An Insulin-Modified pH-Responsive Nanopipette Based on Ion Current Rectification.

The properties of nanopipettes largely rely on the materials introduced onto their inner walls, which allow for a vast extension of their sensing capabilities. The challenge of simultaneously enhancing the sensitivity and selectivity of nanopipettes for pH sensing remains, hindering their practical applications. Herein, we report insulin-modified nanopipettes with excellent pH response performances, which were prepared by introducing insulin onto their inner walls via a two-step reaction involving silanization and amidation. The pH response intensity based on ion current rectification was significantly enhanced by approximately 4.29 times when utilizing insulin-modified nanopipettes compared with bare ones, demonstrating a linear response within the pH range of 2.50 to 7.80. In addition, insulin-modified nanopipettes featured good reversibility and selectivity. The modification processes were monitored using the I-V curves, and the relevant mechanisms were discussed. The effects of solution pH and insulin concentration on the modification results were investigated to achieve optimal insulin introduction. This study showed that the pH response behavior of nanopipettes can be greatly improved by introducing versatile molecules onto the inner walls, thereby contributing to the development and utilization of pH-responsive nanopipettes.

Genetically predicted circulating interleukin-18 levels are associated with risk of systemic lupus erythematosus and type 1 diabetes.

OBJECTIVE: Interleukin-18 (IL-18) is a proinflammatory cytokine. This study aims to determine whether there is a causal relationship between circulating IL-18 concentrations and the risk of inflammatory and autoimmune diseases. METHODS: We collected significant single nucleotide polymorphisms (SNPs) associated with circulating IL-18 levels (p < 5 × 10-8) as instrumental variables (IVs) from a genome-wide association study (GWAS) involving 21,758 individuals of European descent. We mainly employed the inverse-variance weighed (IVW) method of two-sample Mendelian randomization (TSMR) analysis to estimate the causality of circulating IL-18 levels on inflammatory and autoimmune diseases. RESULTS: The IVW method results showed evidence of a causal relationship between IL-18 and the risk of systemic lupus erythematosus (SLE) (OR = 1.32; 95% CI 1.15, 1.50; p < .001) and type 1 diabetes (T1D) (OR = 1.22; 95% CI 1.06, 1.42; p = .007) in individuals of European ancestry. No significant heterogeneity or horizontal pleiotropy for SLE and T1D was detected. The sensitivity analysis, which involved removing confounding SNP, produced similar results for SLE and T1D. The results of sensitivity analysis using leave-one-out method indicated no single SNP significantly influenced the analysis results. However, we did not find any significant findings for multiple sclerosis, psoriasis, asthma, and osteoarthritis. CONCLUSIONS: Our analyses suggest that circulating IL-18 is significantly related to SLE and T1D and may serve as a potential target for the treatment of these diseases.

Telomere Length and Development of Systemic Lupus Erythematosus: A Mendelian Randomization Study.

OBJECTIVE: Previous observational studies demonstrated that a subset of patients with systemic lupus erythematosus (SLE) have markedly short telomere length in leukocytes. This study was undertaken to test whether leukocyte telomere length is causally associated with risk of SLE. METHODS: A 2-sample Mendelian randomization (MR) analysis was conducted to estimate causality of telomere length on SLE in European populations. A replication 2-sample MR study using Asian genetic data was also conducted. A reverse MR analysis was then performed to test the effects of SLE on telomere length. The autoantibodies targeting telomere-associated protein (telomeric repeat-binding factor 1 [TERF1] autoantibodies) were detected in patients with SLE, healthy controls, and patients with rheumatoid arthritis. RESULTS: The results of the inverse variance-weighted method (odds ratio [OR] 2.96 [95% confidence interval (95% CI) 1.58-5.55], P < 0.001) showed strong evidence for a causal relationship between longer telomere length and risk of SLE in people with European ancestry. The outcomes of MR-Egger regression analysis (OR 29.46 [95% CI 3.02-287.60], P = 0.033) and MR pleiotropy residual sum and outlier analysis (OR 3.62 [95% CI 2.03-6.46], P = 0.002) also showed that longer telomere length was significantly associated with increased risk of SLE in a European population. Sensitivity analyses using different methods and summary data sets showed that the results were still broadly consistent. A replication MR study using Asian genetic data yielded similar findings. However, the reverse MR analysis showed that genetically predicted SLE was not causally associated with telomere length. In addition, we found that TERF1 autoantibodies were present in 2 of 40 SLE patients (5.0%). CONCLUSION: In contrast with previous observational studies, MR analyses show that longer telomere length is significantly associated with increased risk of SLE.

Genetic variant in microRNA-146a gene is associated with risk of rheumatoid arthritis.

OBJECTIVE: To investigated the association between single nucleotide polymorphisms (SNPs) in microRNA-146a (miR-146a) gene and susceptibility of rheumatoid arthritis (RA). METHODS: We systemically extracted the genetic data of miR-146a from previous genome-wide association studies (GWASs) of RA. Subsequently, we performed a replication study in an independent Chinese cohort for selected variant. A meta-analysis combined the previous GWASs with the replication study was also conducted. The epigenetic annotation and cytokine assay were used for exploring potential variant function. RESULTS: The extracted genetic association data from three previous GWASs showed that the allele T of functional SNP rs2431697 increased RA susceptibility. The significant association for the SNP was also found in the Chinese replication cohort (OR = 1.24, 95% CI = 1.06-1.46, p = 8.69E-03). The estimated effect size for this SNP was larger in Asian population than that in European population (Asian meta-analysis: OR = 1.15, 95% CI = 1.09-1.22, p = 4.37E-07; Tran-ethnic meta-analysis: OR = 1.07, 95% CI = 1.04-1.10, p = 1.79E-06). The cytokine assay also showed that the risk allele T of the SNP rs2431697 is inversely associated with plasma TNF-α levels in health controls (p = .016). CONCLUSIONS: In summary, this study supports that genetic variant in miR-146a gene is associated with RA risk.KEY MESSAGESThe association between SNPs in miR-146a gene and susceptibility of RA was unclear.We investigated the genetic association using GWASs data and a replication study.The SNP rs2431697 in miR-146a gene is associated with RA risk.

Identification of new susceptibility loci associated with rheumatoid arthritis.

OBJECTIVES: The present study aimed to discover novel susceptibility loci associated with risk of rheumatoid arthritis (RA). METHODS: We performed a new genome-wide association study (GWAS) in Chinese subjects (1027 RA cases and 2879 controls) and further conducted an expanded meta-analysis with previous GWAS summary data and replication studies. The functional roles of the associated loci were interrogated using publicly available databases. Dual-luciferase reporter and cytokine assay were also used for exploring variant function. RESULTS: We identified five new susceptibility loci (IL12RB2, BOLL-PLCL1, CCR2, TCF7 and IQGAP1; pmeta <5.00E-08) with same effect direction in each study cohort. The sensitivity analyses showed that the genetic association of at least three loci was reliable and robust. All these lead variants are expression quantitative trait loci and overlapped with epigenetic marks in immune cells. Furthermore, genes within the five loci are genetically associated with risk of other autoimmune diseases, and genes within four loci are known functional players in autoimmunity, which supports the validity of our findings. The reporter assay showed that the risk allele of rs8030390 in IQGAP1 have significantly increased reporter activity in HEK293T cells. In addition, the cytokine assay found that the risk allele of rs244672 in TCF7 was most significantly associated with increased plasma IL-17A levels in healthy controls. Finally, identified likely causal genes in these loci significantly interacted with RA drug targets. CONCLUSION: This study identified novel RA risk loci and highlighted that comprehensive genetic study can provide important information for RA pathogenesis and drug therapy.

Enantioselective intramolecular crossed Rauhut-Currier reactions through cooperative nucleophilic activation and hydrogen-bonding catalysis: scope and mechanistic insight.

A highly efficient and enantioselective intramolecular crossed Rauhut-Currier (RC) reaction of nitroolefins with tethered enonates has been developed through cooperative nucleophilic activation and a hydrogen-bonding catalytic strategy (≤98% ee and 98% yield). The reaction features simple experimental procedures and is completely chemoselective and atom-economic in character. The potential synthetic applications have been demonstrated by the conversion of the RC reaction products into biologically and pharmaceutically valuable compounds with highly diastereoselectivity. In addition, computational investigations were employed to support the proposed mechanism and to obtain a good understanding of the origin of the stereoselectivity in RC reactions.

Catalytic asymmetric aza-Michael-Michael addition cascade: enantioselective synthesis of polysubstituted 4-aminobenzopyrans.

A catalytic asymmetric aza-Michael-Michael addition cascade of anilines to nitroolefin enoates in the presence of chiral bifunctional thiourea catalysts has been disclosed. This reaction provides a mild and efficient approach to polysubstituted chiral 4-aminobenzopyrans bearing three consecutive stereocenters in high yields with excellent stereoselectivities.

An enantioselective approach to highly substituted tetrahydrocarbazoles through hydrogen bonding-catalyzed cascade reactions.

A hydrogen bonding-mediated double Michael addition-aromatization cascade of 2-propenylindoles and nitroolefins has been disclosed. The methodology allows an efficient synthesis of diverse and structurally complex tetrahydrocarbazoles in good to excellent enantioselectivities and diastereoselectivities.

Highly enantioselective organocatalytic Michael addition of nitroalkanes to 4-oxo-enoates.

A useful Michael addition reaction using nitroalkanes as the nucleophile and 4-oxo-enoates as the Michael acceptor has been disclosed, and the reaction allows expedient access to functionalized chiral gamma-keto esters in high yields and excellent enantioselectivities (up to 98% ee), with a low catalyst loading.

Brønsted acid mediated tandem Diels-Alder/aromatization reactions of vinylindoles.

A Brønsted acid catalyzed tandem Diels-Alder/aromatization reaction of 2-vinylindoles has been developed. The reaction provides a highly efficient and concise approach to 3-indolyl-substituted tetrahydrocarbazoles with various substituents in high yields under mild conditions.

Catalytic asymmetric intramolecular hydroarylations of omega-aryloxy- and arylamino-tethered alpha,beta-unsaturated aldehydes.

Economical approach: The first organocatalytic asymmetric intramolecular hydroarylation of phenol- and aniline-derived enals offers one of the most straightforward and atom-economic approaches to enantioriched chromans and tetrahydroquinolines (up to 96% ee; see scheme).

Rational combination of two privileged chiral backbones: highly efficient organocatalysts for asymmetric direct aldol reactions between aromatic aldehydes and acylic ketones.

A new class of organocatalysts has been designed by rational combination of proline with cinchona alkaloids. The chiral amine 3a, prepared from l-proline and cinchonidine, has been found to be an efficient catalyst for the direct aldol reactions of acetone or 2-butanone with a wide range of aldehydes (up to 98% ee). The cinchonidine backbone is essential to the reaction efficiency and enantioselectivity.

Dimethyl [1-(1-allyl-5-iodo-1H-indol-3-yl)-3-hydroxy-prop-yl]phospho-nate.

In the title compound, C(16)H(21)INO(4)P, the mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O hydrogen-bond inter-action. The crystal packing is stabilized by strong inter-molecular O-H ⋯ O hydogen-bonding inter-actions to form a zigzag packing arrangement.