Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038002 (splenomegaly)
 9,873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The global health impact of malaria is enormous, with an estimated 300-500 million clinical cases and 1 million annual deaths. In humans, initial susceptibility to infection with Plasmodium species, disease severity and ultimate outcome of malaria (self-healing or lethal) are under complex genetic control. Alleles associated with sickle cell anemia, beta-thalassemia and deficiency in glucose-6-phosphate dehydrogenase have a protective effect against malaria and may have been retained by positive selection in areas of endemic malaria. Likewise, genetic variations in erythrocyte antigens and levels of host cytokines affect type and severity of disease. A mouse model of infection with Plasmodium chabaudi was used to study the genetic component of malaria susceptibility. Segregation analyses in informative F2 crosses derived from resistant C57BL/6J and susceptible A/J, C3H and SJL strains using extent of blood stage replication of the parasite and survival as traits mapped three P. chabaudi resistance (Char) loci on chromosomes 9 (Char1), 8 (Char2) and 17 (Char3, MHC-linked). Recombinant congenic strains AcB55 and AcB61 are unusually resistant to malaria despite carrying susceptibility alleles at Char1 and Char2. Malaria resistance in AcB55 and AcB61 is associated with splenomegaly and constitutive reticulocytosis, is inherited in an autosomal recessive fashion and is controlled by a locus on chromosome 3 (Char4). Sequencing of candidate genes from the Char4 region identified a loss-of-function mutation (269T-->A, resulting in the amino acid substitution I90N) in the pyruvate kinase gene (Pklr) that underlies the malaria resistance in AcB55 and AcB61. These results suggest that pyruvate kinase deficiency may similarly protect humans against malaria.
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PMID:Pyruvate kinase deficiency in mice protects against malaria. 1459 40

The recombinant congenic mouse strains AcB55 and AcB61 are extremely resistant to malaria (Plasmodium chabaudi AS) despite the presence of susceptibility alleles at the known Char1/Char2 resistance loci. Resistance in AcB55 and AcB61 is controlled by a locus on chromosome 3 (Char4) shown to be allelic with or tightly linked to a loss-of-function mutation in pyruvate kinase (Pklr). AcB55 and AcB61 show important splenomegaly prior to infection caused by the expansion of the red pulp, and display histological signs of extramedullary erythropoiesis in the liver. Examination of splenic cell populations by flow cytometry demonstrates elevated numbers of TER119-positive erythroid precursor cells (>30% of total spleen cells), while RNA expression studies show elevated expression of erythrocyte-specific transcripts such as globin, transferrin receptor, and Nramp2/Slc11a2 in the spleen of both strains. Hematological profiling in both strains is consistent with the presence of anemia as evidenced by low total erythrocyte counts, decreased hemoglobin, as well as abnormally high numbers of circulating reticulocytes (15-20%). These results strongly suggest that the mutant Pklr allele (Pklr(269A)) of AcB55/61 strains causes hemolytic anemia compensated by constitutive erythropoiesis, which in turn protects the mice against P. chabaudi infection. The possible molecular basis of the Pklr protective effect is discussed and is under current investigation in these two strains.
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PMID:Phenotypic expression of pyruvate kinase deficiency and protection against malaria in a mouse model. 1502 38

Significant hyperbilirubinaemia, anemia, and splenomegaly are common features in patients with severe haemolysis due to pyruvate kinase (PK) deficiency. Until now, severe neonatal PK deficiency has not been associated with fatal liver disease at this age. We present two neonatal cases of severe PK deficiency complicated with progressive fatal liver disease. The patients presented with severe haemolysis, progressive cholestasis, and hepatosplenomegaly, and both patients ultimately developed liver failure at a very young age. Despite extensive investigations, no specific explanation for liver disease and failure was found. We suggest that the PK deficiency itself directly led to liver dysfunction.
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PMID:Pyruvate kinase deficiency associated with severe liver dysfunction in the newborn. 1765 6

Therapy based on targeted inhibition of BCR-ABL tyrosine kinase has greatly improved the prognosis for patients with Philadelphia chromosome (Ph)-positive leukemia and tyrosine kinase inhibitors (TKI) have become standard therapy. However, some patients acquire resistance to TKI that is frequently associated with point mutations in BCR-ABL. We previously reported that a medium-chain fatty-acid derivative AIC-47 induced transcriptional suppression of BCR-ABL and perturbation of the Warburg effect, leading to growth inhibition in Ph-positive leukemia cells. Herein, we showed that AIC-47 had anti-leukemic effects in either wild type (WT)- or mutated-BCR-ABL-harboring cells. AIC-47 suppressed transcription of BCR-ABL gene regardless of the mutation through downregulation of transcriptional activator, c-Myc. Reprogramming of the metabolic pathway has been reported to be associated with resistance to anti-cancer drugs; however, we found that a point mutation of BCR-ABL was independent of the profile of pyruvate kinase muscle (PKM) isoform expression. Even in T315I-mutated cells, AIC-47 induced switching of the expression profile of PKM isoforms from PKM2 to PKM1, suggesting that AIC-47 disrupted the Warburg effect. In a leukemic mouse model, AIC-47 greatly suppressed the increase in BCR-ABL mRNA level and improved hepatosplenomegaly regardless of the BCR-ABL mutation. Notably, the improvement of splenomegaly by AIC-47 was remarkable and might be equal to or greater than that of TKI. These findings suggest that AIC-47 might be a promising agent for overcoming the resistance of Ph-positive leukemia to therapy.
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PMID:Potent antiproliferative effect of fatty-acid derivative AIC-47 on leukemic mice harboring BCR-ABL mutation. 3054 79


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