increased tPA activity, prevented neurovascular uncoupling, and ameliorated cognition in 11- to 12-month-old tg2576 mice, effects associated with a reduction of cerebral amyloid angiopathy but not amyloid plaques. The data unveil a selective role of the tPA in the suppression of functional hyperemia induced by Aß and in the mechanisms of cerebral amyloid angiopathy, and support the possibility that modulation of the PAI-1-tPA pathway may be beneficial in diseases associated with amyloid accumulation.SIGNIFICANCE STATEMENT Amyloid-ß (Aß) peptides have profound neurovascular effects that may contribute to cognitive impairment in Alzheimer's disease. We found that Aß attenuates the increases in blood flow evoked by neural activation through a reduction in tissue plasminogen activator (tPA) caused by upregulation of its endogenous inhibitor plasminogen inhibitor-1 (PAI-1). tPA deficiency prevents NMDA receptors from triggering nitric oxide production, thereby attenuating the flow increase evoked by neural activity. PAI-1 inhibition restores tPA activity, rescues neurovascular coupling, reduces amyloid deposition around blood vessels, and improves cognition in a mouse model of Aß accumulation. The findings demonstrate a previously unappreciated role of tPA in Aß-related neurovascular dysfunction and in vascular amyloid deposition. Restoration of tPA activity could be of therapeutic value in diseases associated with amyloid accumulation.

Pseudolaric acid B ameliorates synovial inflammation and vessel formation by stabilizing PPARγ to inhibit NF-κB signalling pathway.

Synovial macrophage polarization and inflammation are essential for osteoarthritis (OA) development, yet the molecular mechanisms and regulation responsible for the pathogenesis are still poorly understood. Here, we report that pseudolaric acid B (PAB) attenuated articular cartilage degeneration and synovitis during OA. PAB, a diterpene acid, specifically inhibited NF-κB signalling and reduced the production of pro-inflammatory cytokines, which further decreased M1 polarization and vessel formation. We further provide in vivo and in vitro evidences that PAB suppressed NF-κB signalling by stabilizing PPARγ. Using PPARγ antagonist could abolish anti-inflammatory effect of PAB and rescue the activation of NF-κB signalling during OA. Our findings identify a previously unrecognized role of PAB in the regulation of OA and provide mechanisms by which PAB regulates NF-κB signalling through PPARγ, which further suggest targeting synovial inflammation or inhibiting vessel formation at early stage could be an effective preventive strategy for OA.

Adropin: a hepatokine modulator of vascular function and cardiac fuel metabolism.

Adropin is a nutritionally regulated peptide hormone, secreted primarily by the liver, which modulates metabolic homeostasis in a number of tissues. Growing evidence suggests that adropin is an important regulatory component in a number of cardiovascular pathologies, and may be central to the control of cardiac fuel metabolism and vascular function. In this mini-review, we examine the known facets of adropin biology, discuss open questions in the field, and speculate on the therapeutic potential of targeting adropin-related signaling pathways in cardiovascular diseases.

The incidence rate of pulmonary arterial hypertension and scleroderma renal crisis in systemic sclerosis patients with digital ulcers on endothelin antagonist receptors (ERAs) and phosphodiesterase-5 inhibitors (PDE5i).

INTRODUCTION: Endothelin antagonist receptors (ERAs) and phosphodiesterase-5 inhibitors (PDE5i) are beneficial in pulmonary arterial hypertension (PAH) and digital ulcers (DU) and prevent from DU recurrences. Our study aimed to determine the difference in the incidence rate of PAH and scleroderma renal crisis (SRC) in patients with SSc and DU (SSc-DU) under ERAs/PDE5i or without treatment. METHODS: We conducted a retrospective cohort study including SSc-DU patients from the Spanish Scleroderma Registry (RESCLE). The primary outcome was the incidence rate of PAH and SRC in patients under ERAs/PDE5i or not. RESULTS: Some 544 patients out of 1817 (29.9%) in the RESCLE database had DU, 221 (40.6%) under ERAs/PDE5i and 323 (59.4%) not. The incidence rate (95% CI) difference between patients under treatment or not under did not reach statistical significance in PAH [-0.1 (-4.8, 4.69), P = 0.988] or in SRC [0.7 (-2.2, 3.7), P = 0.620]. However, the time from the first DU to the diagnosis of SRC was delayed in treated patients [mean (s.d.) 7.6 (5.8) years vs 2.9 (5.3); P = 0.021]. The dcSSc subset was more prevalent in the treatment group (36 vs 26%; P = 0.018), along with anti-topoisomerase I antibodies (34 vs 18%; P < 0.001) and tendon friction rubs (12 vs 6%; P = 0.038), whereas the lcSSc subset was more prevalent in the no-treatment group (57 vs 66%; P = 0.031) along with ACA (37 vs 46%; P = 0.031). CONCLUSION: There was no difference in the incidence rate of PAH and SRC between groups. However, treatment with ERAs and/or PDE5i appeared to delay the occurrence of SRC.

Possible Mechanism of Human Recombinant Leptin-Induced VEGF A Synthesis via PI3K/Akt/mTOR/S6 Kinase Signaling Pathway while Inducing Angiogenesis: An Analysis Using Chicken Chorioallantoic Membrane Model.

INTRODUCTION: The present study aimed to realize human recombinant leptin 's ability to synthesize VEGF A while inducing neovascularization through PI3K/Akt/mTOR/S6 kinase involved signaling pathway. METHODS: To examine the PI3K/Akt/mTOR/S6 kinase pathway involvement in leptin-induced VEGF A synthesis, the chick chorioallantoic membrane (CAM) was incubated with human recombinant leptin and specific inhibitors of the proposed signaling molecules (rapamycin and wortmannin). We analyzed the role of specified signaling molecules in human recombinant leptin-induced physiological angiogenesis via VEGF A synthesis in detail with the support of various methodologies. RESULTS: Human recombinant leptin's ability to synthesize VEGF A is diminished significantly in the presence of inhibitors. This observation supported the role of PI3K/Akt/mTOR/S6 kinase signaling molecules in human recombinant leptin-mediated VEGF A synthesis while inducing angiogenesis in CAM. CONCLUSION: Synthesis of VEGF A, followed by the growth of new blood vessels, by human recombinant leptin via the activation of the PI3K/Akt/mTOR/S6 kinase signaling pathway reflects mechanistic therapeutic application of human recombinant leptin. The data also signify the role of mTOR and S6 kinase molecules in angiogenesis under a physiological environment.