Temporal microRNA expression during in vitro myogenic progenitor cell proliferation and differentiation: regulation of proliferation by miR-682

MicroRNAs (miRNAs) regulate gene expression by repressing target genes at the posttranscriptional level. Since miRNAs have unique expression profiles in different tissues, they provide pivotal regulation of many biological processes. The present study defined miRNA expression during murine myogenic progenitor cell (MPC) proliferation and differentiation to identify miRNAs involved in muscle regeneration. Muscle-related gene expression analyses revealed that the time course and expression of myosin heavy chain (MHC) and transcription factors (Myf5, MyoD, myogenin, and Pax7) were similar during in vitro MPC proliferation/differentiation and in vivo muscle regeneration. Comprehensive profiling revealed that 139 or 16 miRNAs were significantly changed more than twofold [false discovery rate (FDR) < 0.05] during MPC differentiation or proliferation, respectively; cluster analyses revealed five distinct patterns of miRNA expression during the time course of MPC differentiation. Not unexpectedly, the largest miRNA changes occurred in muscle-specific miRNAs (miR-1, -133a, and -499), which were upregulated >10-fold during MPC differentiation (FDR < 0.01). However, several previously unreported miRNAs were differentially expressed, including miR-10b, -335-3p, and -682. Interestingly, the temporal patterns of miR-1, -499, and -682 expression during in vitro MPC proliferation/differentiation were remarkably similar to those observed during in vivo muscle regeneration. Moreover, in vitro inhibition of miR-682, the only miRNA upregulated in proliferating compared with quiescent MPC, led to decreased MPC proliferation, further validating our in vitro assay system for the identification of miRNAs involved in muscle regeneration. Thus the differentially expressed miRNAs identified in the present study could represent new regulatory elements in MPC proliferation and differentiation.

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CircFAM13B promotes the proliferation of hepatocellular carcinoma by sponging miR-212, upregulating E2F5 expression and activating the P53 pathway

Cancer Cell International ◽

10.1186/s12935-021-02120-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Ying Xie ◽

Xiaofeng Hang ◽

Wensheng Xu ◽

Jing Gu ◽

Yuanjing Zhang ◽

...

Keyword(s):

Gene Expression ◽

Hepatocellular Carcinoma ◽

Gene Expression Omnibus ◽

Differentially Expressed ◽

In Vivo Studies ◽

Circular Rnas ◽

Novel Target ◽

Underlying Mechanisms

Abstract Background Most of the biological functions of circular RNAs (circRNAs) and the potential underlying mechanisms in hepatocellular carcinoma (HCC) have not yet been discovered. Methods In this study, using circRNA expression data from HCC tumor tissues and adjacent tissues from the Gene Expression Omnibus database, we identified out differentially expressed circRNAs and verified them by qRT-PCT. Functional experiments were performed to evaluate the effects of circFAM13B in HCC in vitro and in vivo. Results We found that circFAM13B was the most significantly differentially expressed circRNA in HCC tissue. Subsequently, in vitro and in vivo studies also demonstrated that circFAM13B promoted the proliferation of HCC. Further studies revealed that circFAM13B, a sponge of miR-212, is involved in the regulation of E2F5 gene expression by competitively binding to miR-212, inhibits the activation of the P53 signalling pathway, and promotes the proliferation of HCC cells. Conclusions Our findings revealed the mechanism underlying the regulatory role played by circFAM13B, miR-212 and E2F5 in HCC. This study provides a new theoretical basis and novel target for the clinical prevention and treatment of HCC.

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3 IN VITRO MATURATION ALTERS GENE EXPRESSION IN MOUSE OOCYTES

Reproduction Fertility and Development ◽

10.1071/rdv20n1ab3 ◽

2008 ◽

Vol 20 (1) ◽

pp. 82

Author(s):

M. Paczkowski ◽

C. Bidwell ◽

D. Spurlock ◽

J. Waddell ◽

R. L. Krisher

Keyword(s):

Gene Expression ◽

Cell Death ◽

Dna Methyltransferase ◽

In Vitro Maturation ◽

Fold Increase ◽

Developmental Competence ◽

Differentially Expressed ◽

Dna Methyltransferase 1

The in vitro culture environment significantly impacts nuclear maturation, fertilization, embryonic development, and epigenetic competence; however, our knowledge of the effects of in vitro maturation on oocyte developmental competence, and specifically cytoplasmic maturation, is limited. The objective of this experiment was to identify alterations in the transcriptome of oocytes matured in vitro compared to those matured in vivo that correlate to developmental competence. Immature oocytes were collected from Day 26 and 7-8-week-old B6D2F1 mice 48 h post-pregnant mare serum gonadotropin (PMSG) administration and matured for 16 h in Gmat supplemented with 0.5 mm citric acid, 0.5 mm cysteamine, 100 ng mL–1 epidermal growth factor (EGF), 0.05% insulin-transferrin-selenium (ITS; v/v), 0.01% recombumin (v/v) and 2 mg mL–1 fetuin. In vivo-matured oocytes from females of the same ages were collected from the oviducts 62 h post-PMSG and 14 h post-hCG and mating to vasectomized males. In vivo- and in vitro-matured oocytes were identified visually by the presence of the first polar body. Mature oocytes were pooled into three groups of 150 oocytes per treatment and lysed; poly A+ RNA was extracted. Samples were processed through two cycles of linear amplification and hybridized to the GeneChip� Mouse Genome 430 2.0 Array (Affymetrix, Inc., Santa Clara, CA, USA), with three arrays per treatment. Microarray data were sorted and filtered to include genes that were classified as having two present calls per treatment. The data were then normalized to the chip median and analyzed using a one-way analysis of variance; the level of significance was calculated at P < 0.01. In total, 2.17% (482/22170) and 1.61% (358/22170) of genes were differentially expressed between in vitro- and in vivo-matured oocytes in Day 26 and 7–8-week-old mice, respectively. However, 72.82% (351/482) and 67.87% (243/358) of differentially expressed genes had increased abundance in the in vitro- and in vivo-matured oocytes, respectively. Transcripts involved in gene expression, cellular growth and proliferation, and cellular development were increased in in vivo-matured oocytes from both age groups compared to those matured in vitro. Cell death was one of the higher ranking functional groups increased in the 7–8-week-old in vitro-matured oocytes compared to the 7–8-week-old in vivo-matured oocytes. Specific genes altered by in vitro maturation conditions in Day 26 oocytes were DNA methyltransferase 1 (>7-fold increase in vivo), caspase 8 (>4-fold increase in vivo), and eukaryotic translation initiation factor 1B (>4-fold increase in vivo). DNA methyltransferase 1 and ubiquitin-conjugating enzyme E2T were significantly increased in in vivo-matured 7–8-week-old oocytes (>3-fold and >5-fold, respectively). These results indicate that gene expression is altered in oocytes matured in vitro compared to those matured in vivo. Based on the functional annotations of genes differentially expressed, dysregulation of gene expression in the oocyte resulting in altered DNA methylation and an up-regulation in cell death pathways are potential developmental mechanisms influenced by in vitro culture conditions that correlate to reduced embryonic developmental potential.

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177 GENE EXPRESSION PROFILES OF IN VITRO- AND IN VIVO-DERIVED BOVINE EMBRYOS

Reproduction Fertility and Development ◽

10.1071/rdv23n1ab177 ◽

2011 ◽

Vol 23 (1) ◽

pp. 190

Author(s):

D. Aktoprakligil Aksu ◽

C. Agca ◽

S. Aksu ◽

T. Akkoc ◽

A. Tas Caputcu ◽

...

Keyword(s):

Gene Expression ◽

Functional Annotation ◽

Differentially Expressed ◽

Annotation Tool ◽

Bovine Embryos ◽

University Of Missouri ◽

Total Rna ◽

David Functional Annotation Tool

Microarray technology is one of the most powerful tools for gene expression profiling in animal sciences. The objectives of this study were to determine the effect of vitrification on gene expression in in vitro- and in vivo-derived bovine embryos, and to identify differential mRNA expression patterns between embryos produced by in vivo v. in vitro conditions. Three pools of in vivo- and in vitro-derived blastocyst-stage embryos were used for microarray analysis. Total RNA was isolated using the PicoPure RNA Isolation Kit (Arcturus Bioscience, Mountain View, CA). Bovine ovarian tissue total RNA was used as the reference. Total RNA samples were amplified using an Ovation® Pico WTA System (NuGEN Technologies, San Carlos, CA). The bovine 16 846-member microarrays spotted with 70-mer oligonucleotides were purchased from the Bovine Genomics Laboratory, University of Missouri. Amplified cDNA samples were labeled with Alexa Fluor 647 and 546 dyes (Molecular Probes, Eugene, OR), respectively. Combined, labeled samples were dried and resuspended in hybridization buffer containing 50% formamide (vol/vol), 5× SSC, and 0.1% sodium dodecyl sulfate (wt/vol). After denaturation and cooling, cDNA was applied onto a microarray slide. Microarrays were hybridized overnight at 42°C. Following hybridization, the slides were washed with different stringency buffers and water. After drying by centrifugation, the arrays were scanned on a GenePix 4000B scanner (Axon Instruments, Union City, CA). GenePix Pro4.1 software was used for griding and analysis of spot intensities. Good-quality spots were analyzed using the GeneSpring 7.3 software (Agilent Technologies, Inc., CA, Santa Clara, CA). The data were normalized per spot and per array by Lowess normalization. When comparing two treatments, the Welch t-test with Benjamini and Hochberg multiple testing correction was performed to determine the differentially expressed genes between embryo groups. Microarray experiments were performed in 3 biological and 2 technical replicates for all embryo samples. Differentially expressed genes between all embryo groups were identified. The DAVID Functional Annotation Tool was used to analyze the genes that were differentially expressed. The DAVID Functional Annotation Tool determined the co-occurrence probability and provided gene-GO term enrichment analysis to highlight the most relevant GO terms associated with a given gene list. Differentially expressed Kyoto Encyclopedia of Genes and Genomes pathways are as follows: Ribosome, oxidative phosphorylation, spliceosome, and oocyte meiosis were significantly upregulated in the fresh embryos, whereas sphingolipid and purine metabolism was the upregulated in the vitrified in vitro-derived embryos. Gene expression was very similar between fresh and vitrified in vivo-derived, as opposed to in vitro-derived, embryos. This study was funded by the TUBITAK (Project no. KAMAG107G027) and startup funds to Yuksel Agca at the University of Missouri.

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196 EMBRYO BIOPSY TRANSCRIPTOMICS: A POTENTIAL TOOL TO IDENTIFY TRANSCRIPTS DIRECTLY RELATED TO THE ABILITY OF THE EMBRYO TO INDUCE PREGNANCY AFTER TRANSFER

Reproduction Fertility and Development ◽

10.1071/rdv21n1ab196 ◽

2009 ◽

Vol 21 (1) ◽

pp. 196

Author(s):

D. Tesfaye ◽

N. Ghanem ◽

F. Rings ◽

E. Tholen ◽

C. Phatsara ◽

...

Keyword(s):

Gene Expression ◽

Pregnancy Outcome ◽

Expression Profile ◽

Expression Profiles ◽

Transcript Abundance ◽

Differentially Expressed ◽

Embryo Biopsy ◽

Bovine Embryo

The incidence of pregnancy loss due to embryonic mortality in cattle is one of the major causes of reproductive failure. The early embryonic loss can be due to problems with the embryo itself, the uterine environment, or interactions between the embryo and the uterus. So, this study was conducted to investigate the gene expression profile of bovine embryo biopsies produced in vivo and in vitro that resulted in different pregnancy outcomes. For this, biopsies representing 30 to 40% of the intact in vitro and in vivo blastocysts were taken, and 60 to 70% part was allowed to re-expand prior to transfer to recipients. Based on the pregnancy outcome after transfer, biopsies (n = 10 per pool) were grouped into 3 distinct phenotypes: those that resulted in no pregnancy, those that resulted in resorption, and those that resulted in successful pregnancy and subsequent calf delivery. A bovine cDNA microarray with 2000 clones was used to analyze the gene expression profiles of 3 replicates from each embryo biopsy group. Array data analysis revealed a total of 50 and 52 genes to be differentially expressed between biopsies derived from in vivo blastocysts that resulted in no pregnancy v. calf delivery and resorption v. calf delivery, respectively. Similarly, a total of 52 and 58 transcripts were differentially expressed between biopsies derived from in vitro-produced blastocysts that resulted in no pregnancy v. calf delivery and resorption v. calf delivery, respectively. Quantitative real-time PCR has confirmed the expression profile of 6 selected candidate genes. A distinct set of genes were found to be commonly expressed between in vitro- and in vivo-derived blastocyst biopsies, which ended up with the same pregnancy outcome. Biopsies, which ended up with calf delivery, were found to be enriched with transcripts involved in nucleosome assembly (KRT8), translation (RPLPO), electron transport (COX-2), and placenta specific (PLAC8). On the other hand, transcripts regulating immune response (TNFa), response to stress (HSPD1), and cell adhesion (CD9) were up-regulated in embryos that resulted in no pregnancy or resorption. Differences in transcript abundance of some genes have been seen between biopsies derived from in vitro and in vivo blastocysts. Biopsies from in vivo-derived blastocysts and that ended up with resorption were found to be enriched with transcripts regulating calcium-binding protein (S100A10, S100A14). Transcription factor-related transcripts (CDX2, HOXB7) were up-regulated in vitro-derived blastocyst biopsies that resulted in no pregnancy. In conclusion, the results evidenced that embryos derived from either in vitro or in vivo have more similarities than differences in their transcript abundance with respect to the ability in initiating pregnancy.

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The global gene expression outline of the bovine blastocyst: reflector of environmental conditions and predictor of developmental capacity

BMC Genomics ◽

10.1186/s12864-021-07693-0 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Dessie Salilew-Wondim ◽

Dawit Tesfaye ◽

Franca Rings ◽

Eva Held-Hoelker ◽

Dennis Miskel ◽

...

Keyword(s):

Gene Expression ◽

Ribosomal Proteins ◽

Gene Clusters ◽

Differentially Expressed ◽

Eukaryotic Translation ◽

Initiation Factors ◽

Developmental Capacity ◽

Eukaryotic Translation Initiation Factors

Abstract Background Morphological evaluation of embryos has been used to screen embryos for transfer. However, the repeatability and accuracy of this method remains low. Thus, evaluation of an embryo’s gene expression signature with respect to its developmental capacity could provide new opportunities for embryo selection. Since the gene expression outline of an embryo is considered as an aggregate of its intrinsic characteristics and culture conditions, we have compared transcriptome profiles of in vivo and in vitro derived blastocysts in relation to pregnancy outcome to unravel the discrete effects of developmental competence and environmental conditions on bovine embryo gene expression outlines. To understand whether the gene expression patterns could be associated with blastocyst developmental competency, the global transcriptome profile of in vivo (CVO) and in vitro (CVT) derived competent blastocysts that resulted in pregnancy was investigated relative to that of in vivo (NVO) and in vitro (NVT) derived blastocysts which did not establish initial pregnancy, respectively while to unravel the effects of culture condition on the transcriptome profile of embryos, the transcriptional activity of the CVO group was compared to the CVT group and the NVO group was compared to the NVT ones. Results A total of 700 differentially expressed genes (DEGs) were identified between CVO and NVO blastocysts. These gene transcripts represent constitutive regions, indel variants, 3′-UTR sequence variants and novel transcript regions. The majority (82%) of these DEGs, including gene clusters like ATP synthases, eukaryotic translation initiation factors, ribosomal proteins, mitochondrial ribosomal proteins, NADH dehydrogenase and cytochrome c oxidase subunits were enriched in the CVO group. These DEGs were involved in pathways associated with glycolysis/glycogenesis, citrate acid cycle, pyruvate metabolism and oxidative phosphorylation. Similarly, a total of 218 genes were differentially expressed between CVT and NVT groups. Of these, 89%, including TPT1, PDIA6, HSP90AA1 and CALM, were downregulated in the CVT group and those DEGs were overrepresented in pathways related to protein processing, endoplasmic reticulum, spliceasome, ubiquitone mediated proteolysis and steroid biosynthesis. On the other hand, although both the CVT and CVO blastocyst groups resulted in pregnancy, a total of 937 genes were differential expressed between the two groups. Compared to CVO embryos, the CVT ones exhibited downregulation of gene clusters including ribosomal proteins, mitochondrial ribosomal protein, eukaryotic translation initiation factors, ATP synthases, NADH dehydrogenase and cytochrome c oxidases. Nonetheless, downregulation of these genes could be associated with pre and postnatal abnormalities observed after transfer of in vitro embryos. Conclusion The present study provides a detailed inventory of differentially expressed gene signatures and pathways specifically reflective of the developmental environment and future developmental capacities of bovine embryos suggesting that transcriptome activity observed in blastocysts could be indicative of further pregnancy success but also adaptation to culture environment.

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Identification of a signal transducer and activator of transcription (STAT) binding site in the mouse metallothionein-I promoter involved in interleukin-6-induced gene expression

Biochemical Journal ◽

10.1042/bj3370059 ◽

1998 ◽

Vol 337 (1) ◽

pp. 59-65 ◽

Cited By ~ 34

Author(s):

Dae Kee LEE ◽

Javier CARRASCO ◽

Juan HIDALGO ◽

Glen K. ANDREWS

Keyword(s):

Gene Expression ◽

Binding Site ◽

Time Course ◽

Proximal Promoter ◽

Type I ◽

Mobility Shift ◽

Knock Out ◽

I Gene

Mechanisms of regulation of mouse metallothionein (MT)-I gene expression in response to bacterial endotoxin-lipopolysaccharide (LPS) were examined. Northern blot analysis of hepatic MT-I mRNA in interleukin (IL)-6 or tumour necrosis factor (TNF)-receptor type I knock-out mice demonstrated that IL-6, not TNF-α, is of central importance in mediating hepatic MT-I gene expression in vivo after LPS injection. In vivo genomic footprinting of the MT-I promoter demonstrated a rapid increase, after LPS injection, in the protection of several guanine residues in the -250 to -300 bp region of the MT-I promoter. The protected bases were within sequences which resemble binding sites for the signal transducers and activators of transcription (STAT) transcription factor family. Electrophoretic mobility-shift assays using oligonucleotides from footprinted MT-I promoter regions showed that injection of LPS resulted in a rapid increase in the specific, high-affinity, in vitro binding of STAT1 and STAT3 to a binding site at -297 bp (TTCTCGTAA). Western blotting of hepatic nuclear proteins showed that the time-course for changes of total nuclear STAT1 and STAT3 after LPS injection paralleled the increased complex formation in vitro using this oligonucleotide, and binding was specifically competed for by a functional STAT-binding site from the rat α2-macroglobulin promoter. Furthermore, the MT-I promoter -297 bp STAT-binding site conferred IL-6 responsiveness in the context of a minimal promoter in transient transfection assays using HepG2 cells. This study suggests that the effects of LPS on hepatic MT-I gene expression are mediated by IL-6 and involve the activation of STAT-binding to the proximal promoter.

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Gene expression profiles of RAW264.7 macrophages stimulated with preparations of LPS differing in isolation and purity

Innate Immunity ◽

10.1177/1753425910393540 ◽

2011 ◽

Vol 18 (1) ◽

pp. 80-88 ◽

Cited By ~ 14

Author(s):

Holly R Rutledge ◽

Weiwen Jiang ◽

Jun Yang ◽

Laura A Warg ◽

David A Schwartz ◽

...

Keyword(s):

Gene Expression ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Differentially Expressed ◽

Transcriptional Networks ◽

Molecular Pathways ◽

Raw264.7 Macrophages ◽

Lps Treatment

Lipopolysaccharide is a major component of the cell wall of Gram-negative bacteria and a potent stimulator of innate immune response via TLR4. Studies on the LPS action both in vivo and in vitro have used different preparations of LPS, including ultra-pure LPS (LIST) and a less pure but less expensive form (Sigma) isolated from Escherichia coli serotype O111:B4. The difference between the effects of these compounds has not been well studied although this information is important in understanding TLR stimulation. In this study, we compared response of RAW264.7 macrophage cells treated LIST or Sigma LPS for 6 h and 24 h. Gene expression data were analyzed to identify specific genes and pathways that are in common and unique to the two LPS preparations. Seven hundred fifty-five genes were differentially expressed at 6 h in response to Sigma LPS and 973 were differentially expressed following LIST LPS treatment, with 503 in common. At 24 h, Sigma LPS induced or repressed 901 genes while 1646 genes were differentially regulated by LIST LPS treatment; 701 genes were shared by two forms of LPS. Although considerably more genes were differentially expressed in response to LIST LPS, similar molecular pathways and transcriptional networks were activated by the two LPS preparations. We also treated bone marrow-derived macrophages (BMMs) from three strains of mice with different concentrations of LIST and Sigma LPS and showed that BMMs produced more IL-6 and TNF-α in response to LIST LPS at low LPS concentrations but, at higher LPS concentrations, more cytokines were produced in response to stimulation by Sigma LPS. Together, these findings suggest that, despite activation of similar molecular pathways by LIST and Sigma LPS preparations, residual protein impurities in the Sigma LPS preparation may nevertheless influence the transcriptional profile attributed to TLR4 stimulation.

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Genome-wide transcriptional response of primary alveolar macrophages following infection with porcine reproductive and respiratory syndrome virus

Journal of General Virology ◽

10.1099/vir.0.2008/003244-0 ◽

2008 ◽

Vol 89 (10) ◽

pp. 2550-2564 ◽

Cited By ~ 87

Author(s):

Sem Genini ◽

Peter L. Delputte ◽

Roberto Malinverni ◽

Maria Cecere ◽

Alessandra Stella ◽

...

Keyword(s):

Gene Expression ◽

Alveolar Macrophages ◽

Time Course ◽

Viral Infections ◽

Interleukin 10 ◽

Innate Immune ◽

Differentially Expressed ◽

Respiratory Syndrome Virus ◽

Swine Industry

Porcine reproductive and respiratory syndrome is a major cause of economic loss for the swine industry worldwide. Porcine reproductive and respiratory syndrome virus (PRRSV) triggers weak and atypical innate immune responses, but key genes and mechanisms by which the virus interferes with the host innate immunity have not yet been elucidated. In this study, genes that control the response of the main target of PRRSV, porcine alveolar macrophages (PAMs), were profiled in vitro with a time-course experiment spanning the first round of virus replication. PAMs were obtained from six piglets and challenged with the Lelystad PRRSV strain, and gene expression was investigated using Affymetrix microarrays and real-time PCR. Of the 1409 differentially expressed transcripts identified by analysis of variance, two, five, 25, 16 and 100 differed from controls by a minimum of 1.5-fold at 1, 3, 6, 9 and 12 h post-infection (p.i.), respectively. A PRRSV infection effect was detectable between 3 and 6 h p.i., and was characterized by a consistent downregulation of gene expression, followed by the start of the host innate immune response at 9 h p.i. The expression of beta interferon 1 (IFN-β), but not of IFN-α, was strongly upregulated, whilst few genes commonly expressed in response to viral infections and/or induced by interferons were found to be differentially expressed. A predominance of anti-apoptotic transcripts (e.g. interleukin-10), a shift towards a T-helper cell type 2 response and a weak upregulation of tumour necrosis factor-α expression were observed within 12 h p.i., reinforcing the hypotheses that PRRSV has developed sophisticated mechanisms to escape the host defence.

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Time Course of Microbiologic Outcome and Gene Expression in Candida albicans during and following In Vitro and In Vivo Exposure to Fluconazole

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.4.1311-1319.2006 ◽

2006 ◽

Vol 50 (4) ◽

pp. 1311-1319 ◽

Cited By ~ 27

Author(s):

A. Lepak ◽

J. Nett ◽

L. Lincoln ◽

K. Marchillo ◽

D. Andes

Keyword(s):

Gene Expression ◽

Candida Albicans ◽

Time Course ◽

Dependent Manner ◽

Time Points ◽

In Vivo Expression ◽

The Impact ◽

The Relationship

ABSTRACT Pharmacodynamics (PD) considers the relationship between drug exposure and effect. The two factors that have been used to distinguish the PD behaviors of antimicrobials are the impact of concentration on the extent of organism killing and the duration of persistent microbiologic suppression (postantibiotic effect). The goals of these studies were (i) to examine the relationship between antimicrobial PD and gene expression and (ii) to gain insight into the mechanism of fluconazole effects persisting following exposure. Microarrays were used to estimate the transcriptional response of Candida albicans to a supra-MIC F exposure over time in vitro. Fluconazole at four times the MIC was added to a log-phase C. albicans culture, and cells were collected to determine viable growth and for microarray analyses. We identified differential expression of 18% of all genes for at least one of the time points. More genes were upregulated (n = 1,053 [16%]) than downregulated (174 [3%]). Of genes with known function that were upregulated during exposure, most were related to plasma membrane/cell wall synthesis (18%), stress responses (7%), and metabolism (6%). The categories of downregulated genes during exposure included protein synthesis (15%), DNA synthesis/repair (7%), and transport (7%) genes. The majority of genes identified at the postexposure time points were from the protein (17%) and DNA (7%) synthesis categories. In subsequent studies, three genes (CDR1, CDR2, and ERG11) were examined in greater detail (more concentration and time points) following fluconazole exposure in vitro and in vivo. Expression levels from the in vitro and in vivo studies were congruent. CDR1 and CDR2 transcripts were reduced during in vitro fluconazole exposure and during supra-MIC exposure in vivo. However, in the postexposure period, the mRNA abundance of both pumps increased. ERG11 expression increased during exposure and fell in the postexposure period. The expression of the three genes responded in a dose-dependent manner. In sum, the microarray data obtained during and following fluconazole exposure identified genes both known and unknown to be affected by this drug class. The expanded in vitro and in vivo expression data set underscores the importance of considering the time course of exposure in pharmacogenomic investigations.

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