MdATG18a overexpression improves basal thermotolerance in transgenic apple by decreasing damage to chloroplasts

High temperature is an abiotic stress factor that threatens plant growth and development.Autophagy in response to heat stress involves the selective removal of heat-induced protein complexes.Previously,we showed that a crucial autophagy protein from apple,MdATG18a,has a positive effect on drought tolerance.In the present study,we treated transgenic apple(Malus domestica)plants overexpressing MdATG18a with high temperature and found that autophagy protected them from heat stress.Overexpression of MdATG18a in apple enhanced antioxidase activity and contributed to the production of increased beneficial antioxidants under heat stress.Transgenic apple plants exhibited higher photosynthetic capacity,as shown by the rate of CO_(2) assimilation,the maximum photochemical efficiency of photosystem II(PSII),the effective quantum yield,and the electron transport rates in photosystems I and II(PSI and PSII,respectively).We also detected elevated autophagic activity and reduced damage to chloroplasts in transgenic plants compared to WT plants.In addition,the transcriptional activities of several HSP genes were increased in transgenic apple plants.In summary,we propose that autophagy plays a critical role in basal thermotolerance in apple,primarily through a combination of enhanced antioxidant activity and reduced chloroplast damage.

microRNA-18a Promotes Cell Migration and Invasion Through Inhibiting Dicer l Expression in Hepatocellular Carcinoma In Vitro

Objective To investigate the effects of microRNA-18a(miR-18a) on migration and invasion of hepatocellular carcinoma(HCC) cells,and its possible mechanism associated with Dicer l. Methods HepG 2 and HepG 2.2.15 cells were transfected with miR-18 a inhibitor using Lipofectamine. Cell invasion was evaluated by transwell invasion assay,and cell migration was detected by transwell migration and wound-healing assays. Moreover,luciferase reporter assay was used to identify whether Dicer expression was regulated by miR-18 a. Real-time RT-PCR and western blot were performed to analyze Dicer 1 expression. In addition,a functional restoration assay was performed to investigate whether miR-18 a promotes HCC cell migration and invasion by directly targeting Dicer 1. Results miR-18 a inhibitor can suppress the migration and invasion of HCC cells. Furthermore,suppression of Dicer l expression by small interfering RNA essentially abolished the inhibition of cell migration and invasion induced by miR-18 a inhibitor,restorating these activities to levels similar to the parental HCC cells. Interestingly,suppression of miR-18 a in HCC cells resulted in enhanced expression of Dicer l. In addition,the results of a luciferase assay demonstrated targeted regulation of Dicer l by miR-18 a. Conclusion Our findings suggest that miR-18 a promotes migration and invasion of HCC cells by inhibiting Dicer l expression.

Metal complexes induced ferroptosis for anticancer therapy

Metal complexes for anti-tumor treatment have been developed rapidly in recent decades since the application of cisplatin in clinics.However,some tumor cells are resistant to apoptosis and not sensitive to metallodrugs that function through the apoptotic pathway.Recently,metal complexes have been reported to cause ferropto-sis against tumor cells,which offers new opportunities for anticancer therapy.In this perspective,ferroptosis-inducing metal complexes and their working mechanisms are introduced,while the challenges and opportunities are also discussed.

Photoinduced Carbene for Effective Photodynamic Therapy Against Hypoxic Cancer Cells

Photodynamic therapy(PDT)has attracted much attention because of its advantages over chemotherapy,such as broad spectrum,high selectivity,and low drug resistance.However,most photosensitizers(PSs)used in PDT are O_(2)-dependent and show limited therapeutic efficacy toward hypoxic solid tumors.Therefore,developing PSs that produce reactive oxygen species(ROS)in an O_(2)-independent manner is highly demanded.Herein,we constructed a novel O_(2)-independent PS(TPA-N)based onα-diazo-aryl acetate,which could generate reactive carbene under visible light irradiation.Photoinduced carbene could react with biosubstrates and cause significant carbene stress and ROS,effectively killing tumor cells even under hypoxic conditions.TPA-N showed much less O_(2)dependence compared with traditional PDT reagent protoporphyrin IX.A mechanistic study suggested that TPAN could induce mitochondrial membrane potential collapse and upregulate apoptosis-related proteins upon light irradiation.This work provided a reliable strategy for developing O_(2)-independent PSs against hypoxic tumor cells through photoinduced carbene.

Type I Photoreaction and Photoinduced Ferroptosis by a Ru(II)Complex to Overcome Tumor Hypoxia in Photodynamic Therapy

Photodynamic therapy(PDT)usually shows limited efficacy in solid tumors since traditional PDT is O_(2)^(-)dependent while solid tumors are inherently hypoxic.In addition,hypoxic tumor cells possess antiapoptotic pathways that resist PDT-induced apoptosis.Therefore,developing photosensitizers(PSs)that show low O_(2)^(-)dependency and can induce nonapoptotic cell death pathways is critically needed.Herein,a series of Ru(II)polypyridine complex-based PSs,RuNMe,RuH,and RuCN,were synthesized,and their applications against hypoxic tumor cells through PDT were investigated.All three complexes showthe ability to generate the superoxide anion radical(·O_(2)^(-)),which is the type I photoreaction and less O_(2)^(-)dependent.RuNMe shows the best PDT performance against MCF-7 cells and three-dimensional multicellular spheroids,due to its higher cellular uptake and more reactive oxygen species generation.More importantly,RuNMe-incubated MCF-7 cells show photoinduced ferroptosis as evidenced by glutathione peroxidase 4 downregulation and lipid peroxide accumulation.This work not only develops a novel ferroptosis-inducing Ru(II)complex with the type I PDT process but also offers an effective strategy to solve tumor hypoxia in PDT.

BODIPY-derived ratiometric fluorescent sensors: pH-regulated aggregation-induced emission and imaging application in cellular acidification triggered by crystalline silica exposure

Modification of classic fluorophore to possess the emission transitions between aggregation-induced emission(AIE)and intrinsic emission offers reliable approach to the design of ratiometric fluorescent sensors.In this study,a proton acceptor benzimidazole was integrated with BODIPY to form three compounds,BBI-1/2/3,which demonstrated the AIE(~595 nm,I_(agg))in neutral aqueous medium and intrinsic BODIPYemission(~510 nm,I_(int))in acidic medium.All the three showed the ratiometric pH sensing behavior in a dual excitation/dual emission mode,yet BBI-3 displayed still the dual emission ratiometric pH sensing ability.The pH-dependent emission ratio I_(int)/I_(agg)of the three were fully reversible,and no interference was observed from normal abundant chemical species in live cells.Their different p K_a(BBI-1,p K_a4.4;BBI-2,p K_a2.7;BBI-3,p K_a3.6)suggested that the substituents on benzimidazole moiety were essential to govern their functioning pH range.The ratiometric imaging of BBI-1 in A549 cells provided an effective intracellular pH(pH_i)calibration formula corresponding to emission ratio of I_(int)/I_(agg).Ratiometric pH_iimaging in A549 cells upon small particle exposure confirmed the particle-induced cellular acidification with this formula.Both particle size and the chemical nature of the particle contribute to the observed acidification effect.The synchronization of lysosome disruption to cellular acidification in A549 cells upon crystalline silica exposure was directly observed for the first time with BBI-1,showing the potential application of BBI-1 in the study of silicosis and other related diseases.This study demonstrated that endowing fluorophore with AIE/intrinsic emission transition could be a promising strategy for ratiometric sensor design.

Nanoscale monitoring of mitochondria and lysosome interactions for drug screening and discover

Technology advances in genomics,proteomics,and metabolomics largely expanded the pool of potential therapeutic targets.Compared with the in vitro setting,cell-based screening assays have been playing a key role in the processes of drug discovery and development.Besides the commonly used strategies based on colorimetric and cell viability,we reason that methods that capture the dynamic cellular events will facilitate optimal hit identification with high sensitivity and specificity.Herein,we propose a live-cell screening strategy using structured illumination microscopy (SIM) combined with an automated cell colocalization analysis software,CellprofilerTM,to screen and discover drugs for mitochondria and lysosomes interaction at a nanoscale resolution in living cells.This strategy quantitatively benchmarks the mitochondria-lysosome interactions such as mitochondria and lysosomes contact (MLC) and mitophagy.The automatic quantitative analysis also resolves fine changes of the mitochondria-lysosome interaction in response to genetic and pharmacological interventions.Super-resolution live-cell imaging on the basis of quantitative analysis opens up new avenues for drug screening and development by targeting dynamic organelle interactions at the nanoscale resolution,which could facilitate optimal hit identification and potentially shorten the cycle of drug discovery.

Research progress on train operation safety in Xinjiang railway under wind environment

Railway lines in the Xinjiang wind area face severe wind disasters year-round,which seriously affects the safety and economy of the railway in China.Therefore,the wind characteristics and statistics of wind-induced accidents along the Xinjiang railway lines are presented and the basic research route for evaluating the train running safety under crosswinds and effective measures to improve the windproof performances of trains are proposed,which are meaningful to deal with wind-induced train accidents.Based on this research route,a series of numerical simulations are conducted to evaluate train safety and the corresponding measures are provided.The results show the following.The running safety of the train under crosswinds mainly depends on the aerodynamic loads acting on the train.The relationships between the safe speed limit and train type,the load weight,the embankment height,the road cutting depth,the railway line curve parameters,the yaw angle and other factors are obtained.The critical wind-vehicle speed relationship,as well as the engineering speed limit value under different running conditions,are determined.Large values of the aerodynamic and dynamic indices mainly appear in special locations,such as near earth-embankment-type windbreak walls,shallow cuttings and the transition sections between various types of windbreak walls.Measures such as increasing the height of the earth-embankment-type windbreak walls,adding wind barriers with reasonable heights in shallow cuttings and optimizing the design of different types of transition sections are proposed to significantly improve the safe speed limits of trains under crosswinds.

A ratiometric fluorescent sensor for tracking Cu(Ⅰ) fluctuation in endoplasmic reticulum

A two-photon ratiometric fluorescent sensor for Cu^+ in endoplasmic reticulum(ER), CNSB, was developed via coumarin/ASBD integration based on FRET mechanism. In solution, CNSB shows reversible, highly-specific ratiometric response to Cu^+ .Moreover, CNSB exhibits suitable K_d value, suggesting the possibility of detecting Cu^+ in the living cells. The probe can enter the MCF-7 cells easily and specifically locates in the ER. The highly specific ratiometric response of CNSB toward Cu^+ in MCF-7 cells provides the sensor the capacity to visualize both exogenous and endogenous Cu^+ in the ER via fluorescence imaging.Next, CNSB was utilized to detect the fluctuation and distribution of Cu^+ under ER stress in MCF-7 cells, which confirmed directly the relationship between Cu^+ enhancement and ER stress. Meanwhile, the two-photon ability of coumarin facilitated the sensor to visualize Cu^+ fluctuation via two-photon fluorescence imaging. In addition, the spatial distribution of Cu^+ in the heart slice of the 14-day-old rat was demonstrated using CNSB. This study demonstrates the promising potential of CNSB in clarifying the Cu^+ -dependent signaling in the ER stress-related diseases.

A β-sheet-targeted theranostic agent for diagnosing and preventing aggregation of pathogenic peptides in Alzheimer’s disease

Amyloid-βpeptide(Aβ)aggregates,particularly Aβoligomers,are established biomarker and toxic species in Alzheimer’s disease(AD).Early detection and disaggregation of Aβaggregates are of great importance for the treatment of AD due to the unavailability of therapy at the advanced stages of the disease.A multitalented agent,2-{2-[(1 H-benzoimidazol-2-yl)methoxy]phenyl}benzothiazole(BPB),is designed by merging twoβ-sheet targeting groups into one molecule to detect and inhibit the Aβaggregation.BPB can quantitatively measure theβ-sheet level of soluble Aβoligomers and specifically distinguish the aggregates of Aβ40 and Aβ42 by unique luminescence spectrum.Animal tests demonstrate that BPB can efficiently penetrate the blood brain barrier and precisely stain Aβplaques in the brain;more importantly,it can differentiate the blood of APP transgenic mice from that of normal ones.In addition to the diagnostic potential,BPB also suppresses the generation of ROS,protects the neurons from neurotoxicity,and disaggregates the Aβaggregates in brain homogenates of APP transgenic mice induced by metal ions or self-assembly.In view of its detective ability toward Aβoligomers and inhibition to Aβ-related neurotoxicity,BPB may be developed into a sensitive probe for screening blood samples in the early diagnosis of AD as well as an effective inhibitor for diminishing Aβaggregates in the treatment of the disease.

The induction of PANoptosis in KRAS-mutant pancreatic ductal adenocarcinoma cells by a multispecific platinum complex

Oncogenic KRAS reprograms pancreatic ductal adenocarcinoma(PDAC) cells to a state that is awfully resistant to apoptosis.An alternative coping strategy is to trigger a nonapoptotic cell death.Herein,a multi specific platinum complex SEP was constructed by conjugating a quinone derivative seratrodast to a prodrug of cisplatin.Interestingly,SEP-treated KRAS-mutant PDAC cells showed the characteristics of pyroptosis,apoptosis and necroptosis,similar to PANoptosis(a newfound inflammatory cell death).Mechanistically,SEP could enter cancer cells effectively,then damage nuclear DNA,boost mitochondrial superoxide anion radicals and affect various signaling pathways related to redox homeostasis and tumor metabolism.To our best knowledge,SEP is the first metal complex,even small molecule,to elicit PANoptosis(pyroptosis,apoptosis and necroptosis) in cancer cells,providing a new strategy to overcome apoptotic resistance of KRAS-mutant PDAC.

A dual-modal probe for NIR fluorogenic and ratiometric photoacoustic imaging of Cys/Hcy in vivo

Biothiols, such as cysteine(Cys) and homocysteine(Hcy), play vital roles in biological homeostasis and are closely related to various pathological and physiological processes in the living systems. Therefore, the in vivo detection of biothiols is of great importance for early diagnosis of diseases and assessment of disease progression. In this work, we developed a near-infrared(NIR) fluorescence and photoacoustic dual-modal molecular probe(NIR-S) that can be specifically activated by Cys or Hcy. The aryl-thioether substituted cyanine probe can undergo nucleophilic substitution and Smiles rearrangement reaction, resulting in specific turn-on NIR fluorescence and ratiometric photoacoustic responses for Hcy/Cys. Thus, NIR-S not only realizes the specific NIR fluorescence and photoacoustic dual mode imaging to detect Hcy/Cys in solution, but also can be applied to living cells and mice to detect Hcy/Cys. This work provided a practical tool to detect Hcy/Cys levels in vivo, which would be beneficial for the early diagnosis and progress of diseases.

A recursive model for static empty container allocation

Backlogged empty containers have gradually turned into a serious burden to shipping networks. Empty container allocation has become an urgent settlement issue for the container shipping industry on a global scale. Therefore, this paper proposes an improved immune algorithm based recursive model for optimizing static empty container allocation which integrates with the global maritime container shipping network. This model minimizes the operating and capital costs during container shipping considering 0-1 mixed-integer programming. So an immune algorithm procedure based on a special two- dimensional chromosome encoding is proposed. Finally, computational experiments are performed to optimize a 10-port static empty container shipping system. The results indicate that the proposed recursive model for static empty container allocation is effective in making an optimal strategy for empty container allocation.

A ferroptosis-inducing iridium(III) complex

Ferroptosis is a recently emerging non-apoptotic mode of cell death involving the production of iron-dependent reactive oxygen species(ROS).Here we described a mitochondria-targeted iridium(III)complex Ir FN that exhibited potent antiproliferative activity against a variety of cancer cells,especially the A2780 human ovarian cancer cells,through the ferroptosis pathways.Mechanistic studies by label-free quantitative proteomics profiling indicated that heme oxygenase 1(HMOX1)-mediated ferroptosis process was activated by Ir FN.The study on iron-dependent cell death,ROS accumulation,lipid peroxidation,and over released iron further confirmed the ferroptosis processes.m RNA transcription quantification,in vitro over-expression of HMOX1,and RNAi-mediated knock-down experiments suggested that Ir FN activated the over-expression of HMOX1.Our report revealed the first case of anticancer iridium complex leading to ferroptosis,highlighting ferroptosis as a promising approach in future design of metallodrugs.

Fine Tuning of the Electronic Properties of Novel BTPE Using Oligosilanyl Linkages and Their Application in Rapid High-Resolution Visualization of Latent Fingerprints

Structural modifications throughπ-interactions usually result in redshifts in luminescence and,as a consequence,the loss of the natural color of the chromophore.Besides,employing Si-Siσ-bridging to manipulate the electronic properties of organic materials has remained largely unexplored.Herein,we report a series of novel bis-tetraphenylethenes(BTPEs)with oligosilanyl linkages,termed BTPE-Sin molecules,used to manipulate the photophysical properties of luminogens subtly throughσ–πconjugation.These oligosilanyl-bridged molecules were thermally,highly stable,and exhibited enhanced aggregation-induced emissions,as well as luminescence efficiencies while retaining most of their original color.Our current BTPEs fabrications have easy-to-operate,fast,and high-resolution identification properties toward LFPs.Also,they are highly specific to individuals,and hence,vital in forensic investigations.We achieved these features through the introduction of oligosilanyl chains that increased the lipophilicity of the significantly.This work offers a universal and straightforward approach for the generation of highly emissive organic materials and enables fine-tuning of their electronic properties for multifunctional applications.

Novel Germoles and Their Ladder-Type Derivatives:Modular Synthesis,Luminescence Tuning,and Electroluminescence

Considerable effort has been devoted to the design of silicon-containingπ-conjugated materials for application in optoelectronic devices and fluorescent bioimaging.However,the synthesis and spectroscopic tuning of germanium(Ge)-conjugated systems are challenging because of the paucity of synthetically useful methods.Herein,we report a simple and effective method of lithium naphthalenide-induced intramolecular cyclization to construct architecturally diverse Ge-containingπ-conjugated molecules,including benzogermoles and their ladder-type derivatives,with high yields of up to 92%.The photophysical properties of these molecules can befinely controlled by the introduction of electrondonating or-withdrawing substituents,and intense luminescence ranging from deep-blue to red regions in the solid state was observed.A quantitative model based on the Hammett constant against the luminescence wavelength showed a good linear correlation,allowing us to reliably predict and design luminescent materials with specific properties for applications.Notably,Ge-bridged ladder-type derivatives exhibited high photoluminescence and efficient deep-blue electroluminescence with good color purity.We believe this study will open a new avenue to organogermanium chemistry and offers greater flexibility for electronic structural tuning.