Differential expression and analysis of extrachromosomal circular DNAs as serum biomarkers in pulmonary arterial hypertension.

BACKGROUND: Extrachromosomal circular DNAs (eccDNAs) have been reported to play a key role in the occurrence and development of various diseases. However, the characterization and role of eccDNAs in pulmonary arterial hypertension (PAH) remain unclear. METHODS: In the discovery cohort, we first explored eccDNA expression profiles by Circle-sequencing analysis. The candidate eccDNAs were validated by routine polymerase chain reaction (PCR), TOPO-TA cloning and Sanger sequencing. In the validation cohort, 30 patients with PAH and 10 healthy controls were recruited for qPCR amplification to detect the candidate eccDNAs. Datas at the baseline were collected, including clinical background, biochemical variables, echocardiography and hemodynamic factors. Receiver operating characteristic curve was used to investigate the diagnostic effect of the eccDNA. RESULTS: We identified a total of 21,741 eccDNAs in plasma samples of 3 IPAH patients and 3 individuals in good health, and the expression frequency, GC content, length distribution, and genome distribution of the eccDNAs were thoroughly characterized and analyzed. In the validation cohort, 687 eccDNAs were differentially expressed in patients with IPAH compared with healthy controls (screening threshold: |FC|≥2 and P < 0.05). Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the specific eccDNAs in IPAH were significantly enriched in calcium channel activity, the mitogen-activated protein kinase pathway, and the wnt signaling pathway. Verification queue found that the expression of eccDNA-chr2:131208878-131,424,362 in PAH was considerably higher than that in healthy controls and exhibited a high level of accuracy in predicting PAH with a sensitivity of 86.67% and a specificity of 90%. Furthermore, correlation analysis disclosed a significant association between serum eccDNA-chr2:131208878-131,424,362 and mean pulmonary artery pressure (mPAP) (r = 0.396, P = 0.03), 6 min walking distance (6MWD) (r = -0.399, P = 0.029), N-terminal pro-B-type natriuretic peptide (NT-proBNP) (r = 0.685, P < 0.001) and cardiac index (CI) (r = - 0.419, P = 0.021). CONCLUSIONS: This is the first study to identify and characterize eccDNAs in patients with PAH. We revealed that serum eccDNA-chr2:131208878-131,424,362 is significantly overexpressed and can be used in the diagnosis of PAH, indicating its potential as a novel non-invasive biomarker.

Vitamin D receptor enhances NLRC4 inflammasome activation by promoting NAIPs-NLRC4 association.

Inflammasomes are cytosolic multiprotein complexes that initiate host defense against bacterial pathogens. The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family caspase-associated recruitment domain-containing protein 4 (NLRC4) inflammasomes plays a critical role in the inflammatory response against intracellular bacterial infection. The NLR family apoptosis inhibitory proteins (NAIPs) detect Flagellin or type III secretion system (T3SS) microbial components to activate NLRC4 inflammasome. However, the underlying mechanism of NLRC4 inflammasome activation is not completely understood. Here, we show that the vitamin D receptor (VDR) is an essential immunological regulator of the NLRC4 inflammasome. Conditional VDR knockout mice (VDRflox/flox lyz2-Cre) exhibited impaired clearance of pathogens after acute Salmonella Typhimurium infection leading to poor survival. In macrophages, VDR deficiency reduced caspase-1 activation and IL-1ß secretion upon S. Typhimurium infection. For NAIPs act as upstream sensors for NLRC4 inflammasome assembly, the further study demonstrated that VDR promoted the NAIP-NLRC4 association and triggered NAIP-NLRC4 inflammasome activation, not NLRP3 activation. Moreover, Lys123 residue of VDR is identified as the critical amino acid for VDR-NLRC4 interaction, and the mutant VDR (K123A) effectively attenuates the NLRC4 inflammasome activation. Together, our findings suggest that VDR is a critical regulator of NAIPs-NLRC4 inflammasome activation, mediating innate immunity against bacterial infection.

Parkin increases the risk of colitis by downregulation of VDR via autophagy-lysosome degradation.

Parkin, an E3 ubiquitin ligase, plays an essential role in mitophagy. Emerging evidence indicates that mitophagy is involved in various processes closely related to immune diseases, including inflammatory bowel diseases (IBD). Here, the authors show that Parkin increases the occurrence of colitis and severe inflammation. Deletion of Parkin resulted in marked reductions in colonic inflammation and exhibited high resistance to DSS-induced colitis. Mechanism investigation indicated that Parkin interacts with Vitamin D receptors (VDR), a critical inhibitory regulator in IBD. Parkin promotes VDR degradation via the p62-related autophagy-lysosome pathway. Comparison of colitis in Parkin-/- and Parkin-/-Vdr-/- mice showed that the protective effect of Parkin deletion against colitis was abolished by VDR deletion. The result suggests that the regulatory effect of Parkin in colitis is a VDR-dependent pathway. Our research provides a new role of Parkin in colitis by downregulating VDR, which provides a potential strategy for treating IBD.

Synthesis and Evaluation of Anti-inflammatory N-Substituted 3,5-Bis(2-(trifluoromethyl)benzylidene)piperidin-4-ones.

A total of 24 N-substituted 3,5-bis(2-(trifluoromethyl)benzylidene)piperidin-4-one derivatives were synthesized via aldol condensation, and their anti-inflammatory activities were evaluated. These compounds were found to have no significant cytotoxicity against mouse bone marrow cells in vitro. However, some compounds, such as c6 (N-(3-methylbenzoyl)-3,5-bis-(2-(trifluoromethyl)benzylidene)piperidin-4-one) and c10 (N-(2-chlorobenzoyl)-3,5-bis-(2-(trifluoromethyl)benzylidene)piperidin-4-one), displayed potent anti-inflammatory activity by inhibiting lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), IL-1ß, prostaglandin E2 (PGE2), and nitric oxide (NO) production in RAW 264.7 cells. Treatment with c6 or c10 at 2.5 or 10 mg kg-1 significantly decreased the paw edema induced by carrageenan in rats, and the anti-inflammatory effects of these compounds were found to be better than those of celecoxib or indomethacin as well as their parent compound C66 (2,6-bis-(2-(trifluoromethyl)benzylidene)cyclohexanone). Pharmacokinetic analysis indicated that c6 has better bioavailability than curcumin. Therefore, these compounds may be valuable leads for the development of new anti-inflammatory drugs.

Design, Synthesis, and Biological Evaluation of C-2 Substituted 3Hthieno[ 2,3-d]pyrimidin-4-one Derivatives as Novel FGFR1 Inhibitors.

BACKGROUND: Thienopyrimidinone is a newly designed, selective fibroblast growth factor receptor 1 (FGFR1) inhibitor with an excellent anticancer effect. OBJECTIVE: The goal of the present study was to design and synthesize better FGFR1 inhibitors through modifications of the lead compound thienopyrimidinone. METHODS: In the present study, a series of C-2 substituted derivatives of thienopyrimidinone, namely L1-L16, were synthesized, and their inhibitory effects on FGFR1 were evaluated. The anti-proliferative activities of these compounds were assessed by MTT assay. RESULTS: Among the novel derivatives, L11 was found to exert remarkable FGFR1 inhibitory activity (79.93% at 10 µM) and anti-proliferative activity, with IC50 values of 2.1, 2.5, and 3.5 .M in the FGFR1-overexpressing cell lines, H460, HT-1197, and B16F10, respectively. CONCLUSION: Our newly synthesized thienopyrimidinone derivatives may be candidate FGFR1 inhibitors for future development as novel anticancer agents.

Synthesis and Evaluation of Biological and Antitumor Activities of Tetrahydrobenzothieno[2,3-d]Pyrimidine Derivatives as Novel Inhibitors of FGFR1.

A series of tetrahydrobenzothieno[2,3-d]pyrimidine derivatives were designed, synthesized, and evaluated as inhibitors of FGFR1. These analogs were synthesized via Gewald's reaction under mild conditions. The structures of the synthesized compounds were characterized by spectroscopic data (IR, (1) H NMR and MS). Their antitumor activities were evaluated against H460, A549 and U251 cell lines in vitro. Results revealed that the tested compounds showed moderate antitumor activities. Structure-activity relationship analyses indicated that compounds with an aromatic ring substituted in the C-2 position or with larger molecules such as 3g, 4c, and 7 were more effective than others. The compound, 3g (78.8% FGFR1 inhibition at 10 µm), was identified to have the most potent antitumor activities, with IC50 values of 7.7, 18.9, and 13.3 µm against the H460, A549, and U251 cell lines, respectively. Together, the results suggested that tetrahydrobenzothieno[2,3-d]pyrimidine derivatives may serve as a potential agent for the treatment of FGFR1-mediated cancers.