scholarly journals MmpS5-MmpL5 Transporters Provide Mycobacterium smegmatis Resistance to imidazo[1,2-b][1,2,4,5]tetrazines

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 166 ◽  
Author(s):  
Dmitry A. Maslov ◽  
Kirill V. Shur ◽  
Aleksey A. Vatlin ◽  
Valery N. Danilenko
Keyword(s):  
Gene Expression ◽  
Mycobacterium Smegmatis ◽  
Drug Resistant ◽  
Wild Type ◽  
Efflux System ◽  
Mechanisms Of Resistance ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
Mutant Genes

The emergence and spread of drug-resistant Mycobacterium tuberculosis strains (including MDR, XDR, and TDR) force scientists worldwide to search for new anti-tuberculosis drugs. We have previously reported a number of imidazo[1,2-b][1,2,4,5]tetrazines – putative inhibitors of mycobacterial eukaryotic-type serine-threonine protein-kinases, active against M. tuberculosis. Whole genomic sequences of spontaneous drug-resistant M. smegmatis mutants revealed four genes possibly involved in imidazo[1,2-b][1,2,4,5]tetrazines resistance; however, the exact mechanism of resistance remain unknown. We used different approaches (construction of targeted mutants, overexpression of the wild-type (w.t.) and mutant genes, and gene-expression studies) to assess the role of the previously identified mutations. We show that mutations in MSMEG_1380 gene lead to overexpression of the mmpS5-mmpL5 operon in M. smegmatis, thus providing resistance to imidazo[1,2-b][1,2,4,5]tetrazines by increased efflux through the MmpS5-MmpL5 system, similarly to the mechanisms of resistance described for M. tuberculosis and M. abscessus. Mycobacterial MmpS5-MmpL5 transporters should be considered as an MDR-efflux system and they should be taken into account at early stages of anti-tuberculosis drug development.

scholarly journals Selection of reference genes for measuring the expression of aiiO in Ochrobactrum quorumnocens A44 using RT-qPCR

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dorota M. Krzyżanowska ◽  
Anna Supernat ◽  
Tomasz Maciąg ◽  
Marta Matuszewska ◽  
Sylwia Jafra
Keyword(s):  
Gene Expression ◽  
Quorum Sensing ◽  
Reference Genes ◽  
Significance Threshold ◽  
Expression Studies ◽  
Reverse Transcription Quantitative Pcr ◽  
Gene Expression Studies ◽  
The Stability ◽  
Selection Of

Abstract Reverse transcription quantitative PCR (RT-qPCR), a method of choice for quantification of gene expression changes, requires stably expressed reference genes for normalization of data. So far, no reference genes were established for the Alphaproteobacteria of the genus Ochrobactrum. Here, we determined reference genes for gene expression studies in O. quorumnocens A44. Strain A44 was cultured under 10 different conditions and the stability of expression of 11 candidate genes was evaluated using geNorm, NormFinder and BestKeeper. Most stably expressed genes were found to be rho, gyrB and rpoD. Our results can facilitate the choice of reference genes in the related Ochrobactrum strains. O. quorumnocens A44 is able to inactivate a broad spectrum of N-acyl homoserine lactones (AHLs) – the quorum sensing molecules of many Gram-negative bacteria. This activity is attributed to AiiO hydrolase, yet it remains unclear whether AHLs are the primary substrate of this enzyme. Using the established RT-qPCR setup, we found that the expression of the aiiO gene upon exposure to two AHLs, C6-HLS and 3OC12-HSL, does not change above the 1-fold significance threshold. The implications of this finding are discussed in the light of the role of quorum sensing-interfering enzymes in the host strains.

Role of Non-PTS dependent glucose permease (GlcU) in maintaining the fitness cost during acquisition of nisin-resistance by Enterococcus faecalis

2019 ◽  
Author(s):  
Sandeep Kumar ◽  
Kapil Singh Narayan ◽  
Shruti Shandilya ◽  
Shiv Kumar Sood ◽  
Suman Kapila
Keyword(s):  
Gene Expression ◽  
Glucose Uptake ◽  
Buffalo Milk ◽  
Food Preservation ◽  
Sensitive Strain ◽  
Fitness Cost ◽  
Expression Studies ◽  
Significant Difference ◽  
Gene Expression Studies

ABSTRACT Nisin is used for food preservation due to its antibacterial activity. However, some bacteria survive under the prevailing conditions owing to the acquisition of resistance. This study aimed to characterize nisin-resistant E. faecalis isolated from raw buffalo milk and investigate their fitness cost. FE-SEM, biofilm and cytochrome-c assay were used for characterization. Growth kinetics, HPLC, qPCR, and western-blotting were performed to confer their fitness cost. Results revealed that nisin-resistant E. faecalis were morphologically different from sensitive strain and internalize more glucose. However, no significant difference was observed in the growth pattern of the resistant strain compared to that of the sensitive strain. A non-phosphotransferase glucose permease (GlcU) was found to be associated with enhanced glucose uptake. Conversely, Mpt, a major phospho-transferase system responsible for glucose uptake, did not play any role, as confirmed by gene expression studies and western blot analysis of HPr protein. The phosphorylation of His-15 residue of HPr phosphoprotein was reduced, while that of the Ser-46 residue increased with progression in nisin-resistance, indicating that it may be involved in the regulation of pathogenicity. In conclusion, resistance imposes a significant fitness cost and GlcU plays a key role in maintaining the fitness cost in nisin-resistant variants.

259. Reproductive phenotype of the female aromatase overexpressing mouse

2005 ◽  
Vol 17 (9) ◽  
pp. 105
Author(s):  
J. Liew ◽  
A. E. Drummond ◽  
M. E. Jones ◽  
M. Poutanen ◽  
J. K. Findlay
Keyword(s):  
Gene Expression ◽  
Ovarian Function ◽  
Rna Isolation ◽  
Fat Pad ◽  
Vaginal Smears ◽  
Expression Studies ◽  
Abnormal Pattern ◽  
Gene Expression Studies ◽  
Reproductive Phenotype

Aromatase, the product of the Cyp 19 gene, converts androgens to estrogens. The role of estrogens within the ovary has recently been revisited; using the aromatase knockout (ArKO) mouse, we investigated the effect of estrogen deficiency on ovarian function. We now have an aromatase overexpressing (AROM+) female mouse model with elevated levels of estrogens. These mice were fertile and bred with FVB/N wildtype (WT) males, the AROM+ male being infertile. In this study we characterised the reproductive phenotype of the female AROM+ mouse. 5 WT and 10 AROM+ mice, 22–27 weeks of age were used in the study. The mice were subject to vaginal smears and killed during estrus. The ovaries, uterine horns and gonadal fat were collected and weighed. One ovary and the uterine horns were fixed in formalin for histological assessment, while the other ovary was snap frozen in Ultraspec solution for RNA isolation and gene expression studies. Serum was collected for hormone measurements. All AROM+ mice exhibited an abnormal pattern of cycling that in general, alternated between estrus and post-estrus. AROM+ mice were significantly heavier than their WT counterparts (WT 35.28 ± 2.89 g v. AROM+ 43.38 ± 2.11 g, P < 0.05). Ovarian, uterine and gonadal fat pad weights were not significantly different between the 2 groups (ovary: WT 17.4 ± 1.14 mg v. AROM+ 17.9 ± 0.06 mg; uterine horns: WT 89.7 ± 11.40 mg v. AROM+ 92.1 ± 6.64 mg; gonadal fat pads: WT 2.47 ± 0.62 g v. AROM+ 3.46±0.26 g). Histological, gene expression and hormone analyses are in progress. Our preliminary analyses indicated no significant effect of excess estrogen on ovarian, uterine and gonadal fat pad weights, despite the AROM+ mice being heavier. It remains to be determined as to whether the ovaries and uterine horns are histologically normal. Supported by the NHMRC (Regkeys 241000, 338510, 198705)

scholarly journals Role of innate immunity-triggered pathways in the pathogenesis of Sickle Cell Disease: a meta-analysis of gene expression studies

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Bidossessi Wilfried Hounkpe ◽  
Maiara Marx Luz Fiusa ◽  
Marina Pereira Colella ◽  
Loredana Nilkenes Gomes da Costa ◽  
Rafaela de Oliveira Benatti ◽  
...  
Keyword(s):  
Gene Expression ◽  
Innate Immunity ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Meta Analysis ◽  
Cell Disease ◽  
Expression Studies ◽  
Gene Expression Studies

Recent advances in psychoneuroimmunology: Inflammation in psychiatric disorders

2011 ◽  
Vol 2 (2) ◽  
Author(s):  
Monojit Debnath ◽  
Karen Doyle ◽  
Camilla Langan ◽  
Colm McDonald ◽  
Brian Leonard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bipolar Disorder ◽  
Psychiatric Disorders ◽  
Molecular Mechanisms ◽  
Molecular Genetic ◽  
Major Depressive ◽  
Immune System Dysfunction ◽  
Expression Studies ◽  
Gene Expression Studies

AbstractPsychiatric disorders are common and complex and their precise biological underpinnings remain elusive. Multiple epidemiological, molecular, genetic and gene expression studies suggest that immune system dysfunction may contribute to the risk for developing psychiatric disorders including schizophrenia, bipolar disorder, and major depressive disorder. However, the precise mechanisms by which inflammation-related events confer such risk are unclear. In this review, we examine the peripheral and central evidence for inflammation in psychiatric disorders and the potential molecular mechanisms implicated including inhibition of neurogenesis, apoptosis, the HPA-axis, the role of brain-derived neurotrophic factor and the interplay between the glutamatergic, dopaminergic and serotonergic neurotransmitter systems.

BCL-6 negatively regulates macrophage proliferation by suppressing autocrine IL-6 production

Blood ◽  
2005 ◽  
Vol 105 (4) ◽  
pp. 1777-1784 ◽  
Author(s):  
Raymond Yick-Loi Yu ◽  
Xing Wang ◽  
Fiona J. Pixley ◽  
J. Jessica Yu ◽  
Alexander L. Dent ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sequence Motifs ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
Antigen Presenting ◽  
Expression Program ◽  
Transcription 3 ◽  
Th2 Differentiation ◽  
Precise Role

Abstract The transcription repressor BCL-6 is known to play critical roles in B-cell lymphomagenesis, germinal center formation, and balanced Th1/Th2 differentiation. In macrophages, although BCL-6 has also been shown to regulate the expression of several chemokine genes, its function in other aspects of macrophage biology has not been studied. In addition, the precise role of BCL-6 in cell proliferation is poorly understood in general. Here we report that BCL-6-/- macrophages hyperproliferate due to an accelerated G1/S transition accompanied by increased cyclin D2 and c-myc and decreased expression of p27. Crucial to this enhanced proliferation is spontaneous interleukin 6 (IL-6) production and signal transducer and activator of transcription 3 (STAT3) activation in BCL-6-/- macrophages. In colony-forming assays, BCL- 6-/- bone marrow progenitor cells form spontaneous macrophage colonies that can be inhibited by anti-IL-6 antibodies. Gene expression studies demonstrate that BCL-6 binds to several sequence motifs scattered in the IL-6 locus and can repress IL-6 transcription both in 293T cells and in macrophages. In conclusion, our results indicate that BCL-6 negatively regulates proliferation of the monocytic/macrophage lineage by suppressing an autocrine IL-6/STAT3-mediated gene expression program. Our work also suggests that BCL-6 prevents abnormal Th2 differentiation by suppressing basal level IL-6 production in antigen-presenting cells (APCs). (Blood. 2005;105:1777-1784)

Phylogenetic profiling and gene expression studies implicate a primary role of PSORS1C2 in terminal differentiation of keratinocytes

2017 ◽  
Vol 26 (4) ◽  
pp. 352-358 ◽  
Author(s):  
Salman Abbas Zadeh ◽  
Veronika Mlitz ◽  
Julia Lachner ◽  
Bahar Golabi ◽  
Michael Mildner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Terminal Differentiation ◽  
Primary Role ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
Phylogenetic Profiling

scholarly journals Isogenic-induced endothelial cells enhance osteogenic differentiation of mesenchymal stem cells on silk fibroin scaffold

2019 ◽  
Vol 14 (7) ◽  
pp. 647-661 ◽  
Author(s):  
Sindhuja D Eswaramoorthy ◽  
Nandini Dhiman ◽  
Gayathri Korra ◽  
Carlo M Oranges ◽  
Dirk J Schaefer ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Endothelial Cells ◽  
Mesenchymal Stem Cells ◽  
Osteogenic Differentiation ◽  
Silk Fibroin ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
Endothelial Gene Expression

Aim: We investigated the role of induced endothelial cells (iECs) in mesenchymal stem cells (MSCs)/iECs co-culture and assessed their osteogenic ability on silk fibroin nanofiber scaffolds. Methods: The osteogenic differentiation was assessed by the ALP assay, calcium assay and gene expression studies. Results: The osteogenic differentiation of the iECs co-cultures was found to be higher than the MSCs group and proximal to endothelial cells (ECs) co-cultures. Furthermore, the usage of isogenic iECs for co-culture increased the osteogenic and endothelial gene expression. Conclusion: These findings suggest that iECs mimic endothelial cells when co-cultured with MSCs and that one MSCs source can be used to give rise to both MSCs and iECs. The isogenic MSCs/iECs co-culture provides a new option for bone tissue engineering applications.

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