Gene/Protein
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Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
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Target Concepts:
Gene/Protein
Disease
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Enzyme
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Query: UMLS:C0038187 (
starvation
)
24,951
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Latent tuberculosis (TB) infects one-third of the world. We present evidence for the existence of a latent state of TB in humans, cite new approaches to diagnosis and treatment, and identify several models that attempt to mimic the latent state.
Persistent infection
in mice and in vitro systems of microaerophilic and/or anaerobic growth and nutrient
starvation
have been the most productive models in yielding insights into the host and mycobacterial pathways involved in the latent state. These pathways may serve as targets for better diagnosis, treatment, and prevention of latent TB in man.
...
PMID:Latent tuberculosis: models, mechanisms, and novel prospects for eradication. 1249 Dec 32
Flaviviruses include the most prevalent and medically challenging viruses.
Persistent infection
with flaviviruses of epithelial cells and hepatocytes that do not undergo cell death is common. Here, we report that, in epithelial cells, up-regulation of autophagy following flavivirus infection markedly enhances virus replication and that one flavivirus gene, NS4A, uniquely determines the up-regulation of autophagy. Dengue-2 and Modoc (a murine flavivirus) kill primary murine macrophages but protect epithelial cells and fibroblasts against death provoked by several insults. The flavivirus-induced protection derives from the up-regulation of autophagy, as up-regulation of autophagy by
starvation
or inactivation of mammalian target of rapamycin also protects the cells against insult, whereas inhibition of autophagy via inactivation of PI3K nullifies the protection conferred by flavivirus. Inhibition of autophagy also limits replication of both Dengue-2 and Modoc virus in epithelial cells. Expression of flavivirus NS4A is sufficient to induce PI3K-dependent autophagy and to protect cells against death; expression of other viral genes, including NS2A and NS4B, fails to protect cells against several stressors. Flavivirus NS4A protein induces autophagy in epithelial cells and thus protects them from death during infection. As autophagy is vital to flavivirus replication in these cells, NS4A is therefore also identified as a critical determinant of flavivirus replication.
...
PMID:Flavivirus NS4A-induced autophagy protects cells against death and enhances virus replication. 2151 46
The interaction and communication between bacteria and their hosts modulate many aspects of animal physiology and behavior. Dauer entry as a response to chronic exposure to pathogenic bacteria in
Caenorhabditis elegans
is an example of a dramatic survival response. This response is dependent on the RNA interference (RNAi) machinery, suggesting the involvement of small RNAs (sRNAs) as effectors. Interestingly, dauer formation occurs after two generations of interaction with two unrelated moderately pathogenic bacteria. Therefore, we sought to discover the identity of
C. elegans
RNAs involved in pathogen-induced diapause. Using transcriptomics and differential expression analysis of coding and long and small noncoding RNAs, we found that
mir-243-3p
(the mature form of
mir-243
) is the only transcript continuously upregulated in animals exposed to both
Pseudomonas aeruginosa
and
Salmonella enterica
for two generations. Phenotypic analysis of mutants showed that
mir-243
is required for dauer formation under pathogenesis but not under
starvation
. Moreover, DAF-16, a master regulator of defensive responses in the animal and required for dauer formation was found to be necessary for
mir-243
expression. This work highlights the role of a small noncoding RNA in the intergenerational defensive response against pathogenic bacteria and interkingdom communication.
IMPORTANCE
Persistent infection
of the bacterivore nematode
C. elegans
with bacteria such as
P. aeruginosa
and
S. enterica
makes the worm diapause or hibernate. By doing this, the worm closes its mouth, avoiding infection. This response takes two generations to be implemented. In this work, we looked for genes expressed upon infection that could mediate the worm diapause triggered by pathogens. We identify
mir-243-3p
as the only transcript commonly upregulated when animals feed on
P. aeruginosa
and
S. enterica
for two consecutive generations. Moreover, we demonstrate that
mir-243-3p
is required for pathogen-induced dauer formation, a new function that has not been previously described for this microRNA (miRNA). We also find that the transcriptional activators DAF-16, PQM-1, and CRH-2 are necessary for the expression of
mir-243
under pathogenesis. Here we establish a relationship between a small RNA and a developmental change that ensures the survival of a percentage of the progeny.
...
PMID:Intergenerational Pathogen-Induced Diapause in Caenorhabditis elegans Is Modulated by
mir-243
. 3296 7