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Intraneuronal inclusions of alpha-synuclein (α-synuclein, α-syn) are commonly found in the brain of patients with Parkinson's disease (PD). The pathogenesis of the abundant α-syn protein in the blood has been extensively studied to understand its properties better. In recent years, peptidome analysis has received increasing attention. In this study, we identified and analyzed serum peptides from wild-type (WT) and the (Thy-1)-h[A30P] alpha-synuclein transgenic mice (SNCA-A30P mice) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). One thousand eight hundred fifty-six peptides from 771 proteins were analyzed. Among them, 151 peptides from 107 proteins were significantly differentially expressed. The glycoprotein VI platelet pathway (GP6) was the pathway's most significant differentially expressed signaling pathway. Cleavage sites of the differentially expressed peptides may reflect protease distribution and activity. We selected the most significantly differentially expressed peptide, VGGDPI, and found that it contained cathepsin K (Ctsk) and trypsin-1 cleavage sites, suggesting that Ctsk and trypsin-1 may be key peptidases in PD. α-syn is a protein associated with the pathogenesis of PD. mutations in several genes, including SNCA, which encodes α-syn, are associated with the development of PD. Bioinformatics analysis of the physiological pathways related to SNCA genes and apoptosis genes found the five most markedly up-regulated proteins: formin homology 2 domain-containing 1 (FHOD1), insulin receptor substrate 1(IRS1), TRPM8 channel-associated factor 1 (TCAF1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and interleukin-16 (IL-16). Therefore, the differentially expressed peptides in the five precursor protein domains may be potential bioactive peptides associated with α-syn and apoptosis. This study provides a validated peptidomics profile of SNCA-A30P mice and identifies potentially bioactive peptides linked to α-syn and apoptosis.

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BACKGROUND: BCL11A encodes a C2H2 type zinc-finger protein. During normal haematopoietic cell differentiation BCL11A expression is down-regulated. Data in mice suggest up-regulation of BCL11A is involved in the pathogenesis of myeloid leukaemias. BCL11A expression in persons with acute myeloid leukaemia (AML) is not systematically studied. OBJECTIVE: Interrogate associations between BCL11A expression at diagnosis and clinical and laboratory valuables and outcomes in newly-diagnosed persons with AML. METHODS: We determined BCL11A mRNA levels in bone marrow and blood mononuclear cells in 292 consecutive newly-diagnosed subjects with AML by reverse transcript and real-time polymerase chain reaction. Data were compared to mRNA levels in bone marrow cells of normals. RESULTS: Subjects with BCL11A transcript levels at diagnosis exceeding the median value of 2.434 (±3.423 SD; 25th-75th inter-quartile range, 1.33-4.29) had higher WBC levels, a greater proportion of bone marrow myeloblasts, were more likely to be FAB M0 subtype, less likely to be FAB M3 subtype, more likely to be in the intermediate cytogenetic risk cohort, less likely to have a complex karyotype and more likely to have DNMT3A(R882) and FLT3-ITD mutations than subjects with transcript levels below the median value. In 89 subjects receiving conventional induction chemotherapy the complete remission rate was 54% (95% confidence interval [CI]; 33, 75%) in the lower BCL11A cohort and 65% (45, 85%; P=0.26) in the higher BCL11A cohort. 3 year survival was 33% (2, 65%) in the lower BCL11A cohort and 15% (0, 39%; P=0.35) in the high BCL11A cohort. CONCLUSION: BCL11A transcript levels at diagnosis was significantly associated with several clinical and laboratory variables. There were also non-significant associations with complete remission rate and survival. These data suggest a possible role for BCL11A expression in AML biology.

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Ecotropic viral integration site-1 (EVI1) proto-oncogene expression in patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) requires further investigation. Here, EVI1 expression levels were measured in 216 Chinese patients with AML and 67 with ALL via quantitative real-time polymerase chain reaction. We found that EVI1 expressed at a high level (H-EVI1) was present in 11.1% of patients with AML versus 20.9% with ALL. Low levels of EVI1 expression occurred in 23.1% with AML versus 43.3% with ALL. This suggested that alteration of EVI1 expression was more profound in ALL than in AML. H-EVI1 was significantly enriched in 30-60-year-old patients. French-American-British (FAB) M3 subtype was significantly correlated with H-EVI1. Interestingly, we found that EVI1 expression was negatively associated with presence of the Philadelphia chromosome (Ph+) and MLL rearrangements in AML. However, Ph+, but not MLL rearrangements, was inversely correlated with EVI1 expression in B-ALL. These results for the first time suggest a mutually exclusive relationship between EVI1 expression and Ph+ karyotype.

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The mechanisms underlying acute myeloid leukemia (AML) treatment failure are not clear. Here, we established a mouse model of AML by syngeneic transplantation of BXH-2 derived myeloid leukemic cells and developed an efficacious Ara-C-based regimen for treatment of these mice. We proved that leukemic cell load was correlated with survival. We also demonstrated that the susceptibility of leukemia cells to Ara-C could significantly affect the survival. To examine the molecular alterations in cells with different sensitivity, genome-wide expression of the leukemic cells was profiled, revealing that overall 366 and 212 genes became upregulated or downregulated, respectively, in the resistant cells. Many of these genes are involved in the regulation of cell cycle, cellular proliferation, and apoptosis. Some of them were further validated by quantitative PCR. Interestingly, the Ara-C resistant cells retained the sensitivity to ABT-737, an inhibitor of anti-apoptosis proteins, and treatment with ABT-737 prolonged the life span of mice engrafted with resistant cells. These results suggest that leukemic load and intrinsic cellular resistance can affect the outcome of AML treated with Ara-C. Incorporation of apoptosis inhibitors, such as ABT-737, into traditional cytotoxic regimens merits consideration for the treatment of AML in a subset of patients with resistance to Ara-C. This work provided direct in vivo evidence that leukemic load and intrinsic cellular resistance can affect the outcome of AML treated with Ara-C, suggesting that incorporation of apoptosis inhibitors into traditional cytotoxic regimens merits consideration for the treatment of AML in a subset of patients with resistance to Ara-C.

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The difficulty in manipulation of leukemia cells has long hindered the dissection of leukemia pathogenesis. We have introduced a non-genetic approach of marking blood cells, using quantum dots. We compared quantum dots complexed with different vehicles, including a peptide Tat, cationic polymer Turbofect and liposome. Quantum dots-Tat showed the highest efficiency of marking hematopoietic cells among the three vehicles. Quantum dots-Tat could also label a panel of leukemia cell lines at varied efficiencies. More uniform intracellular distributions of quantum dots in mouse bone marrow and leukemia cells were obtained with quantum dots-Tat, compared with the granule-like formation obtained with quantum dots-liposome. Our results suggest that quantum dots have provided a photostable and non-genetic approach that labels normal and malignant hematopoietic cells, in a cell type-, vehicle-, and quantum dot concentration-dependent manner. We expect for potential applications of quantum dots as an easy and fast marking tool assisting investigations of various types of blood cells in the future.

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