Publications by authors named "Zhengnan Shen"

Cisplatin (CDDP) is commonly used as an anticancer drug in clinical practice, but severe nephrotoxicity restricts it from exerting anticancer effects. Natural drugs, such as resveratrol, can alleviate the side effects of cisplatin, but their low solubility and gastrointestinal effects prevent them from working. Herein, we developed nanoparticles for kidney injury consisting of a biocompatible material, zein, as a carrier.

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The SARS-CoV-2 papain-like protease (PLpro), essential for viral processing and immune response disruption, is a promising target for treating acute infection of SARS-CoV-2. To date, there have been no reports of PLpro inhibitors with both submicromolar potency and animal model efficacy. To address the challenge of PLpro's featureless active site, a noncovalent inhibitor library with over 50 new analogs was developed, targeting the PLpro active site by modulating the BL2-loop and engaging the BL2-groove.

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The bromodomain and extra-terminal domain (BET) proteins are epigenetic readers, regulating transcription via two highly homologous tandem bromodomains, BD1 and BD2. Clinical development of nonselective pan-BD BET inhibitors has been challenging, partly due to dose-limiting side effects such as thrombocytopenia. This has prompted the push for domain-selective BET inhibitors to achieve a more favorable therapeutic window.

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Depletion of nicotinamide adenine dinucleotide (NAD) is associated with aging and disease, spurring the study of dietary supplements to replenish NAD. The catabolism of NAD to nicotinamide (NAM) requires the salvage of NAM to replenish cellular NAD, which relies on the rate-limiting enzyme nicotinamide phosphoribosyltransferase (NAMPT). Pharmacological activation of NAMPT provides an alternative to dietary supplements.

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Background: Chinese herbal injections (CHIs) are commonly prescribed in China as adjuvant therapy for acute exacerbation of chronic obstructive pulmonary disease (AECOPD). However, evidence supporting the effect of CHIs on inflammatory factors for patients with AECOPD is insufficient, posing a challenge for clinicians to choose the optimal CHIs for AECOPD. This network meta-analysis (NMA) aimed to compare the effectiveness of several CHIs combined with Western Medicine (WM) and WM alone on the inflammatory factors in AECOPD.

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In aging and disease, cellular nicotinamide adenine dinucleotide (NAD) is depleted by catabolism to nicotinamide (NAM). NAD supplementation is being pursued to enhance human healthspan and lifespan. Activation of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting step in NAD biosynthesis, has the potential to increase the salvage of NAM.

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Background: Ischemic stroke is one of the leading causes of mortality worldwide. The available treatments are not effective. Phosphodiesterase 9A (PDE9A) is an intracellular cyclic guanosine monophosphate (cGMP) hydrolase considered to be a promising therapeutic target for brain diseases.

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Pancreatic ductal adenocarcinoma (PDAC) is associated with extensive dysregulation of the epigenome and epigenetic regulators, such as bromodomain and extraterminal motif (BET) proteins, have been suggested as potential targets for therapy. However, single-agent BET inhibition has shown poor efficacy in clinical trials, and no epigenetic approaches are currently used in PDAC. To circumvent the limitations of the current generation of BET inhibitors, we developed the compound XP-524 as an inhibitor of the BET protein BRD4 and the histone acetyltransferase EP300/CBP, both of which are ubiquitously expressed in PDAC tissues and cooperate to enhance tumorigenesis.

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Antiviral agents that complement vaccination are urgently needed to end the COVID-19 pandemic. The SARS-CoV-2 papain-like protease (PLpro), one of only two essential cysteine proteases that regulate viral replication, also dysregulates host immune sensing by binding and deubiquitination of host protein substrates. PLpro is a promising therapeutic target, albeit challenging owing to featureless P1 and P2 sites recognizing glycine.

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Article Synopsis
  • Carbohydrates like oligosaccharides and polysaccharides are important biopolymers involved in various biological processes and often studied after being isolated from natural sources.
  • Pure compounds with well-defined structures, obtained via chemical or enzymatic synthesis, are necessary for accurate analysis, and new synthetic techniques have made it easier to access larger polysaccharides.
  • The study uses advanced MALDI FT-ICR mass spectrometry to analyze synthetic carbohydrates of different sizes, revealing details about their monosaccharide content and linkage types through the identification of fragment ions, enhancing our understanding of their composition and structures.
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Antiviral agents blocking SARS-CoV-2 viral replication are desperately needed to complement vaccination to end the COVID-19 pandemic. Viral replication and assembly are entirely dependent on two viral cysteine proteases: 3C-like protease (3CLpro) and the papain-like protease (PLpro). PLpro also has deubiquitinase (DUB) activity, removing ubiquitin (Ub) and Ub-like modifications from host proteins, disrupting the host immune response.

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Filoviridae, including Ebola (EBOV) and Marburg (MARV) viruses, are emerging pathogens that pose a serious threat to public health. No agents have been approved to treat filovirus infections, representing a major unmet medical need. The selective estrogen receptor modulator (SERM) toremifene was previously identified from a screen of FDA-approved drugs as a potent EBOV viral entry inhibitor, via binding to EBOV glycoprotein (GP).

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Glycans are involved in various life processes and represent critical targets of biomedical developments. Nevertheless, the accessibility to long glycans with precise structures remains challenging. Here we report on the synthesis of glycans consisting of [→4)-α-Rha-(1 → 3)-β-Man-(1 → ] repeating unit, which are relevant to the O-antigen of Bacteroides vulgatus, a common component of gut microbiota.

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Acquired resistance to fulvestrant and palbociclib is a new challenge to treatment of estrogen receptor positive (ER+) breast cancer. ER is expressed in most resistance settings; thus, bromodomain and extra-terminal protein inhibitors (BETi) that target BET-amplified ER-mediated transcription have therapeutic potential. Novel pyrrolopyridone BETi leveraged novel interactions with L92/L94 confirmed by a cocrystal structure of with BRD4.

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The clinical steroidal selective estrogen receptor (ER) degrader (SERD), fulvestrant, is effective in metastatic breast cancer, but limited by poor pharmacokinetics, prompting the development of orally bioavailable, nonsteroidal SERDs, currently in clinical trials. These trials address local breast cancer as well as peripheral metastases, but patients with brain metastases are generally excluded because of the lack of blood-brain barrier penetration. A novel family of benzothiophene SERDs with a basic amino side arm (B-SERDs) was synthesized.

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The β-(1→2)-linked 6-deoxy-l-altropyranose di- to pentasaccharides 2-5, relevant to the O-antigen of the infectious Yersinia enterocolitica O:3, were synthesized for the first time. The challenging 1,2-cis-altropyranosyl linkage was assembled effectively via glycosylation with 2-O-benzyl-3,4-di-O-benzoyl-6-deoxy-l-altropyranosyl ortho-hexynylbenzoate (7) under the catalysis of PPhAuNTf. NMR and molecular modeling studies showed that the pentasaccharide (5) adopted a left-handed helical conformation.

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Stereoselective β-rhamnopyranosylation remains a challenge, due to the unfavorable anomeric effect and steric hindrance of the C2-substituent; herein, this challenge is addressed with a gold(I)-catalyzed SN2-like glycosylation protocol employing α-rhamnopyranosyl 2-alkynyl-4-nitro-benzoates as donors.

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We previously reported that 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), the most potent agonist for peroxisome proliferator-activated receptor gamma (PPAR gamma), induces apoptosis of human chondrosarcoma cell line OUMS-27. The current study aimed to explore the mechanism of 15d-PGJ(2)-induced apoptosis and inhibition of cell proliferation in OUMS-27 cells. The preliminary results of cDNA microarray analysis showed the down-regulation of anti-apoptotic Bcl-xL and up-regulation of pro-apoptotic Bax in the process of 15d-PGJ(2)-induced apoptosis.

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Objective: To examine whether depsipeptide (FK228), a histone deacetylase (HDA) inhibitor, has inhibitory effects on the proliferation of synovial fibroblasts from rheumatoid arthritis (RA) patients, and to examine the effects of systemic administration of FK228 in an animal model of arthritis.

Methods: Autoantibody-mediated arthritis (AMA) was induced in 19 male DBA/1 mice (6-7 weeks old); 10 of them were treated by intravenous administration of FK228 (2.5 mg/kg), and 9 were used as controls.

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