Detection and tracking of cytoplasmic G-quadruplexes in live cells.

A TTPP probe was developed to distinguish G-quadruplexes (G4s) from other nucleic acid topologies through longer fluorescence lifetimes and higher quantum yields. In fluorescence lifetime imaging microscopy, TTPP enabled the visualization of cytoplasmic G4s in live cells, and showed the potential to detect cell apoptosis and ferroptosis by tracking cytoplasmic G4s.

A Golgi-Targeted Platinum Complex Plays a Dual Role in Autophagy Regulation for Highly Efficient Cancer Therapy.

Regulating autophagy to control the homeostatic recycling process of cancer cells is a promising anticancer strategy. Golgi apparatus is a substrate of autophagy but the Golgi-autophagy (Golgiphagy) mediated antitumor pathway is rarely reported. Herein, we have developed a novel Golgi-targeted platinum (II) complex Pt3, which is ca. 20 times more cytotoxic to lung carcinoma than cisplatin and can completely eliminate tumors after intratumoral administration in vivo. Its nano-encapsulated system for tail vein administration also features a good anti-tumor effect. Mechanism studies indicate that Pt3 induces substantial Golgi stress, indicated by the fragmentation of Golgi structure, down-regulation of Golgi proteins (GM130, GRASP65/55), loss of Golgi-dependent transport and glycosylation. This triggers Golgiphagy but blocks the subsequent fusion of autophagosomes with lysosomes, that is a dual role in autophagy regulation, resulting in loss of proteostasis and apoptotic cell death. As far as we know, Pt3 is the first Golgi-targeted Pt complex that can trigger Golgi stress-mediated dual-regulation of autophagic flux and autophagy-apoptosis crosstalk for highly efficient cancer therapy.

Disruption of Zinc Homeostasis by a Novel Platinum(IV)-Terthiophene Complex for Antitumor Immunity.

Zinc homeostatic medicine is of great potential for cancer chemo-immunotherapy; however, there are few reports on antitumor compounds that can trigger Zn2+ -mediated immune responses. In this work, we developed a novel cyclometalated PtIV -terthiophene complex, Pt3, that not only induces DNA damage and cellular metabolism dysregulation, but also disrupts zinc homeostasis as indicated by the abnormal transcriptional level of zinc regulatory proteins, excess accumulation of Zn2+ in cytoplasm, and down-regulation of metallothioneins (MTs), which further caused redox imbalance. The simultaneous disruption of zinc and redox homeostasis in response to Pt3 treatment activated gasdermin-D mediated pyroptosis accompanied by cytoskeleton remodeling, thus releasing pro-inflammatory cytokines to promote dendritic cell (DC) maturation and T cell tumor-infiltration, eventually eliminating both primary and distant tumors in vivo. As far as we know, this is the first metal complex that can regulate zinc homeostasis to activate antitumor immunity.

A platinum-ruthenium hybrid prodrug with multi-enzymatic activities for chemo-catalytic therapy of hypoxic tumors.

Regulation of tumor hypoxia and redox homeostasis is a promising strategy for cancer therapy. Nanocatalytic medicine has played more and more important roles in this field because it can cleverly convert the efficiency and selectivity of catalysis into high therapeutic efficiency. Herein, we developed a platinum(iv)-ruthenium hybrid prodrug, named as Pt-Ru, for efficient chemo-catalytic synergistic therapy of hypoxic tumors. The ruthenium hybridization endowed the Pt(iv) prodrug with multi-enzyme catalytic activity, that is, mimicking catalase (CAT) to generate O2 in situ, mimicking peroxidase (POD) to produce reactive oxygen species, and mimicking glutathione peroxidase (GPx) to deplete GSH, thus effectively overcoming tumor hypoxia and cisplatin resistance. As a result, Pt-Ru treatment led to a superior anticancer efficacy to cisplatin both in vitro and in vivo. This work suggested redox homeostasis regulation as a tantalizing angle for developing the next generation of platinum drugs.

Solution structure of a thrombin binding aptamer complex with a non-planar platinum(ii) compound.

Thrombin Binding Aptamer (TBA) is a monomolecular well-defined two G-tetrad antiparallel G-quadruplex DNA that inhibits the activity of human α-thrombin. In this report, we synthesized a quasi-cross-shaped platinum(ii) compound (L'2LPt) with one cyclometalated and two carbene ligands. We found L'2LPt has selective affinity to bind the TBA G-quadruplex. A fibrinogen clotting assay revealed that L'2LPt can abrogate the inhibitory activity of TBA against thrombin. We solved the 1 : 1 L'2LPt-TBA complex structure by NMR, which revealed a unique self-adaptive property of L'2LPt upon binding to TBA. In the complex, a carbene ligand of L'2LPt rotates to pair with the cyclometalated ligand to form a plane stacking over half of the TBA G-tetrad and covered by lateral TT loops. It is notable that the heavy atom Pt stays out of the G-tetrad. Meanwhile, the other carbene ligand remains relatively perpendicular and forms a hydrogen bond with a guanine to anchor the L'2LPt position. This structure exhibits a quasi-cross-shaped Pt(ii) compound bound to the G-quadruplex with an unusual "wall-mounted" binding mode. Our structures provide insights into the specific recognition of antiparallel G-quadruplex DNA by a self-adaptive Pt(ii) compound and useful information for the design of selective G-quadruplex targeting non-planar molecules.

Selectivity and Targeting of G-Quadruplex Binders Activated by Adaptive Binding and Controlled by Chemical Kinetics.

G-quadruplexes (G4s) are prevalent in oncogenes and are potential antitumor drug targets. However, binding selectivity of compounds to G4s still faces challenges. Herein, we report a platinum(II) complex (Pt1), whose affinity to G4-DNA is activated by adaptive binding and selectivity controlled by binding kinetics. The resolved structure of Pt1/VEGF-G4 (a promoter G4) shows that Pt1 matches 3'-G-tetrad of VEGF-G4 through Cl- -dissociation and loop rearrangement of VEGF-G4. Binding rate constants are determined by coordination bond breakage/formation, correlating fully with affinities. The selective rate-determining binding step, Cl- -dissociation upon G4-binding, is 2-3 orders of magnitude higher than dsDNA. Pt1 potently targets G4 in living cells, effectively represses VEGF expression, and inhibits vascular growth in zebrafish. We show adaptive G4-binding activation and controlled by kinetics, providing a complementary design principle for compounds targeting G4 or similar biomolecules.

[Factors influencing recovery from childhood inguinal herniorrhaphy-induced vas deferens obstruction after microscopic vasovasostomy].

OBJECTIVE: To investigate the factors influencing the recovery from childhood inguinal herniorrhaphy (IH)-induced vas deferens obstruction following microscopic vasovasostomy. METHODS: We retrospectively analyzed the clinical data on 41 cases of microscopic vasovasostomy for obstructive azoospermia in our hospital from July 2015 to September 2018. All the patients had a history of inguinal hernia treated by IH in the childhood. We performed scrotal ultrasonography, semen analysis and seminal plasma biochemistry to confirm vas deferens obstruction preoperatively. If sperm was observed for ≥2 times in semen examination after vasovasostomy, we considered the vas deferens successfully unobstructed. RESULTS: Microscopic vasovasostomy was successfully completed in 39 of the cases, of which2 were lost to follow-up, with a follow-up rate of 94.8% (37/39). The patients, at the mean age of (25.54 ± 2.85) years and with body mass index (BMI) of (24.92 ± 2.79) kg/m2 and post-IH time of (18.97 ± 2.58) years, were followed up for (13.05 ± 3.74) months. Successful recovery from vas deferens obstruction was observed in 78.4% (29/37) of the patients after IH, 80.0% (16/20) in the < 26-year-olds, 76.5% (13/17) in the ≥26-year-olds (P = 0.795), 75.0% (12/16) in those with BMI < 24.92 kg/m2 , 81.0% (17/21) in those with BMI ≥24.92 kg/m2 (P = 0.807), 78.6% (11/14) in those with post-IH time of < 19 years, 18.3% (18/23) in those with post-IH time of ≥19 years (P = 0.982), 60.0% (12/20) in those with sperm and 82.4% (14/17) in those without sperm found intraoperatively (P = 0.428), 42.9% (3/7) in those treated by unilateral and 82.4% (26/30) in those by bilateral vasovasostomy (P = 0.027). Multivariate logistic regression analysis showed a close correlation between the operation side and postoperative recovery from vas deferens obstruction (P = 0.022). CONCLUSIONS: For male patients undergoing microscopic vasovasostomy for childhood IH-induced vas deferens obstruction, the operation side is an independent factor influencing postoperative recovery, while age, BMI, post-IH time, and intraoperative presence or absence of sperm are not significantly correlated with it.

Synthesis of Pyrrolo[2,1,5-cd]indolizine Rings via Visible-Light-Induced Intermolecular [3+2] Cycloaddition of Indolizines and Alkynes.

A range of indolizine smoothly underwent visible-light-induced intermolecular [3+2] annulations with internal alkynes to afford pyrrolo[2,1,5-cd]indolizine in good to excellent yields with high regioselectivity. Through this cascade reaction, a series of fluoroactive fused indolizines with a large π-system were conveniently synthesized. The usage of visible light as energy source with air as a stoichiometric oxidant under simple conditions makes this process attractive and practical.

cis-{1-Butyl-3-[2-(phenyl-sulfan-yl)eth-yl]-4-imidazolin-2-yl-κ2 C 2,S'}di-chlorido-platinum(II).

The asymmetric unit of the title compound, [PtCl2(C15H20N2S)], comprises one PtII ion, one N-heterocyclic carbene(NHC)-thio-ether ligand and two chloride ions. The PtII ion is four-coordinated by one C atom and one S atom of the NHC-thio-ether ligand, and by two chloride ions, forming an approximately square-planar geometry. In the crystal, the mol-ecules are linked via C-H⋯Cl and C-H⋯π inter-actions, forming a layer parallel to the ab plane.

Generation and efficacy evaluation of a recombinant adenovirus expressing the E2 protein of classical swine fever virus.

Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), which causes significant economic losses to the pig industry worldwide. The E2 glycoprotein of CSFV is the main target for neutralizing antibodies. This study was aimed to develop a recombinant human adenovirus type 5 expressing the CSFV E2 gene (rAdV-E2) and evaluate its efficacy in rabbits and pigs. The results showed that the rabbits and the pigs immunized with the rAdV-E2 developed high-level CSFV-specific neutralizing antibodies. The rAdV-E2-immunized rabbits were protected from fever induced by infection with C-strain, which is pathogenic to the rabbit, and the rAdV-E2-immunized pigs were protected from lethal challenge with highly virulent Shimen strain. This indicates that the recombinant adenovirus can be an attractive candidate vaccine for preventing CSF.

Immune responses induced by a BacMam virus expressing the E2 protein of classical swine fever virus in mice.

Non-replicating baculovirus-mediated gene transfer into mammalian cells has been developed as a vaccine strategy against a number of diseases in several animal models. In the present study, the BacMam vector, a baculovirus pseudotyped with the glycoprotein from vesicular stomatitis virus, was used as a recombinant vector to express classical swine fever virus (CSFV) E2 protein under the control of the immediate early 1 (ie1) promoter from shrimp white spot syndrome virus. The E2 gene was efficiently expressed in both insect and mammalian cells. Intramuscular injection of mice with the recombinant baculovirus resulted in the production of high-titers of CSFV-specific neutralizing antibodies. Specific lymphoproliferative responses to CSFV stimulation were detected in the splenocytes of the immunized mice as demonstrated by CFSE staining assay and WST-8 assay. This study demonstrates that the BacMam virus vector can efficiently express the E2 protein and effectively induce immune responses against CSFV. This is a first step in the demonstration that the pseudotyped baculovirus-delivered CSFV E2 gene can be a potential non-replicating vaccine against CSFV infections.