Astrocytes are the most abundant cells in the central nervous system that play roles in maintaining the blood-brain-barrier and in neural injury, including cerebral malaria, a severe complication of Plasmodium falciparum infection. Prostaglandin (PG) D2 is abundantly produced in the brain and regulates the sleep response. Moreover, PGD2 is a potential factor derived from P. falciparum within erythrocytes. Heme oxygenase-1 (HO-1) is catalyzing enzyme in heme breakdown process to release iron, carbon monoxide, and biliverdin/bilirubin, and may influence iron supply to the P. falciparum parasites. Here, we showed that treatment of a human astrocyte cell line, CCF-STTG1, with PGD2 significantly increased the expression levels of HO-1 mRNA by RT-PCR. Western blot analysis showed that PGD2 treatment increased the level of HO-1 protein, in a dose- and time-dependent manner. Thus, PGD2 may be involved in the pathogenesis of cerebral malaria by inducing HO-1 expression in malaria patients.
Animals ; Astrocytes/*enzymology ; Blotting, Western ; Cell Line ; Gene Expression Profiling ; Heme Oxygenase-1/*biosynthesis ; Humans ; Malaria, Cerebral/*pathology ; Malaria, Falciparum/*complications/*pathology ; Plasmodium falciparum/*pathogenicity ; Prostaglandins/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction

The onset, severity, and ultimate outcome of malaria infection are influenced by parasite-expressed virulence factors and individual host responses to these determinants. In both humans and mice, liver injury is involved after parasite entry, which persists until the erythrocyte stage after infection with the fatal strain Plasmodium falciparum (Pf). Hepatocyte growth factor (HGF) has strong anti-apoptotic effects in various kinds of cells, and also has diverse metabolic functions. In this work, Pf-subtilisin-like protease 2 (Pf-Sub2) 5'untranslated region (UTR) was analyzed and its transcriptional activity was estimated by luciferase expression. Fourteen TATA boxes were observed but only one Oct-1 and c-Myb were done. In addition, host HGF interaction with Pf-Sub2 was evaluated by co-transfection of HGF- and Pf-Sub2-cloned vector. Interestingly, -1,422/+12 UTR exhibited the strongest luciferase activity but -329 to +12 UTR did not exhibit luciferase activity. Moreover, as compared with the control of unexpressed HGF, the HGF protein suppressed luciferase expression driven by the 5'untranslated region of the Pf-Sub2 promoter. Taken together, it is suggested that HGF controls and interacts with the promoter region of the Pf-Sub2 gene.
*5' Untranslated Regions ; Artificial Gene Fusion ; Cell Line ; Genes, Reporter ; Hepatocyte Growth Factor/*metabolism ; Hepatocytes/parasitology ; *Host-Parasite Interactions ; Humans ; Luciferases/genetics/metabolism ; Plasmodium falciparum/*pathogenicity ; Protein Binding ; Subtilisins ; *Transcription, Genetic

OBJECTIVETo identify and clone the gene named pfstom gene which encoding the protein belonging to band 7 family and to do primary research on its function.

METHODSBased on the finished data in international public malaria database, coding sequence of pfstom cDNA was obtained by RT-PCR from FCC1/HN. Its phylogenetic profiles and the homogeny were analyzed by some softwares. After Prokaryotic expression, C terminal of Pfstom protein was expressed by Pet30a system. Recombinant Pfstom protein was used to immol/Lunize rabbit and then serum was harvested and the IgG was purified for Western blot.

RESULTSThe coding sequence of pfstom is 1,125 bp which encoding 374 amino acids with C-terminal fragment being homogenous to stomatin-like protein which belongs to band 7 family. Phylogenetic profiles analysis revealed its homogeny to stomatin. Western blot showed its stage-specific expression in trophozoite.

CONCLUSIONPfstom belongs to band-7 family. It was expressed specifically in trophozoite in erythrocyte stage of plasmodium falciparum. It was not expressed in ring stage. And it is membrane-related protein. All these results provided the foundation for further research on pfstom.

Amino Acid Sequence ; Animals ; Blood Proteins ; biosynthesis ; genetics ; immunology ; DNA, Complementary ; genetics ; Membrane Proteins ; biosynthesis ; genetics ; immunology ; Molecular Sequence Data ; Phylogeny ; Plasmodium falciparum ; chemistry ; genetics ; pathogenicity ; Protozoan Proteins ; biosynthesis ; genetics ; immunology ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics

OBJECTIVETo sequence the gene encoding glutamate rich protein (GLURP) and identify the genotypes of geographically different Plasmodium falciparum (P. f) isolates from China.

METHODSThe gene of R2 repeat region of GLURP was amplified by nested polymerase chain reaction and cloned into T-vector. The nucleotide sequence of GLURP gene was determined by automatic sequencer (Dideoxy termination method) and analyzed by DNA Star software.

RESULTSAt least 7 different GLURP genotypes ranging from 600 bp to 1,500 bp were found in Yunnan and Hainan provinces. R2 region of GLURP gene consisted of several repeat units. Each repeat unit was composed of 19-20 residues which were shown to be highly conserved. GLURP gene was also size polymorphic due to differences in the number of repeat units, whereas the repeat sequence was conserved. Sequence analysis showed that DNA sequences and deduced amino acid sequences were highly homologous among the geographically dispersed isolates or various isolates from the same geographical region. No obvious differences were found in the GLURP gene sequences among geographically different isolates.

CONCLUSIONGLURP gene is highly structure conserved and size polymorphic, and so is useful in searching for malaria vaccine candidate antigen and developing a genotyping method for malaria research.

Amino Acid Sequence ; Animals ; China ; epidemiology ; DNA, Bacterial ; genetics ; Genotype ; Geography ; Malaria ; epidemiology ; genetics ; Malaria Vaccines ; Molecular Sequence Data ; Plasmodium falciparum ; genetics ; isolation & purification ; pathogenicity ; Polymorphism, Genetic ; Protozoan Proteins ; genetics ; Sequence Analysis, DNA