Catalytic metalloporphyrin protects against paraquat neurotoxicity in vivo.

OBJECTIVE: To examine the neuroprotective effects of a novel manganese porphyrin, manganese (III) meso-tetrakis (N,N'-diethylimidazolium-2-yl) porphyrin (MnTDM), in the mouse model of Parkinson's disease (PD) induced by paraquat (PQ). METHODS: Male C57BL/6 mice were subcutaneously injected with either saline or PQ at 2-day intervals for a total of 10 doses, MnTDM was subcutaneously injected with the PQ 2 h before treatment. Performance on the pole and swim test were measured 7 days after the last injection and animals were sacrificed one day later. Levels of dopamine (DA) and its metabolites in the striatum were measured by high-performance liquid chromatography with an electrochemical detector (HPLC-ECD). Thiobarbituric acid (TBA) method was used to assay the lipid peroxidation product, malondialdehyde (MDA), and the number of tyrosine hydroxylase (TH) positive neurons was estimated using immunohistochemistry. RESULTS: Pretreatment with MnTDM significantly attenuated PQ-impaired behavioral performance, depleted dopamine content in striata, increased MDA, and dopaminergic neuron loss in the substantia nigra. CONCLUSIONS: Oxidative stress plays an important role in PQ-induced neurotoxicity which can be potentially prevented by manganese porphyrin. These findings also propose a possible therapeutical strategy for neurodegenerative disorders associated with oxidative stress such as PD.

[Establishment of CPP-SOM integrated cDNA microarray technology].

OBJECTIVE: To get an insight into the molecular mechanisms of diseases development and targeted therapy at the transcriptome level and search for potential therapeutic targets. METHODS: The present researchers established a cDNA microarray platform and applied component plane presentation integrated self-organizing map (CPP-SOM) to the microarray data obtained from a differentiation model, all trans retinoic acid-induced differentiation in NB4 cells. RESULTS: The platform included 12630 unique clones, including 9436 known genes. By CPP-SOM, the researchers were able to not only well classify the regulated genes into functionally distinct categories but also depict transcriptional changes throughout the process of the development of diseases or drug treatment. CONCLUSION: The platform has proven to be steady and reliable, and the CPP-SOM could serve as an important and good tool for analysis of microarray data.

[Expression changes of genes related to calcium pathway in all-trans retinoic acid-induced differentiation of APL cells].

In order to investigate the role of calcium pathway in myeloid differentiation, the expression level of genes related to calcium pathway in all-trans retinoic acid (ATRA)-induced NB4 cell differentiation was detected by cDNA microarray, some of which were further confirmed by quantitative real time RT-PCR. At the same time, the expressions of these genes in NB4-R1 cells treated with ATRA and 8-CPT-cAM P alone or in combination, and in differentiation of primary cells from ATRA-induced newly diagnosed APL patients were detected by real time RT-PCR. The results showed that during differentiation of ATRA-induced NB4 cells, the expressions of genes related to calcium concentration had changed, the expression of downstream effectors in calcium pathway was up-regulated and confirmed by real time RT-PCR assay. The expression of genes related to calcium concentration did not change significantly when NB4-R1 cells were treated by ATRA or 8-CPT-cAMP alone, but expression changes of those genes were similar to the changes in ATRA-induced NB4 cell differentiation when NB4-R1 cells were treated by ATRA combined with 8-CPT-cAMP. In addition, the expression changes of those genes in ATRA-induced primary cells of patients with APL were also similar to changes in ATRA-induced NB4 cell differentiation. It is concluded that calcium pathway may be involved in ATRA-induced differentiation in APL cell.

[Expression level changes of inhibitor of differentiation 1 during ATRA-induced acute promyelocytic leukemia cells differentiation].

OBJECTIVE: To study the role of inhibitor of differentiation 1 (ID1) in ATRA-induced acute promyelocytic leukemia (APL) cells differentiation. METHODS: The expression of ID1 was detected by cDNA microarray, cycloheximide inhibition test, real-time RT-PCR and western blot. RESULTS: The expression of ID1 gene was up-regulated in ATRA-induced NB4 cells and APL cells from two patients and was independent on other proteins synthesis. ID1 expression level reached the peak at 2 h in NB4 cells induced by ATRA, its relative expression level was (359.4 +/- 48.7)-fold greater than control. ID1 expression level reached the peak at 2 h in bone marrow cells from APL patents treated with ATRA, and its level detected 3 times in one of the patient was (311.1 +/- 48.7) fold of control. The expression of ID1 protein was not up-regulated in ATRA resistant NB4-R2 cells after ATRA treatment. CONCLUSION: ID1 may be involved in ATRA-induced granulocytic differentiation as an ATRA-targeted gene.

Systems analysis of transcriptome and proteome in retinoic acid/arsenic trioxide-induced cell differentiation/apoptosis of promyelocytic leukemia.

Understanding the complexity and dynamics of cancer cells in response to effective therapy requires hypothesis-driven, quantitative, and high-throughput measurement of genes and proteins at both spatial and temporal levels. This study was designed to gain insights into molecular networks underlying the clinical synergy between retinoic acid (RA) and arsenic trioxide (ATO) in acute promyelocytic leukemia (APL), which results in a high-quality disease-free survival in most patients after consolidation with conventional chemotherapy. We have applied an approach integrating cDNA microarray, 2D gel electrophoresis with MS, and methods of computational biology to study the effects on APL cell line NB4 treated with RA, ATO, and the combination of the two agents and collected in a time series. Numerous features were revealed that indicated the coordinated regulation of molecular networks from various aspects of granulocytic differentiation and apoptosis at the transcriptome and proteome levels. These features include an array of transcription factors and cofactors, activation of calcium signaling, stimulation of the IFN pathway, activation of the proteasome system, degradation of the PML-RARalpha oncoprotein, restoration of the nuclear body, cell-cycle arrest, and gain of apoptotic potential. Hence, this investigation has provided not only a detailed understanding of the combined therapeutic effects of RA/ATO in APL but also a road map to approach hematopoietic malignancies at the systems level.