Expanding the "minimalist" small molecule tagging approach to different bioactive compounds

"Minimalist" small molecule tagging (MSMT) is a promising approach that easily converts bioactive compounds into affinity-based probes (AfBPs) for proteomic studies. In this work, seven bioactive compounds targeting diversified protein classes were installed with "minimalist" linkers through common reactions to generate the corresponding AfBPs. These probes were evaluated for cell-based protein profiling and target validation. Among them, the entinostat-derived probe EN and the camptothecin-derived probe CA were further utilized in cellular imaging and SILAC-based large-scale target identification. Our extensive studies suggest that the "minimalist" small molecule tagging approach could be expanded to different classes of bioactive compounds for modification into AfBPs as a dual functional tool for both proteomics and cellular imaging.

Supervised Autonomous Electrosurgery via Biocompatible Near-Infrared Tissue Tracking Techniques

Autonomous robotic surgery systems aim to improve patient outcomes by leveraging the repeatability and consistency of automation and also reducing human induced errors. However, intraoperative autonomous soft tissue tracking and robot control still remains a challenge due to the lack of structure, and high deformability of such tissues. In this paper, we take advantage of biocompatible Near-Infrared (NIR) marking methods and develop a supervised autonomous 3D path planning, filtering, and control strategy for our Smart Tissue Autonomous Robot (STAR) to enable precise and consistent incisions on complex 3D soft tissues. Our experimental results on cadaver porcine tongue samples indicate that the proposed strategy reduces surface incision error and depth incision error by 40.03% and 51.5%, respectively, compared to a teleoperation strategy via da Vinci. Furthermore, compared to an autonomous path planning method with linear interpolation between the NIR markers, the proposed strategy reduces the incision depth error by 48.58% by taking advantage of 3D tissue surface information.

Involvement of CHOP in activin A‑induced myeloma NS‑1 cell apoptosis

Activin A, a multifunctional cytokine, is a member of transforming growth factor-β (TGF-β) superfamily. It is associated with a variety of pathophysiological processes, including inflammation, fibrosis, and tumorigenesis. Chronic or prolonged endoplasmic reticulum (ER) stress can lead to cells apoptosis. However, whether ER stress-related proteins, such as CHOP, GADD34 are involved in activin A-induced myeloma cell apoptosis remains unknown. In the present study, it was revealed that activin A inhibited the proliferation of myeloma cell line NS-1 cells and induced NS-1 cell apoptosis. Activin A upregulated the expression of CHOP, GADD34, caspase-3, and caspase-12. Moreover, both Smad3 and p-Smad3 levels were increased with treatment of activin A. Further studies revealed that the overexpression of activin signaling protein Smad3 in NS-1 cells increased the levels of CHOP, caspase-3, and p-Smad3. These data indicated that the CHOP protein of the ER stress pathway may be involved in activin A-induced NS-1 cell apoptosis, and also indicated the potential therapy of activin A-induced apoptosis via CHOP signaling for multiple myeloma.

P6306Hyperlipidemia inhibits the protective effect of lisinopril after myocardial infarction via activation of dendritic cells

Background

In clinical situation, patients with myocardial infarction (MI) usually suffered from hyperlipidemia, hypertension, renal dysfunction or diabetes as well and the interaction of those risk factors may affect the effectiveness of ACEI. Dendritic cell (DC) is a potent central immunoregulator that orchestrates various types of inflammatory cells in innate and adoptive immunity. The role of DCs in the inflammation of cardiovascular disease is a hotspot of international research.

Purpose

To investigate the improvement of cardiac remodeling and inflammatory immune response after MI via ACEI regulating DCs and explore that whether the protective effect of ACEI is under the circumstance of hyperlipidemia.

Methods

In vivo, MI mice models were created via coronary artery ligation. We detected the survival and left ventricular function on day 7 after MI. Tissue samples of the myocardium, spleen, bone marrow and peripheral blood were obtained and assessed for Ang2 concentration, inflammatory cytokines and DCs expression via immunohistochemistry, ELISA, flow cytometry and western blot. In vitro, we treated DCs with ox-LDL+AngIIfor 48 hours simulating the internal environment of MI in ApoE−/− mice to explore the mechanism involved in the DCs maturation and inflammation.

Results

Under the circumstance of hyperlipidemia, the cardioprotective effect of ACEI is attenuated through regulating DCs maturation and inflammation after MI, including survival rate (Figure 1) and left ventricular function. The number of DCs in cardiac tissue were increased in MI mice with hyperlipidemia (Figure 2), when compared with the WT group. The expression of the maturity phenotype related molecules, such as CD83, on the DCs in spleen were also increased in the ApoE−/− mice. Then, the expressions of inflammatory cytokines, such as IL-6 and TNF-α. In vitro, it was found that the immune maturation and inflammation of DCs could be further induced by ox-LDL on the basis of AngIItreatment, as indicated by the upregulation of CD83 and CD86, the expressions of cytokines and chemokines. Furthermore, ox-LDL could activate the toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88) signaling pathway, promoting the phosphorylation of interleukin-1 receptor associated kinase (IRAK)-4 and the nuclear transferring of nuclear factor-kappaB (NF-κB).

Conclusion

We proved ACEI reduces the recruitment of DCs to the infarct, leading to a higher survival rate and improved function and remodeling through decreased inflammation resulting from immune response after MI. However, this effect was inhibited under the circumstance of hyperlipidemia. TLR4-MyD88 signaling pathway might be the possible molecular mechanism involved in the immune maturation and inflammation of DCs induced by ox-LDL on the basis of AngII.

Acknowledgement/Funding

the Youth fund of the National Natural Science Foundation of China, Grant 81600280

P6501Recurrent genetic aberrations in bicuspid aortic valve disease patients with isolated severe aortic regurgitation

Background

The etiology of bicuspid aortic valve disease (BAVD) is still unclear. Recent studies have demonstrated elevated prevalence of genetic defects in BAV patients with root phenotype, which includes aortic regurgitation and root-predominant dilatation.

Purpose

The present study intended to illustrate the feature of genetic defects among early-onset BAV patients with isolated severe aortic regurgitation.

Methods

From June 2015 to December 2017, whole exome sequencing was performed upon 27 BAVD patients with isolated severe aortic regurgitation under 45 years in our institution. Patients were categorized into right-left (R-L, n=16) and non-RL (n=11) cusp fusion types, and those with complex cardiac defects were excluded from the present study.

Results

Among 27 patients with a median age of 30.5 (18–44) years, only one was female with a rare left-non-coronary cusp fusion type. The prevalence of root phenotype was markedly higher in RL patients (56.3% vs 9.1%, p=0.018). In RL patients, the numbers of rare genetic variants (RGVs) were 15 in extracellular matrix genes, 8 in TGF-β signaling pathway genes, 2 in smooth muscle cell contraction apparatus genes, and 3 in familiar BAV related genes. In non-RL patients, the number of RGVs were 15, 3, 4, and 5, respectively. On the other hand, the number of RGVs in above gene clusters were 9, 6, 3, 2 in patients with a root phenotype, and 21, 5, 3, 6 in those without. Eight recurrent genetic variants were identified in 6 genes (see Table). An interesting observation was that ADAMTS2 variants were exclusively found among non-RL patients without root phenotype, as FBN2 variants among RL patients with root phenoype.

Recurrent Rare Genetic Variants Gene Reference sequence Variant 1000G 1000G-East Asia Patients TGFBR2 NM_001024847.2 p.Val216Ile/c.646G>A 0.004 0.018 A16, A23 TGFBR2 NM_001024847.2 p.Thr340Met/c.1019C>T 0.003 0.015 A03, A05, A07 ADAMTS2 NM_014244.4 p.Gly1169Val/c.3506G>T 0.0044 0.021 A03, A15 FBN2 NM_001999.3 p.Gly475Val/c.1424G>T 0.0004 0.002 A19, A24 ELN NM_001278939.1 p.Pro93Leu/c.278C>T 0.0014 0.0069 A22, A26 COL4A5 NM_033380.2 p.Gly953Val/c.2858G>T 0.0079 0.03 A11, A17 MYLK NM_053025.3 p.Ser243Trp/c.728C>G 0.0002 0.001 A01, A02 MYLK NM_053025.3 p.Asp717Tyr/c.2149G>T 0.0024 0.011 A04, A21

Conclusion

Recurrent genetic variants could be identified in a cohort of early-onset BAVD patients with isolated severe aortic regurgitation and staggering male predominance. The incidence and clinical relevance of these variants should be validated in an extended real-world BAV cohort.

P4348Early assessment of left ventricular function by layer-specific strain and its relationship to pulsatile arterial load in patients with coronary slow flow

Background

Previous studies reported controversial Left ventricular (LV) function impairment and pathophysiology in patients with coronary slow flow (CSF). Greater arterial load has been shown to increase aortic impedance and endothelial shear stress, potentially affecting coronary anatomy and function. We investigated LV systolic function by a new layer-specific strain technology and assessed the association between pulsatile arterial load and contractility.

Methods and results

A total of 70 patients with CSF and 50 controls with normal coronary angiography were included in the study. Layer-specific longitudinal and circumferential strains were assessed from endocardium, mid-myocardium and epicardium (GLS-endo, GLS-mid, GLS-epi and GCS-endo, GCS-mid, GCS-epi) by two-dimensional speckle tracking imaging (2D-STI). Pulsatile arterial load was estimated by indexed arterial compliance (ACI). Layer-specific GLS showed a decreasing gradient from the endocardium to the epicardium in both controls and CSF group. GLS-endo and GLS-mid in CSF group were significantly lower than the control group (all P<0.05). Layer-specific longitudinal strain showed a good correlation with the number of affected coronary arteries (all P<0.05) and the mean thrombolysis in myocardial infarction frame count (TFC) (all P<0.05). ACI was lower in CSF patients (P=0.005) and ACI was correlated negatively with layer-specific GLS (all P<0.05).

Conclusion

Layer-specific evaluation of the LV provides an understanding of the layer-specific properties of the LV wall and the possible process of the LV impairment in patients with CSF. Greater pulsatile arterial load, as manifested by a lower ACI, is coupled with worse LV longitudinal function in CSF patients.

P916The effect of a novel, user-friendly, transcatheter edge-to-edge mitral valve repair device in a porcine model of mitral regurgitation

Objective

A new technique has been devised to treat mitral regurgitation (MR) through the transapical route by replicating the edge-to-edge repair surgery. This system encompasses an easy-to-use leaflet clamp and a smaller-sized delivery system (14F–16F). We aimed to evaluate the effectiveness of this device in a porcine model of acute MR.

Methods

Acute MR was induced in 36 anesthetized porcine subjects by severing the major chordae supporting the corresponding segment of the leaflet. This device was then transapically implanted on the prolapsing segment under 3D epicardial echocardiographic guidance. All of the animals were killed 30 days after the procedure to verify the proper location of the implanted devices.

Results

Cutting the major chordae induced an eccentric MR jet (MR grade: 3+, 27.8%/4+, 72.2%) in all of the animals. Every single pig was then successfully implanted with one clamp. The duration of catheterization ranged from 18 to 40 minutes. Overt MR reduction was observed following the procedure through echocardiography; residual MR was mild in 8 cases, trivial in 19 cases, and absent in 9 cases. In terms of hemodynamic parameters, the mean and maximum mitral valve pressure gradients were increased significantly (p<0.01), but these values were less than 4 mmHg in all of the cases. Autopsy demonstrated that all but one device were precisely placed to clip the prolapsing segment of the mitral valve, and there was no evidence of thrombosis, thromboembolism or impairment of the cardiac structure.

Table 1. Changes in hemodynamic parameters, cardiac size, and functional parameters after the procedure Preoperation Postoperation P value MR-maxA (mm2) 7.27±2.13 1.54±1.29 0.000 MVPG-max (mmHg) 1.95±0.47 3.66±0.62 0.000 MVPG-mean (mmHg) 0.87±0.31 1.7±0.28 0.000 LVEDD (mm) 46.08±2.85 46.44±3.53 0.239 LVESD (mm) 29.11±3.44 29.08±3.62 0.940 LVEF (%) 66.53±6.4 67.14±4.93 0.256 LAD (mm) 35.75±2.24 36.42±1.99 0.057 LAA (mm2) 12.95±2.22 12.64±1.55 0.301

Figure 1

Conclusions

Transapical implantation of the novel mitral valve repair device is effective and safe in reducing acutely induced MR in pigs; thus, suggesting that it has great potential for clinical benefit in patients with MR.

Acknowledgement/Funding

Shanghai Science and Technology Committee

P711Histamine promotes atherosclerotic plaque instability via STAT6-dependent macrophage pyroptosis

Background

Atherosclerotic plaque formation and rupture is the primary cause for cardiovascular diseases. It's known that cell death and inflammation are crucial processes leading to atherosclerosis, which involves an important role of histamine. The aim of the present study is to determine the function of signal transducer and activator of transcription 6 (STAT6) in histamine-induced macrophage pyroptosis and plaque instability.

Methods

We constructed APOE/STAT6 double knock out (DKO) mice via hybridization of ApoE−/− and STAT6−/− mice. 20 ApoE−/− mice (control) and 20 DKO mice were challenged with high-fat diet for 12 weeks while 10 in each group were intraperitoneally infused with histamine (400ug/kg) every other day. The extent and instability of atherosclerotic plaque were determined by oil-red staining, HE staining, immunofluorescence staining and electron microscopy. Changes in subsets of immune cells were evaluated by flow cytometry. Plasma cytokines were assessed by ELISA. Microarray analysis was applied to detect gene expressions while Western blot and real-time PCR was used to assess gene expression levels.

Results

Morphology studies revealed that histamine could promote plaque formation and vulnerability in ApoE−/− mice, whereas this effect was inhibited in DKO mice. FACS data showed that histamine injection could increase CD11b+Ly6Chigh M1 macrophages differentiation and pyroptosis and facilitate foam cells formation in ApoE−/− mice, which was also inhibited in DKO mice. Microarray analysis and in vitro studies exhibited that histamine could induce the up-regulation of pyrotosis-related proteins such as NLRP3, caspase-1 and MMPs via a STAT6-dependent pathway to promote macrophage pyroptosis and foam cell formation.

Conclusions

We have characterized a novel role for histamine in modulating atherosclerotic lesion development and progression. Moreover, our work have figured out the detailed mechanisms by which histamine modulates the pyroptosis of macrophages and the progress of unstable atherosclerotic plaques. We envision that this study may provide several potential therapeutic targets benefit for atherosclerosis treatment.

P4378Comparison between left bundle branch pacing and His bundle pacing using two-dimensional speckle tracking echocardiography

Background

Although his bundle pacing (HBP) can achieve physiological electrical activation of the ventricles, its clinical use is limited by lower success rates, high and unstable pacing thresholds and loss of capture. Left bundle branch pacing (LBBP) has been proved to be able to correct Left bundle branch block (LBBB) and generate a narrower QRS duration than conventional RV pacing. However, its effects on ventricular synchronism and contraction function remains unknown. The current study is aimed to compare the echocardiographic characteristics between HBP and LBBP, and to explore whether LBBP leads to a comparable cardiac synchrony and deformation in comparison with HBP.

Methods

Forty-six pacing-indicated patients were prospectively enrolled. Twenty-nine patients underwent LBBP (17 male patients, mean age 69.6±13.7yrs, the LBBP group) and 17 patients underwent HBP (13 male patients, mean age 70.4±14.7yrs, the HBP group). LBBP was achieved by trans-septal method in the basal ventricular septum. Left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), left ventricular ejection fraction (LVEF), and tricuspid annulus plane systolic excursion (TAPSE) were obtained. Strains and time to peak strains of right ventricular free wall and 16 left ventricle segments were analyzed using two-dimensional speckle tracking echocardiography (2D STE). The standard deviation of time to peak strains of 16 left ventricular segments was calculated as PSD.

Results

Compared to the baseline, time to peak longitudinal strain (TTPS) of apical septum, apical lateral wall were shortened after 6 months of HBP, while they didn't change significantly after 6 months of LBBP. After pacemaker implantation, the LBBP group had a delayed TTPS of apical septum, apical lateral wall and basal RV free wall than the HBP group (LBBP vs. HBP: apical septum,358.44±61.98ms vs. 296.43±29.47ms; apical lateral wall, 373.11±55.80ms vs. 299.00±83.45ms; basal RV free wall, 404.31±72.93ms vs. 334.50±39.95ms, all p<0.05).However, PSD was comparable between the two groups (p>0.05).

Compared to the baseline, global left ventricular longitudinal strain (LVGLS) and longitudinal strain of RV free wall (RVLS) were deteriorated after 6 months of HBP, while they were preserved in the LBBP group. After 6-month pacing, LVGLS and RVLS were significantly stronger in the LBBP group than those in the HBP group. (LVGLS, −16.10±3.75% vs. −13.18±4.11%; RVLS, −17.50±5.46% vs. −13.70±4.35%, both p<0.05).

Conclusion

Patients received LBBP had a comparable left ventricular synchronism and a better myocardial contraction compared to patients with HBP. LBBP may be a promising alternative pacing strategy. Two-dimensional STE is more sensitive than conventional echocardiography in assessing cardiac synchrony and segmental deformation.

Differently Tagged Probes for Protein Profiling of Mitochondria

The mitochondrion is one of the most important organelles in the eukaryotic cell. Characterization of the mitochondrial proteome is a prerequisite for understanding its cellular functions at the molecular level. Here we report a proteomics method based on mitochondrion-targeting groups and click chemistry. In our strategy, three different mitochondrion-targeting moieties were each augmented with a clickable handle and a cysteine-reactive group. Fluorescence-based bioimaging and fractionation experiments clearly showed that most signals arising from the labels were localized in the mitochondria of cells, as a result of covalent attachment between probe and target proteins. The three probes had distinct profiling characteristics. Furthermore, we successfully identified more than two hundred mitochondrial proteins. The results showed that different mitochondrion-targeting groups targeted distinct proteins with partial overlap. Most of the labeled proteins were localized in the mitochondrial matrix and inner mitochondrial membrane. Our results provide a tool for chemoproteomic analysis of mitochondrion-related proteins.

Live-cell imaging and profiling of c-Jun N-terminal kinases using covalent inhibitor-derived probes

c-Jun N-terminal kinases (JNKs) are involved in critical cellular functions. Herein, small-molecule JNK-targeting probes are reported based on a covalent inhibitor. Together with newly developed two-photon fluorescence Turn-ON reporters and chemoproteomic studies, we showed that some probes may be suitable for live-cell imaging and profiling of JNKs.

Recent advances in reaction-based fluorescent probes for detecting monoamine oxidases in living systems

This Minireview summarizes the recent advances in reaction based MAO type fluorescent probes and their imaging applications in living systems.

[Changes of intestinal mucosal barrier in mice with chronic ulcerative colitis]

Objective: To study the damage and mechanism of intestinal mucosal barrier function in mice with ulcerative colitis induced by Dextran sulphate sodium (DSS). Methods: Mice models of chronic ulcerative colitis induced by DSS were established. The mice were completely randomized into normal control group and DSS group, 25 mice in each group. The body weight and colon length of the mice were monitored. The pathological examination of colon tissue was confirmed the success of the model and assessed the integrity of the colonic mucosal barrier; Evan's Blue's intestinal permeability analysis assessed the function of colon mucosal barrier; immunofluorescence staining and Western blot were used to evaluate the expression of intestinal mucosal barrier integrity-related proteins. Results: Compared with the normal control group, the DSS group had lower body weight [(25.6±0.7)g vs (23.5±0.7)g, t=2.14, P<0.05], and the colon length was shorter [(7.3±0.4)cm vs (5.6±0.2)cm, t=3.975, P<0.001]; colonic pathological results showed that the intestinal mucosa became thinner and part of the intestinal mucosa was defective; Evan's Blue instilled into the intestinal lumen was more abundant into the intestinal mucosa, and the optical density at 620 nm (OD(620))/colon tissue weight (g) was higher [(0.11±0.01) vs (0.15±0.01), t=4.174, P<0.05]; immunofluorescence and Western blot results showed lower expression of ZO-1, Claudin-1, and F-actin in colonic mucosa. Conclusion: The structure and function of intestinal mucosal barrier in DSS-induced chronic ulcerative colitis mice is impaired.

Transport stress induces heart damage in newly hatched chicks via blocking the cytoprotective heat shock response and augmenting nitric oxide production

Transport stress affects the animal's metabolism and psychological state. As a pro-survival pathway, the heat shock response (HSR) protects healthy cells from stressors. However, it is unclear whether the HSR plays a role in transport stress-induced heart damage. To evaluate the effects of transport stress on heart damage and HSR protection, newly hatched chicks were treated with transport stress for 2 h, 4 h and 8 h. Transport stress caused decreases in body weight and increases in serum creatine kinase (CK) activity, nitric oxide (NO) content in heart tissue, cardiac nitric oxide syntheses (NOS) activity and NOS isoforms transcription. The mRNA expression of heat shock factors (HSFs, including HSF1-3) and heat shock proteins (HSPs, including HSP25, HSP40, HSP47, HSP60, HSP70, HSP90 and HSP110) in the heart of 2 h transport-treated chicks was upregulated. After 8 h of transport stress in chicks, the transcription levels of the same HSPs and HSF2 were reduced in the heart. It was also found that the changes in the HSP60, HSP70 and HSP90 protein levels had similar tendencies. These results suggested that transport stress augmented NO generation through enhancing the activity of NOS and the transcription of NOS isoforms. Therefore, this study provides new evidence that transport stress induces heart damage in the newly hatched chicks by blocking the cytoprotective HSR and augmenting NO production.

Mitochondrial Specific H2S n Fluorogenic Probe for Live Cell Imaging by Rational Utilization of a Dual-Functional-Photocage Group

Reactive sulfur species play a very important role in modulating neural signal transmission. Hydrogen polysulfides (H₂S _n, n > 1) are recently suggested to be the actual signaling molecules. There are still few spatiotemporal controllable-based probes to detect H₂S _n. In this work, for the first time, we proposed the photocleavage product of the common photoremovable protecting group (2-nitrophenyl moiety) capable of trapping H₂S _n. Taking advantage of this, we constructed the probe H1 containing a photocontrollable group, a mitochondrial directing unit and a signal reporter fluorescein dye. H1 exhibited excellent fluorescence enhancement (50-fold) in response to H₂S _n under the aqueous buffer only after UV irradiation. H1 also showed high selectivity and sensitivity for H₂S _n over other reactive sulfur species, reactive oxygen species, and other analytes, especially biothoils including hydrogen sulfide, cysteine, homocysteine, and glutathione. We showed the utility of H1 to image H₂S _n in living cells with high spatiotemporal resolution.