Objective The role of receptors for endogenous metabolic danger signals-associated molecular patterns (DAMPs) has been characterized recently as bridging innate immune sensory systems for DAMPs 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 DAMPs 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, immunological, pathological and bone marrow transplantation methods together with the generation of new apoplipoprotein E (ApoE)−/−/caspase-1−/− double knock-out 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 pro-inflammatory 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 ROS mechanism. Caspase-1 inhibition resulted in accumulation of sirtuin 1 (Sirt1) in the ApoE−/− aorta, and Sirt1 inhibited caspase-1 upregulated genes via activator protein-1 (AP-1) pathway. Conclusions Our results demonstrate for the first time that early hyperlipidemia promotes EC activation before monocyte recruitment via a caspase-1-Sirt1-AP-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.
Rationale Endothelial injury is an initial mechanism mediating cardiovascular disease. Objective Here, we investigated the effect of hyperhomocysteinemia (HHcy) on programed cell death in endothelial cells (EC). Methods and Results We established a novel flow-cytometric gating method to define pyrotosis (Annexin V−/Propidium iodide+). In cultured human EC, we found that: 1). Hcy and Lipopolysaccharide (LPS) individually and synergistically induced inflammatory pyroptotic and non-inflammatory apoptotic cell death. 2). Hcy/LPS induced caspase-1 activation prior to caspase-8, -9, -3 activations. 3). Caspase-1/3 inhibitors rescued Hcy/LPS-induced pyroptosis/apoptosis, but caspase-8/9 inhibitors had differential rescue effect. 4). Hcy/LPS induced NLRP3 protein, caused NLRP3-containing inflammasome assembly, caspase-1 activation and IL-1β cleavage/activation. 5). Hcy/LPS elevated intracellular reactive oxidative species (ROS). 6). Intracellular oxidative gradient determined cell death destiny as intermediate intracellular ROS levels are associated with pyroptosis, whereas, high ROS corresponded to apoptosis. 7). Hcy/LPS induced mitochondrial membrane potential collapse and cytochrome-c release, and increased Bax/Bcl-2 ratio which were attenuated by antioxidants and caspase-1 inhibitor. 8). Antioxidants extracellular superoxide dismutase and catalase prevented Hcy/LPS-induced caspase-1 activation, mitochondrial dysfunction and pyroptosis/apoptosis. In cystathionine β-synthase deficient (Cbs−/−) mice, severe HHcy induced caspase-1 activation in isolated lung EC and caspase-1 expression in aortic endothelium, and elevated aortic caspase-1,9 protein/activity and Bax/Bcl-2 ratio in Cbs−/− aorta and HUVEC. Finally, Hcy-induced DNA fragmentation was reversed in caspase-1−/− EC. HHcy-induced aortic endothelial dysfunction was rescued in caspase-1−/− and NLRP3−/− mice. Conclusion HHcy preferentially induces EC pyroptosis via caspase-1-dependent inflammasome activation leading to endothelial dysfunction. We termed caspase-1 responsive pyroptosis and apoptosis as pyrop-apoptosis.
Cpf1 nucleases were recently reported to be highly specific and programmable nucleases with efficiencies comparable to those of SpCas9. AsCpf1 and LbCpf1 require a single crRNA and recognize a 5′-TTTN-3′ protospacer adjacent motif (PAM) at the 5′ end of the protospacer for genome editing. For widespread application in precision site-specific human genome editing, the range of sequences that AsCpf1 and LbCpf1 can recognize is limited due to the size of this PAM. To address this limitation, we sought to identify a novel Cpf1 nuclease with simpler PAM requirements. Specifically, here we sought to test and engineer FnCpf1, one reported Cpf1 nuclease (FnCpf1) only requires 5′-TTN-3′ as a PAM but does not exhibit detectable levels of nuclease-induced indels at certain locus in human cells. Surprisingly, we found that FnCpf1 possesses DNA cleavage activity in human cells at multiple loci. We also comprehensively and quantitatively examined various FnCpf1 parameters in human cells, including spacer sequence, direct repeat sequence and the PAM sequence. Our study identifies FnCpf1 as a new member of the Cpf1 family for human genome editing with distinctive characteristics, which shows promise as a genome editing tool with the potential for both research and therapeutic applications.
The neurorestorative effect of the parenchymal transplantation of olfactory ensheathing cells (OECs) for cord trauma remains clinically controversial. The aim of this article is to study the long-term result of OECs for patients with complete chronic spinal cord injury (SCI). One hundred and eight patients suffered from complete chronic SCI were followed up successfully within the period of 3.47 ± 1.12 years after OEC therapy. They were divided into two groups based on the quality and quantity of their rehabilitative training: group A (n = 79) in sufficient rehabilitation (or active movement-target enhancement-neurorehabilitation therapy, AMTENT) and group B (n = 29) in insufficient rehabilitation. All patients were assessed by using the American Spinal Injury Association (ASIA) standard and the International Association of Neurorestoratology Spinal Cord Injury Functional Rating Scale (IANR-SCIFRS). Thirty-one patients were evaluated by the tests of magnetic resonance imaging (MRI), electromyography (EMG), and paravertebral sensory evoked potential (PVSEP). We found the following. 1) According to ASIA and IANR-SCIFRS assessment for all 108 patients, averaged motor scores increased from 37.79 ± 18.45 to 41.25 ± 18.18 (p < 0.01), light touch scores from 50.32 ± 24.71 to 55.90 ± 24.46 (p < 0.01), pin prick scores from 50.53 ± 24.92 to 54.53 ± 24.62 (p < 0.01); IANR-SCIFRS scores increased from 19.32 ± 9.98 to 23.12 ± 10.30 (p < 0.01).2) The score changes in terms of motor, light touch, pin prick, and IANR-SCIFRS in group A were remarkably different (all p < 0.01). The score changes in group B were remarkably different in terms of motor (p < 0.05) and IANR-SCIFRS (p < 0.01), but not light touch or pin prick (p > 0.05). 3) Comparing group A with group B, the increased scores in terms of motor, light touch, and pin prick were remarkably different (all p < 0.01), but not IANR-SCIFRS (p > 0.05). 4) Fourteen of 108 patients (12.96%) became ASIA B from ASIA A; 18 of 108 (16.67%) became ASIA C from ASIA A. Nine of them (8.33%) improved their walk ability or made them rewalk by using a walker with or without assistance; 12 of 84 men (14.29%) improved their sex function. 5) MRI examinations were taken for 31 patients; there were no neoplasm, bleeding, swelling, cysts, neural tissue destruction or infection (abscess) or any other pathological changes in or around OEC transplant sites. 6) EMG examinations were done on 31 patients; 29 showed improvement and the remaining 2 had no change. PVSEP tests were performed in 31 patients; 28 showed improvements and the remaining 3 had no change. 7) No deterioration or complications were observed in our patients within the follow-up period. Our data suggest OEC therapy is safe and can improve neurological functions for patients with complete chronic SCI and ameliorate their quality of life; the AMTENT most likely plays a critical role in enhancing functional recovery after cell-based neurorestorotherapy.
Background: Interleukin-35 is a novel inhibitory cytokine. Results: Interleukin-35 inhibits vascular endothelial cell activation by suppressing MAPK-AP1-mediated VACM-1 expression in LPS-induced acute inflammation. Conclusion: Interleukin-35 suppresses acute vascular endothelium response. Significance: Interleukin-35 may be an attractive reagent for anti-inflammatory therapy.
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