Atherosclerosis, a dominant and growing cause of death and disability worldwide, involves inflammation from its inception to the emergence of complications. Targeting inflammatory pathways could therefore provide a promising new avenue to prevent and treat atherosclerosis. Indeed, clinical studies have now demonstrated unequivocally that modulation of inflammation can forestall the clinical complications of atherosclerosis. This progress pinpoints the need for preclinical investigations to refine strategies for combatting inflammation in the human disease. In this Review, we consider a gamut of attractive possibilities for modifying inflammation in atherosclerosis, including targeting pivotal inflammatory pathways such as the inflammasomes, inhibiting cytokines, manipulating adaptive immunity and promoting pro-resolution mechanisms. Along with lifestyle measures, pharmacological interventions to mute inflammation could complement traditional targets, such as lipids and hypertension, to make new inroads into the management of atherosclerotic risk. The contribution of inflammation to atherosclerosis is substantial, and is just beginning to be understood. In this Review, Soehnlein and Libby discuss how inflammation promotes atherosclerosis and its consequences, and how such processes could be targeted therapeutically. The potential pitfalls of targeting immune processes — namely the increased potential for infections — are also discussed, along with ways to modulate cardiovascular therapies in time and space to make them more effective.

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Targeting inflammation in atherosclerosis — from experimental insights to the clinic

Caspases are cysteine proteases that mediate apoptosis, which is a form of regulated cell death that effectively and efficiently removes extra and unnecessary cells during development. In the mature nervous system, caspases are not only involved in mediating cell death but also regulatory events that are important for neural functions, such as axon pruning and synapse elimination, which are necessary to refine mature neuronal circuits. Furthermore, caspases can be reactivated to cause cell death as well as non-lethal changes in neurons during numerous pathological processes. Thus, although a global activation of caspases leads to apoptosis, restricted and localized activation may control normal physiology and pathophysiology in living neurons. This Review explores the multiple roles of caspase activity in neurons.

Apoptotic and non-apoptotic roles of caspases in neuronal physiology and pathophysiology.

Ischemic stroke is associated with motor impairment and increased incidence of affective disorders such as anxiety/clinical depression. In non-stroke populations, successful management of such disorders and symptoms has been reported following diet supplementation with long chain omega-3-polyunsaturated-fatty-acids (PUFAs). However, the potential protective effects of PUFA supplementation on affective behaviors after experimentally induced stroke and sham surgery have not been examined previously. This study investigated the behavioral effects of PUFA supplementation over a 6-week period following either middle cerebral artery occlusion or sham surgery in the hooded-Wistar rat. The PUFA diet supplied during the acclimation period prior to surgery was found to be associated with an increased risk of acute hemorrhage following the reperfusion component of the surgery. In surviving animals, PUFA supplementation did not influence infarct size as determined 6 weeks after surgery, but did decrease omega-6-fatty-acid levels, moderate sickness behaviors, acute motor impairment, and longer-term locomotor hyperactivity and depression/anxiety-like behavior.

/pdf/fish-oil-diet-associated-with-acute-reperfusion-related-3lseailzqt.pdf

Fish Oil Diet Associated with Acute Reperfusion Related Hemorrhage, and with Reduced Stroke-Related Sickness Behaviors and Motor Impairment

Cell based therapies for ischemic stroke: from basic science to bedside.

Atherosclerosis: Recent developments

Background: Smooth muscle cells (SMCs) play significant roles in atherosclerosis via phenotypic switching, a pathological process in which SMC dedifferentiation, migration, and transdifferentiation...

https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.120.048378?download=true

Single-Cell Genomics Reveals a Novel Cell State During Smooth Muscle Cell Phenotypic Switching and Potential Therapeutic Targets for Atherosclerosis in Mouse and Human.

Despite extensive research to develop an effective neuroprotective strategy for the treatment of ischemic stroke, therapeutic options remain limited. Although caspase-dependent death is thought to play a prominent role in neuronal injury, direct evidence of active initiator caspases in stroke and the functional relevance of this activity have not previously been shown. Using an unbiased caspase-trapping technique in vivo, we isolated active caspase-9 from ischemic rat brain within 1 h of reperfusion. Pathogenic relevance of active caspase-9 was shown by intranasal delivery of a novel cell membrane-penetrating highly specific inhibitor for active caspase-9 at 4 h postreperfusion (hpr). Caspase-9 inhibition provided neurofunctional protection and established caspase-6 as its downstream target. The temporal and spatial pattern of expression demonstrates that neuronal caspase-9 activity induces caspase-6 activation, mediating axonal loss by 12 hpr followed by neuronal death within 24 hpr. Collectively, these results support selective inhibition of these specific caspases as an effective therapeutic strategy for stroke.

https://www.jneurosci.org/content/jneuro/31/24/8894.full.pdf

Intranasal delivery of caspase-9 inhibitor reduces caspase-6-dependent axon/neuron loss and improves neurological function after stroke.

Macrophages play important roles in many diseases. We describe a protocol and the associated resources for the differentiation of human induced pluripotent stem cell-derived macrophages (IPSDM) and their applications in understanding human macrophage physiology and relevant diseases. The protocol uses an embryoid body-based approach with a combination of serum-free condition for hematopoiesis specification, followed by adherent culture with serum and M-CSF for myeloid expansion and macrophage maturation. The protocol produced an almost pure culture of CD45+ /CD18+ macrophages yielding up to 2 × 107 cells per 6-well plate of iPSCs within 24 days, demonstrating high efficiency, purity, and scalability. The IPSDM and monocyte-derived macrophages (HMDM) cultured in the same medium were compared at morphological, functional and transcriptomic levels by RNA-sequencing. IPSDM and HMDM showed broadly similar profiles of coding transcriptome, alternative splicing events, and long noncoding RNAs, with advantages and successful applications in disease modeling using patients-derived and CRISPR-edited iPSC lines. © 2018 by John Wiley & Sons, Inc.

Differentiation of Human-Induced Pluripotent Stem Cells to Macrophages for Disease Modeling and Functional Genomics


 Background:
 Dysfunctional adipose tissue (AT), characterized by increased inflammation and immune cell recruitment, plays a central role in the development of T2DM and atherosclerotic CVDs. LincRNAs are important emerging regulators of cellular functions.
 
 
 Methods:
 RNA-seq of human AT during low-dose endotoxemia, identified novel lincRNAs regulated by inflammation. LincADAIN was identified as 1)specifically expressed in AT 2)reduced in both obesity-induced chronic and LPS-induced acute AT inflammation (-77% and -53%, p<0.05). Most lincRNAs (~80%) are not conserved hence, we utilized a humanized mouse model. NSG mice are transplanted with human ASC-adipocytes that have undergone lentiviral shRNA knockdown and adipogenic induction
 in vitro
 , prior to injection. After 16 weeks, implants are extracted and analyzed for adipocyte morphology, immune cell infiltration and gene expression changes. Biotinylated lincRNA pulldown assay was used to identify interacting proteins by Mass Spectrometry (MS) and hits validated via RNA IP assays. Cytokines from LPS stimulated adipocytes after Linc-ADAIN KD were measured via cytokine array.
 
 
 Results:
 Human LincADAIN expression negatively correlates to BMI in obese AT (p<0.001, r2-0.3042). PPARγ antagonist treatment reduced LincADAIN expression. KD of LincADAIN in ASC-adipocytes, increased protein but not mRNA levels of inflammatory cytokines, IL-8 and MCP-1. Cellular fractionation shows that LincADAIN is mostly cytoplasmic. MS analysis of LincADAIN pulldown proteins revealed central RNA binding proteins (RBPs) such as HuR, as potential interactors, which may post-transcriptionally regulate inflammatory cytokines. Changes in human circulating adiponectin was detected in the NSG mouse serum, indicating the implants are functional.
 
 
 Conclusion:
 Linc-ADAIN is a novel lincRNA that can regulate AT inflammation potentially through modulation of RNA translation via RBPs. Our mouse model provides a foundation to uncover Linc-ADAIN’s role in AT inflammation
 in vivo
 and to study other non-conserved human lincRNAs. Functional investigations of lincRNAs, such as these are warranted, as recent genomic studies suggest that lincRNAs are likely the causal element driving human disease at some GWAS loci.


Wen Liu

Papers

Single-Cell Genomics Reveals a Novel Cell State During Smooth Muscle Cell Phenotypic Switching and Potential Therapeutic Targets for Atherosclerosis in Mouse and Human.

Intranasal delivery of caspase-9 inhibitor reduces caspase-6-dependent axon/neuron loss and improves neurological function after stroke.

Differentiation of Human-Induced Pluripotent Stem Cells to Macrophages for Disease Modeling and Functional Genomics

Abstract 432: Linc-ADAIN, A Novel Human Adipose LincRNA Modulated By Obesity, Can Regulate Adipocyte Cytokine Secretion.