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Natural products have remarkable structural diversity and biological characteristics, providing researchers with more possibilities to develop novel drugs for disease therapeutics. Andrographolide, an ent-labdane diterpenoid from traditional Chinese medicines, Andrographis paniculata, exhibits a broad range of biological activities, which has been a hot area of research for several years. Up to now, lots of its derivatives with multiple bioactivities have been prepared through chemical modification. This review summarizes andrographolide derivatives prepared in the last ten years (2006-present), classifies them by different biological activities, and provides some discussion about the design of novel and potent derivatives.

Abstract: Natural products have been proven as the main source of biologically active compounds, which are potentially useful for drug development. As one of the most studied pentacyclic triterpenes, oleanolic acid (OA) exhibits a broad range of biological activities and serves as a good scaffold for the development of novel derivatives that could be vital in drug discovery for various ailments. Till now, many of its derivatives with multiple bioactivities have been prepared through chemical modifi-cation. This review summarizes the recent reports of OA derivatives (2016-present) and their biologi-cal effects and action mechanisms in vitro and in vivo models, and discusses the design of novel and potent derivatives.

The chemical transformations that occur in metal oxides under operating conditions limit their applications for artificial photosynthesis. Understanding these chemical changes is a prerequisite to achieve sustainable production of solar fuels and chemicals. Herein, we use a correlative approach to unravel how cuprous oxide (Cu2O) photoelectrodes change under reaction conditions and, consequently, provide a protection scheme to mitigate degradation. In agreement with theoretical predictions, we find that under illumination the Cu2O concurrently undergoes reduction by photoelectrons and oxidation by holes in the material at electrolyte-dependent degradation rates. These mechanistic insights led us to design a protection scheme that uses a silver catalyst to accelerate transfer of photogenerated electrons and a Z-scheme heterojunction to extract holes. The resulting photocathode exhibits a stable photocurrent for CO2 reduction with ~60% Faradaic efficiency for ethylene with a balance of hydrogen for hours, whereas bare Cu2O degrades within minutes. Photoelectrodes for light-driven CO2 reduction to fuels and chemicals often suffer drastic decreases in performance due to changes in the material under illumination. Here the authors investigate the degradation pathways that occur in Cu2O photocathodes for ethylene synthesis and put forward strategies to mitigate them.

Osteoporosis is a systemic bone metabolism disorder, which increases the risk of fractures, and in severe cases it may cause disability or even death. An important factor contributing to osteoporosis is the imbalance between bone formation and resorption. Naringin was reported to promote osteoblast differentiation, thus enhancing bone formation and alleviating osteoporosis development. However, the signalling pathways related to the regulatory mechanism of naringin in osteoporosis development are not clear. Proliferation of bone mesenchymal stem cells (BMSCs) treated with naringin in vitro was detected by CCK-8. An osteogenesis differentiation medium supplemented with naringin was applied to explore the effects of naringin on BMSC osteogenic differentiation, as detected by Alizarin red staining. Ovariectomy (OVX)-induced postmenopausal osteoporosis (PMOP) rats were orally administered with naringin. Dual-energy X-ray absorptiometry (DEXA) and micro-CT were applied to measure bone mineral density (BMD), bone volume/total volume (BV/TV), trabecula thickness (Tb.Th), trabecula number (Tb.N), trabecular separation (Tb.Sp) and bone surface/bone volume (BS/BV). H&E staining was performed to show pathological changes of the femur in PMOP rats after naringin treatment. Bone metabolism indicators were assessed by ELISA. We found that naringin suppressed the activation of the JAK2/STAT3 pathway. Naringin promoted BMSC proliferation and osteogenic differentiation. Furthermore, naringin alleviates bone loss and improves abnormal bone metabolism of PMOP rats. Collectively, naringin promotes BMSC osteogenic differentiation to ameliorate osteoporosis development by targeting JAK2/STAT3 signalling.

Enantioselective C(sp3)–C(sp3) coupling substantially impacts organic synthesis but remains challenging. Cobalt has played an important role in the development of homogeneous organometallic catalysis, but there are few examples of its use in asymmetric cross-coupling. Here we report a cobalt-catalysed enantioselective C(sp3)–C(sp3) coupling reaction, namely, alkene hydroalkylation, to access chiral fluoroalkanes. This reaction represents a catalyst-controlled enantioselective coupling mode in which a tailor-made auxiliary is unnecessary; via this reaction, an aliphatic C–F stereogenic centre can be introduced at the desired position in an alkyl chain. Enantioselective C(sp3)–C(sp3) coupling plays an important role in organic synthesis, but limitations remain. Now, cobalt-catalysed enantioselective C(sp3)–C(sp3) coupling between achiral fluoroalkenes and alkyl halides enables the streamlined and auxiliary-free synthesis of chiral fluoroalkanes.

Gallic acid (GA) is a natural ingredient in functional foods, which has various health-promoting and antitumour effects. Peptidyl-prolyl cis/trans isomerase Pin1 plays an important role in preventing the development of some malignant tumours. However, whether there was an interaction between Pin1 and GA remains unknown. In this work, the binding information of GA and Pin1 was investigated systematically using multiple spectral and computational methods. GA bound to Pin1 directly with moderate binding affinity in the order of 104 mol/L, therefore decreasing the activity of Pin1. Also, the binding process of GA to Pin1 was driven through weak van der Waals forces, hydrogen bonds, and electrostatic forces. In addition, the important residues Lys63, Arg68, and Arg69 played a significant role in maintaining the binding stability between Pin1 and GA. Interestingly, GA reduced the activity of Pin1 by affecting its conformational characteristics. Our present work showed that GA binds to Pin1 and inhibits its activity, affecting its structural and functional properties, which may contribute to the therapy of Pin1-related diseases.

The wound-healing process is a natural response to burn injury. Resveratrol (RES) may have potential as a therapy for wound healing, but how and whether RES regulates skin repair remains poorly understood. Human epidermal keratinocyte (HaCaT) cells were treated with lipopolysaccharide (LPS), and a mouse skin wound-healing model was established. Cell viability and apoptosis were analyzed by 3-(4,5-dimethyl-2-thiazolyl)−2,5-diphenyl-2-H-tetrazolium bromide or flow cytometry. Cell proliferation was assessed by cell viability and colony-formation analyses. Cell migration was tested by wound-healing analysis. The microRNA-212 (miR-212) and caspase-8 (CASP8) levels were determined by quantitative reverse transcription polymerase chain reaction and western blotting. The correlation between miR-212 and CASP8 was analyzed by dual-luciferase reporter analysis. Skin wound healing in mice was assessed by measuring the wound area and gap after hematoxylin–eosin (HE) staining. RES reduced the LPS-induced reduction in viability and apoptosis in HaCaT cells. miR-212 expression was reduced by LPS and increased by exposure to RES. RES promoted cell proliferation and migration after LPS treatment by increasing miR-212 levels. CASP8 was a target of miR-212. CASP8 silencing promoted cell proliferation and migration, which was reversed by miR-212 knockdown in LPS-treated HaCaT cells. RES promoted skin wound healing in mice, which was reduced by miR-212 knockdown. Thus, RES facilitates cell proliferation and migration in LPS-treated HaCaT cells and promotes skin wound-healing in a mouse model by regulating the miR-212/CASP8 axis. The authors aimed to provide new insights into the pathogenesis and treatment of cutaneous burns. They show that the plant polyphenol resveratrol contributes to cell proliferation and migration in lipopolysaccharide-stimulated human epidermal keratinocyte cells. Resveratrol promotes wound healing in a mouse skin wound model via regulation of the miR-212/CASP8 axis.

The lithium-sulfur (Li-S) battery is one of the most promising substitutes for current energy storage systems because of its low cost, high theoretical capacity, and high energy density. However, the high solubility of intermediate products (i.e., lithium polysulfides) and the resultant shuttle effect lead to rapidly fading capacity and a low coulombic efficiency, which hinder the practical application of Li-S batteries. In this study, block copolymers are constructed with both an ethylene oxide unit and a styrene unit and then used as binders for Li-S batteries. Electrochemical performance improvements are attributed to the synergistic effects contributed by the different units of the block copolymer. The ethylene oxide unit traps polysulfide, which bonds strongly with the intermediate lithium polysulfide, and enhances the transport of lithium ions to reach high capacity. Meanwhile, the styrene unit maintains cathode integrity by improving the mechanical properties and elasticity of the constructed block copolymer to accommodate the large volume changes. By enabling multiple functions via different units in the polymer chain, high sulfur utilization is achieved, polysulfide diffusion is confined, and the shuttle effect is suppressed during the cycle life of Li-S batteries, as revealed by operando ultraviolet–visible spectroscopy and S K-edge X-ray absorption spectroscopy.

Parkinson's disease (PD), the typical neurodegenerative disease, is characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN). However, no therapeutic agent used currently could slow down neuronal cell loss so as to decelerate or halt the progression of PD. Traditional Chinese medicine (TCM) has been utilized to treat the dysfunction of the autonomic nervous system. Wen-Shen-Yang-Gan decoction (WSYGD) has a good effect on the clinical treatment of PD with constipation. However, it is not clear which ingredients and what mechanism are responsible for the therapeutic effect. In this study, the pharmacodynamic study of WSYGD in PD mice was applied. Concurrently, a novel method for the identification of metabolic profiles of WSYGD has been developed. Finally, we found that WSYGD could protect the PD mice induced by rotenone. The underlying mechanism of the protective effect may be related to the reduction of the DA neurons apoptosis via reducing inflammatory reaction. By virtue of UPLC-MS and chemoinformatics method, 35 prototype compounds and 27 metabolites were filtered out and tentatively characterized. In conclusion, this study provides an insight into the metabolism of WSYGD in vivo to enable understanding of the metabolic process and therapeutic mechanism of PD.

Background To explore the effect of albiflorin (AL) on streptozotocin (STZ)-induced Alzheimer's disease (AD) in rats. Methods A mouse model of diabetic encephalopathy was established by intraperitoneal injection of 1%STZ. Step down test and water maze test were used to test the cognitive function of rats. Congo Red Staining was used to detect the distribution of Aβ plaques in the hippocampus of rats. Cytokine levels in serum and hippocampus were measured using ELISA. Serum insulin, oral glucose tolerance (OGTT), serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured by commercial kits. And the content of Nrf-2/HO-1/HMGB1/NF-kB in the hippocampus of diabetic rats were detected by western blot. Results and conclusion Compared with the STZ model group, the average escape latency of rats in the AL group in the Morris water maze test was significantly shortened, and the average number of platform crossings and the ratio of distance/total swimming distance in the target quadrant were increased significantly. Staining of tissue sections and ELISA showed a decrease in Aβ plaque density in the hippocampus of rats in the AL group. And serum insulin levels of rats in the ALgroup were significantly reduced and OGTT was improved. In addition, AL could also regulate the Nrf-2/HO-1/HMGB1/NF-kB signal pathway in the hippocampus. Therefore, AL may ameliorate STZ-induced cognitive impairment in rats by regulating oxidative stress and inflammation in the brain.

An asymmetric [3 + 2] cycloaddition of vinyl ethylenecarbonates (VECs) and (E)-3-arylvinyl substituted benzo[d] isothiazole 1,1-dioxides has been developed using the Pd complex of a bidentate phosphoramidite (Me-BIPAM) as the catalyst, providing a wide variety of chiral multistereogenic vinyltetrahydrofurans in good yields with excellent diastereo- and enantioselectivities (up to >20:1 dr, 99% ee).

Ferroptosis is a type of cell death accompanied by iron-dependent lipid peroxidation, thus stimulating ferroptosis may be a potential strategy for treating gastric cancer, therapeutic agents against which are urgently required. Jiyuan oridonin A (JDA) is a natural compound isolated from Jiyuan Rabdosia rubescens with anti-tumor activity, unclear anti-tumor mechanisms and limited water solubility hamper its clinical application. Here, we showed a2, a new JDA derivative, inhibited the growth of gastric cancer cells. Subsequently, we discovered for the first time that a2 induced ferroptosis. Importantly, compound a2 decreased GPX4 expression and overexpressing GPX4 antagonized the anti-proliferative activity of a2. Furthermore, we demonstrated that a2 caused ferrous iron accumulation through the autophagy pathway, prevention of which rescued a2 induced ferrous iron elevation and cell growth inhibition. Moreover, a2 exhibited more potent anti-cancer activity than 5-fluorouracil in gastric cancer cell line-derived xenograft mice models. Patient-derived tumor xenograft models from different patients displayed varied sensitivity to a2, and GPX4 downregulation indicated the sensitivity of tumors to a2. Finally, a2 exhibited well pharmacokinetic characteristics. Overall, our data suggest that inducing ferroptosis is the major mechanism mediating anti-tumor activity of a2, and a2 will hopefully serve as a promising compound for gastric cancer treatment., Graphical abstract Natural product derivative, a2, exhibited anti-tumor activity by inducing ferroptosis through decreasing GPX4 and causing ferrous iron accumulation in gastric cancer cells.Image 1

Tissue-engineered plant scaffolds have shown promising applications in in vitro studies. To assess the applicability of natural plant scaffolds as vascular patches, we tested decellularized leaf and onion cellulose in a rat inferior vena cava patch venoplasty model. The leaf was decellularized, and the scaffold was loaded with polylactic-co-glycolic acid (PLGA)-based rapamycin nanoparticles (nanoparticles). Nanoparticle-perfused leaves showed decreased neointimal thickness after implantation on day 14; there were also fewer CD68-positive cells and PCNA-positive cells in the neointima in the nanoparticle-perfused patches than in the control patches. Onion cellulose was decellularized, coated with rapamycin nanoparticles, and implanted in the rat; the nanoparticle-coated onion cellulose patches also showed decreased neointimal thickness. These data show that natural plant-based scaffolds may be used as novel scaffolds for tissue-engineered vascular patches. However, further modifications are needed to enhance patch strength for artery implantations.

Enantioselective copper-catalyzed cascade inter- and intramolecular amidation was achieved between ethynyl benzoxazinanones and α-halohydroxamates in the presence of an indapybox ligand. The one-pot cascade transformation was triggered by the attack of hydroxamates to dipolar copper–allenylidene intermediates, followed by a nucleophilic annulation reaction. Thus, a series of exo-methylene 3-aminoindoline derivatives were obtained in good yields with high enantioselectivities under mild reaction conditions.

Apelin is an important contributor to the renin-angiotensin axis, regulating cardiovascular, metabolic, and neurological functions. Apelin-17 has especially potent cardio-physiological effects but is rapidly degraded in human blood (t0.5 ∼ 4 min). Angiotensin-converting enzyme 2 (ACE-2), neprilysin (NEP), and plasma kallikrein (KLKB1) cleave and inactivate it, with the latter cutting within the arginine-arginine site. Here, we show that analogues with an N-terminal polyethylene glycol (PEG) extension as well as peptide bond isosteres resist KLKB1 cleavage but that only the PEG-extended analogues significantly improve physiologically activity. The PEGylated analogues feature comparatively high log D7.4 values and high plasma protein binding, adding to their stability. An alanine scan of apelin-17 reveals that the integrity and conformational flexibility of the KFRR motif are necessary for cardio-physiological activity. An optimized Cbz-PEG6 analogue is presented that is stable in blood (t0.5 ∼ 18 h), has significant blood-pressure lowering effect, and shows fast recovery of heart function in Langendorff assay.

LiErF4 was commonly used as a dipolar-coupled antiferromagnet, and was rarely considered as a luminescent material. Herein, we achieved the strong red upconversion emission of LiErF4 simply by an inert shell coating, i.e., LiErF4@LiYF4. Owing to the unique and intrinsic ladder-like energy levels of Er3+ ions, this LiErF4 core-shell nanostructures present red emission (∼ 650 nm) under multi-band excitation in the near-infrared (NIR) region (∼ 808, ∼ 980, and ∼ 1,530 nm). A brighter and monochromic red emission can be further obtained via doping 0.5% Tm3+ into the LiErF4 core, i.e., LiErF4: 0.5% Tm3+@LiYF4. The enriched Er3+ ions and strong monochromic red emission natures make LiErF4: 0.5% Tm3+@LiYF4 nanocrystals very sensitive for trace water probing in organic solvents with detection limit of 30 ppm in acetonitrile, 50 ppm in dimethyl sulfoxide (DMSO), and 58 ppm in N, N-dimethylformamide (DMF) under excitation of 808 nm. Due to their superior chemical and physical stability, these nanoprobes exhibit excellent antijamming ability and recyclability, offering them suitable for real-time and long-term water monitoring.

Solid-state Li–S batteries are attractive due to their high energy density and safety. However, it is unclear whether the concepts from liquid electrolytes are applicable in the solid state to improve battery performance. Here, we demonstrate that the nanoscale encapsulation concept based on Li2S@TiS2 core–shell particles, originally developed in liquid electrolytes, is effective in solid polymer electrolytes. Using in situ optical cell and sulfur K-edge X-ray absorption, we find that polysulfides form and are well-trapped inside individual particles by the nanoscale TiS2 encapsulation. This TiS2 encapsulation layer also functions to catalyze the oxidation reaction of Li2S to sulfur, even in solid-state electrolytes, proven by both experiments and density functional theory calculations. A high cell-level specific energy of 427 W·h·kg–1 is achieved by integrating the Li2S@TiS2 cathode with a poly­(ethylene oxide)-based electrolyte and a lithium metal anode. This study points to the fruitful direction of borrowing concepts from liquid electrolytes into solid-state batteries.

The combination of chiral binaphthyl box-copper(II) with triflimide (Tf2NH) was identified as an efficient catalytic system for the asymmetric Michael/ketalization of (E)-2-hydroxyaryl-2-oxobut-3-e...

In the present work, the interactions of astragalin (AST) with human serum albumin (HSA) were studied systematically thought fluorescence spectra, ultraviolet-visible (UV-vis) absorption spectra, circular dichroism (CD), molecular docking and molecular dynamics (MD) simulations. Fluorescence spectra elaborated that AST reduced the intrinsic fluorescence of HSA through static quenching and non-radiative energy transfer with moderate binding constants in the order of 104 mol/L. Thermodynamic parameters and computational simulations elaborated that hydrogen bond, van der Walls force and hydrophobic interaction played a major role in the binding process of AST to HSA. UV-vis absorption, synchronous fluorescence, three-dimensional (3D) fluorescence and CD spectra illustrated that AST disturbed slightly the microenvironment of tryptophan (Trp) and tyrosine (Tyr) residues and decreased α-helical structure content. The effect of some biologically significant metal ions, such as Mg2+, Cu2+ and Fe3+, on the binding of AST to HSA was also investigated in detail. Binding displacement and docking studies revealed that AST was located in the binding site I of subdomain IIA in HSA. Finally, MD simulations evaluated the binding stability of the HSA-AST system in a simulated environment. Communicated by Ramaswamy H. Sarma

We prepared the H3PW12O40-doped pyromellitic diimide (PMDI) photocatalysts via thermal transformation using urea phosphotungstate and pyromellitic dianhydride as precursors (UPWPI) and calcination of PMDI with phosphotungstic acid directly (UPIPW). The influences of the strategies on the morphology, light absorption, and visible-light photocatalytic degradation efficiency of H3PW12O40-doped PMDI are systematically investigated by various characterization methods. By comparing the structure of UPWPI and UPIPW, the adoption of urea phosphotungstate as precursors can promote the separation of PMDI into small particles and the inclusion of phosphotungstic acid. Moreover, the visible-light (λ > 420 nm) absorption efficiency of UPWPI is also enhanced compared with that of UPIPW because of the improved photogenerated electron transfer efficiency between PMDI and HPW. With a catalyst dosage of 100 mg and the degradation time of 3 h, the photocatalytic degradation efficiency of imidacloprid on UPWPI was 97.12% and the degradation rate constant was 0.93 h−1.

Divergent catalysis represents a powerful strategy for increasing molecular complexity and exploring catalytic modes in organic synthesis. Herein, we report, a nickel-catalyzed, chemodivergent 1,1-...

Hydrophilicity of fast-growing plantation wood is the major restriction for its outdoor applications. Herein, a novel method is reported for improving the hydrophobicity of Cathay poplar (Populus cathayana Rehd.) by using a paraffin/carnauba (5:5 and 7:3)-mixed wax emulsion system. The poplar samples were impregnated in the single or mixed wax O/W emulsions of 4% solid content with subsequent drying treatment at 70 °C, which was higher than the paraffin wax melting point but lower than that of carnauba wax. The images obtained by field emission scanning electron microscopy confirmed that the mixed wax emulsion treatment developed textured surfaces in the inner lumen surface of wood cells and on the external surfaces of the samples comprising a continuous paraffin wax film with carnauba wax micropillars embedded in it. Contact angle analysis and water absorption tests show that the textured surface imparted the mixed wax emulsion-treated wood good hydrophobicity, rendering the initial contact angle greater than 140° and improving not only the surface property but also the long-term (120 or 192 h immersion) water repellency. In addition, free and bound water fractions in the treated wood were measured quantitatively using low-field nuclear magnetic resonance. The results show that the mixed wax emulsion treatment significantly decreased the free water content and delayed the bound water adsorption. In conclusion, this mixed wax emulsion treatment can be potentially utilized as a highly efficient wood hydrophobization method for expanding wood applications outdoors.

Rationally designing efficient, low-cost and stable catalysts toward the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) is of significant importance to the development of renewable energy technologies. In this work, we have systematically investigated a series of potentially efficient and stable single late transition metal atom doped phthalocyanines (TM@Pcs, TM = Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Ir and Pt) as single-atom catalysts (SACs) for applications toward the OER and ORR through a computational screening approach. Our calculations indicate that TM atoms can tightly bind with Pc monolayers with high diffusion energy barriers to prevent the isolated atoms from clustering. The interaction strength between intermediates and TM@Pc governs the catalytic activities for the OER and ORR. Among all the considered TM@Pc catalysts, Ir@Pc and Rh@Pc were found to be efficient OER electrocatalysts with overpotentials ηOER of 0.41 and 0.44 V, respectively, and for the ORR, Rh@Pc exhibits the lowest overpotential ηORR of 0.44 V followed by Ir@Pc (0.55 V), suggesting that Rh@Pc is an efficient bifunctional catalyst for both the OER and ORR. Moreover, it is worth noting that the Rh@Pc catalyst can remain stable against dissolution under the pH = 0 condition. Ab initio molecular dynamic calculations suggest that Rh@Pc could remain stable at 300 K. Our findings highlight a novel family of two-dimensional (2D) materials as efficient and stable SACs and offer a new strategy for catalyst design.

Cross-coupling reactions have developed into powerful approaches for carbon–carbon bond formation. In this work, a Ni-catalyzed migratory Suzuki–Miyaura cross-coupling featuring high benzylic or allylic selectivity has been developed. With this method, unactivated alkyl electrophiles and aryl or vinyl boronic acids can be efficiently transferred to diarylalkane or allylbenzene derivatives under mild conditions. Importantly, unactivated alkyl chlorides can also be successfully used as the coupling partners. To demonstrate the applicability of this method, we showcase that this strategy can serve as a platform for the synthesis of terminal, partially deuterium-labeled molecules from readily accessible starting materials. Experimental studies suggest that migratory cross-coupling products are generated from Ni(0/II) catalytic cycle. Theoretical calculations indicate that the chain-walking occurs at a neutral nickel complex rather than a cationic one. In addition, the original-site cross-coupling products can be obtained by alternating the ligand, wherein the formation of the products has been rationalized by a radical chain process., Migratory cross-coupling reactions are powerful tools to form bonds at predictable positions. Here the authors report a nickel-catalyzed migratory Suzuki–Miyaura cross-coupling of unactivated alkyl electrophiles with aryl and vinyl boron reagents and provide experimental and computational mechanistic evidence.

A bifunctional organocatalyst catalyzed tandem annulation reaction between β,γ-unsaturated α-ketoesters with α-arylidene pyrazolinones was reported. The tandem Michael–aldol process allows access to optically active bi-spirocyclic pyrazolone and oxindole compounds in high yields with good to excellent enantioselectivity and diastereoselectivity. The resulting bi-spirocyclic compounds possess highly dense functionalized substituents, two all-carbon spiro quaternary stereocenters and one hemiketal stereogenic centers.

Proteasome inhibitors have shown remarkable success in the treatment of hematologic neoplasm. There has been a lot of attention to applying these drugs for solid tumor treatment. Recent preclinical study has signified the effectiveness on cell proliferation inhibition in lung adenocarcinoma treated by carfilzomib (CFZ), a second generation proteasome inhibitor. However, no insight has been gained regarding the mechanism. In this study, we have systematically investigated the CFZ functions in cell proliferation and growth, cell cycle arrest, and apoptosis in lung adenocarcinoma cells. Flow cytometry experiments showed that CFZ significantly induced G2/M cell cycle arrest and apoptosis in lung adenocarcinoma. MTS and colony formation assays revealed that CFZ substantially inhibited survival of lung adenocarcinoma cells. All results were consistently correlated to the upregulation expression of Gadd45a, which is an important gene in modulating cell cycle arrest and apoptosis in response to physiologic and environmental stresses. Here, upregulation of Gadd45a expression was observed after CFZ treatment. Knocking down Gadd45a expression suppressed G2/M arrest and apoptosis in CFZ-treated cells, and reduced cytotoxicity of this drug. The protein expression analysis has further identified that the AKT/FOXO3a pathway is involved in Gadd45a upregulation after CFZ treatment. These findings unveil a novel mechanism of proteasome inhibitor in anti-solid tumor activity, and shed light on novel preferable therapeutic strategy for lung adenocarcinoma. We believe that Gadd45a expression can be a highly promising candidate predictor in evaluating the efficacy of proteasome inhibitors in solid tumor therapy.

A chiral N-heterocyclic-carbene-catalyzed cascade asymmetric desymmetrization reaction of cyclopentenediones with enals has been successfully initiated, followed with tandem aldol annulation, aromatization, as well as sequential methylation. The reactions proceeded well under mild reaction conditions, with broad substrate scope and good functional group tolerance, providing a rapid access to highly functionalized chiral 2,2-disubstituted 1,3-indandione derivatives containing an all-carbon quaternary stereogenic center in moderate to good yields with high enantioselectivities.

BackgroundColorectal cancer (CRC) is one of the most common malignant gastrointestinal cancers in the world with a 5-year survival rate of approximately 68%. Although researchers accumulated many scientific studies, its pathogenesis remains unclear yet. Detecting and removing these malignant polyps promptly is the most effective method in CRC prevention. Therefore, the analysis and disposal of malignant polyps is conducive to preventing CRC.MethodsIn the study, metabolic profiling as well as diagnostic biomarkers for CRC was investigated using untargeted GC-MS-based metabolomics methods to explore the intervention approaches. In order to better characterize the variations of tissue and serum metabolic profiles, orthogonal partial least-square discriminant analysis was carried out to further identify significant features. The key differences in tR–m/z pairs were screened by the S-plot and VIP value from OPLS-DA. Identified potential biomarkers were leading in the KEGG in finding interactions, which show the relationships among these signal pathways.ResultsFinally, 17 tissue and 13 serum candidate ions were selected based on their corresponding retention time, p-value, m/z, and VIP value. Simultaneously, the most influential pathways contributing to CRC were inositol phosphate metabolism, primary bile acid biosynthesis, phosphatidylinositol signaling system, and linoleic acid metabolism.ConclusionsThe preliminary results suggest that the GC-MS-based method coupled with the pattern recognition method and understanding these cancer-specific alterations could make it possible to detect CRC early and aid in the development of additional treatments for the disease, leading to improvements in CRC patients’ quality of life.

Purpose The causes and pathogenetic mechanisms underlying abdominal aortic aneurysms (AAAs) and pseudoaneurysms are not fully understood. We hypothesized that inhibiting programmed death-1 (PD-1) can decrease AAA and pseudoaneurysm formation in mouse and rat models. Methods Human AAA samples were examined in conjunction with an adventitial calcium chloride (CaCl2) application mouse model and an aortic patch angioplasty rat model. Single-dose PD-1 antibody (4 mg/kg) or BMS-1 (PD-1 inhibitor-1) (1 mg/kg) was administered by intraperitoneal (IP) or intraluminal injection. In the intramural injection group, PD-1 antibody was injected after CaCl2 incubation. The rats were divided into three groups: (1) the control group was only decellularized without other special treatment, (2) the PD-1 antibody-coated patch group, and (3) the BMS-1 coated patch group. Patches implanted in the rat abdominal aorta were harvested on day 14 after implantation and analyzed. Results Immunohistochemical analysis showed PD-1–positive cells, PD-1 and CD3, PD-1 and CD68, and PD-1 and α-actin co-expressed in the human AAA samples. Intraperitoneal (IP) injection or intraluminal injection of PD-1antibody/BMS-1 significantly inhibited AAA progression. PD-1 antibody and BMS-1 were each successfully conjugated to decellularized rat thoracic artery patches, respectively, by hyaluronic acid. Patches coated with either humanized PD-1 antibody or BMS-1 can also inhibit pseudoaneurysm progression and inflammatory cell infiltration. Conclusion PD-1 pathway inhibition may be a promising therapeutic strategy for inhibiting AAA and pseudoaneurysm progression.

Removal of 5′ cap on cellular mRNAs by the African Swine Fever Virus (ASFV) decapping enzyme g5R protein (g5Rp) is beneficial to viral gene expression during the early stages of infection. As the only nucleoside diphosphate linked moiety X (Nudix) decapping enzyme encoded in the ASFV genome, g5Rp works in both the degradation of cellular mRNA and hydrolyzation of the diphosphoinositol polyphosphates. Here, we report the structures of dimeric g5Rp and its complex with inositol hexakisphosphate (InsP6). The two g5Rp protomers interact head-to-head to form a dimer, and the dimeric interface is formed by extensive polar and nonpolar interactions. Each protomer composed a unique N-terminal helical domain and C-terminal classic Nudix domain. As a mRNA decapping enzyme, we identified key residues, including K8, K94, K95, K98, K175, R221, and K243 located on the substrate RNA binding interfaces of g5Rp, are important to RNA binding and decapping enzyme activity. Furthermore, we identified that the g5Rp-mediated mRNA decapping was inhibited by the InsP6. The g5Rp–InsP6 complex structure showed that the InsP6 molecules occupy the same regions that primarily mediate g5Rp-RNA interaction, elucidating the roles of InsP6 in the regulation of the viral decapping activity of g5Rp in mRNA degradation. Collectively, these results provide the structural basis of interaction between RNA and g5Rp and highlight the inhibitory mechanism of InsP6 on mRNA decapping by g5Rp.

Inspired by the success of dual-targeting drugs, especially bispecific antibodies, we propose to combine the concept of proteolysis targeting chimera (PROTAC) and dual targeting to design and synthesize dual PROTAC molecules with the function of degrading two completely different types of targets simultaneously. A library of novel dual-targeting PROTAC molecules has been rationally designed and prepared. A convergent synthetic strategy has been utilized to achieve high synthetic efficiency. These dual PROTAC structures are characterized using trifunctional natural amino acids as star-type core linkers to connect two independent inhibitors and E3 ligands together. In this study, gefitinib, olaparib, and CRBN or VHL E3 ligands were used as substrates to synthesize novel dual PROTACs. They successfully degraded both the epidermal growth factor receptor (EGFR) and poly(ADP-ribose) polymerase (PARP) simultaneously in cancer cells. Being the first successful example of dual PROTACs, this technique will greatly widen the range of application of the PROTAC method and open up a new field for drug discovery.

Venous neointimal hyperplasia can be a problem after vein interventions. We hypothesized that inhibiting programmed death-1 (PD-1) can decrease venous neointimal hyperplasia in a rat inferior vena cava (IVC) patch venoplasty model. The rats were divided into four groups: the control group was only decellularized without other special treatment; the PD-1 group was injected with a single dose of humanized PD-1 antibody (4 mg/kg); the PD-1 antibody coated patches group; the BMS-1 (a PD-1 small molecular inhibitor) coated patches group (PD-1 inhibitor-1). Patches were implanted to the rat IVC and harvested on day 14 and analyzed. Immunohistochemical analysis showed PD-1-positive cells in the neointima in the human samples. There was high protein expression of PD-1 in the neointima in the rat IVC venoplasty model. PD-1 antibody injection can significantly decrease neointimal thickness (p < 0.0001). PD-1 antibody or BMS-1 was successfully conjugated to the decellularized rat thoracic artery patch by hyaluronic acid with altered morphology and reduced the water contact angle (WCA). Patches coated with humanized PD-1 antibody or BMS-1 both can also decrease neointimal hyperplasia and inflammatory cells infiltration. PD-1-positive cells are present in venous neointima in both human and rat samples. Inhibition of the PD-1 pathway may be a promising therapeutic strategy to inhibit venous neointimal hyperplasia.

The synthesis and characterization of the chiral bifunctional NHC ligands based on the imidazo[1,5-a]pyridine (ImPy) scaffold are described. These ligands possess a fluxional biaryl axis and a chiral center. The configurational stability of the biaryl axis in their gold(I) complexes is investigated. The application of these axially chiral ImPy-based AuCl complexes in a series of gold catalysis is explored, and varying degrees of asymmetric induction are observed. In most cases, the ligand (aS,R)-L8-H with its cyclohexyl group pointing to the reaction site and hence exerting asymmetric steric influence is more effective in asymmetric induction.

Two-dimensional (2D) materials have attracted significant interest because of their large surface-to-volume ratios and electron confinement. Compared to common 2D materials such as graphene or metal hydroxides, with their intrinsic layered atomic structures, the formation mechanisms of 2D metal oxides with a rocksalt structure are not well understood. Here, we report the formation process for 2D cobalt oxide and cobalt nickel oxide nanosheets, after analysis by in situ liquid-phase transmission electron microscopy. Our observations reveal that three-dimensional (3D) nanoparticles are initially formed from the molecular precursor solution and then transform into 2D nanosheets. Ab initio calculations show that a small nanocrystal is dominated by positive edge energy, but when it grows to a certain size, the negative surface energy becomes dominant, driving the transformation of the 3D nanocrystal into a 2D structure. Uncovering these growth pathways, including the 3D-to-2D transition, provides opportunities for future material design and synthesis in solution. Liquid phase transmission electron microscopy reveals the growth pathway of 2D cobalt oxide and cobalt nickel oxide, in which 3D nanoparticles are formed first and then spread and transform into 2D nanosheets.

Two series of andrographolide derivatives with introduction of amide moiety into ring A by Beckmann rearrangement were synthesized. In series 1, the ring A was converted to caprolactam, and an amide moiety was linked to C-19 of ring A in series 2. Among them, compound 8h exhibited obvious inhibition on HK2 enzyme activity (IC50 = 9.36 ± 0.08 μM) and LPS-induced NO production in RAW264.7 cells (IC50 = 22.38 ± 3.57 μM), and potent binding affinity with HK2 (Kd = 5.12 ± 0.82 μM). The preliminary structure-activity relationships (SARs) suggested that the formation of caprolactam of ring A and esterification of C-19-hydroxyl could improve the inhibitory effects on HK2 enzyme of andrographolide derivatives. Furthermore, compound 8h significantly reduced the levels of IL-1β and IL-6, down-regulated the expressions of iNOS and COX-2. Its anti-inflammatory effect was related to the inhibition of both NF-κB pathway and glycolysis enzyme HK2. Since HK2 could be a novel and effective target for anti-inflammation, compound 8h might be a new anti-inflammatory agent targeting at HK2, or serve as a lead compound to design and synthesize more HK2 inhibitors with better inflammatory effects.

An unprecedented nickel-catalyzed 1,1-alkylboration of electronically unbiased alkenes has been developed, providing straightforward access to secondary aliphatic boronic esters from readily available materials under very mild reaction conditions. The regioselectivity of this reaction is governed by a unique pyridyl carboxamide ligated catalyst, rather than the substrates. Moreover, this transformation shows excellent chemo- and regio-selectivity and remarkably good functional-group tolerance. We also demonstrate that under balloon pressure, ethylene can also be utilized as a substrate. Additionally, competence experiments indicate that selective bond formation is favored at the α-position of boron and preliminary mechanistic studies indicate that the key step in this three-component reaction involves a 1,2-nickel migration.

Summary In lithium-sulfur (Li-S) batteries, the insulating nature of sulfur and lithium sulfide (Li2S) results in large polarization and low sulfur utilization while the soluble polysulfides lead to internal shuttle upon cycling. Furthermore, the redox reaction via the dissolution-precipitation route destroys the electrode architecture by passivating the active interface responsible for the redox reaction, and thus the performance deteriorates with cycling. Here, we employ the redox chemistry of quinone to realize efficient, fast, and stable operation of Li-S batteries using Li2S microparticles. By adding a quinone derivative with tailored properties (e.g., oxidation potential, solubility, and electrochemical stability) to an electrolyte as a redox mediator (RM), initial charging of Li2S electrodes occurs below 2.5 V at 0.5C, and the subsequent discharge capacity is as high as 1,300 mAh gs−1. Moreover, deposition of dead Li2S, which was the primary cause of increasing polarization and decreasing capacity upon cycling, is effectively prevented with the RM.

The appropriate inflammatory response is essential for normal wound repair, and skin commensal Staphylococcus epidermidis has been shown to regulate TLR3-mediated inflammatory response to maintain skin homeostasis after injury. However, the underlying mechanism by which S. epidermidis regulates wound-induced inflammation remains largely unexplored. In this study we identified a previously unknown lipopeptide 78 (LP78) from S. epidermidis and showed that LP78 inhibited TLR3-mediated skin inflammation to promote wound healing. Skin injury activated TLR3/NF-κB to promote the interaction of p65 and PPARγ in nuclei and then initiated the inflammatory response in keratinocytes. LP78 activated TLR2-SRC to induce β-catenin phosphorylation at Tyr654. The phospho–β-catenin translocated into nuclei to bind to PPARγ, thus disrupting the interaction between p65 and PPARγ. The disassociation between p65 and PPARγ reduced the expression of TLR3-induced inflammatory cytokines in skin wounds of normal and diabetic mice, which correlated with accelerated wound healing. Our data demonstrate that S. epidermidis–derived LP78 inhibits skin inflammation to promote wound healing and suggest that LP78 might be a potential compound for the treatment of delayed or unhealed wounds.

We have reported the 1,4-diazabicyclo[2.2.2]octane (DABCO)-catalyzed [3 + 3] cycloaddition reaction of α-arylidene pyrazolinones and 2-benzylidenemalononitriles under mild reaction conditions, which afforded the spirocyclohexadiene-pyrazolones in good yields with moderate to good diastereoselectivities. By the use of a cinchona alkaloid derived bifunctional squaramide-tertiary amine catalyst, an asymmetric variant of this [3 + 3] cycloaddition reaction has also been developed to provide optically active spirocyclohexadiene-pyrazolones bearing an all-carbon quaternary chiral center in good yields with excellent enantioselectivities and moderate diastereoselectivities.

Highly active single-atom catalysts (SACs) have recently been intensively studied for their potential in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Due to the existence of many such SAC systems, a general understanding of the trend and designing principle is necessary to discover an optimal SAC system. In this work, by using density functional theory (DFT), we investigated a series of late single transition metals (TM = Fe, Co, Ni, Cu, and Pd) anchored on various N doped graphenes (xN-TM, x = 1-4) as electrocatalysts for both the HER and OER. Solvent effects were taken into account using an implicit continuum model. Our results reveal that the catalytic activity of SACs is determined by the local coordination number of N and TM in the catalysts. Among the considered catalysts, a low-coordinated Co site, i.e. a triple-coordinated Co, exhibits a high catalytic activity toward the HER with a calculated hydrogen adsorption free energy of -0.01 eV, whereas a high-coordinated Co center, i.e. a quadruple-coordinated Co is a promising candidate for the OER with a low computed overpotential of -0.39 V, which are comparable to those of noble metal catalysts, indicating superior HER and OER performance of N-Co co-doped graphenes. The results shed light on the potential applications of TM and N co-doped graphenes as efficient single-atom bifunctional catalysts for water splitting, thereby functioning as promising candidates for hydrogen/oxygen production.

Ellagitannins, found abundantly in berries, pomegranates, walnuts and almonds, have been increasingly investigated for their health benefits. Geraniin (GE), an ellagitannin, found predominantly in herbal plants, as well has been shown to exhibit a number of biological activities. Like many hydrolysable tannins, geraniin is water-soluble and readily undergoes hydrolysis in the presence of hot water, weak acids and weak bases to yield several metabolites including corilagin (CO), ellagic acid (EA) and gallic acid (GA). There are numerous studies on the pharmacological effectiveness of GE, CO and GA. However, the intestinal permeability of GE and CO has never been investigated before. Caco-2 cell transport assay was utilized to evaluate the in vitro permeability of GE and its metabolites. GE, CO and EA were found to have no apparent permeability (Papp) while GA displayed a Papp value of 31.3 ± 1.1 × 10-6 cm s-1. Mass balance studies showed a loss of geraniin and its metabolites during transport. Chemical stability studies in the transport buffers revealed that GE and CO were hydrolyzed in the HBSS buffers. Experiments using lysed cells revealed that GE and its metabolites were metabolized during transport. Absorption and desorption studies confirmed the accumulation of EA inside the cells. The above results indicate that the compounds have poor oral absorption. To consider these compounds or their natural extracts as oral nutraceutical candidates, formulation strategies are mandatory.

The search for high efficiency and low-cost catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is vital to overall water splitting. In this work, on the basis of first-principles calculations, we screened a series of late transition metal atoms supported on a C9N4 monolayer (TM@C9N4, where TM represents Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Ir, and Pt) as electrocatalysts for both the HER and OER. Our results demonstrate that the TM atoms can be bonded with the nitrogen atoms around the hole to form stable structures, and the bonded TM atoms are stable against diffusion. Co@C9N4 exhibits high catalytic activity toward the HER. In particular, the N active sites in the Co@C9N4, Ni@C9N4, and Pt@C9N4 systems demonstrate relatively high performance for the HER. However, Co@C9N4 and Pt@C9N4 exhibit low OER activities with large overpotentials. Among the ten cases of TM@C9N4 considered here, only Ni@C9N4 performs as a promising bifunctional electrocatalyst with N and Ni atoms as catalytic active sites for the HER and OER, with a calculated hydrogen adsorption Gibbs free energy (ΔGH*) of -0.04 eV and an OER overpotential (ηOER) of 0.31 V. The results demonstrate that TM@C9N4 is a promising single-atom catalytic system, which can be used as the non-noble metal bifunctional electrocatalyst for overall water splitting.

Searching for highly efficient, stable and cost-effective catalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is vital to resolve energy security and environmental problems. Herein, by means of computational screening based on the density functional theory (DFT), we studied a wide range of transition metal (TM) atoms embedded into the double carbon vacancy of C3N monolayers (VCC), denoted as TM-VCC (TM = Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Ir and Pt), as efficient single-atom catalysts (SACs) for OER and ORR. The calculated results showed that all the considered TM-VCC composites exhibited a metallic feature that ensured efficient charge transfer during reactions. The interaction strength between intermediates and TM-VCC has direct correlation with the d-band center of TM, which can be tuned by changing the TM atoms with different numbers of d electrons. The best catalyst for OER was Rh-VCC with an overpotential (ηOER) of 0.35 V, followed by Co-VCC (0.43 V). For the ORR process, Rh-VCC exhibited the lowest ORR overpotential (ηORR) of 0.27 V, followed by Co-VCC (0.42 V). The results suggested that the performances of the newly predicted Rh-VCC and Co-VCC SACs are comparable to those of the noble-metal benchmark catalysts for OER and ORR. Ab initio molecular dynamic simulations indicated that Rh-VCC and Co-VCC SACs could remain stable under 300 K and possessed high energy barriers to prevent the isolated Rh and Co atoms from clustering. Our results highlight a new family of efficient and stable catalysts with a single atom anchored on carbon nitride-based materials, which provides a useful guideline for catalyst design and practical applications.

Recent experiments have shown that CO reduction on oxide derived Cu nanoparticles (NP) are highly selective toward C2+ products. However, understanding of the active sites on such NPs is limited, because the NPs have ∼200 000 atoms with more than 10 000 surface sites, far too many for direct quantum mechanical calculations and experimental identifications. We show here how to overcome the computational limitation by combining multiple levels of theoretical computations with machine learning. This approach allows us to map the machine learned CO adsorption energies on the surface of the copper nanoparticle to construct the active site visualization (ASV). Furthermore, we identify the structural criteria for optimizing selective reduction by predicting the reaction energies of the potential determining step, ΔEOCCOH, for the C2+ product. Based on this structural criterion, we design a new periodic copper structure for CO reduction with a theoretical faradaic efficiency of 97%.

The dilational rheology of two different types of polyether demulsifiers solutions, linear propylene glycol polyether and branched glycerol polyether, at the water-crude oil interface have been investigated by dilational rheological measurements. This paper research that except the concentration of 10 ppm, linear propylene glycol polyether appears higher moduli than those of branched polyether because branched one has shorter chain at the same molecular weight, which will result in the faster diffusion. However, at optimized concentration, the modulus of branched one is higher than that of linear one, which can be attributed to the stronger interactions between branched chains at interface. The linear demulsifier propylene glycol polyether shows stronger ability of reducing modulus for diluted crude oil with higher viscosity. On the contrary, branched demulsifier glycerol polyether acts well when concentrations of diluted crude oils are lower. The reason is that linear demulsifier has the stronger ability of adsorption and branched one shows the stronger ability of replacement of natural active fractions.

To increase the reliability and success rate of drug discovery, efforts have been made to increase the C(sp3) fraction and avoid flat molecules. sp3-Rich enantiopure amines are most frequently encountered as chiral auxiliaries, synthetic intermediates for pharmaceutical agents and bioactive natural products. Streamlined construction of chiral aliphatic amines has long been regarded as a paramount challenge. Mainstream approaches, including hydrogenation of enamines and imines, C–H amination, and alkylation of imines, were applied for the synthesis of chiral amines with circumscribed skeleton structures; typically, the chiral carbon centre was adjacent to an auxiliary aryl or ester group. Herein, we report a mild and general nickel-catalysed asymmetric reductive hydroalkylation to effectively convert enamides and enecarbamates into drug-like α-branched chiral amines and derivatives. This reaction involves the regio- and stereoselective hydrometallation of an enamide or enecarbamate to generate a catalytic amount of enantioenriched alkylnickel intermediate, followed by C–C bond formation via alkyl electrophiles., Enantiopure aliphatic amines are frequently encountered as chiral auxiliaries and synthetic intermediates for bioactive compounds. Here, the authors report a mild nickel-catalysed asymmetric reductive hydroalkylation to convert enamides and enecarbamates into α-branched chiral amines and derivatives.

Inspired by the success of dual targeting drugs, especially bispecific antibodies, we propose to combine the concept of protac and dual targeting to design and synthesize dual protac molecules with the function of degrading two completely different types of targets simultaneously. A library of novel dual targeting protac molecules have been rationally designed and prepared. A convergent synthetic strategy has been utilized to achieve high synthetic efficiency. These dual protac structures are characterized by using trifunctional natural amino acids as star-type core linkers to connect two independent inhibitors and E3 ligands together. In this study, gefitinib, olaparib, and CRBN or VHL E3 ligand were used as substrates to synthesize novel dual protacs. They successfully degraded both EGFR and PARP simultaneously in cancer cells. Being the first successful example of dual protacs, this technique will greatly widen the range of application of the protac method and open up a new field for drug discovery.

15-Lipoxygenase-2(15-LOX-2) is thought to regulate inflammation and immunological function however, its mechanisms of action are still unclear. Furthermore, it has been reported that salidroside has anti inflammatory properties , but its role in macrophage function has not been understood yet In this study, we aimed to determine how 15-LOX-2 expression level s affect the function of macrophages and the effect of salidroside on 15-LOX-2 deficient macrophages We used multiple functional genetic strategies to determine 15-LOX-2 function in macrophages. 15-LOX-2 deficiency promotes phagocytosis and proliferation of macrophages and impairs their apoptosis Mechanistically, t he expression levels of cyclophilinB (CypB) were upregulated in 15-LOX-2 deficient Ana 1 macrophages, whereas those of caspase 3 were down regulated. Furthermore, RNA-seq analysis showed that inflammation, complement, and TNF-α signaling pathway s were all activated in 15-LOX-2 deficient Ana 1 macrophages. Treatment of 15-LOX-2 deficient macrophages with salidroside, a natural product derived from Rhodiola species, effectively reversed the effects of 15-LOX-2 deficiency on caspase 3 and CypB levels, as well as on apoptosis and proliferation. In conclusion, our study shows that there is a newly identified link between 15-LOX-2 deficiency and salidroside in regulating macrophage survival, proliferation, and function. Salidroside may be a promising therapeutic strategy for treating inflammation related diseases resulting from 15-LOX-2 deficiency.

The elderly population is prone to tendinopathy due to aging-related tendon changes such as cellular senescence and a decreased ability to modulate inflammation. Aging can render tendon stem/progenitor cells (TSCs) into premature senescence. We investigated the effects of rapamycin, a specific mTOR inhibitor, on the senescence of TSCs. We first showed that after treatment with bleomycin in vitro, rat patellar TSCs (PTSCs) underwent senescence, characterized by morphological alterations, induction of senescence-associated β-galactosidase (SA-β-gal) activity, and an increase in p53, p21, and p62 protein expression. Senescence of PTSCs was also characterized by the elevated expression of MMP-13 and TNF-α genes, both of which are molecular hallmarks of chronic tendinopathy. We then showed that rapamycin treatment was able to reverse the above senescent phenotypes and increase autophagy in the senescent PTSCs. The activation of autophagy and senescence rescue was, at least partly, due to the translocation of HMGB1 from the nucleus to the cytosol that functions as an autophagy promoter. By reducing TSC senescence, rapamycin may be used as a therapeutic to inhibit tendinopathy development in the aging population by promoting autophagy.