Bis(benzonitrile) dichloroplatinum (II) interrupts PD-1/PD-L1 interaction by binding to PD-1.

Checkpoint inhibitors such as PD-1/PD-L1 antibody therapeutics are a promising option for the treatment of multiple cancers. Due to the inherent limitations of antibodies, great efforts have been devoted to developing small-molecule PD-1/PD-L1 signaling pathway inhibitors. In this study we established a high-throughput AlphaLISA assay to discover small molecules with new skeletons that could block PD-1/PD-L1 interaction. We screened a small-molecule library of 4169 compounds including natural products, FDA approved drugs and other synthetic compounds. Among the 8 potential hits, we found that cisplatin, a first-line chemotherapeutic drug, reduced AlphaLISA signal with an EC50 of 8.3 ± 2.2 µM. Furthermore, we showed that cisplatin-DMSO adduct, but not semplice cisplatin, inhibited PD-1/PD-L1 interaction. Thus, we assessed several commercial platinum (II) compounds, and found that bis(benzonitrile) dichloroplatinum (II) disturbed PD-1/PD-L1 interaction (EC50 = 13.2 ± 3.5 µM). Its inhibitory activity on PD-1/PD-L1 interaction was confirmed in co-immunoprecipitation and PD-1/PD-L1 signaling pathway blockade bioassays. Surface plasmon resonance assay revealed that bis(benzonitrile) dichloroplatinum (II) bound to PD-1 (KD = 2.08 µM) but not PD-L1. In immune-competent wild-type mice but not in immunodeficient nude mice, bis(benzonitrile) dichloroplatinum (II) (7.5 mg/kg, i.p., every 3 days) significantly suppressed the growth of MC38 colorectal cancer xenografts with increasing tumor-infiltrating T cells. These data highlight that platinum compounds are potential immune checkpoint inhibitors for the treatment of cancers.

Specific pupylation as IDEntity reporter (SPIDER) for the identification of protein-biomolecule interactions.

Protein-biomolecule interactions play pivotal roles in almost all biological processes. For a biomolecule of interest, the identification of the interacting protein(s) is essential. For this need, although many assays are available, highly robust and reliable methods are always desired. By combining a substrate-based proximity labeling activity from the pupylation pathway of Mycobacterium tuberculosis and the streptavidin (SA)-biotin system, we developed the Specific Pupylation as IDEntity Reporter (SPIDER) method for identifying protein-biomolecule interactions. Using SPIDER, we validated the interactions between the known binding proteins of protein, DNA, RNA, and small molecule. We successfully applied SPIDER to construct the global protein interactome for m6A and mRNA, identified a variety of uncharacterized m6A binding proteins, and validated SRSF7 as a potential m6A reader. We globally identified the binding proteins for lenalidomide and CobB. Moreover, we identified SARS-CoV-2-specific receptors on the cell membrane. Overall, SPIDER is powerful and highly accessible for the study of protein-biomolecule interactions.

Identification and characterization of isocitrate dehydrogenase 1 (IDH1) as a functional target of marine natural product grincamycin B.

Grincamycins (GCNs) are a class of angucycline glycosides isolated from actinomycete Streptomyces strains that have potent antitumor activities, but their antitumor mechanisms remain unknown. In this study, we tried to identify the cellular target of grincamycin B (GCN B), one of most dominant and active secondary metabolites, using a combined strategy. We showed that GCN B-selective-induced apoptosis of human acute promyelocytic leukemia (APL) cell line NB4 through increase of ER stress and intracellular reactive oxygen species (ROS) accumulation. Using a strategy of combining phenotype, transcriptomics and protein microarray approaches, we identified that isocitrate dehydrogenase 1(IDH1) was the putative target of GCN B, and confirmed that GCNs were a subset of selective inhibitors targeting both wild-type and mutant IDH1 in vitro. It is well-known that IDH1 converts isocitrate to 2-oxoglutarate (2-OG), maintaining intracellular 2-OG homeostasis. IDH1 and its mutant as the target of GCN B were validated in NB4 cells and zebrafish model. Knockdown of IDH1 in NB4 cells caused the similar phenotype as GCN B treatment, and supplementation of N-acetylcysteine partially rescued the apoptosis caused by IDH1 interference in NB4 cells. In zebrafish model, GCN B effectively restored myeloid abnormality caused by overexpression of mutant IDH1(R132C). Taken together, we demonstrate that IDH1 is one of the antitumor targets of GCNs, suggesting wild-type IDH1 may be a potential target for hematological malignancies intervention in the future.

Development and evaluation of a real-time fluorogenic loop-mediated isothermal amplification assay integrated on a microfluidic disc chip (on-chip LAMP) for rapid and simultaneous detection of ten pathogenic bacteria in aquatic animals.

Rapid, low-cost, and user-friendly strategies are urgently needed for early disease diagnosis and timely treatment, particularly for on-site screening of pathogens in aquaculture. In this study, we successfully developed a real-time fluorogenic loop-mediated isothermal amplification assay integrated on a microfluidic disc chip (on-chip LAMP), which was capable of simultaneously detecting 10 pathogenic bacteria in aquatic animals, i.e., Nocardia seriolae, Pseudomonas putida, Streptococcus iniae, Vibrio alginolyticus, Vibrio anguillarum, Vibrio fluvialis, Vibrio harveyi, Vibrio parahaemolyticus, Vibrio rotiferianus, and Vibrio vulnificus. The assay provided a nearly-automated approach, with only a single pipetting step per chip for sample dispensing. This technique could achieve limits of detection (LOD) ranging from 0.40 to 6.42pg per 1.414µL reaction in less than 30 min. The robust reproducibility was demonstrated by a little variation among duplications for each bacterium with the coefficient of variation (CV) for time to positive (Tp) value less than 0.10. The clinical sensitivity and specificity of this on-chip LAMP assay in detecting field samples were 96.2% and 93.8% by comparison with conventional microbiological methods. Compared with other well-known techniques, on-chip LAMP assay provides low sample and reagent consumption, ease-of-use, accelerated analysis, multiple bacteria and on-site detection, and high reproducibility, indicating that such a technique would be applicable for on-site detection and routine monitoring of multiple pathogens in aquaculture.

[Experimental study of TGF-ß2 antisense oligonucleotide on inhibiting corneal scar hyperplasia in rabbits].

OBJECTIVE: To investigate the influence of TGF-ß2 antisense oligonucleotide (ASON) on preventing corneal scar hyperplasia in rabbits and to provide experimental evidence for its clinical application. METHODS: It was an experimental study. One hundred and ninety two New Zealand white rabbits were randomly divided into 4 groups (groups A, B, C and D). Corneal injury models were established in all groups. There were 48 experimental animals in each group. TGF-ß2 ASON was dropped into right eyes in group A, dexamethasone was dropped into right eyes in group B, deionized water was dropped into right eyes in group C and nothing was dropped into right eyes in group D after the operation. The corneas were surgically removed and assessed by hematoxylin eosin (HE) staining, immunohistochemical study and real time PCR at four different time points (4 d, 7 d, 14 d and 28 d) after surgery. RESULTS: HE staining: at the same time point, fibroblasts in the groups A and B were significantly fewer than that in the groups C and D, the difference was statistically significant (P < 0.05), but there was no significant difference between groups A and B or groups C and D. Immunohistochemical observation found that the expression of α-smooth muscle actin (α-SMA) positive fibroblasts could be observed by the 4th day (9.44 ± 0.47/HP), reached a climax by the 7th day (12.50 ± 0.81/HP), and returned to the baseline levels by the 14th day (0.85 ± 0.43/HP) in the group A, which was similar to that in the group B (9.49 ± 0.95, 12.42 ± 0.70, 0.86 ± 0.79/HP) at the same time point (P > 0.05), but it was significantly fewer than that in the group C(20.14 ± 0.78, 18.19 ± 1.28, 4.87 ± 0.58/HP) and group D(20.21 ± 0.92, 18.25 ± 1.39, 5.00 ± 2.217/HP), which was statistical significant (P < 0.05). The staining intensity of fibronectin (FN) in groups A and B was significantly weaker than that in groups C and D. Real time PCR analysis showed that at each time point, the expression of TGF-ß2 mRNAs in groups A and B was significantly lower than that in groups C and D (P < 0.05). CONCLUSIONS: TGF-ß2 ASON can effectively prevent the proliferation of corneal tissue by inhibiting the activity of TGF-ß2 after injury. The early stage of corneal repair is 7 days after injury, so it is important to use TGF-ß2 ASON at this stage to inhibit the scar hyperplasia. In addition, it is safe to apply TGF-ß2 ASON topically to protect the cornea from obvious side effects.

[Evaluation of calcium dobesilate for its anti-cataract potential in experimental rat models].

OBJECTIVE: To investigate the preventive and therapeutic effects of agent calcium dobesilate(CDO) with different doses on the galactose cataract of rats. METHODS: We chose fifty Wistar rats at 20- day old. Then, they were divided into 3 groups at random. Choose 10 rats as the control group and gave normal diet; 10 rats as the model group and fed with Gal solution ( drink 12.5% Gal solution from 1 to 7 days and 10%Gal solution from 8 to 21 days except for normal diet ) ; 30 rats as the treatment group and fed with the same Gal solution as the model group, besides they were divided into high dosage group, medium dosage group and low dosage group equally and gave 300 mg×kg(-1)×d(-1), 150 mg×kg(-1)×d(-1), 75 mg×kg(-1)×d(-1) dose of calcium dobesilate respectively from the first day to the end of experiment. The experiment lasts 21 days. Lens opacity were observed and recorded by slit-lamp examination regularly. Activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) and content of malondialdehyde (MDA) were determined to estimate the effect of CDO . Lens fibers changes and Histological changes were observed by scanning electron microscope (SEM) and light microscope (LM) separately. The apoptosis rate of lens epithelium were determined by TUNEL assay. RESULTS: The appearance of Lens opacity in model group was more quickly than that in treatment group in model group, 3 eyes in degree IV, 7 eyes in degree V, while in treatment group, 5 eyes in degree III, 3 eyes in degree IV, 2 eyes in degree V (H = 7.12, P < 0.05). The activity of SOD and GSH-px in treatment group is higher than mode group, but lower than control group on 8th day, there was difference noticed in the activity of SOD (50.01 ± 1.19), (39.39 ± 1.70) , treatment group (46.57 ± 1.09, 46.42 ± 0.87, 45.70 ± 1.46) U/mgProt (F = 88.70, P < 0.05) and the activity of GSH-px (42.92 ± 0.97) , (12.70 ± 1.17) , treatment group (29.16 ± 1.05, 29.08 ± 0.98, 28.25 ± 0.98) nmol/mgprot (F = 1071.89, P < 0.05) ]in 3 groups. The content of MDA in model group (3.43 ± 0.15)nmol/mgprot is higher than treatment group (2.89 ± 0.11, 2.99 ± 0.12, 2.99 ± 0.09)nmol/mgprot (F = 64.62; P < 0.05). There were no statistic significant differences among high dosage group, medium dosage group and low dosage group . The texture of lens fibres detected by SEM in the rats of model was more disorder than treatment group. After HE staining, Lens epithelial cell detected by LM in control group have a clear structure, however, Lens epithelial cell both in model group and treatment group have changed from the initial single layer to multi-storey. Junction between lenses fibers became decreased even disappeared . The apoptosis rate of lens epithelium in treatment group[(2.37 ± 0.17)%, (2.46 ± 0.26)%, (2.79 ± 0.41)%] is higher than control group (0.23 ± 0.07) %, but is much fewer than model group (4.99 ± 0.51) % (χ(2) = 40.41;P < 0.05). CONCLUSION: CDO with different doses could protect lens of rats against galactose damage and there were no significant differences among the different doses of groups.

[Clinical observation of visual quality after aspherical intraocular lens implantation in traumatic cataract].

OBJECTIVE: To observe the visual quality of aspherical intraocular lens (IOL) implantation in traumatic cataract patients. METHODS: Prospective clinical study.96 traumatic cataract patients (96 eyes) suffered from penetrating corneal trauma chosen from the first affiliated hospital of Zhengzhou university during June 2009 to June 2012. They were divided into two groups based on the different type of intraocular lens. The experimental group (48 eyes) was implanted with aspherical IOL and the control group (48 eyes) was implanted with traditional sphere IOL.Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), contrast sensitivity (CS) and stereoscopic vision were observed at 1 month, 3 months, and 6 months after surgery. At the same time, questionnaire survey about the satisfaction of patients was also performed. The t test was used to compare the preoperative general condition, postoperative visual acuity, contrast sensitivity and stereoscopic vision of the two groups, and the rank sum test was used to compare the astigmatism and the satisfaction of patients. RESULTS: There was no significant difference in UCVA (t = 1.37, 1.28,0.71, P > 0.05) between the experimental group (0.56 ± 0.22, 0.68 ± 0.13,0.84 ± 0.15) and the control group (0.51 ± 0.17, 0.61 ± 0.20,0.81 ± 0.17) at three time points. There was no significant difference in BCVA (t = 0.87, 1.38, 1.39, P > 0.05) between the experimental group (0.62 ± 0.13, 0.74 ± 0.21, 0.87 ± 0.10) and the control group (0.57 ± 0.25,0.69 ± 0.22,0.84 ± 0.15) . The same result happened in stereoscopic vision at 6 months after surgery (far stereopsis:123.5 ± 7.8 vs 126. 9 ± 5.9, t = 0.64, P > 0.05;near stereopsis:90.5 ± 7.8 vs 95.2 ± 3.5; t = 1.36, P > 0.05) between experimental group and control group. The contrast sensitivity of the experimental group in every stage (3 c/d:1.52 ± 0.18, 6 c/d:1.68 ± 0.19, 12 c/d:1.29 ± 0.14, 18 c/d:1.04 ± 0.20) was superior to the control group (3 c/d:1.49 ± 0.27, 6 c/d:1.57 ± 0.21, 12 c/d:1.14 ± 0.20, 18 c/d:0.85 ± 0.14) , especially on the glare sensitivity (the experimental group:3 c/d:1.40 ± 0.15, 6 c/d:1.52 ± 0.22, 12 c/d:1.21 ± 0.18, 18 c/d:0.91 ± 0.14, the control group:3 c/d:1.13 ± 0.13, 6 c/d:1.13 ± 0.28, 12 c/d:0.92 ± 0.13, 18 c/d:0.54 ± 0.16) Compared two groups of difference have statistical significance (free from glare:3 c/d:t = 2.829, 6 c/d:t = 4.092, 12 c/d:t = 3.055, 18 c/d:t = 2.093;glare:3 c/d:t = 2.650, 6 c/d:t = 3.105, 12 c/d:t = 3.395, 18 c/d:t = 2.215;P < 0.05) .Questionnaire survey showed the experimental group (72.9%) was statistically significantly higher (t = 3.016, P < 0.05) than that in the control group (54.1%) on the satisfaction of patients. CONCLUSIONS: The visual quality with implantation of aspherical IOL in traumatic cataract patients is superior to traditional sphere IOL. Aspherical IOL is more appropriate for the patients with small and peripheral corneal scar.It can reduce the visual function damage to minimum caused by trauma.

[Quantitative observation on changes of anterior segment by ultrasound biomicroscopy after posterior chamber phakic intraocular lens implantation].

OBJECTIVE: The objective is to study the safety and effectiveness of implantation of posterior chamber phakic intraocular contact lens (ICL) by observing the changes in anterior segment using ultrasound biomicroscopy (UBM). METHODS: It was a perspective study. The study sampled 30 high myopia patients (30 eyes) who were treated with posterior chamber phakic ICL implant. Central anterior chamber depth (ACD), trabecular-iris angle (TIA), angle opening distance (AOD500), trabecular-ciliary processes distance (TCPD) and iris-ciliary processes distance (ICPD) were measured using UBM preoperatively, 3 months and 1 year postoperatively. The distance from ICL to the central surface of lens and peripheral lens and intra-ocular pressure were measured postoperatively and examined using slit-lamp biomicroscope. One-way ANOVA was used to analyze the distance between peripheral surface of ICL and the lens. One-way repeated measures ANOVA and Bonferroni were conducted. RESULTS: Preoperatively, 3 months and 1 year postoperatively, ACD were (3.16±0.08) mm, (2.76±0.13) mm, (2.74±0.14) mm; AOD500 were (0.45±0.04) mm, (0.41±0.04) mm, (0.41±0.03) mm; TIA were (35.00±3.24)°, (32.47±3.56)°, (32.40±3.23)°, respectively. There were significant difference in TIA, ACD and AOD (P<0.05) between preoperative and postoperative data. There was no significant difference between the two postoperative periods tested. TCPD and ICPD showed no significant difference between various time points (F=0.49, F=0.57; P>0.05). CONCLUSIONS: The decrease in ACD depth and correction in TIA and AOD were the noticeable changes observed in morphological structure of the ocular anterior segment after the ICL treatment. The incidence of complication did not increase as the result of the minor changes in morph structure during the course of the study. However, the long-term effects would require further long-term observation.