Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Identification of genes regulated by L-lactate and by DL-lactate in Lactobacillus plantarum

ABSTRACT: L. plantarum is known to possess an L-lactate inducible lactate racemase activity (Goffin et al. 2005. J. Bacteriol. 187:6750). In the present study, microarrays were used in order to identify all genes that are up-regulated by L-lactate, but not by a racemic mixture of D- and L-lactate. A mutant of L. plantarum NCIMB8826 deficient for NAD-dependent L-lactate activity (TF101; Ferain et al. 1994. 176:596), and thus producing no L-lactate, was grown in MRS medium at 28Â°C until mid-exponential phase (OD600nm 0.75). The culture was then divided into 3 sub-cultures. Optically pure sodium L-lactate (200 mM) was added to the first sub-culture (TF101 + L-lac 200 mM). An equimolar mixture of sodium D- and L-lactate (100 mM each) was added to the second sub-culture (TF101 + L/D-lac 200 mM). The third sub-culture was not treated (TF101; reference sample). The three sub-cultures were further incubated at 28Â°C for 1h30 (a time known to be sufficient for induction of lactate racemase activity by L-lactate). Cells were harvested by centrifugation. Microarray data were used ot identify genes that are specifically induced by L-lactate (comparison of TF101 with TF101 + L-lac 200 mM), but not by DL-lactate (comparison of TF101 with T101 + L/D-lac 200 mM). There are no biological replicates.

ORGANISM(S): Lactobacillus plantarum

SUBMITTER: Michiel Wels

PROVIDER: E-GEOD-43518 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:Lactic acidosis and hypoxia are two prominent tumor microenvironmental stresses that are both known to exert important influences on gene expression and phenotypes of cancer cells. But very little is known about the cross-talk and interaction between these two stresses. We performed gene expression analysis of MCF7 cells exposed to lactic acidosis, hypoxia and combined lactic acidosis and hypoxia. We found the hypoxia response elicited under hypoxia was mostly abolished upon simultaneous exposure to lactic acidosis. The repression effects are due to loss of HIF-1Î± protein synthesis under lactic acidosis. In addition, we showed lactic acidosis strongly synergizes with hypoxia to activate the unfold protein response (UPR) and inflammation response which are highly similar to amino acid deprivation responses (AAR). The statistical factor analysis of hypoxia and lactic acidosis responses indicated that ATF4 locus, an important activator in the UPR/AAR pathway, is amplified in subsets of breast tumors and cancer cell lines. Varying ATF4 levels dramatically affect the ability to survive the post-stress recovery from hypoxia and lactic acidosis and may suggest its selection of ATF4 amplification in human cancers. These data suggest that lactic acidosis interacts with hypoxia by both inhibiting the canonical hypoxia response and while activating the UPR and inflammation response. Gain of ATF4 locus may offer survival advantages to allow successful adaptation to frequent fluctuations of oxygen and acidity in tumor microenvironment. Collectively, our studies have provided linkage between the short-term transcriptional responses to the long term selection of the DNA copy number alterations (CNAs) under tumor microenvironmental stresses. RNAs from MCF7 cells exposed to control condition (ambient air ~21% O2, no lactate and neutral pH), lactic acidosis (ambient air, 10 mM Lactate and pH 6.7), hypoxia (1% pO2, no lactate and neutral pH) and the combined lactic acidosis and hypoxia (1% pO2, 10 mM Lactate and pH 6.7) condition for 24 hours were extracted by miRVana kits (Ambion) and hybridized to Affymetrix Human genome 133A 2.0 arrays with standard protocol.

Dataset Information

Identification of genes regulated by L-lactate and by DL-lactate in Lactobacillus plantarum

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure