MicroRNA-155 Deficiency Leads to Decreased Atherosclerosis, Increased White Adipose Tissue Obesity, and Non-alcoholic Fatty Liver Disease: A NOVEL MOUSE MODEL OF OBESITY PARADOX.

Obesity paradox (OP) describes a widely observed clinical finding of improved cardiovascular fitness and survival in some overweight or obese patients. The molecular mechanisms underlying OP remain enigmatic partly due to a lack of animal models mirroring OP in patients. Using apolipoprotein E knock-out (apoE-/-) mice on a high fat (HF) diet as an atherosclerotic obesity model, we demonstrated 1) microRNA-155 (miRNA-155, miR-155) is significantly up-regulated in the aortas of apoE-/- mice, and miR-155 deficiency in apoE-/- mice inhibits atherosclerosis; 2) apoE-/-/miR-155-/- (double knock-out (DKO)) mice show HF diet-induced obesity, adipocyte hypertrophy, and present with non-alcoholic fatty liver disease; 3) DKO mice demonstrate HF diet-induced elevations of plasma leptin, resistin, fed-state and fasting insulin and increased expression of adipogenic transcription factors but lack glucose intolerance and insulin resistance. Our results are the first to present an OP model using DKO mice with features of decreased atherosclerosis, increased obesity, and non-alcoholic fatty liver disease. Our findings suggest the mechanistic role of reduced miR-155 expression in OP and present a new OP working model based on a single miRNA deficiency in diet-induced obese atherogenic mice. Furthermore, our results serve as a breakthrough in understanding the potential mechanism underlying OP and provide a new biomarker and novel therapeutic target for OP-related metabolic diseases.

Interleukin-17A Promotes Aortic Endothelial Cell Activation via Transcriptionally and Post-translationally Activating p38 Mitogen-activated Protein Kinase (MAPK) Pathway.

Interleukin-17 (IL-17)-secreting T helper 17 cells were recently identified as a CD4(+) T helper subset and implicated in various inflammatory and autoimmune diseases. The issues of whether and by what mechanism hyperlipidemic stress induces IL-17A to activate aortic endothelial cells (ECs) and enhance monocyte adhesion remained largely unknown. Using biochemical, immunological, microarray, experimental data mining analysis, and pathological approaches focused on primary human and mouse aortic ECs (HAECs and MAECs) and our newly generated apolipoprotein E (ApoE)(-/-)/IL-17A(-/-) mice, we report the following new findings. 1) The hyperlipidemia stimulus oxidized low density lipoprotein up-regulated IL-17 receptor(s) in HAECs and MAECs. 2) IL-17A activated HAECs and increased human monocyte adhesion in vitro. 3) A deficiency of IL-17A reduced leukocyte adhesion to endothelium in vivo. 3) IL-17A activated HAECs and MAECs via up-regulation of proinflammatory cytokines IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), chemokine CXC motif ligand 1 (CXCL1), and CXCL2. 4) IL-17A activated ECs specifically via the p38 mitogen-activated protein kinases (MAPK) pathway; the inhibition of p38 MAPK in ECs attenuated IL-17A-mediated activation by ameliorating the expression of the aforementioned proinflammatory cytokines, chemokines, and EC adhesion molecules including intercellular adhesion molecule 1. Taken together, our results demonstrate for the first time that IL-17A activates aortic ECs specifically via p38 MAPK pathway.

Inhibition of Caspase-1 Activation in Endothelial Cells Improves Angiogenesis: A NOVEL THERAPEUTIC POTENTIAL FOR ISCHEMIA.

Deficient angiogenesis may contribute to worsen the prognosis of myocardial ischemia, peripheral arterial disease, ischemic stroke, etc. Dyslipidemic and inflammatory environments attenuate endothelial cell (EC) proliferation and angiogenesis, worsening the prognosis of ischemia. Under these dyslipidemic and inflammatory environments, EC-caspase-1 becomes activated and induces inflammatory cell death that is defined as pyroptosis. However, the underlying mechanism that correlates caspase-1 activation with angiogenic impairment and the prognosis of ischemia remains poorly defined. By using flow cytometric analysis, enzyme and receptor inhibitors, and hind limb ischemia model in caspase-1 knock-out (KO) mice, we examined our novel hypothesis, i.e. inhibition of caspase-1 in ECs under dyslipidemic and inflammatory environments attenuates EC pyroptosis, improves EC survival mediated by vascular endothelial growth factor receptor 2 (VEGFR-2), angiogenesis, and the prognosis of ischemia. We have made the following findings. Proatherogenic lipids induce higher caspase-1 activation in larger sizes of human aortic endothelial cells (HAECs) than in smaller sizes of HAECs. Proatherogenic lipids increase pyroptosis significantly more in smaller sizes of HAECs than in larger sizes of the cells. VEGFR-2 inhibition increases caspase-1 activation in HAECs induced by lysophosphatidylcholine treatment. Caspase-1 activation inhibits VEGFR-2 expression. Caspase-1 inhibition improves the tube formation of lysophosphatidylcholine-treated HAECs. Finally, caspase-1 depletion improves angiogenesis and blood flow in mouse hind limb ischemic tissues. Our results have demonstrated for the first time that inhibition of proatherogenic caspase-1 activation in ECs improves angiogenesis and the prognosis of ischemia.

Early hyperlipidemia promotes endothelial activation via a caspase-1-sirtuin 1 pathway.

OBJECTIVE: The role of receptors for endogenous metabolic danger signals-associated molecular patterns has been characterized recently as bridging innate immune sensory systems for danger signals-associated molecular patterns to initiation of inflammation in bone marrow-derived cells, such as macrophages. However, it remains unknown whether endothelial cells (ECs), the cell type with the largest numbers and the first vessel cell type exposed to circulating danger signals-associated molecular patterns in the blood, can sense hyperlipidemia. This report determined whether caspase-1 plays a role in ECs in sensing hyperlipidemia and promoting EC activation. APPROACH AND RESULTS: Using biochemical, immunologic, pathological, and bone marrow transplantation methods together with the generation of new apoplipoprotein E (ApoE)(-/-)/caspase-1(-/-) double knockout mice, we made the following observations: (1) early hyperlipidemia induced caspase-1 activation in ApoE(-/-) mouse aorta; (2) caspase-1(-/-)/ApoE(-/-) mice attenuated early atherosclerosis; (3) caspase-1(-/-)/ApoE(-/-) mice had decreased aortic expression of proinflammatory cytokines and attenuated aortic monocyte recruitment; and (4) caspase-1(-/-)/ApoE(-/-) mice had decreased EC activation, including reduced adhesion molecule expression and cytokine secretion. Mechanistically, oxidized lipids activated caspase-1 and promoted pyroptosis in ECs by a reactive oxygen species mechanism. Caspase-1 inhibition resulted in accumulation of sirtuin 1 in the ApoE(-/-) aorta, and sirtuin 1 inhibited caspase-1 upregulated genes via activator protein-1 pathway. CONCLUSIONS: Our results demonstrate for the first time that early hyperlipidemia promotes EC activation before monocyte recruitment via a caspase-1-sirtuin 1-activator protein-1 pathway, which provides an important insight into the development of novel therapeutics for blocking caspase-1 activation as early intervention of metabolic cardiovascular diseases and inflammations.

Fetal demise and Wernicke-Korsakoff syndrome in a patient with hyperemesis gravidarum: a case report.

BACKGROUND: Wernicke-Korsakoff syndrome is a neuropsychiatric disorder caused by thiamine deficiency composed of two related disorders accounting for an acute presentation and chronic progression. Hyperemesis gravidarum presents a significant risk factor for Wernicke-Korsakoff syndrome as symptoms may rapidly progress in the setting of pregnancy. We present the first-reported case of hyperemesis-gravidarum-associated Wernicke encephalopathy in a patient in the first half of pregnancy in which a missed diagnosis led to septic shock, fetal demise, and eventual profound Korsakoff syndrome. CASE PRESENTATION: We present the case of a 33-year-old primigravid African American woman at 15 weeks gestational age who initially presented at a community emergency department with nausea and vomiting that ultimately progressed to severe hyperemesis-gravidarum-associated Wernicke-Korsakoff syndrome, fetal demise, and septic shock. The patient received a total of 6 weeks of high-dose parenteral thiamine. Magnetic resonance imaging of the head and formal neuropsychological assessment following treatment plateau confirmed the diagnosis of Wernicke-Korsakoff syndrome. CONCLUSIONS: The multisystem complications seen in severe thiamine deficiency can delay timely administration of high-dose thiamine, particularly in pregnancy, in which the classic triad of Wernicke-Korsakoff syndrome may not raise clinical suspicion due to rapid progression of neurological sequelae in this population. We advise a low threshold for parenteral thiamine repletion in pregnant women with persistent vomiting as hyperemesis gravidarum-induced severe thiamine deficiency can result in Wernicke-Korsakoff syndrome, sepsis, and fetal demise.

Association Among Chronic Obstructive Pulmonary Disease Severity, Exacerbation Risk, and Anxiety and Depression Symptoms in the SPIROMICS Cohort.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a common, progressive lung disease that often manifests with psychiatric symptoms. Despite this, patients with COPD are not routinely screened for anxiety and depression, which substantially contribute to COPD-related morbidity. OBJECTIVE: To determine the relationship among COPD symptom severity, exacerbation risk, and clinically significant anxiety and depression symptoms in ever smokers with COPD. METHODS: We used baseline data from the Subpopulations and Intermediate Outcome Measures In COPD Study (SPIROMICS) cohort to examine ever smokers with COPD across Global Initiative for Obstructive Lung Disease (GOLD) disease severity groups. Multivariable logistic regression models were used to calculate odds ratios for clinically significant anxiety and depression for each GOLD group, which was compared to the control group of ever smokers without COPD. Odds ratios were adjusted for subject demographics, medical comorbidities, and substance use covariates, and comparisons were completed using 2-tailed tests. RESULTS: Of the 2664 subjects studied, 784 (29.4%) had clinically significant anxiety, and 497 (18.7%) had clinically significant depression. In the multivariable analysis, high pulmonary symptom groups, groups B and D, had increased adjusted odds of clinically significant anxiety (group B: adjusted odds ratios [AOR] 1.28, P = 0.03; group D: AOR 1.95, P < 0.0001) and depression (group B: AOR 2.09, P < 0.0001; group D: AOR 3.04, P < 0.0001). GOLD group D, the group with high pulmonary symptoms and high COPD exacerbation risk, had the greatest risk of both anxiety and depression among the GOLD groups. CONCLUSIONS: High COPD symptom severity, even in the absence of elevated COPD exacerbation risk, is associated with clinically significant anxiety and depression. Our separate analyses of anxiety and depression symptoms in a large, multisite, national cohort are unique within the literature and have important treatment implications for COPD patients. Our findings also highlight the utility of screening patients with high COPD symptom severity for anxiety and depression.

Endothelial Immunity Trained by Coronavirus Infections, DAMP Stimulations and Regulated by Anti-Oxidant NRF2 May Contribute to Inflammations, Myelopoiesis, COVID-19 Cytokine Storms and Thromboembolism.

To characterize transcriptomic changes in endothelial cells (ECs) infected by coronaviruses, and stimulated by DAMPs, the expressions of 1311 innate immune regulatomic genes (IGs) were examined in 28 EC microarray datasets with 7 monocyte datasets as controls. We made the following findings: The majority of IGs are upregulated in the first 12 hours post-infection (PI), and maintained until 48 hours PI in human microvascular EC infected by middle east respiratory syndrome-coronavirus (MERS-CoV) (an EC model for COVID-19). The expressions of IGs are modulated in 21 human EC transcriptomic datasets by various PAMPs/DAMPs, including LPS, LPC, shear stress, hyperlipidemia and oxLDL. Upregulation of many IGs such as nucleic acid sensors are shared between ECs infected by MERS-CoV and those stimulated by PAMPs and DAMPs. Human heart EC and mouse aortic EC express all four types of coronavirus receptors such as ANPEP, CEACAM1, ACE2, DPP4 and virus entry facilitator TMPRSS2 (heart EC); most of coronavirus replication-transcription protein complexes are expressed in HMEC, which contribute to viremia, thromboembolism, and cardiovascular comorbidities of COVID-19. ECs have novel trained immunity (TI), in which subsequent inflammation is enhanced. Upregulated proinflammatory cytokines such as TNFα, IL6, CSF1 and CSF3 and TI marker IL-32 as well as TI metabolic enzymes and epigenetic enzymes indicate TI function in HMEC infected by MERS-CoV, which may drive cytokine storms. Upregulated CSF1 and CSF3 demonstrate a novel function of ECs in promoting myelopoiesis. Mechanistically, the ER stress and ROS, together with decreased mitochondrial OXPHOS complexes, facilitate a proinflammatory response and TI. Additionally, an increase of the regulators of mitotic catastrophe cell death, apoptosis, ferroptosis, inflammasomes-driven pyroptosis in ECs infected with MERS-CoV and the upregulation of pro-thrombogenic factors increase thromboembolism potential. Finally, NRF2-suppressed ROS regulate innate immune responses, TI, thrombosis, EC inflammation and death. These transcriptomic results provide novel insights on the roles of ECs in coronavirus infections such as COVID-19, cardiovascular diseases (CVD), inflammation, transplantation, autoimmune disease and cancers.

Canonical Secretomes, Innate Immune Caspase-1-, 4/11-Gasdermin D Non-Canonical Secretomes and Exosomes May Contribute to Maintain Treg-Ness for Treg Immunosuppression, Tissue Repair and Modulate Anti-Tumor Immunity via ROS Pathways.

We performed a transcriptomic analyses using the strategies we pioneered and made the following findings: 1) Normal lymphoid Tregs, diseased kidney Tregs, splenic Tregs from mice with injured muscle have 3, 17 and 3 specific (S-) pathways, respectively; 2) Tumor splenic Tregs share 12 pathways with tumor Tregs; tumor splenic Tregs and tumor Tregs have 11 and 8 S-pathways, respectively; 3) Normal and non-tumor disease Tregs upregulate some of novel 2641 canonical secretomic genes (SGs) with 24 pathways, and tumor Tregs upregulate canonical secretomes with 17 pathways; 4) Normal and non-tumor disease tissue Tregs upregulate some of novel 6560 exosome SGs with 56 exosome SG pathways (ESP), tumor Treg ESP are more focused than other Tregs; 5) Normal, non-tumor diseased Treg and tumor Tregs upregulate some of novel 961 innate immune caspase-1 SGs and 1223 innate immune caspase-4 SGs to fulfill their tissue/SG-specific and shared functions; 6) Most tissue Treg transcriptomes are controlled by Foxp3; and Tumor Tregs had increased Foxp3 non-collaboration genes with ROS and 17 other pathways; 7) Immune checkpoint receptor PD-1 does, but CTLA-4 does not, play significant roles in promoting Treg upregulated genes in normal and non-tumor disease tissue Tregs; and tumor splenic and tumor Tregs have certain CTLA-4-, and PD-1-, non-collaboration transcriptomic changes with innate immune dominant pathways; 8) Tumor Tregs downregulate more immunometabolic and innate immune memory (trained immunity) genes than Tregs from other groups; and 11) ROS significantly regulate Treg transcriptomes; and ROS-suppressed genes are downregulated more in tumor Tregs than Tregs from other groups. Our results have provided novel insights on the roles of Tregs in normal, injuries, regeneration, tumor conditions and some of canonical and innate immune non-canonical secretomes via ROS-regulatory mechanisms and new therapeutic targets for immunosuppression, tissue repair, cardiovascular diseases, chronic kidney disease, autoimmune diseases, transplantation, and cancers.

Caspase-1 Plays a Critical Role in Accelerating Chronic Kidney Disease-Promoted Neointimal Hyperplasia in the Carotid Artery.

To determine whether caspase-1 is critical in chronic kidney disease (CKD)-mediated arterial neointimal hyperplasia (NH), we utilized caspase(-/-) mice and induced NH in carotid artery in a CKD environment, and uremic sera-stimulated human vascular smooth muscle cells (VSMC). We made the following findings: (1) Caspase-1 inhibition corrected uremic sera-mediated downregulation of VSMC contractile markers, (2) CKD-promoted NH was attenuated in caspase(-/-) mice, (3) CKD-mediated downregulation of contractile markers was rescued in caspase null mice, and (4) expression of VSMC migration molecule αvß3 integrin was reduced in caspase(-/-) tissues. Our results suggested that caspase-1 pathway senses CKD metabolic danger signals. Further, CKD-mediated increase of contractile markers in VSMC and increased expression of VSMC migration molecule αvß3 integrin in NH formation were caspase-1 dependent. Therefore, caspase-1 is a novel therapeutic target for the suppression of CKD-promoted NH.

Pathological conditions re-shape physiological Tregs into pathological Tregs.

CD4+FOXP3+ regulatory T cells (Tregs) are a subset of CD4 T cells that play an essential role in maintaining peripheral immune tolerance, controlling acute and chronic inflammation, allergy, autoimmune diseases, and anti-cancer immune responses. Over the past 20 years, significant progress has been made since Tregs were first characterized in 1995. Many concepts and principles regarding Tregs generation, phenotypic features, subsets (tTregs, pTregs, iTregs, and iTreg35), tissue specificity (central Tregs, effector Tregs, and tissue resident Tregs), homeostasis (highly dynamic and apoptotic), regulation of Tregs by receptors for PAMPs and DAMPs, Treg plasticity (re-differentiation to other CD4 T helper cell subsets, Th1, Th2, Tfh and Th17), and epigenetic regulation of Tregs phenotypes and functions have been innovated. In this concise review, we want to briefly analyze these eight new progresses in the study of Tregs. We have also proposed for the first time a novel concept that "physiological Tregs" have been re-shaped into "pathological Tregs" in various pathological environments. Continuing of the improvement in our understanding on this important cellular component about the immune tolerance and immune suppression, would lead to the future development of novel therapeutics approaches for acute and chronic inflammatory diseases, allergy, allogeneic transplantation-related immunity, sepsis, autoimmune diseases, and cancers.

Epigenetic enzymes are the therapeutic targets for CD4(+)CD25(+/high)Foxp3(+) regulatory T cells.

CD4(+)CD25(+/high)Foxp3(+) regulatory T (Treg) cells are a subset of CD4(+) T cells that play an essential role in maintaining peripheral immune tolerance. Several transcriptional cofactors have been recently identified, which form complexes with transcription factor Foxp3 of Treg cells and contribute in the suppressive function of Treg cells. However, Foxp3 is still defined as a "master" (multiple pathway) regulator gene that controls the development and stability of Treg cells. Because of its importance, the regulatory mechanisms underlying Foxp3 expression have been a focus of intensive investigation. Recent progress suggests that the epigenetic mechanisms responsible for regulating the Foxp3 gene expression are key components of suppressive activity of Treg cells. This review not only discusses the basic concepts of biology and epigenetic modifications of Treg cells, but also analyzes the translational clinical aspect of epigenetic modifications of Treg cells, focusing on several ongoing clinical trials and the Food and Drugs administration (FDA) approved epigenetic-based drugs. The new progress in identifying epigenetic enzymes functional in Treg cells is a new target for the development of novel therapeutic approaches for autoimmune and inflammatory diseases, graft-vs-host disease and cancers.