Clinically conserved genomic subtypes of gastric adenocarcinoma.

Gastric adenocarcinoma (GAC) is a lethal disease characterized by genomic and clinical heterogeneity. By integrating 8 previously established genomic signatures for GAC subtypes, we identified 6 clinically and molecularly distinct genomic consensus subtypes (CGSs). CGS1 have the poorest prognosis, very high stem cell characteristics, and high IGF1 expression, but low genomic alterations. CGS2 is enriched with canonical epithelial gene expression. CGS3 and CGS4 have high copy number alterations and low immune reactivity. However, CGS3 and CGS4 differ in that CGS3 has high HER2 activation, while CGS4 has high SALL4 and KRAS activation. CGS5 has the high mutation burden and moderately high immune reactivity that are characteristic of microsatellite instable tumors. Most CGS6 tumors are positive for Epstein Barr virus and show extremely high levels of methylation and high immune reactivity. In a systematic analysis of genomic and proteomic data, we estimated the potential response rate of each consensus subtype to standard and experimental treatments such as radiation therapy, targeted therapy, and immunotherapy. Interestingly, CGS3 was significantly associated with a benefit from chemoradiation therapy owing to its high basal level of ferroptosis. In addition, we also identified potential therapeutic targets for each consensus subtype. Thus, the consensus subtypes produced a robust classification and provide for additional characterizations for subtype-based customized interventions.

Transient activation of AMPK preceding left ventricular pressure overload reduces adverse remodeling and preserves left ventricular function.

Coordinated changes in signaling pathways and gene expression in hearts subjected to prolonged stress maintain cardiac function. Loss of steroid receptor coactivator-2 (SRC-2) results in a reversal to the fetal gene program and disrupts the response to pressure overload, accompanied by prominent effects on metabolism and growth signaling, including increased AMPK activation. We proposed that early metabolic stress driven by AMPK activation induces contractile dysfunction in mice lacking SRC-2. We used 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) to activate AMPK transiently before transverse aortic constriction (TAC) in wild-type and cardiomyocyte-specific SRC-2 knockout (CKO) animals. In contrast to AMPK activities during stress, in unstressed hearts, AICAR induced a mild activation of Akt signaling, and, in SRC-2-CKO mice, partially relieved an NAD+ deficiency and increased antioxidant signaling. These molecular changes translated to a mild hypertrophic response to TAC with decreased maladaptive remodeling, including markedly decreased fibrosis. Additionally, preactivation of AMPK in SRC-2-CKO mice was accompanied by a dramatic improvement in cardiac function compared with saline-treated SRC-2-CKO mice. Our results show that altered molecular signaling before stress onset has extended effects on sustained cardiac stress responses, and prestress modulation of transient growth and metabolism pathways may control those effects.-Nam, D. H., Kim, E., Benham, A., Park, H.-K., Soibam, B., Taffet, G. E., Kaelber, J. T., Suh, J. H., Taegtmeyer, H., Entman, M. L., Reineke, E. L. Transient activation of AMPK preceding left ventricular pressure overload reduces adverse remodeling and preserves left ventricular function.

Evaluation of a rapid diagnostic test specific for Plasmodium vivax.

Plasmodium vivax is the only human malaria indigenous to the Republic of Korea (ROK). A rapid and sensitive diagnostic test (RDT) that detects P. vivax is appropriate for evaluating suspected malaria patients with no travel history abroad. The RDTs, SD Malaria Antigen P.v (SD diagnostic, Kyonggi, ROK) specific for P. vivax and the well documented OptiMAL (DiaMed, Cressier, Switzerland) were compared among 282 volunteers for specificity and sensitivity of P. vivax and Plasmodium falciparum malaria infections against Giemsa-stained blood smears read by an experienced microscopist. A total of 137 volunteers were diagnosed with P. vivax, 45 cases (returned travellers from overseas) were diagnosed with P. falciparum and 100 healthy volunteers were diagnosed as negative for malaria. Correspondingly, the SD Malaria Antigen P.v test identified P. vivax infections in 128/137 malaria patients (93.4%) and 0/100 (0%) healthy volunteers. Three patients identified with P. falciparum also were interpreted as P. vivax by the SD Malaria Antigen P.v test; however, these patients were later confirmed as mixed infections of P. vivax and P. falciparum by polymerase chain reaction. OptiMAL interpreted the three mixed infections only as P. falciparum and detected 130/137 (94.9%) patients with P. vivax. The sensitivity of the SD Malaria Antigen P.v test decreased from 100% (>5000 parasite/microl) to 81.3% (1-100 parasites/microl) as parasitaemia levels declined. For the regions where P. vivax is the primary malaria parasite, the SD P. vivax-specific rapid diagnostic test may be useful for screening suspected malaria patients when sufficient material and human resources (e.g. trained microscopists) are unavailable for malaria diagnosis.

Gamma-irradiation enhances RECK protein levels in Panc-1 pancreatic cancer cells.

Radiotherapy is an important treatment for many malignant tumors, but there are recent reports that radiation may increase the malignancy of cancer cells by stimulating expression of type IV collagenases. In this study, we examined changes in matrix metalloproteinase (MMP) inhibitors, such as the tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2 and RECK, in response to irradiation in Panc-1 pancreatic cancer cells. Irradiation increased RECK protein levels but not mRNA levels, whereas no significant changes were found in TIMP-1 and TIMP-2. The enhanced RECK protein levels were associated with an increase in MMP inhibitory activity. However, irradiation slightly but reproducibly increased the invasiveness of the Panc-1 cells. Like irradiation, treatment of Panc-1 cells with transforming growth factor (TGF)-Beta1 led to a 2-fold increase in RECK protein levels. Transient transfection with Smad3 also increased RECK protein levels, but transfection with Smad7 markedly reduced them. Stable expression of Smad7 and treatment with SB431542, an inhibitor of TGF-Beta receptor I kinase, abolished TGF-Beta1- and radiation-mediated effects on RECK. Furthermore, irradiation increased levels of phosphorylated Smad3. We conclude that radiation post-transciptionally enhances RECK protein levels in Panc-1 cells, at least in part, via TGF-Beta signaling, and that irradiation increases Panc-1 invasiveness via a mechanism that may not be linked to MMP-2 activity.

Alteration of platelet counts and lipid profiles after treatment of acute Plasmodium vivax.

During malaria infections, thrombocytopenia and low cholesterol levels are frequently observed changes. We compared these changes in patients admitted with fevers and infected with Plasmodium vivax, patients admitted with fevers with respiratory/urinary infections and afebrile normal (control) non-infected volunteers. Changes in the platelet count and lipid parameters are reported for malaria patients after treatment with hydroxychloroquine and primaquine for acute P. vivax malaria. Of a total 141 participants, 55 patients were diagnosed with malaria (positive blood smear) prior to treatment. Compared to the normal (n=52) and non-malaria fever groups (n=34), there was a significant decrease in five hematologic indices (white blood cell, red blood cell, hemoglobin, hematocrit and platelet) and three lipid parameters (total cholesterol, HDL-c and LDL-c) in the vivax malaria group at day 0 (pre-treatment). Following treatment, the platelet counts returned to normal limits (P<0.05) from 91,058/microL on day 0 to 246,833/microL by day 17 after treatment. However, changes in the lipid parameters of malaria patients showed a slow recovery to normal limits compared to the platelet counts. The HDL-c and LDL-c remained low for 1 month after treatment but increased at 3 and 6 months post-treatment. At 12 months after treatment, the levels of two lipid parameters had fully recovered to the normal limits. Thus, special attention should be applied when interpreting laboratory blood profiles of malaria patients, especially platelet and lipid based tests, until full recovery after treatment.

Celastrol, an NF-κB inhibitor, improves insulin resistance and attenuates renal injury in db/db mice.

The NF-κB pathway plays an important role in chronic inflammatory and autoimmune diseases. Recently, NF-κB has also been suggested as an important mechanism linking obesity, inflammation, and metabolic disorders. However, there is no current evidence regarding the mechanism of action of NF-κB inhibition in insulin resistance and diabetic nephropathy in type 2 diabetic animal models. We investigated the effects of the NF-κB inhibitor celastrol in db/db mice. The treatment with celastrol for 2 months significantly lowered fasting plasma glucose (FPG), HbA1C and homeostasis model assessment index (HOMA-IR) levels. Celastrol also exhibited significant decreases in body weight, kidney/body weight and adiposity. Celastrol reduced insulin resistance and lipid abnormalities and led to higher plasma adiponectin levels. Celastrol treatment also significantly mitigated lipid accumulation and oxidative stress in organs including the kidney, liver and adipose tissue. The treated group also exhibited significantly lower creatinine levels and urinary albumin excretion was markedly reduced. Celastrol treatment significantly lowered mesangial expansion and suppressed type IV collagen, PAI-1 and TGFß1 expressions in renal tissues. Celastrol also improved abnormal lipid metabolism, oxidative stress and proinflammatory cytokine activity in the kidney. In cultured podocytes, celastrol treatment abolished saturated fatty acid-induced proinflammatory cytokine synthesis. Taken together, celastrol treatment not only improved insulin resistance, glycemic control and oxidative stress, but also improved renal functional and structural changes through both metabolic and anti-inflammatory effects in the kidney. These results suggest that targeted therapy for NF-κB may be a useful new therapeutic approach for the management of type II diabetes and diabetic nephropathy.

Adipose-derived stem cells improve renal function in a mouse model of IgA nephropathy.

T-cell dysregulation plays an important role in the pathogenesis of immunoglobulin A nephropathy (IgAN). Adipose-derived stem cells (ASCs) have been reported to be able to prevent tissue damage through immune-modulating effects. To evaluate the effects of ASCs in high IgA ddY (HIGA) mice, ASCs were isolated from HIGA mice with different stages of IgAN before and after disease onset. ASCs were injected at a dose of 5×10(6) cells/kg body weight through the tail vein every 2 weeks for 3 months. Although the administered ASCs were rarely detected in the glomeruli, 24-h proteinuria was markedly decreased in all ASC-treated groups. Although glomerular deposition of IgA was not significantly different among groups, mesangial proliferation and glomerulosclerosis were dramatically decreased in most ASC treatment groups. In addition, levels of fibrotic and inflammatory molecules were markedly decreased by ASC treatment. Interestingly, ASC therapy significantly decreased Th1 cytokine activity in the kidney and caused a shift to Th2 responses in spleen T-cells as determined by FACS analysis. Furthermore, conditioned media from ASCs abrogated aggregated IgA-induced Th1 cytokine production in cultured HIGA mesangial cells. These results suggest that the beneficial effects of ASC treatment in IgAN occur via paracrine mechanisms that modulate the Th1/Th2 cytokine balance. ASCs are therefore a promising new therapeutic agent for the treatment of IgAN.

Genetic polymorphism in pvmdr1 and pvcrt-o genes in relation to in vitro drug susceptibility of Plasmodium vivax isolates from malaria-endemic countries.

Treatment failure of chloroquine for Plasmodium vivax infection has increased in endemic countries. However, the molecular mechanisms for resistance and in vitro susceptibility of P. vivax to chloroquine remain elusive. We investigated the prevalence of mutations in the pvmdr1 and pvcrt-o genes, and the copy number of the pvmdr1 gene in isolates from the Republic of Korea (ROK), Thailand, the Union of Myanmar (Myanmar), and Papua New Guinea (PNG). We also measured in vitro susceptibility of Korean isolates to antimalarial drugs. The pvmdr1 analysis showed that mutations at amino acid position Y976F of pvmdr1 were found in isolates from Thailand (17.9%), Myanmar (13.3%), and PNG (100%), but none from the ROK, and mutation at position F1076L was present in isolates from the ROK (100%), Thailand (60.7%), and Myanmar (46.7%). One copy of the pvmdr1 gene was observed in most isolates and double copy numbers of the gene were observed in two Thai isolates. In the exons of the pvcrt-o gene that were sequenced, a K10 insertion was present in isolates from Thailand (56.0%) and Myanmar (46.2%), and the wild type was found in all Korean isolates. The results suggest that gene polymorphisms and copy number variation was observed in isolates of P. vivax from Southeast Asian countries. In Korean isolates polymorphism as limited to the F1076L variant, and no isolates with high level of resistance were found by in vitro susceptibility determinations. Moreover, our results provide a baseline for future prospective drug studies in malaria-endemic areas.

Emergence of new alleles of the MSP-3alpha gene in Plasmodium vivax isolates from Korea.

Nucleotide sequence analysis of the Plasmodium vivax PvMSP-3alpha gene was conducted on blood from 143 malaria patients admitted to Korea University Medical Center from 1996 to 2007 in the Republic of Korea (ROK). From 1996 to 2002, the PvMSP-3alpha alleles were of two types, SKOR-67 (2.53 kb) and SKOR-69 (1.78 kb), which differed in length and amino acid sequence. Two new variants with similar size to SKOR-67 were first observed in 2002 and in 2006-2007 accounted for nearly 50% (25/51) of the sampled isolates. The new variants had the same amino acid sequence as SKOR-69 in the N-terminal region, but in Blocks I and II and in the C-terminal region, they were similar to previously reported isolates from Thailand, Papua New Guinea, India, Brazil, and Ecuador strains.

Mutations in the antifolate-resistance-associated genes dihydrofolate reductase and dihydropteroate synthase in Plasmodium vivax isolates from malaria-endemic countries.

Parasite dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) are known target enzymes of antifolate drugs used for the treatment and prophylaxis of persons with malaria. We sequenced the Plasmodium vivax dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps) genes to examine the prevalence and extent of point mutations in isolates from malaria-endemic countries. Double mutations (S58R and S117N) or quadruple mutations (F57L/I, S58R, T61M, and S117T) in the pvdhfr gene were found in isolates from Thailand (96.4%) and Myanmar (71.4%), but in only one isolate (1.0%) from Korea, where sulfadoxine-pyrimethamine has never been used. The pvdhfr point mutations correlated strongly with the pvdhps point mutations and ranged from single to triple mutations (S382A, A383G, and A553G), among isolates from Thailand, Myanmar, and Korea. These findings suggests that the prevalence of mutations in pvdhfr and pvdhps in P. vivax isolates from different malaria-endemic countries is associated with selection pressure imposed by sulfadoxine-pyrimethamine.

Evaluation of a malaria antibody enzyme immunoassay for use in blood screening.

Transfusion-transmitted malaria is rare, but it may produce severe problem in the safety of blood transfusion due to the lack of reliable procedure to evaluate donors potentially exposed to malaria. Here, we evaluated a new enzyme-linked immunosorbent assay malaria antibody test (ELISA malaria antibody test, DiaMed, Switzerland) to detect antibodies to Plasmodium vivax (the indigenous malaria) in the blood samples in the Republic of Korea (ROK). Blood samples of four groups were obtained and analyzed; 100 samples from P.vivax infected patients, 35 from recovery patients, 366 from normal healthy individuals, and 325 from domestic travelers of non-endemic areas residents to risky areas of ROK. P.vivax antibody levels by ELISA were then compared to the results from microscopic examination and polymerase chain reaction (PCR) test. As a result, the ELISA malaria antibody test had a clinical sensitivity of 53.0% and a clinical specificity of 94.0% for P.vivax. Twenty out of 325 domestic travelers (6.2%) were reactive and 28 cases (8.6%) were doubtful. Of the reactive and doubtful cases, only two were confirmed as acute malaria by both microscopy and PCR test. Thus we found that the ELISA malaria antibody test was insufficiently sensitive for blood screening of P.vivax in ROK.

Targeting of Bacillus anthracis interaction factors for human macrophages using two-dimensional gel electrophoresis.

Bacillus anthracis, a gram-positive, endospore-forming, aerobic rod-shaped bacterium, interacts with macrophages at various stages of the disease. Spore germination and the outgrowth of vegetative bacilli are crucial steps enabling the bacteria to proliferate actively and to synthesize the virulence factors leading to a massive septicemia. In this study, we performed a proteomic analysis and MALDI-TOF/MS were carried out to identify proteins using human macrophages infected with the spores of B. anthracis live-Sterne or inactivated-Sterne. We identified 21 proteins which are related to the infection of B. anthracis spores on human macrophages at the early stage events. These proteins function in processes such as cytoskeleton regulation, apoptosis, cell division, and protein degradation. Proteins such as PAK 2 revealed a relationship to apoptosis in human macrophages. These proteins play an important role in the macrophage survival and death on human macrophages with infected B. anthracis spores.

Evaluation of a malaria antibody enzyme immunoassay for use in blood screening

Transfusion-transmitted malaria is rare, but it may produce severe problem in the safety of blood transfusion due to the lack of reliable procedure to evaluate donors potentially exposed to malaria. Here, we evaluated a new enzyme-linked immunosorbent assay malaria antibody test (ELISA malaria antibody test, DiaMed, Switzerland) to detect antibodies to Plasmodium vivax (the indigenous malaria) in the blood samples in the Republic of Korea (ROK). Blood samples of four groups were obtained and analyzed; 100 samples from P.vivax infected patients, 35 from recovery patients, 366 from normal healthy individuals, and 325 from domestic travelers of non-endemic areas residents to risky areas of ROK. P.vivax antibody levels by ELISA were then compared to the results from microscopic examination and polymerase chain reaction (PCR) test. As a result, the ELISA malaria antibody test had a clinical sensitivity of 53.0 percent and a clinical specificity of 94.0 percent for P.vivax. Twenty out of 325 domestic travelers (6.2 percent) were reactive and 28 cases (8.6 percent) were doubtful. Of the reactive and doubtful cases, only two were confirmed as acute malaria by both microscopy and PCR test. Thus we found that the ELISA malaria antibody test was insufficiently sensitive for blood screening of P.vivax in ROK.