Project description:Background: Infectious diseases are still a leading cause of death and, with the emergence of drug resistance, pose a great threat to human health. New drugs are thus continually being developed, without their effects on the immune system being studied in-depth. Here we aim to evaluate the impact of a recently release anti-TB drug, named bedaquiline (BDQ), on the response of human macrophages infected with Mycobacterium tuberculosis (MTB). Results: Here, we used MTB resistant to BDQ as a model of bacterial infection to examine the impact of BDQ on the human macrophage response. Gene expression profiling has revealed about 1,500 genes differentially expressed in MTB infected macrophages incubated with BDQ. The expression of 499 genes was upregulated and that of 996 downregulated upon treatment. The gene set up-regulated by BDQ was significantly enriched for genes involved in glucose/phospholipid metabolism, lysosome and autophagy. We found similar results with uninfected macrophages-treated with BDQ. Conclusions: Our results highlight the importance to study the interactions between antibiotics and host cells at the molecular level to better understand the consequences of antibiotic treatment during infection
Project description:Background: Enterobacter cloacae complex (ECC) is a common opportunistic pathogen and is responsible for causing various infections in humans. Owing to its inducible chromosomal AmpC β-lactamase (AmpC), ECC is inherently resistant to the 1st- and 2nd- generation cephalosporins. However, whether β-lactams antibiotics enhance ECC resistance remains unclear. Results: In this study, we found that subinhibitory concentrations (SICs) of cefazolin (CFZ) and imipenem (IMP) can advance the expression of AmpC and enhance its resistance towards β-lactams through NagZ in Enterobacter cloacae (EC). Further, AmpC manifested a substantial upregulation in EC in response to SICs of CFZ and IMP. In nagZ knockout EC (ΔnagZ), the resistance to β-lactam antibiotics was rather weakened and the effect of CFZ and IMP on AmpC induction was completely abrogated. NagZ ectopic expression can rescue the induction effects of CFZ and IMP on AmpC and increase ΔnagZ resistance. More importantly, CFZ and IMP have the potential to induce the expression of AmpR's target genes in a NagZ-dependent manner. Conclusions: Our findings suggest that NagZ is a critical determinant for CFZ and IMP to promote AmpC expression and resistance and that CFZ and IMP should be used with caution since they may aggravate ECC resistance. At the same time, this study further improves our understanding of resistance mechanisms in ECC.
Project description:KMS-11 and KMS-34 cells were exposed to stepwise increasing concentrations of carfilzomib over a period of 18 weeks: cells adapted to growth in 4 nM carfilzomib by 4 weeks, in 6 nM in another 6 weeks and in 12 nM after a further 8 weeks. The resulting cell cultures, denoted KMS-11/Cfz and KMS-34/Cfz, respectively, retained resistance to carfilzomib even when tested after removal of selective pressure for approximately 8 weeks. KMS-11/Cfz and KMS-34/Cfz cells were profiled for gene expression after 1 week of growth in the absence of carfilzomib together with parental KMS-11 and KMS-34 cells which had not been selected in the drug (triplicate samples).
Project description:We profiled Mtb transcriptional response to a range of different antibiotic drug exposures in 7H9 broth culture by RNA-seq. Compound abbreviations: (AMK = amikacin, BDQ = bedaquiline, CPF = ciprofloxacin, LVF = levofloxacin, MXF = moxifloxacin, CFZ = clofazimine, PA824 = pretomanid, RPE = rifapentine, PZA = pyrazinamide). We also hypothesized that an improved Mycobacterium tuberculosis (Mtb) transcriptional regulatory network (TRN) could be inferred using a large, diverse compendium of RNA-seq data and therefore sought to supplement the existing repository of Mtb expression data available on SRA with additional conditions that could inform on Mtb's underlying regulatory programs. We went on to infer Mtb's TRN using a collection of inference methods in combination with this compendium, and employed it to build an interpretable machine learning model of Mtb fitness under stress.
Project description:Carfilzomib (CFZ) is a cornerstone in the treatment of relapsed multiple myeloma (MM). However, its efficacy is limited by resistance mediated by the overexpression of the ABC-transporter P-glycoprotein (P-gp).The signaling pathways driving emergence of P-gp in MM remain unclear. To investigate this, we generated CFZ-resistant AMO-1/CFZ cells with P-gp overexpression by long-term selection. RNA sequencing of control AMO-1 and AMO-1/CFZ, sorted into two subpopulations P-gp HIGH and P-gp LOW, implicated the Ras/MEK/ERK pathway as the most likely signaling cascade involved in P-gp upregulation. We therefore evaluated two clinically used MAPK pathway inhibitors, cobimetinib and ulixertinib, for their ability to re-sensitize AMO-1/CFZ cells to CFZ. Co-administration at non-toxic concentrations enhanced sensitivity 5-fold with cobimetinib and 17-fold with ulixertinib. Analysis of combined MTT assay results, rhodamine efflux experiments, molecular docking, and western blotting revealed distinct actions. Ulixertinib primarily functions as a potent direct P-gp inhibitor. Conversely, non-toxic concentrations of cobimetinib sensitizes cells by suppressing MAPK signaling, though it also exhibits P-gp inhibition at higher concentrations. Both inhibitors at the IC₅₀ concentration reduced P-gp expression. In conclusion, combining CFZ with MAPK pathway inhibitors like cobimetinib or ulixertinib represents a promising strategy to overcome P-gp-mediated resistance in ММ.
Project description:Carfilzomib (CFZ) is a proteasome inhibitor commonly used in the treatment of multiple myeloma, but its clinical application is limited due to its cardiotoxicity. The Neiguan acupoint (PC6) stimulation has been reported to effectively improve cardiac function, but its regulatory mechanism remains unclear. The aim of this study was to investigate the effect and underlying mechanism of electroacupuncture (EA) against CFZ-induced cardiotoxicity in C57BL/6 mice. According to our results, EA treatment significantly reversed CFZ-induced ejection fraction and fractional shortening reduction, which showed great potential effect for heart protection. By using RNA-sequencing, we compared the transcriptome profile of heart samples from DMSO control, CFZ injection, and EA treatment mice, and nearly 40,000,000 valid sequence reads aligned with 20,000 genes from six libraries were obtained. A total of 770 differentially expressed genes (DEGs) were identified in the CFZ (vs. Control) group, including 65 up-regulated and 705 down-regulated genes. Meanwhile, 329 DEGs were obtained in the EA (vs. CFZ) group, including 251 up-regulated and 78 down-regulated genes. Our results shed new insights into the regulatory mechanism of EA at PC6 against CFZ-induced cardiotoxicity, which could further provide theoretical basis for clinical EA therapy.
Project description:ATRA is important for sensitizing MM cells to Cfz. To determine what signalling pathways are affected by ATRA+Cfz in MM cells, MM.1S MM cell line was pulsed with Cfz and then cultured with DMSO or 10µM ATRA for 12 h. Total RNAs of 2 x 106 MM.1S cells for each sample were extracted by RNeasy Mini Kit (Qiagen). 5-10 µg RNA samples were sent to Cancer Genomics Center at The University of Texas (Houston, TX) for genearray followed by data analysis. We use gene experssion profiling data to determine differential expression of genes in MM cells in culture with DMSO, ATRA, Cfz or ATRA+Cfz.
Project description:KMS-11 and KMS-34 cells were exposed to stepwise increasing concentrations of carfilzomib over a period of 18 weeks: cells adapted to growth in 4 nM carfilzomib by 4 weeks, in 6 nM in another 6 weeks and in 12 nM after a further 8 weeks. The resulting cell cultures, denoted KMS-11/Cfz and KMS-34/Cfz, respectively, retained resistance to carfilzomib even when tested after removal of selective pressure for approximately 8 weeks.