Generation of complex bone marrow organoids from human induced pluripotent stem cells.

The human bone marrow (BM) niche sustains hematopoiesis throughout life. We present a method for generating complex BM-like organoids (BMOs) from human induced pluripotent stem cells (iPSCs). BMOs consist of key cell types that self-organize into spatially defined three-dimensional structures mimicking cellular, structural and molecular characteristics of the hematopoietic microenvironment.

Targeting a cell-specific microRNA repressor of CXCR4 ameliorates atherosclerosis in mice.

The CXC chemokine receptor 4 (CXCR4) in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) is crucial for vascular integrity. The atheroprotective functions of CXCR4 in vascular cells may be counteracted by atherogenic functions in other nonvascular cell types. Thus, strategies for cell-specifically augmenting CXCR4 function in vascular cells are crucial if this receptor is to be useful as a therapeutic target in treating atherosclerosis and other vascular disorders.

Ex Vivo Perfusion System to Analyze Chemokine-Driven Leukocyte Adhesion.

At the moment, many researchers are using in vitro techniques to investigate chemokine-driven leukocyte adhesion/recruitment, for example, by using a transwell or flow chamber system. Here we describe a more physiologically relevant, sophisticated, and highly flexible method to study leukocyte adhesion ex vivo in fresh murine carotid arteries under arterial flow conditions. This model mimics an in vivo situation and allows the combination of leukocytes and arteries isolated from different donors in one experiment, generating information on both vascular and leukocyte adhesive properties of both donors.

The Amino Acid Homoarginine Inhibits Atherogenesis by Modulating T-Cell Function.

Background: Amino acid metabolism is crucial for inflammatory processes during atherogenesis. The endogenous amino acid homoarginine is a robust biomarker for cardiovascular outcome and mortality with high levels being protective. However, the underlying mechanisms remain elusive.

Heterocomplexes between the atypical chemokine MIF and the CXC-motif chemokine CXCL4L1 regulate inflammation and thrombus formation.

To fulfil its orchestration of immune cell trafficking, a network of chemokines and receptors developed that capitalizes on specificity, redundancy, and functional selectivity. The discovery of heteromeric interactions in the chemokine interactome has expanded the complexity within this network. Moreover, some inflammatory mediators, not structurally linked to classical chemokines, bind to chemokine receptors and behave as atypical chemokines (ACKs).

Designed peptides as nanomolar cross-amyloid inhibitors acting via supramolecular nanofiber co-assembly.

Amyloid self-assembly is linked to numerous devastating cell-degenerative diseases. However, designing inhibitors of this pathogenic process remains a major challenge. Cross-interactions between amyloid-β peptide (Aβ) and islet amyloid polypeptide (IAPP), key polypeptides of Alzheimer's disease (AD) and type 2 diabetes (T2D), have been suggested to link AD with T2D pathogenesis.

Endothelial ENPP2 (Ectonucleotide Pyrophosphatase/Phosphodiesterase 2) Increases Atherosclerosis in Female and Male Mice.

Background: Maladapted endothelial cells (ECs) secrete ENPP2 (ectonucleotide pyrophosphatase/phosphodiesterase 2; autotaxin)-a lysophospholipase D that generates lysophosphatidic acids (LPAs). ENPP2 derived from the arterial wall promotes atherogenic monocyte adhesion induced by generating LPAs, such as arachidonoyl-LPA (LPA20:4), from oxidized lipoproteins. Here, we aimed to determine the role of endothelial ENPP2 in the production of LPAs and atherosclerosis.

Neuroimmune cardiovascular interfaces control atherosclerosis.

Atherosclerotic plaques develop in the inner intimal layer of arteries and can cause heart attacks and strokes. As plaques lack innervation, the effects of neuronal control on atherosclerosis remain unclear. However, the immune system responds to plaques by forming leukocyte infiltrates in the outer connective tissue coat of arteries (the adventitia).

Targeting platelet-derived CXCL12 impedes arterial thrombosis.

The prevention and treatment of arterial thrombosis continue to be clinically challenging, and understanding the relevant molecular mechanisms in detail may facilitate the quest to identify novel targets and therapeutic approaches that improve protection from ischemic and bleeding events. The chemokine CXCL12 augments collagen-induced platelet aggregation by activating its receptor CXCR4. Here we show that inhibition of CXCR4 attenuates platelet aggregation induced by collagen or human plaque homogenate under static and arterial flow conditions by antagonizing the action of platelet-secreted CXCL12.

Properties and fate of human mesenchymal stem cells upon miRNA let-7f-promoted recruitment to atherosclerotic plaques.

Aims: Atherosclerosis is a chronic inflammatory disease of the arteries leading to the formation of atheromatous plaques. Human mesenchymal stem cells (hMSCs) are recruited from the circulation into plaques where in response to their environment they adopt a phenotype with immunomodulatory properties. However, the mechanisms underlying hMSC function in these processes are unclear.

Tissue Clearing Approaches in Atherosclerosis.

Recent advances in cardiovascular research have led to a more comprehensive understanding of molecular mechanisms of atherosclerosis. It has become apparent that the disease involves three layers of the arterial wall: the intima, the media, and a connective tissue coat termed the adventitia. It is also now appreciated that arteries are surrounded by adipose and neuronal tissues.

Improved Quantification of Cell Density in the Arterial Wall-A Novel Nucleus Splitting Approach Applied to 3D Two-Photon Laser-Scanning Microscopy.

Accurate information on vascular smooth muscle cell (VSMC) content, orientation, and distribution in blood vessels is indispensable to increase understanding of arterial remodeling and to improve modeling of vascular biomechanics. We have previously proposed an analysis method to automatically characterize VSMC orientation and transmural distribution in murine carotid arteries under well-controlled biomechanical conditions. However, coincident nuclei, erroneously detected as one large nucleus, were excluded from the analysis, hampering accurate VSMC content characterization and distorting transmural distributions.

Endothelial Retargeting of AAV9 In Vivo.

Adeno-associated viruses (AAVs) are frequently used for gene transfer and gene editing in vivo, except for endothelial cells, which are remarkably resistant to unmodified AAV-transduction. AAVs are retargeted here toward endothelial cells by coating with second-generation polyamidoamine dendrimers (G2) linked to endothelial-affine peptides (CNN). G2 AAV9-Cre (encoding Cre recombinase) are injected into mTmG-mice or mTmG-pigs, cell-specifically converting red to green fluorescence upon Cre-activity.

MicroRNA-21 Controls Circadian Regulation of Apoptosis in Atherosclerotic Lesions.

Background: The necrotic core partly formed by ineffective efferocytosis increases the risk of an atherosclerotic plaque rupture. Microribonucleic acids contribute to necrotic core formation by regulating efferocytosis and macrophage apoptosis. Atherosclerotic plaque rupture occurs at increased frequency in the early morning, indicating diurnal changes in plaque vulnerability.

Cell-specific and divergent roles of the CD40L-CD40 axis in atherosclerotic vascular disease.

Atherosclerosis is a major underlying cause of cardiovascular disease. Previous studies showed that inhibition of the co-stimulatory CD40 ligand (CD40L)-CD40 signaling axis profoundly attenuates atherosclerosis. As CD40L exerts multiple functions depending on the cell-cell interactions involved, we sought to investigate the function of the most relevant CD40L-expressing cell types in atherosclerosis: T cells and platelets.

T cells armed with C-X-C chemokine receptor type 6 enhance adoptive cell therapy for pancreatic tumours.

The efficacy of adoptive cell therapy for solid tumours is hampered by the poor accumulation of the transferred T cells in tumour tissue. Here, we show that forced expression of C-X-C chemokine receptor type 6 (whose ligand is highly expressed by human and murine pancreatic cancer cells and tumour-infiltrating immune cells) in antigen-specific T cells enhanced the recognition and lysis of pancreatic cancer cells and the efficacy of adoptive cell therapy for pancreatic cancer. In mice with subcutaneous pancreatic tumours treated with T cells with either a transgenic T-cell receptor or a murine chimeric antigen receptor targeting the tumour-associated antigen epithelial cell adhesion molecule, and in mice with orthotopic pancreatic tumours or patient-derived xenografts treated with T cells expressing a chimeric antigen receptor targeting mesothelin, the T cells exhibited enhanced intratumoral accumulation, exerted sustained anti-tumoral activity and prolonged animal survival only when co-expressing C-X-C chemokine receptor type 6.

An integrated set-up for ex vivo characterisation of biaxial murine artery biomechanics under pulsatile conditions.

Ex vivo characterisation of arterial biomechanics enables detailed discrimination of the various cellular and extracellular contributions to arterial stiffness. However, ex vivo biomechanical studies are commonly performed under quasi-static conditions, whereas dynamic biomechanical behaviour (as relevant in vivo) may differ substantially. Hence, we aim to (1) develop an integrated set-up for quasi-static and dynamic biaxial biomechanical testing, (2) quantify set-up reproducibility, and (3) illustrate the differences in measured arterial stiffness between quasi-static and dynamic conditions.

Designed CXCR4 mimic acts as a soluble chemokine receptor that blocks atherogenic inflammation by agonist-specific targeting.

Targeting a specific chemokine/receptor axis in atherosclerosis remains challenging. Soluble receptor-based strategies are not established for chemokine receptors due to their discontinuous architecture. Macrophage migration-inhibitory factor (MIF) is an atypical chemokine that promotes atherosclerosis through CXC-motif chemokine receptor-4 (CXCR4).

A MIF-Derived Cyclopeptide that Inhibits MIF Binding and Atherogenic Signaling via the Chemokine Receptor CXCR2.

Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine and atypical chemokine with a key role in inflammatory diseases including atherosclerosis. Key atherogenic functions of MIF are mediated by noncognate interaction with the chemokine receptor CXCR2. The MIF N-like loop comprising the sequence 47-56 is an important structural determinant of the MIF/CXCR2 interface and MIF(47-56) blocks atherogenic MIF activities.

Autophagy unleashes noncanonical microRNA functions.

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression which act by guiding AGO (argonaute) proteins to target RNA transcripts in the RNA-induced silencing complex (RISC). This macromolecular complex includes multiple additional components (., TNRC6A) that allow for interaction with enzymes mediating inhibition of translation or RNA decay.