Self-assembled copper-based nanoparticles for enzyme catalysis-enhanced chemodynamic/photodynamic/antiangiogenic tritherapy against hepatocellular carcinoma.

As an emerging cancer treatment strategy, reactive oxygen species-based tumor catalytic therapies face enormous challenges due to hypoxia and the overexpression of glutathione (GSH) in the tumor microenvironment. Herein, a self-assembled copper-based nanoplatform, TCCHA, was designed for enzyme-like catalysis-enhanced chemodynamic/photodynamic/antiangiogenic tritherapy against hepatocellular carcinoma. TCCHA was fabricated from Cu2+, 3,3'-dithiobis (propionohydrazide), and photosensitizer chlorine e6 via a facile one-pot self-assembly strategy, after which an aldehyde hyaluronic acid was coated, followed by loading of the antivascular drug AL3818. The obtained TCCHA nanoparticles exhibited pH/GSH dual-responsive drug release behaviors and multienzymatic activities, including Fenton, glutathione peroxidase-, and catalase-like activities. TCCHA, a redox homeostasis disruptor, promotes ⋅OH generation and GSH depletion, thus increasing the efficacy of chemodynamic therapy. TCCHA, which has catalase-like activity, can also reinforce the efficacy of photodynamic therapy by amplifying O2 production. In vivo, TCCHA efficiently inhibited tumor angiogenesis and suppressed tumor growth without apparent systemic toxicity. Overall, this study presents a facile strategy for the preparation of multienzyme-like nanoparticles, and TCCHA nanoparticles display great potential for enzyme catalysis-enhanced chemodynamic/photodynamic/antiangiogenic triple therapy against cancer.

Hyaluronan-decorated copper-doxorubicin-anlotinib nanoconjugate for targeted synergistic chemo/chemodynamic/antiangiogenic tritherapy against hepatocellular carcinoma.

Copper-based nanomaterials show considerable potential in the chemodynamic therapy of cancers. However, their clinical application is restricted by low catalytic activity in tumor microenvironment and copper-induced tumor angiogenesis. Herein, a novel copper-doxorubicin-anlotinib (CDA) nanoconjugate was constructed by the combination of copper-hydrazide coordination, hydrazone linkage and Schiff base bond. The CDA nanoconjugate consists of a copper-3,3'-dithiobis(propionohydrazide)-doxorubicin core and an anlotinib-hyaluronan shell. Benefiting from hyaluronan camouflage and abundant disulfide bonds and Cu2+, the CDA nanoconjugate possessed excellent tumor-targeting and glutathione-depleting abilities and enhanced chemodynamic efficacy. Released doxorubicin significantly improved copper-mediated chemodynamic therapy by upregulating nicotinamide adenine dinucleotide phosphate oxidase 4 expression to increase intracellular H2O2 level. Furthermore, the nanoconjugate produced excessive •OH to induce lipid peroxidation and mitochondrial dysfunction, thus greatly elevating doxorubicin-mediated chemotherapy. Importantly, anlotinib effectively inhibited the angiogenic potential of copper ions. In a word, the CDA nanoconjugate is successfully constructed by combined coordination and pH-responsive linkages, and displays the great potential of copper-drug conjugate for targeted synergistic chemo/chemodynamic/antiangiogenic triple therapy against cancers.

SC-Unext: A Lightweight Image Segmentation Model with Cellular Mechanism for Breast Ultrasound Tumor Diagnosis.

Automatic breast ultrasound image segmentation plays an important role in medical image processing. However, current methods for breast ultrasound segmentation suffer from high computational complexity and large model parameters, particularly when dealing with complex images. In this paper, we take the Unext network as a basis and utilize its encoder-decoder features. And taking inspiration from the mechanisms of cellular apoptosis and division, we design apoptosis and division algorithms to improve model performance. We propose a novel segmentation model which integrates the division and apoptosis algorithms and introduces spatial and channel convolution blocks into the model. Our proposed model not only improves the segmentation performance of breast ultrasound tumors, but also reduces the model parameters and computational resource consumption time. The model was evaluated on the breast ultrasound image dataset and our collected dataset. The experiments show that the SC-Unext model achieved Dice scores of 75.29% and accuracy of 97.09% on the BUSI dataset, and on the collected dataset, it reached Dice scores of 90.62% and accuracy of 98.37%. Meanwhile, we conducted a comparison of the model's inference speed on CPUs to verify its efficiency in resource-constrained environments. The results indicated that the SC-Unext model achieved an inference speed of 92.72 ms per instance on devices equipped only with CPUs. The model's number of parameters and computational resource consumption are 1.46M and 2.13 GFlops, respectively, which are lower compared to other network models. Due to its lightweight nature, the model holds significant value for various practical applications in the medical field.

Identification of small-molecule binding sites of a ubiquitin-conjugating enzyme-UBE2T through fragment-based screening.

UBE2T is an attractive target for drug development due to its linkage with several types of cancers. However, the druggability of ubiquitin-conjugating E2 (UBE2T) is low because of the lack of a deep and hydrophobic pocket capable of forming strong binding interactions with drug-like small molecules. Here, we performed fragment screening using 19 F-nuclear magnetic resonance (NMR) and validated the hits with 1 H-15 N-heteronuclear single quantum coherence (HSQC) experiment and X-ray crystallographic studies. The cocrystal structures obtained revealed the binding modes of the hit fragments and allowed for the characterization of the fragment-binding sites. Further screening of structural analogues resulted in the identification of a compound series with inhibitory effect on UBE2T activity. Our current study has identified two new binding pockets in UBE2T, which will be useful for the development of small molecules to regulate the function of this protein. In addition, the compounds identified in this study can serve as chemical starting points for the development of UBE2T modulators.

Identification and characterization of inhibitors covalently modifying catalytic cysteine of UBE2T and blocking ubiquitin transfer.

UBE2T is an E2 ubiquitin ligase critical for ubiquitination of substrate and plays important roles in many diseases. Despite the important function, UBE2T is considered as an undruggable target due to lack of a pocket for binding to small molecules with satisfied properties for clinical applications. To develop potent and specific UBE2T inhibitors, we adopted a high-throughput screening assay and two compounds-ETC-6152 and ETC-9004 containing a sulfone tetrazole scaffold were identified. Solution NMR study demonstrated the direct interactions between UBE2T and compounds in solution. Further co-crystal structures reveal the binding modes of these compounds. Both compound hydrolysation and formation of a hydrogen bond with the thiol group of the catalytic cysteine were observed. The formation of covalent complex was confirmed with mass spectrometry. As these two compounds inhibit ubiquitin transfer, our study provides a strategy to develop potent inhibitors of UBE2T.

Hydrazide/Metal/Indocyanine Green Coordinated Nanoplatform for Potentiating Reciprocal Ferroptosis and Immunity against Melanoma.

Ferroptosis holds great potential in cancer treatment, but its efficacy is severely limited by a low Fenton reaction efficacy. Meanwhile, the interactive relationship between Ferroptosis and the PD-1 blockade is still vague. Herein, a hydrazide/Cu/Fe/indocyanine green coordinated nanoplatform (TCFI) is constructed by a hydrazide-metal-sulfonate coordination process. The TCFI nanoplatform exhibits Fenton-/catalase-/glutathione oxidase-like triple activities and accordingly can trigger lipid peroxidation, relieve hypoxia, and downregulate the glutathione/glutathione peroxidase 4 axis, thus achieving positively and negatively dually enhanced Ferroptosis in B16F10 cancer cells. Under near-infrared laser irradiation, the TCFI nanoplatform induces robust immunogenic cancer cell death by elevating the intracellular reactive oxygen species level through synergistic photodynamic therapy/Ferroptosis, which significantly potentiates CD8+ T cell infiltration into tumors and interferon-γ secretion. Moreover, upregulated interferon-γ efficiently inhibits system xc- activity and sensitizes cancer cells to Ferroptosis. Interestingly, the PD-1 blockade may strengthen the reciprocal process. The combination of the TCFI nanoplatform and αPD-1 can eliminate primary tumors and inhibit distant tumor growth, lung metastasis, and tumor recurrence. This study presents a simple and novel coordination strategy to fabricate tumor microenvironment-responsive nanodrugs and highlights the enhancement effect of photodynamic therapy on reciprocal Ferroptosis and antitumor immunity.

Tumor Microenvironment Responsive Hollow Nanoplatform for Triple Amplification of Oxidative Stress to Enhance Cuproptosis-Based Synergistic Cancer Therapy.

Cuproptosis is a recently discovered form of programmed cell death and shows great potential in cancer treatment. Herein, a copper-dithiocarbamate chelate-doped and artemisinin-loaded hollow nanoplatform (HNP) is developed via a chelation competition-induced hollowing strategy for cuproptosis-based combination therapy. The HNP exhibits tumor microenvironment-triggered catalytic activity, wherein liberated Cu2+ catalyzes artemisinin and endogenous H2 O2 to produce C-centered radicals and hydroxyl radicals, respectively. Meanwhile, the disulfide bonds-rich HNP can deplete intracellular glutathione, thus triply amplifying tumor oxidative stress. The augmented oxidative stress sensitizes cancer cells to the cuproptosis, causing prominent dihydrolipoamide S-acetyltransferase oligomerization and mitochondrial dysfunction. Moreover, the HNP can activate ferroptosis via inhibiting GPX4 activity and trigger apoptosis via dithiocarbamate-copper chelate-mediated ubiquitinated proteins accumulation, resulting in potent antitumor efficacy. Such a cuproptosis/ferroptosis/apoptosis synergetic strategy opens a new avenue for cancer therapy.

Expanding the eukaryotic genetic code with a biosynthesized 21st amino acid.

Genetic code expansion technology allows for the use of noncanonical amino acids (ncAAs) to create semisynthetic organisms for both biochemical and biomedical applications. However, exogenous feeding of chemically synthesized ncAAs at high concentrations is required to compensate for the inefficient cellular uptake and incorporation of these components into proteins, especially in the case of eukaryotic cells and multicellular organisms. To generate organisms capable of autonomously biosynthesizing an ncAA and incorporating it into proteins, we have engineered a metabolic pathway for the synthesis of O-methyltyrosine (OMeY). Specifically, we endowed organisms with a marformycins biosynthetic pathway-derived methyltransferase that efficiently converts tyrosine to OMeY in the presence of the co-factor S-adenosylmethionine. The resulting cells can produce and site-specifically incorporate OMeY into proteins at much higher levels than cells exogenously fed OMeY. To understand the structural basis for the substrate selectivity of the transferase, we solved the X-ray crystal structures of the ligand-free and tyrosine-bound enzymes. Most importantly, we have extended this OMeY biosynthetic system to both mammalian cells and the zebrafish model to enhance the utility of genetic code expansion. The creation of autonomous eukaryotes using a 21st amino acid will make genetic code expansion technology more applicable to multicellular organisms, providing valuable vertebrate models for biological and biomedical research.

Injectable hyaluronan/MnO2 nanocomposite hydrogel constructed by metal-hydrazide coordinated crosslink mineralization for relieving tumor hypoxia and combined phototherapy.

Hydrogel-based drug delivery holds great promise in topical tumor treatment. However, the simple construction of multifunctional therapeutic hydrogels under physiological conditions is still a huge challenge. Herein, for the first time, a multifunctional hyaluronan/MnO2 nanocomposite (HHM) hydrogel with injectable and self-healing capabilities was constructed under physiological conditions through innovative in situ mineralization-triggered Mn-hydrazide coordination crosslinking. The hydrogel formed from Mn2+ and hydrazided hyaluronan under optimized conditions exhibited a high elastic modulus >1 kPa, injectability, self-healing function, stimuli-responsiveness and catalase-like activity. In vitro and in vivo biological experiments demonstrated that our HHM hydrogel could not only efficiently relieve hypoxia by in situ catalytic decomposition of endogenous H2O2 into O2 but also achieve synergistic photodynamic/photothermal therapy of 4T1 breast cancer in a mouse tumor model. This study presented a novel mineralization-driven metal-hydrazide coordination crosslinking approach and developed a multifunctional therapeutic platform for O2-enhanced efficient topical dual-phototherapy of breast cancer.

Hydrazide-manganese coordinated multifunctional nanoplatform for potentiating immunotherapy in hepatocellular carcinoma.

Immune checkpoint blockade (ICB)-based immunotherapy is a revolutionary therapeutic strategy for hepatocellular carcinoma (HCC). However, tumor immune tolerance and escape severely restrict the therapeutic efficacy of ICB therapy. It is urgent to explore new strategies to potentiate ICB therapy in HCC. Herein, we developed manganese oxide-crosslinked bovine albumin/hyaluronic acid nanoparticles (BHM) by an innovative hydrazide-manganese coordination and desolvation process. Successive loading of doxorubicin (DOX) and indocyanine green (ICG) was achieved via hydrazone linkage and electrostatic interactions, respectively, obtaining DOX/ICG-coloaded BHM nanoplatform (abbreviated as BHMDI). The BHMDI nanoplatform exhibited a high drug content (>46%) and pH/reduction dual-responsive drug release behavior. The nanoplatform could efficiently alleviate tumor hypoxia by catalytic decomposition of intracellular H2O2 to O2 and significantly improve BHMDI-based photodynamic chemotherapy efficacy. The BHMDI nanoplatform downregulated the proportion of alternatively activated (M2) macrophages in tumors and simultaneously induced immunogenic death of HCC cells, thus promoting the maturation of dendritic cells and ensuing priming of CD4+ and CD8+ T cells. Importantly, programmed death-1 (PD-1) blockade in combination with BHMDI nanoplatform not only eradicated primary tumors but inhibited tumor recurrence, abscopal tumor growth and lung metastasis of HCC by triggering robust systemic antitumor immunity. This work proved the feasibility of BHMDI-based photodynamic chemotherapy for potentiating PD-1 blockade immunotherapy by reversing hypoxic and immunosuppressive tumor microenvironment.

MicroRNA-124a Protects the Myocardium Against Ischemia Reperfusion Injury Through Regulation of the Notch Signaling Pathway

Abstract Introduction: This study's objective is to investigate the effect of downregulation of micro ribonucleic acid (miR)-124a on myocardial injury after ischemia reperfusion (I/R) in rats. Methods: Sprague Dawley (SD) rats (n=20) were divided into four groups - sham, I/R, I/R+miR-124a antagomir (I/R+ant-miR-124a), and I/R+ant-normal control (NC). The pathomorphological and infarct size variance of injured myocardial tissues with IR were conducted with hematoxylin (HE) and triphenyltetrazolium chloride (TTC) staining. The expression levels of miR-124a, BAX, nuclear factor kappa B (NF-KB), Notch1, and Hes1 were examined by quantitative real-time polymerase chain reaction or Western blot in myocardium. The inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α) were detected by the enzyme-linked immunosorbent assay, as well as the activity of lactate dehydrogenase (LDH) and creatine kinase (CK) in serum by colorimetry. Results: The expression of miR-124a was increased in the I/R group. Compared with I/R and I/R+ant-NC groups, after downregulating miR-124a, the expression of IL-6, IL-1β, TNF-α, BAX, NF-KB, LDH, and CK were decreased, but the expression of Notch1 and Hes1 were increased. In HE staining, myocardial tissue edema, red blood cell exudation, and myocardial fiber arrangement disorder were accompanied by inflammatory cell infiltration and local necrosis in the I/R group. However, the pathological injury of myocardial tissue was alleviated after downregulating miR-124a. Additionally, TTC results showed that the myocardial infarction area was decreased in the I/R+ant-miR-124a group. Conclusion: Downregulation of miR-124a expression through Notch pathway can significantly reduce myocardial damage after 24 hours of I/R in SD rats. Therefore, miR-124a may become a potential therapeutic target for I/R injury.

LncRNA PCGEM1 promotes colorectal cancer cell proliferation and migration in positive feedback loop through PCGEM1/miR-433-3p/CTCF axis.

BACKGROUND AND OBJECTIVES: Prostate cancer gene expression marker 1 (PCGEM1) has been identified as an oncogenic long non-coding RNA (lncRNA) in diverse cancers, but it has never been linked with colorectal cancer (CRC). Former studies have shown the mutual regulation between lncRNAs and transcription factors (TFs) in cancer. CCCTC binding factor (CTCF) has been reported to transcriptionally activate lncRNAs in cancers. We predicted the binding of CTCF on PCGEM1 promoter through UCSC (https://genome.ucsc.edu/), but their relation has not been studied. We aimed to investigate whether and how PCGEM1 functioned in CRC cells and the interaction between PCGEM1 and CTCF. METHODS AND RESULTS: The impacts of PCGEM1 and CTCF inhibition on CRC cells were verified through loss-of-function experiments. Mechanism experiments were used to prove the binding between CTCF and PCGEM1 in CRC progression. PCGEM1 possessed a high expression level in CRC cells as well as tumors. CTCF transcriptionally activated PCGEM1 expression. Knockdown of PCGEM1 or CTCF impeded proliferation and migration and drove apoptosis of CRC cells. Moreover, PCGEM1 bound miR-433-3p to prevent miR-433-3p from targeting CTCF. CONCLUSION: We first revealed PCGEM1/miR-433-3p/CTCF positive feedback loop as an oncogenic axis in CRC cells, which potentially provides new clues for the advancement of CRC treatment.

The Structure of the Arabidopsis PEX4-PEX22 Peroxin Complex-Insights Into Ubiquitination at the Peroxisomal Membrane.

Peroxisomes are eukaryotic organelles that sequester critical oxidative reactions and process the resulting reactive oxygen species into less toxic byproducts. Peroxisome function and formation are coordinated by peroxins (PEX proteins) that guide peroxisome biogenesis and division and shuttle proteins into the lumen and membrane of the organelle. Despite the importance of peroxins in plant metabolism and development, no plant peroxin structures have been reported. Here we report the X-ray crystal structure of the PEX4-PEX22 peroxin complex from the reference plant Arabidopsis thaliana. PEX4 is a ubiquitin-conjugating enzyme (UBC) that ubiquitinates proteins associated with the peroxisomal membrane, and PEX22 is a peroxisomal membrane protein that anchors PEX4 to the peroxisome and facilitates PEX4 activity. We co-expressed Arabidopsis PEX4 as a translational fusion with the soluble PEX4-interacting domain of PEX22 in E. coli. The fusion was linked via a protease recognition site, allowing us to separate PEX4 and PEX22 following purification and solve the structure of the complex. We compared the structure of the PEX4-PEX22 complex to the previously published structures of yeast orthologs. Arabidopsis PEX4 displays the typical UBC structure expected from its sequence. Although Arabidopsis PEX22 lacks notable sequence identity to yeast PEX22, it maintains a similar Rossmann fold-like structure. Several salt bridges are positioned to contribute to the specificity of PEX22 for PEX4 versus other Arabidopsis UBCs, and the long unstructured PEX22 tether would allow PEX4-mediated ubiquitination of distant peroxisomal membrane targets without dissociation from PEX22. The Arabidopsis PEX4-PEX22 structure also revealed that the residue altered in pex4-1 (P123L), a mutant previously isolated via a forward-genetic screen for peroxisomal dysfunction, is near the active site cysteine of PEX4. We demonstrated in vitro UBC activity for the PEX4-PEX22 complex and found that the pex4-1 enzyme has reduced in vitro ubiquitin-conjugating activity and altered specificity compared to PEX4. Our findings illuminate the role of PEX4 and PEX22 in peroxisome structure and function and provide tools for future exploration of ubiquitination at the peroxisome surface.

Overexpression of pressure-responsive miRNA-5703 inhibits pressure-induced growth and metastasis of liver cancer.

A vast majority of liver cancers coexist with cirrhosis and/or portal hypertension. A high-pressure tumour microenvironment may lead to malignant progression of liver cancer. Through quantitative reverse transcription-polymerase chain reaction, we found that miRNA-5703 was expressed at low levels in HepG2 and Huh-7 cells and pressure-treated MHCC97H implanted mouse cancer tissues, while its potential target gene, sarcoma gene (SRC), was highly expressed. The expression of miRNA-5703 was higher in liver cancer tissues from Barcelona Clinic Liver Cancer (BCLC) stage A1 patients than those from BCLC stage A2-D patients, whereas SRC showed the opposite expression pattern. Bioinformatics analysis, luciferase reporter assay, and western blotting were performed to verify the relationship between miRNA-5703 and its potential target SRC. Using intravital imaging and immunohistochemistry, we demonstrated that pressure promotes tumour growth in subcutaneous tumourigenesis nude mice, and overexpression of miRNA-5703 significantly downregulated Ki67 and upregulated NM23 in tumour tissues of mice, implying the blockage of tumour growth and metastasis. The activation of proliferation, migration, and invasion of HepG2 and Huh-7 cells by pressure, and inhibition by overexpressing miRNA-5703 were observed by cell counting kit-8 assay, flow cycle assay, transwell assay, and wound healing assay. After the intervention of pressure, inhibitor, and lentivirus to hepatoma cells, SRC, focal adhesion kinase (FAK), phosphatidylinositol 3-kinase (PI3K), serum/glucocorticoid regulated kinase-3 (SGK3), phosphoinositide dependent protein kinase 1 (PDK1), and paxillin were upregulated, and forkhead box O1 (FOXO1) and cyclin dependent kinase inhibitor 1B (P27Kip1) were downregulated in pressure-loaded hepatoma cells, which could be reversed by overexpression of miRNA-5703 or SRC knockdown. In conclusion, upregulation of miRNA-5703 inhibited pressure-induced growth and metastasis by suppressing the SRC-FAK-FOXO1 axis and SRC-paxillin axis. This novel perspective may be conducive to the mechano-inspired anticancer drugs of liver cancer.

Photo-crosslinked hyaluronic acid hydrogel as a biomimic extracellular matrix to recapitulate in vivo features of breast cancer cells.

2D cell culture is widely utilized to develop anti-cancer drugs and to explore the mechanisms of cancer tumorigenesis and development. However, the findings obtained from 2D culture often fail to provide guidance for clinical tumor treatments since it cannot precisely replicate the features of real tumors. 3D tumor models capable of recapitulating native tumor microenvironments have been proved to be a promising alternative technique. Herein, we constructed a breast tumor model from novel hyaluronic acid (HA) hydrogel which was prepared through photocrosslinking of methacrylated HA. The hydrogel was used as a biomimetic extracellular matrix to incubate MCF-7 cells. It was found that methacrylation degree had great effects on hydrogel's microstructure, mechanical performances, and liquid-absorbing and degradation abilities. Optimized hydrogel exhibited highly porous morphology, high equilibrium swelling ratio, suitable mechanical properties, and hyaluronidase-responsive degradation behavior. The results demonstrated that the HA hydrogel facilitated MCF-7 cell proliferation and growth in an aggregation manner. Furthermore, 3D-cultured MCF-7 cells not only up-regulated the expression of VEGF, bFGF and interleukin-8 but exhibited greater invasion and tumorigenesis capabilities compared with 2D-cultured cells. Therefore, the HA hydrogel is a reliable substitute for tumor model construction.

Update on the Development of MNK Inhibitors as Therapeutic Agents.

Mitogen-activated protein kinase-interacting kinases 1 and 2 (MNK1/2) represent a central class of enzymes that are activated by extracellular signal-regulated kinase (ERK) or p38 mitogen-activated protein (MAP) kinases. MNK1 and MNK2 coordinate cellular signaling, control production of inflammatory chemokines, and regulate cell proliferation and survival. MNK1/2 are referred to as serine/threonine kinases as they phosphorylate serine or threonine residues on their substrates. Upon activation, MNK1/2 phosphorylate eukaryotic translation initiation factor 4E (eIF4E) at Ser209, which in turn initiates ribosome assembly and protein translation. Deleterious overexpression of MNK1/2 and/or eIF4E have been reported in several diseases including cancers, neurological disorders, autism, and inflammation. Recently, there have been intense efforts toward the development of potent and selective inhibitors of MNK1/2 in both academia and industry. Herein, we review the current understanding of the structural and biological aspects of MNK1/2 and provide an update of pharmacological inhibitors of MNK1/2 including candidates in clinical trials.

MicroRNA-124a Protects the Myocardium Against Ischemia Reperfusion Injury Through Regulation of the Notch Signaling Pathway.

INTRODUCTION: This study's objective is to investigate the effect of downregulation of micro ribonucleic acid (miR)-124a on myocardial injury after ischemia reperfusion (I/R) in rats. METHODS: Sprague Dawley (SD) rats (n=20) were divided into four groups - sham, I/R, I/R+miR-124a antagomir (I/R+ant-miR-124a), and I/R+ant-normal control (NC). The pathomorphological and infarct size variance of injured myocardial tissues with IR were conducted with hematoxylin (HE) and triphenyltetrazolium chloride (TTC) staining. The expression levels of miR-124a, BAX, nuclear factor kappa B (NF-KB), Notch1, and Hes1 were examined by quantitative real-time polymerase chain reaction or Western blot in myocardium. The inflammatory cytokines interleukin (IL)-6, IL-1ß, and tumor necrosis factor alpha (TNF-α) were detected by the enzyme-linked immunosorbent assay, as well as the activity of lactate dehydrogenase (LDH) and creatine kinase (CK) in serum by colorimetry. RESULTS: The expression of miR-124a was increased in the I/R group. Compared with I/R and I/R+ant-NC groups, after downregulating miR-124a, the expression of IL-6, IL-1ß, TNF-α, BAX, NF-KB, LDH, and CK were decreased, but the expression of Notch1 and Hes1 were increased. In HE staining, myocardial tissue edema, red blood cell exudation, and myocardial fiber arrangement disorder were accompanied by inflammatory cell infiltration and local necrosis in the I/R group. However, the pathological injury of myocardial tissue was alleviated after downregulating miR-124a. Additionally, TTC results showed that the myocardial infarction area was decreased in the I/R+ant-miR-124a group. CONCLUSION: Downregulation of miR-124a expression through Notch pathway can significantly reduce myocardial damage after 24 hours of I/R in SD rats. Therefore, miR-124a may become a potential therapeutic target for I/R injury.

Structure-activity relationship studies of allosteric inhibitors of EYA2 tyrosine phosphatase.

Human eyes absent (EYA) proteins possess Tyr phosphatase activity, which is critical for numerous cancer and metastasis promoting activities, making it an attractive target for cancer therapy. In this work, we demonstrate that the inhibitor-bound form of EYA2 does not favour binding to Mg2+ , which is indispensable for the Tyr phosphatase activity. We further describe characterization and optimization of this class of allosteric inhibitors. A series of analogues were synthesized to improve potency of the inhibitors and to elucidate structure-activity relationships. Two co-crystal structures confirm the binding modes of this class of inhibitors. Our medicinal chemical, structural, biochemical, and biophysical studies provide insight into the molecular interactions of EYA2 with these allosteric inhibitors. The compounds derived from this study are useful for exploring the function of the Tyr phosphatase activity of EYA2 in normal and cancerous cells and serve as reference compounds for screening or developing allosteric phosphatase inhibitors. Finally, the co-crystal structures reported in this study will aid in structure-based drug discovery against EYA2.

Hydrazided hyaluronan/cisplatin/indocyanine green coordination nanoprodrug for photodynamic chemotherapy in liver cancer.

It is still a huge challenge for concurrent highly efficient loading of chemotherapeutic agent and photosensitizer into single nanocarrier via stimuli-responsive linkages due to their different physicochemical properties and pharmacokinetics. Herein, based on the discovery of unique cisplatin-hydrazide and cisplatin-indocyanine green (ICG) coordination reactions, a multifunctional coordination nanoprodrug, cisplatin/ICG co-loaded hydrazided hyaluronan/bovine serum albumin (HBCI) nanoparticles, was developed by a desolvation-dual coordination process. The nanoprodrug exhibited ultrahigh drug loading efficiency and glutathione/NIR light dual-responsive drug release behavior. In vitro cellular studies demonstrated efficient internalization and apoptosis-inducing ability of the nanoprodrug in HepG2 cells. In vivo results confirmed the efficacious tumor accumulation and biosafety of HBCI nanoprodrug and synergistic effect of HBCI-based combined photodynamic chemotherapy on inhibiting tumor growth. Overall, this work not only provides a novel dual coordination approach for highly efficient loading of cisplatin and ICG but also verifies the therapeutic potential of HBCI nanoprodrug in combating hepatocellular carcinoma.

A Patent Review on SARS Coronavirus Main Protease (3CLpro ) Inhibitors.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is an unprecedented global health emergency causing more than 4.2 million fatalities as of 30 July 2021. Only three antiviral therapies have been approved or granted emergency use authorization by the FDA. The SARS-CoV-2 3CL protease (3CLpro ) is deemed an attractive drug target as it plays an essential role in viral polyprotein processing and pathogenesis, although no inhibitors have been approved. This patent review discusses SARS coronavirus 3CLpro inhibitors that have been filed up to 30 July 2021, giving an overview on the types of inhibitors that have generated commercial interest, especially amongst drug companies. Insights into the common structural motifs required for active site binding is also discussed.