A far-red/near-infrared fluorescence probe with large Stokes shift for monitoring butyrylcholinesterase (BChE) in living cells and in vivo.

Accurate detection of butyrylcholinesterase (BChE) activity is imperative to understand its biological function and diagnose related disease. Far-red (FR)/Near-Infrared (NIR) fluorescent probe with large Stokes shift for BChE detection is extremely important. In this study, we reported a new "off-on" FR/NIR fluorescent probe (DX-2) with large Stokes shift (110 nm). DX-2 was constructed through cyclopropionate to pull-push the optical tuable hydroxyl group of chloro-substituted dicyanoisophorone fluorophore. DX-2 (λex/λem = 555/665 nm) featured high sensitivity (LOD∼0.08 U/mL) and selectivity, good pH practicability, low toxicity and good cell membrane permeability with a bright emission triggered by BChE. Furthermore, DX-2 exhibited good optical performance to image BChE activity in living cells. More importantly, the FR/NIR probe DX-2 was successfully applied to real-time monitor BChE in live tumor-bearing mouse model. These studies suggest that probe DX-2 has potential applicable value for detecting BChE in living biological systems and diagnosing BChE-related diseases.

Dexmedetomidine improves early postoperative cognitive dysfunction in aged mice.

Postoperative cognitive dysfunction (POCD) is a frequent complication following major surgery in the elderly. However, the exact pathogenic mechanisms are still unknown. Dexmedetomidine, a selective alpha 2 adrenal receptor agonist, was revealed anesthesia and brain protective role. The present study aimed to examine whether dexmedetomdine protects against POCD induced by major surgical trauma under general anesthesia in aged mice. In the present study, cognitive function was assessed by Y-maze. Proinflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor (TNF-α), apoptosis-related factor caspase-3 and Bax were detected by real-time PCR, Western blot or immunohistochemistry. The results showed that anesthesia alone caused weak cognitive dysfunction on the first day after general anesthesia. Cognitive function in mice with splenectomy under general anesthesia was significantly exacerbated at the first and third days after surgery, and was significantly improved by dexmedetomidine administration. Splenectomy increased the expression of IL-1ß, TNF-α, Bax and caspase-3 in hippocampus. These changes were significantly inversed by dexmedetomidine. These results suggest that hippocampal inflammatory response and neuronal apoptosis may contribute to POCD, and selective alpha 2 adrenal receptor excitation play a protective role.

[Correlation between reversing effect of cepharanthine hydrochloride on multidrug resistance and P-glycoprotein expression and function of K562/ADR cells].

In this study, cepharanthine hydrochloride (CH) was tested for its potential ability to modulate the expression and function of P-glycoprotein (P-gp) in the multidrug-resistant human chronic myelogenous leukemia cell line K562/ADR. Cytotoxicity of adriamycin (ADR) alone or in combination with CH or verapamil (VER) in K562 and K562/ADR cells was determined by MTT assay. Based on flow cytometric technology, the effect of CH or VER on the uptake and efflux of rhodamine123 (Rho123) and the accumulation of ADR in these cells was detected by measuring Rho123 or ADR-associated mean fluorescence intensity (MFI). The effects of CH and VER on P-glycoprotein (P-gp) expression in K562 and K562/ADR cells were also measured using a flow cytometry with PE-conjugated P-glycoprotein antibody. The results show that CH significantly enhanced the sensitivity of K562/ADR cells to ADR, 4 micromol x L(-1) of CH enhanced the sensitivity of K562/ADR cells to ADR by 7.43 folds, the reversal activity was 3.19 times higher than that of verapamil. However, CH had no effect on drug-sensitive K562 cells (P < 0.05). CH increased Rho123 and ADR accumulation in a concentration-dependent manner (2-8 micromol x L(-1)) and inhibited the efflux of Rho123 from these cells, but did not affect the accumulation and efflux of Rho123 from the wild-type drug-sensitive K562 cells. The inhibition effect of CH on P-gp expression in K562/ADR cells is in a time- and concentration-dependent manner. The reversal activity of CH is possibility related to inhibition of P-gp function and expression, which lead to an increased intracellular accumulation of anticancer drugs.

In vitro activity of cepharanthine hydrochloride against clinical wild-type and lamivudine-resistant hepatitis B virus isolates.

Hepatitis B virus (HBV) infection causes major public health problems worldwide. The clinical limitation of current antiviral drugs for HBV, such as lamivudine, is the emergence of drug-resistant viral strains during prolonged antiviral therapy. Cepharanthine hydrochloride (CH), a natural alkaloid-derived compound, has been reported to possess potent activity against various viruses. The present study was performed to evaluate the in vitro activity of CH against clinical wild-type and lamivudine-resistant HBV isolates in transiently transfected cells. HBV DNA was extracted from serum samples collected both before lamivudine therapy and at the time of viral breakthrough and was amplified by polymerase chain reaction (PCR). The amplicons were cloned into a novel expression vector, pHY106, which can initiate the intracellular HBV replication cycle after cell transfection. Following transfection of the cloned amplicon into HepG2 cells, a drug susceptibility assay was performed. The level of viral antigen, HBeAg, was determined by enzyme-linked immunosorbent assay (ELISA). Quantitative real-time PCR (Q-PCR) was used for determining the amount of intracellular HBV DNA. Heat stress cognate 70 (Hsc70), a host protein required for HBV replication, was also analyzed by reverse transcription PCR (RT-PCR) to explore the possible antiviral mechanism of CH. The results showed that CH inhibited replication and HBeAg production by either wild-type or lamivudine-resistant HBV clinical isolates in a dose-dependent manner. The Hsc70 mRNA was also downregulated significantly. In conclusion, CH is active against both wild-type and lamivudine-resistant HBV clinical isolates, and its activity may be associated with its inhibition of host Hsc70.

[Establishment of stable subline of K562 cells expressing human leucocyte antigen a1101].

The aim of this study was to establish a stable subline of K562 cells expressing the HLA-A(*)1101 protein, which was expected to provide target cells for characterizing the HLA-I restrictive antigen specific cytotoxic T lymphocyte (CTL) effects against chronic myeloid leukemia (CML). The HLA-A(*)1101 protein encoding gene was amplified from peripheral blood mononuclear cell (PBMNC) of CML patient by RT-PCR; the 2A peptide linker (D-V-E-X-N-P-G-P) gene was linked to the 3'terminal of the HLA-A(*)1101 gene by recombinant PCR, then the recombinant was cloned into the pEGFP-N3 plasmid which contains an enhanced green fluorescent protein gene, and the eukaryotic recombinant expression vector containing HLA-A(*)1101-T2A-EGFP transcription box was constructed; the pEGFP-N3 vector and recombinant vector was separately electroporated into K562 cells. The expression of GFP was monitored by fluorescence microscopy, finally stably transfected sublines of K562 cells containing HLA-A(*)1101 gene, and of K562 containing pEGFP-N3 vector were obtained by G418 selection; the transcriptional or translational expression of HLA-A(*)1101 gene was detected with RT-PCR and flow cytometry respectively. The results indicated that the eukaryotic expression vector HLA-A(*)1101-T2A-EGFP plasmid was successfully constructed; after G418 selection for 2 months, two sublines of K562 cells (HLA-A(*)1101(+)K562, pEGFP-N3(+)K562) expressing GFP were constructed. The expression of HLA-A*A1101 gene could be determined in HLA-A(*)1101(+)K562 cell line by RT-PCR, while the pEGFP-N3(+)K562 cells could not express HLA-A*A1101 gene. HLA-A(*)1101 protein and GFP double positive HLA-A(*)1101(+)K562 cells were up to 88.5%, which was obviously higher than pEGFP-N3(+)K562 cells (0.698%) by flow cytometric analysis. It is concluded that a simple and effective method to select HLA-A(*)1101(+)K562 cells has been established and a subline of K562 cell expressing HLA-A(*)1101 protein on its cell membrane was successfully constructed, which provides the tool cells for further studying the specific cellular immunity against-CML.

[Methylation and expression of RUNX3 gene promoter in papillary thyroid carcinoma].

OBJECTIVE: To study the relationship between status of methylation of human runt-related transcription factor 3 (RUNX3) gene promoter in papillary thyroid carcinoma (PTC). METHODS: Methylation-specific PCR and immunohistochemical SP technique were used to detect the methylation of RUNX3 gene promoter and expression of its protein in 56 cases of PTC and their matched adjacent non-carcinous epithelium (NCE). RESULTS: In NCE, there was no methylation of RUNX3 gene promoter, while in PTC the methylation rate was 35.7%(20/56), which was related to the tumor TNM stage, pathological grade and lymph node metastasis (P < 0.05). The positive rates of RUNX3 protein expression in NCE and PTC were 100.0% and 60.7%, respectively, with a significant difference (χ(2) = 27.378, P < 0.05). In PTC, the positive rates of RUNX3 protein expression in gradeI and grade II were 70.0% and 37.5%, respectively (P < 0.05); the rates were 46.7% and 76.9% in lymph node metastasis group and no metastasis group, respectively (P < 0.05). Moreover, there was a distinct correlation between methylation of RUNX3 gene promoter and expression of its protein (χ(2) = 21.62, P < 0.01). CONCLUSIONS: Methylation of promoter might be one of the important factors of inactivation of RUNX3 gene, and might play an important role in carcinogenesis and progression of PTC.

[Correlation of mRNA and protein expressions of Runx3 gene in papillary thyroid carcinoma].

OBJECTIVE: To explore the mRNA and protein expressions of Runx3 gene in papillary thyroid carcinoma (PTC). METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the Runx3 mRNA and protein levels in 67 human PTC specimens and their matched adjacent non-cancerous epithelium (NCE). RESULTS: The relative expression value of Runx3 mRNA was 0.31 ± 0.07 in PTC versus 0.92 ± 0.08 in NCE (t = 38.251, P < 0.05). In PTC, it was correlated with the tumor pathological grade and lymph node metastasis (χ(2) = 5.511, 6.492, P < 0.05). The integral optical density value of Runx3 protein confirmed was 1012 ± 221 in PTC versus 1993 ± 199 in NCE (t = 18.413, P < 0.05). In PTC, it was correlated with the tumor TNM stage, pathological grade and lymph node metastasis (χ(2) = 5.550, 9.678, 5.070, P < 0.05). Furthermore there was a distinct correlation between the mRNA and protein expressions of Runx3 gene (χ(2) = 42.699, P < 0.05). CONCLUSION: The mRNA and protein expressions of Runx3 gene in PTC were lower than those in NCE. A lower expression of Runx3 gene may play an important role in the carcinogenesis and progression of PTC.

[Expression of Piwil2 and its relationship with tumor invasion and metastasis in papillary thyroid carcinoma].

OBJECTIVE: To study the expressions of Piwil2 protein and mRNA in papillary thyroid carcinoma (PTC) and the relationship between Piwil2 and the invasion and metastasis of PTC. METHODS: Immunohistochemistry and in situ hybridization were used to detect the expression of Piwil2 protein and mRNA in 60 cases of PTC with the matched adjacent non-cancerous epithelium (NCE). RESULTS: The positive rates of Piwil2 protein expression in PTC and NCE were 88.3% (53/60) and 10.0% (6/60) respectively, with significant difference (χ² = 73.654, P < 0.01). The positive rates of Piwil2 mRNA expression in PTC and NCE were 85.0% (51/60) and 6.7% (4/60) respectively, also with significant difference (χ(2) = 74.148, P < 0.01). Up-regulated expressions of Piwil2 protein and mRNA were related to the invasion and metastasis of PTC (P < 0.05). CONCLUSIONS: Piwil2 may play a role in the invasion and metastasis of PTC.

[Structural feature and biological function of PPP2R5C gene].

PPP2R5C is one of the members of regulatory subunits of protein phosphatase 2A (PP2A), which plays a critical role in cell proliferation, differentiation and transformation, based on its induction of dephosphorylation of P53 at various residues. Recently, it was characterized that the alteration of expression pattern of PPP2R5C is associated with cell malignant transformation, thus PPP2R5C was thought as a marker for progressive disease in B-CLL. In this article the gene structure and biological function of PPP2R5C as well as relation of PPP2R5C with genesis and development of cancer were discussed.

[Analysis of CDR3 sequence of TCR Valpha6, Valpha10 and Vbeta23 oligoclonal T cells in one APL case].

AIM: To investigate the clonality and the pattern of CDR3 sequence of TCR Valpha and Vbeta repertoire in patients with acute promyelocytic leukemia (APL). METHODS: The CDR3 of TCR Valpha 29 and Vbeta 24 subfamily genes were amplified in mononuclear cells from peripheral blood of one case with APL using RT-PCR. The positive PCR products were further labeled with fluorescent and analyzed by genescan technique for the CDR3 size, to evaluate clonality of the detectable TCR Valpha and Vbeta T cells. The products of the oligoclonal T cells were analyzed by sequencing to define the sequence of CDR3. RESULTS: Oligoclonal T cells expressed TCR Valpha6, Valpha10 or Vbeta23 genes were identified from the APL patient. The molecular characteristics of the CDR3 of Valpha and Vbeta genes rearrangement were Valpha6NJalpha17, Valpha10NJalpha35 and Vbeta23NDbeta1NJbeta2.7. The amino acid sequence of CDR3 region in TCR Valpha 6, Valpha10 and Vbeta23 subfamilies were CAMRENSAGNK, YLCAGDELLWECA or CASSSKWAGGTYEQY, respectively. These sequences were accepted by GenBank (Accession Number EU544946, EU544947 and EU647219). CONCLUSION: Three idiotype Valpha and Vbeta sequences are identified in a case with APL, which is thought that may mediate the host specific immunity response for leukemia cells in APL. It might provide data for farther research on the specific immunotherapy of APL.

[Construction and expression of idiotype TCR Valpha1-pIRES-TCR Vbeta8 eukaryotic vectors in vitro].

AIM: To construct the eukaryotic vectors with idiotype TCR Valpha1-pIRES-TCR Vbeta8 of Jurkat cell line and investigate their expression in vitro after transferred into eukaryotic cells. METHODS: TCR Valpha and Vbeta subfamilies of Jurkat cells were analyzed by using RT-PCR and genescan technique. Then the monoclonal TCR Valpha1 and Vbeta8 genes of Jurkat cells were cloned into multiple clone site (MCS) A and MCS B of the eukaryotic vector pIRES respectively. Its sequences were identified by restriction enzyme cutting and sequence analysis. The expression of TCR mRNA and idiotypic protein in transferred A549 and Molt4 cells was tested by RT-PCR, indirect immunophenotyping fluorescein dyeing and flow cytometry, respectively. RESULTS: Two recombinavot eukaryotic vectors with idiotype TCR Valpha1-pIRES-TCR Vbeta8 were developed successfully and the expression of both idiotypic TCR mRNA and protein was detected in transferred A549 and Molt4 cells. CONCLUSION: The successful construction of the two eukaryotic vectors with idiotype TCR Valpha1-pIRES-TCR Vbeta8 will provide a basic method for further study of the specific TCR gene modified T cells.

[Significant decrease of recent thymic output function in patients with severe benzene intoxication].

The aim of the present study was to investigate the level of T-cell receptor excision DNA circles (TREC) in peripheral blood mononuclear cells (PBMNC) of patients with severe benzene poison, thereby to evaluate the content of naive T cells and the recent thymic output function. Quantitative detection of TREC in DNA of PBMNCs from 16 normal individuals and 8 cases with severe benzene poison was preformed by real-time PCR using TaqMan technique. The results showed that TREC level was 6.69 +/- 4.79/1 000 PBMNCs in normal individuals, however, significant decrease was shown in patients with severe benzene poison (1.03 +/- 0.44/1 000 PBMNCs, P < 0.01). The TREC level was persistently low in period of benzene poisoning, even if peripheral blood cell counts were at normal levels. In conclusion, the recent thymic output function is remarkably decreased in patients with severe benzene intoxication, that may obviously damage the T cell immune function.