The innate immunity protein IFITM3 modulates γ-secretase in Alzheimer's disease.

Innate immunity is associated with Alzheimer's disease1, but the influence of immune activation on the production of amyloid-ß is unknown2,3. Here we identify interferon-induced transmembrane protein 3 (IFITM3) as a γ-secretase modulatory protein, and establish a mechanism by which inflammation affects the generation of amyloid-ß. Inflammatory cytokines induce the expression of IFITM3 in neurons and astrocytes, which binds to γ-secretase and upregulates its activity, thereby increasing the production of amyloid-ß. The expression of IFITM3 is increased with ageing and in mouse models that express familial Alzheimer's disease genes. Furthermore, knockout of IFITM3 reduces γ-secretase activity and the formation of amyloid plaques in a transgenic mouse model (5xFAD) of early amyloid deposition. IFITM3 protein is upregulated in tissue samples from a subset of patients with late-onset Alzheimer's disease that exhibit higher γ-secretase activity. The amount of IFITM3 in the γ-secretase complex has a strong and positive correlation with γ-secretase activity in samples from patients with late-onset Alzheimer's disease. These findings reveal a mechanism in which γ-secretase is modulated by neuroinflammation via IFITM3 and the risk of Alzheimer's disease is thereby increased.

Evidence That the "Lid" Domain of Nicastrin Is Not Essential for Regulating γ-Secretase Activity.

Understanding of the structure of the γ-secretase complex consisting of presenilin (PS), anterior pharynx-defective 1 (APH-1), nicastrin (NCT), and presenilin enhancer 2 (PEN-2) is of significant therapeutic interest for the design of γ-secretase modulators for Alzheimer disease. The structure of γ-secretase revealed by cryo-EM approaches suggested a substrate binding mechanism for NCT, a bilobar structure that involved rotation of the two lobes around a central pivot and opening of a "lid" region that facilitates substrate recruitment. To validate this proposal, we expressed NCT that lacks the lid entirely, or a variety of NCT variants that harbor mutations at highly conserved residues in the lid region inNCT-deficient cells, and then assessed their impact on γ-secretase assembly, activity, and stability. In addition, we assessed the impact of mutating a critical residue proposed to be a pivot around which the two lobes of NCT rotate. Our results show that neither the mutations on the lid tested here nor the entire lid deletion has any significant impact on γ-secretase assembly, activity, and stability, and that NCT with the mutation of the proposed pivot rescues γ-secretase activity inNCT-deficient cells in a manner indistinguishable from WT NCT. These findings indicate that the NCT lid is not an essential element necessary for γ-secretase assembly, activity, and stability, and that rotation of the two lobes appears not to be a prerequisite for substrate binding and γ-secretase function.

A synthetic antibody fragment targeting nicastrin affects assembly and trafficking of γ-secretase.

The γ-secretase complex, composed of presenilin, nicastrin (NCT), anterior pharynx-defective 1 (APH-1), and presenilin enhancer 2 (PEN-2), is assembled in a highly regulated manner and catalyzes the intramembranous proteolysis of many type I membrane proteins, including Notch and amyloid precursor protein. The Notch family of receptors plays important roles in cell fate specification during development and in adult tissues, and aberrant hyperactive Notch signaling causes some forms of cancer. γ-Secretase-mediated processing of Notch at the cell surface results in the generation of the Notch intracellular domain, which associates with several transcriptional coactivators involved in nuclear signaling events. On the other hand, γ-secretase-mediated processing of amyloid precursor protein leads to the production of amyloid ß (Aß) peptides that play an important role in the pathogenesis of Alzheimer disease. We used a phage display approach to identify synthetic antibodies that specifically target NCT and expressed them in the single-chain variable fragment (scFv) format in mammalian cells. We show that expression of a NCT-specific scFv clone, G9, in HEK293 cells decreased the production of the Notch intracellular domain but not the production of amyloid ß peptides that occurs in endosomal and recycling compartments. Biochemical studies revealed that scFvG9 impairs the maturation of NCT by associating with immature forms of NCT and, consequently, prevents its association with the other components of the γ-secretase complex, leading to degradation of these molecules. The reduced cell surface levels of mature γ-secretase complexes, in turn, compromise the intramembranous processing of Notch.

Isotopic compositions (δD, δ18O) and end-member mixing for the control interface in a complex tidal region.

Identifying the mixing processes of waters and currents in tidal reach is an important aspect of environmental management to protect freshwater resources and prevent water pollution. In this study, three field investigations conducted in a typical tidal reach in August, November and the following April focused on two isotopes (δD and δ18O) and salinity. A salinity-isotope conservative mixing model was established to differentiate water flows of the important control interface (CI) from freshwater, transition zone and saltwater end-members. Results suggested that the average δD and δ18O values during the ebb and flood tides depleted from August to November, then enriched significantly in the following April and were even higher than those in August. The δD and δ18O values in the saltwater zone enriched markedly compared with those in freshwater zone and transition zone due to the stronger evaporation occurring in the saltwater zone. Based on the revised model, the average contributions of freshwater end-member, transition zone end-member and saltwater end-member in three months were, respectively, 51.50 %, 36.93 % and 11.57 %. However, the contributions of freshwater and transition zones in April end-member were equivalent (47.45 % vs 44.31 %). Meanwhile the largest contribution of saltwater end-member was 20.56 % and occurred in August. The proportions of three end-members that contributed to CI changed with different evaporation scenarios and moisture sources of precipitation. Our research provides important information that furthers our understanding of the isotopes and their applications to environmental management in estuarine regions.

The Effects of Chinese Medicine QRD, Antibiotics, and Probiotics on Therapy and Gut Microbiota in Septic Rats.

Sepsis is a common and often treacherous medical emergency with a high mortality and long-term complications in survivors. Though antibiotic therapy can reduce death rate of sepsis significantly, it impairs gut microbiota (GM), which play imperative roles in human health. In this study, we compared the therapeutic effects of antibiotics, probiotics, and Chinese medicine QRD on the survival rates of septic model and observed the GM characteristics of experimental rats via 16S rRNA gene amplicon sequencing. The 72 h survival rates of septic rat demonstrated the significant therapeutic effects in the three groups treated with antibiotics (AT), Chinses medicine QRD (QT), and probiotics (PT), which were elevated from the survival rate of 26.67% for the sepsis control group (ST) to 100.0% for AT, 88.24% for QT, and 58.33% for PT. The original characteristics of GM identified in the sham operation controls (SC) were relatively similar to those in PT and QT; nevertheless, the AT rats were shown dramatically decreased in the GM diversity. In addition, the septic rats in AT were revealed the higher abundances of Escherichia Shigella, Proteus, Morganella, Enterococcus, and Lysinibacillus, but the lower those of Parabacteroides, Alistipes, Desulfovibrio, Bacteroides, Helicobacter, Mucispirillum, Oscillibacter, Lachnospiraceae, and Ruminiclostridium 9, when compared to the PT and QT rats. By contrast, the GM of PT and QT rats shared similar diversity and structure. Our findings indicated that QRD increased the survival rates without impairment of the GM characteristics, which provides novel insights into the role of Chinese medicine in therapy and long-term recovery of sepsis.

Imaging of Cancer γ-Secretase Activity Using an Inhibitor-Based PET Probe.

PURPOSE: Abnormal Notch signaling promotes cancer cell growth and tumor progression in various cancers. Targeting γ-secretase, a pivotal regulator in the Notch pathway, has yielded numerous γ-secretase inhibitors (GSIs) for clinical investigation in the last 2 decades. However, GSIs have demonstrated minimal success in clinical trials in part due to the lack of specific and precise tools to assess γ-secretase activity and its inhibition in vivo. EXPERIMENTAL DESIGN: We designed an imaging probe based on GSI Semagacestat structure and synthesized the radioiodine-labeled analogues [131I]- or [124I]-PN67 from corresponding trimethyl-tin precursors. Both membrane- and cell-based ligand-binding assays were performed using [131I]-PN67 to determine the binding affinity and specificity for γ-secretase in vitro. Moreover, we evaluated [124I]-PN67 by PET imaging in mammary tumor and glioblastoma mouse models. RESULTS: The probe was synthesized through iodo-destannylation using chloramine-T as an oxidant with a high labeling yield and efficiency. In vitro binding results demonstrate the high specificity of this probe and its ability for target replacement study by clinical GSIs. PET imaging studies demonstrated a significant (P < 0.05) increased in the uptake of [124I]-PN67 in tumors versus blocking or sham control groups across multiple mouse models, including 4T1 allograft, MMTV-PyMT breast cancer, and U87 glioblastoma allograft. Ex vivo biodistribution and autoradiography corroborate these results, indicating γ-secretase specific tumor accumulation of [124I]-PN67. CONCLUSIONS: [124I]-PN67 is a novel PET imaging agent that enables assessment of γ-secretase activity and target engagement of clinical GSIs.

[Study on different proportion formulas of activating blood circulation by FTIR].

Fourier transform spectroscopy (FTIR) and two-dimensional correlation spectroscopy were used to analyze different compatibility forms of sargentgloryvine stem, radix paeoniae rubra and cortex moutan in order to study the FTIR spectra of different proportion formulas. The results indicate that different proportion formulas have distinct change regularity in FTIR spectra, second derivative spectra and synchronous 2D. Key components of sargentgloryvine stem's characteristic absorption band are 1 610, 1 518 and 1 446 cm(-1) which are characteristic absorption band of aromatic material, and in the original formula, that shows stronger peak than others, suggesting that original formula can make the best of composition of drug action. In the different proportion formulas, 1 614 cm(-1) is nearer to 1 610 cm(-1), which is sargentgloryvine stem's characteristic absorption band, than to 1 706 cm(-1), illustrating that sargentgloryvine stem is more influential formula than others. According to identification and ascription of characteristic absorption band, it was initially revealed that different proportion of drug dosage can affect pharmacodynamic action of integral formula.

[Analysis and comparison of daxueteng and their extracts by FTIR].

The present study is to compare and analyze Sargentodora cuneata (oliv) Rehd. etwils herbs, the aqueous, anthraquinone extracts and residue in Jiang Xi and An Hui quickly and undamagedly by Fourier transform infrared spectroscopy(FTIR) and two-dimensional correlation spectroscopy. In the spectra of DaXueTeng, there are two strong peak areas at about 1400-1620 cm(-1) and 1000-1200 cm(-1), and it was concluded that DaXueTeng contains much glycoside and anthraquinone. Anthraquinone extracts only exhibit strong peaks of 1400-1620 cm(-1) which were stronger than that of 1000-1200 cm(-1), and this illustrated that this method was adapted to extracting anthraquinone; then aqueous only show powerful peaks of 1000-1200 cm(-1), so the authors know that the craftwork was suitable for extracting glycoside; finally, the authors also found that the residue of DaXueTeng contained much calcium oxalate. All of these illustrated that FTIR could not only analyze and identify traditional Chinese medicine (TCM) and extract components, but also discriminate contents of different extracts of TCM. The authors developed the new method to analyze and evaluate the DaXueTeng and their pharmacodynamic extracts successfully.

Brain Permeable Tafamidis Amide Analogs for Stabilizing TTR and Reducing APP Cleavage.

Tafamidis, 1, a potent transthyretin kinetic stabilizer, weakly inhibits the γ-secretase enzyme in vitro. We have synthesized four amide derivatives of 1. These compounds reduce production of the Aß peptide in N2a695 cells but do not inhibit the γ-secretase enzyme in cell-free assays. By performing fluorescence correlation spectroscopy, we have shown that TTR inhibits Aß oligomerization and that addition of tafamidis or its amide derivative does not affect TTR's ability to inhibit Aß oligomerization. The piperazine amide derivative of tafamidis (1a) efficiently penetrates and accumulates in mouse brain and undergoes proteolysis under physiological conditions in mice to produce tafamidis.

Substrate interaction inhibits γ-secretase production of amyloid-ß peptides.

Combining NMR, mass spectrometry, AlphaLISA and cell assays, we discovered a compound C1 that binds C-terminal juxtamembrane lysines at the transmembrane domain of the amyloid precursor protein (APPTM) and inhibits γ-secretase production of amyloid-ß with µM IC50. Our work suggests that targeting APPTM is a novel and viable strategy in AD drug discovery.

A Pentacyclic Triterpene from Ligustrum lucidum Targets γ-Secretase.

Amyloid-beta peptides generated by ß-secretase- and γ-secretase-mediated successive cleavage of amyloid precursor protein are believed to play a causative role in Alzheimer's disease. Thus, reducing amyloid-beta generation by modulating γ-secretase remains a promising approach for Alzheimer's disease therapeutic development. Here, we screened fruit extracts of Ligustrum lucidum Ait. (Oleaceae) and identified active fractions that increase the C-terminal fragment of amyloid precursor protein and reduce amyloid-beta production in a neuronal cell line. These fractions contain a mixture of two isomeric pentacyclic triterpene natural products, 3-O-cis- or 3-O-trans-p-coumaroyl maslinic acid (OCMA), in different ratios. We further demonstrated that trans-OCMA specifically inhibits γ-secretase and decreases amyloid-beta levels without influencing cleavage of Notch. By using photoactivatable probes targeting the subsites residing in the γ-secretase active site, we demonstrated that trans-OCMA selectively affects the S1 subsite of the active site in this protease. Treatment of Alzheimer's disease transgenic model mice with trans-OCMA or an analogous carbamate derivative of a related pentacyclic triterpene natural product, oleanolic acid, rescued the impairment of synaptic plasticity. This work indicates that the naturally occurring compound trans-OCMA and its analogues could become a promising class of small molecules for Alzheimer's disease treatment.

Beneficial effect of HHI-I on cerebral microcirculation, blood-brain barrier in rats and anti-hypoxic activity in mice.

OBJECTIVE: To investigate the effect of HHI-I (I) on the cerebral microcirculation, the blood-brain barrier permeability in rats and anti-hypoxic activity in mice. METHODS: (1) The blood microcirculation of the brain in rats was investigated by laser Doppler flowmetry with the probes laid on the cerebral pia mater or inserted into the brain parenchyma. (2) The protective action of HHI-I against the brain microcirculation disturbance induced by intravenous injection of high-molecular dextran (10%, 9 mL/kg) was observed. (3) The protective effect of HHI-I against lethal hypoxia in mice was observed with a hypoxic chamber containing 5% oxygen. (4) The disruption of the blood-brain barrier (BBB) permeability in rats was caused by phenylephrine-induced hypertension, and the effect of intravenous injection of HHI-I on the BBB permeability was determined using Evans blue as the marker. RESULTS: HHI-I could increase the blood flow of the cerebral microcirculation in rats and possess some protective effects on the brain microcirculatory disturbance. Besides, HHI-I could decrease the brain edema occurring in the process of lethal hypoxia in mice. While increasing the blood flow of brain, HHI-I could lower the BBB permeability in rats. CONCLUSION: HHI-I has several beneficial effects on the cerebral microcirculation, blood-brain barrier in rats and anti-hypoxic activity in mice.

Overexpression of CHD1L is associated with poor survival and aggressive tumor biology in esophageal carcinoma.

Esophageal carcinoma (EC) is a malignancy with high metastatic potential. Chromosomal helicase/ATPase DNA binding protein 1-like (CHD1L) gene is a newly identified oncogene located at Chr1q21, and it is amplified in many solid tumors. However, the status of CHD1L protein expression in EC and its clinical significance is uncertain. This study was designed to investigate the significance of CHD1L expression in human EC and its biological function in EC cells. The expression of CHD1L was examined by immunohistochemistry in 191 surgically resected ECs. The associations between CHD1L expression and clinical pathological parameters and the prognostic value of CHD1L were analyzed. Western blot analysis showed that CHD1L was overexpressed in EC cell lines. In addition, positive CHD1L expression was strongly related to advanced clinical stage (P<0.01), and lymph node metastasis (P<0.01) of EC. The Kaplan-Meier curve indicated that high expression of CHD1L may result in poor prognosis of EC patients (P<0.01), and multivariate analysis showed that CHD1L overexpression was an independent predictor of overall survival. Furthermore, suppression of CHD1L in EC cells increased apoptosis and decreased cell proliferation invasion ability. Our results suggest that CHD1L is a target oncogene with the potential to serve as a novel prognostic biomarker in EC pathogenesis.

Effect of Tetrandrine on LPS-induced NF-kappaB activation in isolated pancreatic acinar cells of rat.

AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-kappaB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury. METHODS: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to LPS (10 mg/L), Tet (50 micromol/L, 100 micromol/L) or normal media. At different time point (30 min, 1 h, 4 h, 10 h) after treatment with the agents, cell viability was determined by MTT, the product and nuclear translocation of subunit p65 of NF-kappaB was visualized by immunofluorescence staining and nuclear protein was extracted to perform EMSA which was used to assay the NF-kappaB binding activity. RESULTS: LPS induced cell damage directly in a time dependent manner and Tet attenuated LPS-induced cell damage (50 micromol/L, P < 0.05; 100 micromol/L, P < 0.01). NF-kappaB p65 immunofluorescence staining in cytoplasm increased and began showing its nuclear translocation within 30 min and the peak was shown at 1 h of LPS 10 mg/L treatment. NF-kappaB DNA binding activity showed the same alteration pattern as p65 immunofluorescence staining. In Tet group, the immunofluorescence staining in cytoplasm and nuclear translocation of NF-kappaB were inhibited significantly. CONCLUSION: NF-kappaB activation is an important early event that may contribute to inflammatory responses and cell injury in pancreatic acinar cells. Tet possesses the protective effect on LPS-induced acinar cell injury by inhibiting NF-kappaB activation.

[Study on protective effect of tetrandrine on lipopolysaccharide induced pancreatic acinar cell damage and its mechanism].

OBJECTIVE: To evaluate the protective effect of tetrandrine (Tet) on lipopolysaccharide (LPS)-induced pancreatic acinar cell damage and to explore its mechanism. METHODS: SD male rat's pancreatic acinar cells were isolated by collagenase digestion and they were pre-treated with Tet (50 micromol/L and 100 micromol/L), then exposed to LPS (10 mg/L) or conventional culture medium respectively. At 0, 1, 4, 10 hours after treatment with the agents, cell viability was determined by methyl thiazolyl tetrazolium (MTT), and the supernatant supernate of cells was collected for determination of the content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) and phospholipase A(2) (PLA(2)). Some cells were loaded with Fluo-3/AM, and the dynamic change in intracellular Ca(2+) ([Ca(2+)]i) in single pancreatic acinar cell was determined by laser scanning confocal microscopy. RESULTS: Tet attenuated LPS-induced cell damage (P<0.05 and P<0.01) and inhibited the elevation of cytosolic free calcium of rat pancreatic acinar cells. In the supernatant, Tet pretreatment decreased the content of MDA and the activity of PLA(2) and increased the activity of SOD (all P<0.05). CONCLUSION: Tet attenuates LPS-induced cell damage by blocking [Ca(2+)]i overload, inhibiting superoxide response, decreasing activity of pancreatic enzyme, thus it shows a protective effect on pancreatic acinar cells.

Development of Sulfonamide Photoaffinity Inhibitors for Probing Cellular γ-Secretase.

γ-Secretase is a multiprotein complex that catalyzes intramembrane proteolysis associated with Alzheimer's disease and cancer. Here, we have developed potent sulfonamide clickable photoaffinity probes that target γ-secretase in vitro and in cells by incorporating various photoreactive groups and walking the clickable alkyne handle to different positions around the molecule. We found that benzophenone is preferred over diazirine as a photoreactive group within the sulfonamide scaffold for labeling γ-secretase. Intriguingly, the placement of the alkyne at different positions has little effect on probe potency but has a significant impact on the efficiency of labeling of γ-secretase. Moreover, the optimized clickable photoprobe, 163-BP3, was utilized as a cellular probe to effectively assess the target engagement of inhibitors with γ-secretase in primary neuronal cells. In addition, biotinylated 163-BP3 probes were developed and used to capture the native γ-secretase complex in the 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonate (CHAPSO) solubilized state. Taken together, these next generation clickable and biotinylated sulfonamide probes offer new tools to study γ-secretase in biochemical and cellular systems. Finally, the data provide insights into structural features of the sulfonamide inhibitor binding site in relation to the active site and into the design of clickable photoaffinity probes.

Upregulation of human telomerase reverse transcriptase mRNA expression by in vitro transfection of hepatitis B virus X gene into human hepatocarcinoma and cholangiocarcinoma cells.

AIM: To study the changes of human telomerase reverse transcriptase (hTERT) mRNA expression in human hepatocarcinoma cell lines (HepG2) and cholangiocarcinoma cell lines (QBC939) after HBx gene transfection and to illustrate the significance of transcriptional regulation of hTERT gene by HBx gene in the carcinogenesis. METHODS: HepG2 and QBC939 cell lines were cultured and co-transfected with eukaryotic expression vector containing the HBx coding region and cloning vector containing enhanced green fluorescent protein (EGFP) coding sequence using lipid-mediated gene transduction technique. Thirty-six hours after transfection, EGFP expression in cells was used as the indicator of successful transfection. Flow cytometry was performed to determine the transfection efficiency. Cells were harvested and total RNA was extracted using TRIzol reagent. The expression of hTERT mRNA in HepG2 and QBC939 cell lines was assayed by reverse transcription-polymerase chain reaction. The expression of HBx protein in both cell lines was detected by immunocytochemical staining and Western blotting. RESULTS: Flow cytometry showed that the transfection efficiency was 46.4% in HepG2 cells and 29.6% in QBC939 cells for both HBx gene expression vector and blank vector. The expression of hTERT mRNA was meaningfully increased in HepG2 and QBC939 cell lines when transfected with HBx gene expression vector compared to those transfected with OPTI-MEM medium and blank vector. Immunocytochemical staining and Western blotting revealed HBx protein expression in HepG2 and QBC939 cells only when transfected with HBx gene. CONCLUSION: HBx gene transfection can upregulate the transcriptional expression of hTERT mRNA. The transactivation of hTERT gene by HBx gene is a newfound mechanism for pathogenesis of hepatocarcinomas and cholangiocarcinomas after HBV infection.

Overexpression of sterol carrier protein-2 mRNA in patients with cholesterol gallstones.

BACKGROUND: Hypersecretion of biliary cholesterol is believed to be one of the important causes of lithogenic bile. Sterol carrier protein-2(SCP2) participates in cholesterol trafficking and metabolism and may play a key role in cholesterol gallstone formation. This study was undertaken to investigate the expression of liver SCP2 mRNA in patients with cholesterol gallstone and those patients with non-cholesterol gallstone. METHODS: The expression of liver SCP2mRNA was studied in 36 patients with cholesterol gallstone and 30 patients with non-cholesterol gallstone by reverse transcription-polymerase chain reaction (RT-PCR). RESULT: The expression of SCP2 mRNA was increased more significantly in patients with cholesterol gallstone than in patients with non-cholesterol gallstone. CONCLUSION: The SCP2 gene was overexpressed in patients with cholesterol gallstone, indicating that SCP2 may be one of the important causes of cholesterol gallstone.

[A study on the cell differentiation induced by tanshinone IIA and its molecular mechanism in retinoic acid: resistant acute promyelocytic leukemia].

OBJECTIVE: To investigate retinoic acid-resistant acute promyelocytic leukemia (APL) cell differentiation induced by tanshinone IIA (Tan IIA) and its molecular mechanism. METHODS: NB4 cells treated with 0.5 mg/L Tan IIA was regarded as positive control. After in vitro incubation of MR-2 cells with Tan IIA at the concentration of 1.0 mg/L for 4 days, the cell differentiation was observed by growth status, cytomorphology, and nitroblue tetrazolium test. Cell cycle, membrane cluster differentiation (CD) antigens (CD(33), CD(11b)) and expression of some oncogene (c-myc, c-fos, p53 and bcl-2) were analysed by flow cytometry. RESULTS: The growth of MR-2 and NB4 cells was inhibited after Tan IIA treatment, the inhibition rate were 73.5% and 67.7% respectively (P < 0.01, P < 0.01) without significant difference. After Tan IIA treatment, MR-2 and NB4 cells were induced to undergo morphological differentiation, which exhibited small cell bulk decreased nucleus/cytoplasm proportion, rough chromatin, disappearance of nucleolus and formation of azurophil granules and anomalous nucleus. MR-2 cells could be induced to metamyelocyte while NB4 could be induced to band form. NBT reduction of MR-2 and NB4 cells treated with Tan IIA showed that positive cells accounted for (95.30 +/- 0.76)% and (93.20 +/- 1.04)% respectively; but the positive rate of either group of the treated positive cells was significantly higher than that of untreated, being (3.50 +/- 1.32)% and (2.80 +/- 0.29)% respectively (P < 0.01). Flow cytometry showed that the expression of CD(33) was reduced, while that of CD(11b) was increased. The quantity of treated cells in G(0)/G(1) phase increased but that in S phase decreased. The proliferous index was also decreased. After treated with Tan IIA, the expressions of anti-oncogene p53 and c-fos were up-regulated while those of oncogene bcl-2 and c-myc were down-regulated (P < 0.01). CONCLUSIONS: 1.0 mg/L Tan IIA could inhibit proliferation of MR-2 cells and induce differentiation of MR-2 cells into mature granulocyte, the effectivity was the same as 0.5 mg/L Tan IIA treated NB4 cells. Its possible molecular mechanism might be related to modulation of oncogene expressions associated proliferation and differentiation as well as inhibition of DNA synthesis. Tan IIA probably can be applied to treat the patients with APL, particularly to the relapsed and drug resistant patients with broad prospect.

Antioxidant activity of apple peels.

Consumption of fruits and vegetables has been shown to be effective in the prevention of chronic diseases. These benefits are often attributed to the high antioxidant content of some plant foods. Apples are commonly eaten and are large contributors of phenolic compounds in European and North American diets. The peels of apples, in particular, are high in phenolics. During applesauce and canned apple manufacture, the antioxidant-rich peels of apples are discarded. To determine if a useful source of antioxidants is being wasted, the phytochemical content, antioxidant activity, and antiproliferative activity of the peels of four varieties of apples (Rome Beauty, Idared, Cortland, and Golden Delicious) commonly used in applesauce production in New York state were investigated. The values of the peels were compared to those of the flesh and flesh + peel components of the apples. Within each variety, the total phenolic and flavonoid contents were highest in the peels, followed by the flesh + peel and the flesh. Idared and Rome Beauty apple peels had the highest total phenolic contents (588.9 +/- 83.2 and 500.2 +/- 13.7 mg of gallic acid equivalents/100 g of peels, respectively). Rome Beauty and Idared peels were also highest in flavonoids (306.1 +/- 6.7 and 303.2 +/- 41.5 mg of catechin equivalents/100 g of peels, respectively). Of the four varieties, Idared apple peels had the most anthocyanins, with 26.8 +/- 6.5 mg of cyanidin 3-glucoside equivalents/100 g of peels. The peels all had significantly higher total antioxidant activities than the flesh + peel and flesh of the apple varieties examined. Idared peels had the greatest antioxidant activity (312.2 +/- 9.8 micromol of vitamin C equivalents/g of peels). Apple peels were also shown to more effectively inhibit the growth of HepG(2) human liver cancer cells than the other apple components. Rome Beauty apple peels showed the most bioactivity, inhibiting cell proliferation by 50% at the low concentration of 12.4 +/- 0.4 mg of peels/mL. The high content of phenolic compounds, antioxidant activity, and antiproliferative activity of apple peels indicate that they may impart health benefits when consumed and should be regarded as a valuable source of antioxidants.