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HMGB1 is an inflammatory factor produced by macrophages after liver injury, which plays a key role in promoting NASH progression and further developing into liver fibrosis and cirrhosis. In this study, a mannose-modified HMGB1-siRNA loaded stable nucleic acid lipid particle delivery system (mLNP-siHMGB1) was constructed to target liver macrophages with mannose receptor mediation, thereby silencing HMGB1 protein expression and treating NASH. We also examined the effect of co-administration with docosahexaenoic acid (DHA), a kind of unsaturated fatty acid, on NASH. The results showed that mLNP-siHMGB1 could target macrophages through mannose receptors, effectively silence HMGB1 gene, reduce the release of HMGB1 protein in the liver, regulate liver macrophages to be an anti-inflammatory M2 phenotype, effectively reduce hepatic lobular inflammation and bullous steatosis in the liver, and restore the liver function of NASH model mice to a normal level. After 8 weeks of combined treatment with mLNP-siHMGB1 and DHA, the liver function of NASH model mice recovered rapidly and the hepatic steatosis returned to normal level. In view of inflammation, a key factor in the progression of NASH, we provided an actively targeted siRNA delivery system in this study, and clarified the important role of the delivery system in phenotypic regulation of liver macrophages in NASH. In addition, we also demonstrated the effectiveness of DHA co-administration in NASH treatment. This study provided a useful idea and scientific basis for the development of therapeutic strategies for NASH in the future.

Yilin Xiong,1,* Yuqiao Han,1,* Zinan Zhao,1,* Wenting Gao,2 Yong Ma,2 Shiyu Jiang,1 Mengyao Wang,1 Qingqing Zhang,3 Yun Zhou,4 Yang Chen1 1Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People’s Republic of China; 2Institute of Genome Engineered Animal Models for Human Disease, Dalian Medical University, Dalian, People’s Republic of China; 3Laboratory of Pathogenic Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People’s Republic of China; 4Department of Clinical Nutrition, Second Affiliated Hospital of Dalian Medical University, Dalian, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yang ChenDepartment of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, 9 West Section of Lvshun South Road, Dalian, 116044, People’s Republic of ChinaTel/Fax +86 411 86110350Email yangchen@dmu.edu.cnYun ZhouDepartment of Clinical Nutrition, Second Affiliated Hospital of Dalian Medical University, 467 Zhongshan Road, Dalian, 116023, People’s Republic of ChinaTel +86 411 84690722Fax +86 411 84672130Email dmu_yunzhou@yeah.netPurpose: Antibiotic resistance is a growing health crisis that is further complicated by treatment failures caused by bacteria that exhibit heterogeneous susceptibility to antibiotics. The aim of this study was to describe imipenem (IPM)-heteroresistant strains among multidrug-resistant (MDR) ESBL/AmpC-producing Klebsiella pneumoniae clinical isolates, investigate their molecular phenotypic characteristics, and elucidate the outcome of antibiotic treatment in mice infected with the heteroresistant isolates.Materials and Methods: Antimicrobial susceptibility of K. pneumoniae isolates was determined by the disk diffusion and E-test methods. Heteroresistance to IPM was confirmed by population analysis profile (PAP) assays. PCR and sequencing were employed to detect MDR determinants. Molecular differences between the susceptible and resistant subpopulations were evaluated by sequencing and quantitative real-time reverse transcription PCR (qRT-PCR) analysis. The effect of the carbapenem-heteroresistant strains on antibiotic treatment was assessed using a mouse model of peritonitis with heteroresistant K. pneumoniae and subsequent treatment with IPM.Results: In total, 37 MDR ESBL/AmpC-producing clinical isolates of K. pneumoniae were identified between September 2018 and December 2019. These strains were notably resistant to conventional antimicrobials other than carbapenems. Among the isolates, three strains exhibited heteroresistance to IPM and carried several ESBL and/or AmpC genes. Mice infected with a lethal dose of any of the three heteroresistant isolates were unable to survive in the presence of IPM treatment, as the percentage of the IPM-resistant subpopulation of each strain was increased in the peritoneum of these mice at 24 h after infection. The resistant subpopulation of the strains presented pulsed-field gel electrophoresis (PFGE) profiles that were identical to those of the susceptible subpopulation, but ompK36 porin showed a reduction in gene expression (0.09- to 0.50-fold) in the resistant subpopulation.Conclusion: Carbapenem-heteroresistant strains were present among the MDR K. pneumoniae isolates producing ESBL/AmpC β-lactamases, and these heteroresistant strains failed IPM therapy in experimentally infected mice.Keywords: Enterobacteriaceae, imipenem, heterogeneous susceptibility, treatment failure, OmpK porin, in vivo

Klebsiella pneumoniae is an opportunistic pathogen that frequently causes nosocomial urinary tract infection (UTI). The aim of this study was to investigate the prevalence of extended-spectrum β-lactamases (ESBL), plasmid-mediated quinolone resistance (PMQR) genes, in acquired AmpC (ac-AmpC) β‑lactamase‑producing K. pneumoniae isolates from patients with nosocomial UTI and to characterize the transmissibility of plasmids harbouring multiple resistance genes. From January 2017 to June 2018, we collected 46 ac-AmpC-producing K. pneumoniae isolates causing UTI from a tertiary care hospital in China. Antimicrobial susceptibility assays showed that non-susceptibility of all isolates to third-generation cephalosporin and fluoroquinolone was very high (>80%). Diverse types of ESBLs and PMQR genes, including blaSHV-12 (n = 23), blaSHV-27 (n = 1), blaSHV-28 (n = 2), blaSHV-33 (n = 4), blaCTX-M-3 (n = 24), blaCTX-M-14 (n = 6), blaCTX-M-15 (n = 6), blaCTX-M-22 (n = 1) and blaOXA-10 (n = 26), as well as qnrA (n = 2), qnrB (n = 39) and qnrS (n = 2) genes were identified amongst AmpC-producing K. pneumoniae isolates. The blaAmpC, qnrB and several ESBLs genes from six strains harbouring multiple AmpC (at least two ampC) were co-transferrable to recipients via conjugation or electroporation, with IncFIA, IncFIB and IncA/C being the dominant replicons. Conserved genetic context associated with the mobilization of blaampC genes was detected. Forty-six isolates were categorized into 25 enterobacterial repetitive intergenic consensus (ERIC) types, and the 6 isolates harbouring multiple AmpC genes belonged to ST1 lineage. This work reports that the emergence of plasmids co-harbouring multiple resistance determinants and mediating the local prevalence in K. pneumoniae causing UTI in China.

Human mitochondrial peptide deformylase (HsPDF) is responsible for removing the formyl group from N-terminal formylmethionines of newly synthesized mitochondrial proteins and plays important roles in maintaining mitochondria function. It is overexpressed in various cancers and has been proposed as a novel therapeutic target. Actinonin, a naturally occurring peptidomimetic HsPDF inhibitor, was reported to inhibit the proliferation of a broad spectrum of human cancer cells in vitro. However, its efficacy and pharmacokinetic profile requires significant improvement for therapeutic purposes. To obtain HsPDF inhibitors as anticancer therapeutics, we screened an in-house collection of actinonin derivatives and found two initial hits with antiproliferation activity. Further optimization along the peptidomimetic backbone lead to two series of compounds containing substituted phenyl moieties. They are potent HsPDF inhibitors and exhibited greatly improved antiproliferation activity in selected cancer cell lines. Finally, compound 15m significantly inhibited the growth of human colon cancer in xenograft animal models.

PI3K-Akt-mTOR signaling pathway has been validated as an effective targeting pathway for cancer therapy. However, no PI3K/mTOR dual inhibitor has been approved by the FDA yet. Therefore, it is still essential to discover a candidate with good efficacy and low toxicity. In our design, a series of imidazo[1,2-a]pyridine derivatives had been synthesized and subjected to activity assessment in vitro and in vivo. 15a was proved to be a potent PI3K/mTOR dual inhibitor with excellent kinase selectivity, modest plasma clearance, and acceptable oral bioavailability. Besides, 15a displayed significant inhibition of tumor growth in HCT116 and HT-29 xenografts without obvious effect on body weight.

Due to unknown pathogenesis and unidentified drug target, no drug for the treatment of osteosarcoma (OS) has been launched to the market. Herein, thiazolidinone 1a was discovered as a hit compound by phenotypic screening with an in-house patrimonial collection of structural diversity. The following SAR (Structure-Activity Relationship) study affords the final water-soluble lead compound (R)-8i as a potential inhibitor for the proliferation of OS cells by the modulation of solubility of the compounds with remarkable cellular potency (IC50 = 21.9 nM for MNNG/HOS cells) and in vivo efficacy (52.9% inhibition OS growth in mice), as well as pharmacokinetic properties. (R)-8i also significantly suppresses OS cell migration in vitro and showed to be well-tolerated. Our preliminary investigation shows that the effects of (R)-8i are not dependent on p53 and myoferlin (MYOF). These results suggest that (R)-8i might be a potential drug candidate for OS treatment.

Retinal membrane peeling requires delicate manipulation. The presence of the surgeon's physiological tremor, the high variability and often low quality of the ophthalmic image, and excessive forces make the tasks more challenging. Preventing unintended movement caused by tremor and unintentional forces can reduce membrane injury. With the use of an actively stabilized handheld robot, we employ a monocular camera-based surface reconstruction method to estimate the retinal plane and we propose the use of a virtual fixture with the application of a hard stop and motion scaling to improve control of the tool tip during delaminating in a laboratory simulation of retinal membrane peeling. A hard stop helps to limit downward force exerted on the surface. Motion scaling also improves the user's control of contact force when delaminating. We demonstrate a reduction of maximum force and maximum surface-penetration distance from the estimated retinal plane using the proposed technique.

Background: Klebsiella pneumoniae is a pathogen that frequently causes nosocomial urinary tract infection (UTI), and the prevalence of plasmid-mediated resistance determinants among clinical isolates of K. pneumoniae leads to the appearance of resistance to antibiotics. The aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance (PMQR) genes in acquired AmpC (ac-AmpC) β‑lactamase‑producing K. pneumoniae isolates from patients with nosocomial UTI and to characterize the transmissibility of plasmids co-harbouring blaAmpC and PMQR genes.Methods: From January 2017 to June 2018, we collected 46 AmpC-producing K. pneumoniae isolates causing nosocomial UTI from a tertiary care hospital in China. β-lactamase, PMQR and virulence genes were detected by PCR and sequencing. Clonal relatedness was assessed using ERIC-PCR and multilocus sequence typing (MLST). Plasmids carrying multiple blaAmpC and PMQR genes were characterized by PCR-based replicon typing (PBRT) and S1-PFGE. Conjugation and electroporation experiments were carried out to assess resistance transfer mediated by plasmids. Overlapping PCR was used to map the genetic context of the blaAmpC genes. Results: In the studied isolates, non-susceptibility of third-generation cephalosporin and fluoroquinolone was very high (>80%). blaCMY-2, blaDHA-1, and quinolone resistance gene (qnr) were detected in 11, 41 and 33 isolates, respectively. Among the isolates, 6 strains co-harboured multiple AmpC and qnrB genes. The blaAmpC and qnrB genes from these six isolates were co-transferrable to recipients via conjugation or electroporation, with IncFIA, IncFIB and IncA/C being the dominant replicons (sizes from ~78 to 217 kb). Forty-six isolates were categorized into 25 ERIC types, and the 6 isolates harbouring multiple blaAmpC and qnrB genes belonged to ST1/STnew1. The conserved genetic structures in blaCMY-2 and blaDHA-1 were identical to those described in the pNF4656 and pSAL-1 plasmids, respectively.Conclusion: This work reports that qnrB is highly prevalent in AmpC-producing K. pneumoniae isolates and illustrates the emergence of plasmids co-harbouring multiple acquired blaAmpC and qnrB genes in K. pneumoniae causing UTI in China. We determined that the IncFIA, IncFIB and IncA/C plasmids carrying blaAmpC with qnrB resistance genes and several mobile genetic elements mediate the local prevalence in K. pneumoniae UTI. The genetic context of blaAmpC was highly conserved.

Blockage of p53-MDM2 protein-protein interaction has long been a promising strategy of drug development for cancers with wild type p53. In this study, we report a new p53-MDM2 interaction inhibitor, CYZ2017, which could induce p53 nuclear translocation and possess p53-dependent anti-proliferation activity in a range of cancer cells. CYZ2017 treatment led to increase of p53 levels and induced the transactivation of its target genes p21. In addition, CYZ2017 induced G0/G1 cell cycle arrest and apoptosis in HCT116 cells. Besides, CYZ2017 suppressed tumor growth in a HCT116 xenograft model without visible toxicity. These results support that CYZ2017 might be a promising p53-MDM2 interaction inhibitor with good anti-tumor activity. Our finding provides some cues for further investigation of developing anti-tumor drugs based on the blockage of p53-MDM2 interaction.

Rare and endangered plants (REPs) and their associated endophytes survived in unique habitats are promising sources for natural product-derived drug discovery. In this study, six new (cephaloverines A–F, 1–6, resp.) and 16 known (11–26) cephalotaxine-type alkaloids, together with three new (oliverbiflavones A–C, 7–9, resp.) and 11 known (27–37) biflavonoids were isolated and characterized from the twigs and leaves of Cephalotaxus oliveri, an endangered plant endemic to China. Meanwhile, a preliminary investigation on the secondary metabolites from a selected fungal endophyte (i.e., Alternaria alternate Y-4–2) associated with the title plant led to the isolation of 21 structurally distinct polyketides including one new dimeric xanthone (10). The new structures (1–10) with the absolute configurations were determined by detailed spectroscopic analyses, electronic circular dichroism (ECD) or Na2MoO4-induced ECD, the modified Mosher’s method, and some chemical transformations. Compounds 1–4 are the first representatives of naturally occurring N-oxides of cephalotaxine esters, while compounds 7–9 have a special structural feature of having a C-methylated biflavonoid skeleton. The Cephalotaxus alkaloids with ester side-chains at C-3 (1–6, 13–22, and 26) and four biflavonoids (27–29 and 34) were found to show pronounced cytotoxicities against a small panel of human cancer cell lines (A549, NCI-H460, HL60, NCI-H929, and RPMI-8226), with IC50 values mainly ranging from 0.003 to 9.34 μM. The most potent compound, deoxyharringtonine (16), generally exhibited IC50 values less than 10 nM. The structure–activity relationship (SAR) of the aforementioned Cephalotaxus alkaloids was briefly discussed.

PI3K-Akt-mTOR signaling pathway has been validated as an effective targeting pathway for cancer therapy. However, no PI3K/mTOR dual inhibitor has been approved by the FDA yet. Therefore, it is still essential to discover a candidate with good efficacy and low toxicity. In our design, a series of imidazo[1,2

Retinoic acid can cause many types of cells, including mouse neuroblastoma Neuro-2A cells, to differentiate into neurons. However, it is still unknown whether microRNAs (miRNAs) play a role in this neuronal differentiation. To address this issue, real-time polymerase chain reaction assays were used to detect the expression of several differentiation-related miRNAs during the differentiation of retinoic acid-treated Neuro-2A cells. The results revealed that miR-124 and miR-9 were upregulated, while miR-125b was downregulated in retinoic acid-treated Neuro-2A cells. To identify the miRNA that may play a key role, miR-124 expression was regulated by transfection of miRNA mimics or inhibitors. Morphological analysis results showed that inhibition of miR-124 expression reversed the effects of retinoic acid on neurite outgrowth. Moreover, miR-124 overexpression alone caused Neuro-2A cells to differentiate into neurons, and its inhibitor could block this effect. These results suggest that miR-124 plays an important role in retinoic acid-induced differentiation of Neuro-2A cells.

Novel conducting polypyrrole (PPy) films with microlens arrays (MLAs) were successfully fabricated by combination of breath figures (BFs) and replica molding methods. Polycarbonate (PC) molds prepared by BFs method contain concave cavities with a diameter of about 3–4 μm and a depth of about 2.5 μm in the center of the cavity as were revealed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). PPy MLAs were achieved by the chemically oxidative polymerization of pyrrole on the surface of PC molds initiated by FeCl3 and subsequent removal of PC molds with CHCl3. The PPy MLAs possess well-ordered convex with a height of about 2.1 μm in the center of the microlens as revealed by SEM and AFM, which is highly related to the morphology of PC molds. In addition, the effect of the polymerization time of pyrrole on the electrical conductivity of the resulting patterned PPy films was investigated by standard four probe technique.

A series of water-soluble, thermosensitive copolymers based on N-isopropylacrylamide (NIPAM) and methacrylate derivatives of deoxycholic acid (MEDCA) were synthesized using free radical copolymerization method by varying feed ratios of monomers. The composition ratios and structure of copolymers were determined by 1H NMR spectroscopy. The glass transition temperature was examined by DSC. The thermoresponsive behaviors of polymeric solutions were investigated by turbidity measurement using UV-Visible spectroscopy. The resultant copolymers exhibit systematic changes in their LCSTs as a function of their chemical composition, as the incorporation of amphiphilic comonomers MEDCA results in a lower and broader LCST of the copolymer solution. An aqueous solution of the copolymer above a critical concentration (2 wt%) experiences four distinct phases such as clear solutions, cloud solutions, gel and shrunken gel upon heating. Finally, the mechanism of the phase transitions was tentatively discussed based on the observations.