Genomic structural variation contributes to evolved changes in gene expression in high-altitude Tibetan sheep.

Tibetan sheep were introduced to the Qinghai Tibet plateau roughly 3,000 B.P., making this species a good model for investigating genetic mechanisms of high-altitude adaptation over a relatively short timescale. Here, we characterize genomic structural variants (SVs) that distinguish Tibetan sheep from closely related, low-altitude Hu sheep, and we examine associated changes in tissue-specific gene expression. We document differentiation between the two sheep breeds in frequencies of SVs associated with genes involved in cardiac function and circulation. In Tibetan sheep, we identified high-frequency SVs in a total of 462 genes, including EPAS1, PAPSS2, and PTPRD. Single-cell RNA-Seq data and luciferase reporter assays revealed that the SVs had cis-acting effects on the expression levels of these three genes in specific tissues and cell types. In Tibetan sheep, we identified a high-frequency chromosomal inversion that exhibited modified chromatin architectures relative to the noninverted allele that predominates in Hu sheep. The inversion harbors several genes with altered expression patterns related to heart protection, brown adipocyte proliferation, angiogenesis, and DNA repair. These findings indicate that SVs represent an important source of genetic variation in gene expression and may have contributed to high-altitude adaptation in Tibetan sheep.

Overexpression of IFIT2 inhibits the proliferation of chronic myeloid leukemia cells by regulating the BCR­ABL/AKT/mTOR pathway.

Chronic myeloid leukemia (CML) is a myeloproliferative disorder that accounts for ~10% of all newly diagnosed leukemia cases. Early diagnosis is essential for long­term beneficial outcomes. The present study observed that interferon­induced protein with tetratricopeptde repeats 2 (IFIT2) expression levels were reduced in bone marrow samples from CML patients compared with control samples using RNA sequencing and reverse transcription­PCR. IFIT2 expression levels were restored in patients treated with tyrosine kinase inhibitors. To investigate the effect of IFIT2 on CML patients, a stable IFIT2 expressing K562 cell line was established. It was demonstrated that IFIT2 overexpression in K562 cells inhibits cell proliferation and arrests the cell cycle at the G1 phase. In addition, it was demonstrated by western blotting that IFIT2 inhibits the BCR­ABL oncoprotein and regulates its downstream AKT/mTOR signaling pathway. IFIT2 could induce cell cycle arrest­associated gene p27kip1 by degrading cullin1­mediated E3 ligases. In summary, the present study demonstrated that IFIT2 was efficacious in inhibiting CML and is a potential therapeutic target.

The novel three-way variant t(6;17;15)(p21;q21;q22) in acute promyelocytic leukemia with an FLT3-ITD mutation: A case report.

Acute promyelocytic leukemia (APL) is characterized by the reciprocal translocation t(15;17)(q22;q21), resulting in the fusion of the promyelocytic leukemia gene at 15q22 with the retinoic acid receptor α at 17q21. Additionally, all patients with APL who have additional chromosome abnormalities (ACA) and gene mutations are resistant to all-trans retinoic acid (ATRA), the drug that causes disease regression specifically in patients with APL globally. The present study describes a case of a 19-year-old female with APL carrying a novel complex variant translocation t(6;17;15)(p21;q21;q22), add(7)(q32) and an FMS-related tyrosine kinase 3 internal tandem duplication (FLT3-ITD) mutation. Complete remission was attained following a course of chemotherapy with ATRA and arsenic trioxide. To the best of our knowledge, this is the first report of a novel three-way translocation of 6p21 and a FLT3-ITD mutation involved with APL.

Inhibition of CRL-NEDD8 pathway as a new approach to enhance ATRA-induced differentiation of acute promyelocytic leukemia cells.

The cullin-RING ligase (CRL)-NEDD8 pathway maintains essential cellular processes, including cell cycle progression, apoptosis, autophagy, DNA repair, antigen processing and signal transduction. Growing evidence demonstrates that the alteration of the CRL-NEDD8 pathway in some cancers constitutes an attractive target for therapeutic intervention, but the roles of CRL-NEDD8 pathway in acute promyelocytic leukemia (APL) is still unclear. In the present study, we found that ATRA could decrease the expression of NEDD8-activating enzyme E1 (NAE1) and inhibit the neddylation of cullin1 and cullin3 in the APL cell line NB4. Inactivation of cullin neddylation promoted self-degradation of F-box proteins (Skp2, KLHL20, ßTrCP) and up-regulated the protein expression of p27kip, DEPTOR and DAPK1. MLN4924, a novel inhibitor of NAE1, significantly suppressed cell growth and enhanced apoptosis of APL cells by blocking cullin neddylation and subsequent accumulation of CRL E3 substrates. Furthermore, MLN4924 effectively enhanced ATRA-induced differentiation of APL cells by promoting autophagy. Our findings not only provide further insights into the mechanism of the CRL-NEDD8 axis, but also provide a better understanding of this pathway as a potential target for therapeutic intervention in APL.

Lnc RNA SNHG20 participated in proliferation, invasion, and migration of breast cancer cells via miR-495.

To explore the mechanism of lnc SNHG20 in the regulation of proliferation, invasion, and migration of breast cancer cells. mRNA levels of SNHG20, miR-495, and HER2 were detected by qRT-PCR. Protein level of HER2 was measured by Western blot. Cell proliferation, invasion, and migration were detected by CCK-8 assay, Boyden chamber assay, and Transwell assay. The combination between SNHG20 and miR-495 was confirmed by RNA pull down assay. The combination between miR-495 and HER2 was confirmed by luciferase report assays. We also established breast cancer-bearing mice model and analyzed tumor volumes. Our data showed SNHG20 expression was significantly upregulated, miR-495 expression was significantly downregulated, and HER2 expression was significantly upregulated in breast cancer tissues and cell lines. Besides, SNHG20 promoted the proliferation, invasion, and migration of breast cancer cells. We also found SNHG20 negatively regulated miR-495, and miR-495 could negatively regulate HER2. Moreover, we discovered that SNHG20 regulated HER2 via miR-495. SNHG20 regulated proliferation, invasion, and migration of breast cancer cells via miR-495/HER2. Finally, we confirmed the mechanism of SNHG20 in the regulation of proliferation, invasion, and migration in breast cancer-bearing mice model. SNHG20 regulates HER2 via miR-495 to promote proliferation, invasion, and migration of breast cancer cells.

[Genetic Analysis of A Case of Congenital Dysfibrinogenemia Caused by Arg16His Mutation in Exon 2 of FGA].

OBJECTIVE: To analyze the phenotype and genotype of a family with congenital dysfibrinogenemia. METHODS: Assays of coagulation, including activated partial thromboplastin time(APTT), pro-thrombin time(PT)and thrombin time(TT) were carried out with Sysmex CA-7000 in the proband and his family members. The quality and quantity of fibrinogen in plasma were determined by Clauss and electrophoresis, respectively. Fibrinogen and inconstituent were analyzed by Native-PAGE. All exon and exon intron boundaries of fibringen genes were analyzed by direct sequencing. RESULTS: The proband had normal APTT, but prolonged PT and TT. The activity of fibrinogen in plasma was decreased while its quantity was normal. These abnormalities were also found in his sisters and daughter, while his wife was normal. Genetic analysis revealed heterozygous G1233A in the exon 2 of FGA which resulted in Arg16His missense mutation. CONCLUSION: Inherited dysfibrinogenemia is caused by Arg16His mutation in exon 2 of FGA.

Inhibition of Proteasome Activity Induces Aggregation of IFIT2 in the Centrosome and Enhances IFIT2-Induced Cell Apoptosis.

IFN-induced protein with tetratricopeptide repeats 2 (IFIT2), one of the most highly responsive interferon-stimulated genes, inhibits the proliferation and migration of cancer cells and regulates viral replication. IFIT2 has been demonstrated to be a cytoskeleton-associated protein that becomes enriched in the mitotic spindle of cells. However, the molecular mechanisms by which IFIT2 executes biological functions are largely unclear. The findings of this study showed that inhibiting the activation of proteasome led to the enrichment of IFIT2 and induced the aggregation of IFIT2 protein in the centrosome. Microtubule inhibitor colchicine and dynein inhibitor ciliobrevin inhibited the proteasome inhibitor-induced aggregation of IFIT2 protein in the centrosome. Intriguingly, IFIT2 and proteasome inhibitor worked together to induce the apoptosis of cancer cells. The results of the present study revealed that the inhibition of proteasome activity blocked the degradation of IFIT2 and promoted the aggregation of IFIT2 in the centrosome, which in turn induced cell apoptosis. In short, IFIT2 may be a potential target for cancer therapeutics.

Curcumin induces apoptosis in human leukemic cell lines through an IFIT2-dependent pathway.

Curcumin, the primary bioactive component isolated from turmeric, has been shown to possess variety of biologic functions including anti-cancer activity. However, molecular mechanisms in different cancer cells are various. In the present study, we demonstrated that curcumin induced G2/M cell cycle arrest and apoptosis by increasing the expression levels of cleaved caspase-3, cleaved PARP and decreasing the expression of BCL-2 in U937 human leukemic cells but not in K562 cells. We found some interferon induced genes, especially interferon-induced protein with tetratricopeptide repeats 2 (IFIT2), were significantly upregulated when treated with curcumin in U937 cells by gene expression chip array, and further confirmed that the expression of IFIT2 was obviously higher in U937 than that in K562 cells by Western blot assay. In addition, inhibiting the expression of IFIT2 by shRNA in U937 rescued curcumin-induced apoptosis and exogenous overexpression of IFIT2 by lentiviral transduction or treating with IFNγ in K562 cells enhanced anti-cancer activity of curcumin. These results indicated for the first time that curcumin induced leukemic cell apoptosis via an IFIT2-dependent signaling pathways. The present study identified a novel mechanism underlying the antitumor effects of curcumin, and may provide a theoretical basis for curcumin combined with interferon in the cancer therapeutics.

[Isolation and cultivation of a wild microcytin-RR-producing cyanobacterium and verification of its toxin by high performance liquid chromatography and acute oral toxicity].

OBJECTIVE: Attempting to isolate and cultivate the microcytin-RR-producing cyanobacteria from natural blooms as well as to further investigate some characteristics of their growth and metabolite toxicity. METHODS: Capillary-pipette method was used to isolate wild Microcystis strains collected from eutrophicated lakes. The isolated strains were cultured in BG11 media at (25 ± 1) °C, under 2 000 lx illumination of fluorescent light with a light-dark rhythm of 12-12 h. The growth curve was observed by measuring optical density of culture suspension, toxin-related genes and the metabolite toxins were identified separately by PCR and HPLC, and its acute toxicity was carried out by orally administered toxins to Kunming (KM) mice. RESULTS: One of five toxigenic strains from 198 collected samples was confirmed to be a MC-RR producing blue-green alga by existing two specific toxin-synthesized enzyme genes and showing specific chromatographic peak of the toxin compared with standard MC-RR through both PCR and HPLC methods. The toxic strain was classified as Microcystin aeruginosa by morphologic and phylogenetic tree analysis. The growth length of the strain lasted nearly 81 days with 55-60 days' exponential phase and the maximal concentration of 5.52 × 107 cell/ml. The LD50 of the MC-RR to the KM mice ranged from 10.75 mg/kg to 13.45 mg/kg of body weight. As a result of the acute toxicity, the enzymatic indexes in serum such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) were significantly higher than those in the control group. The levels of ALT, AST, ALP and LDH in the treated group at 45 min were (157.08 ± 20.38), (333.00 ± 68.53), (392.70 ± 89.59) and (1 071.13 ± 160.22) U/L respectively, and at 4 h were (514.68 ± 156.87), (593.15 ± 40.41), (618.55 ± 208.76) and (2 281.72 ± 866.67) U/L respectively, and meanwhile the values of ALT, AST, ALP and LDH in the control group were (40.30 ± 4.89), (142.70 ± 26.59), (56.90 ± 11.89) and (509.50 ± 94.75) U/L separately (t values at 45 min were -11.20, -5.77, -7.38, -6.60 respectively, and at 4 h were -6.04, -20.21, -5.35, -4.07 respectively, P values were all <0.01). The liver coefficient in the treated group at 45 min and 4 h were 6.855 ± 0.225 and 8.409 ± 0.276, significantly higher than that (5.784 ± 0.286) in the control group (t values were -3.96 and -12.22, P values were both <0.01). The histopathological changes of liver were hyperemia obviously. CONCLUSION: Isolated from the bloom waters, a strain of Microcystis aeruginosa is obtained with characteristics of longer growth duration, positive microcystin synthetase genes, and dominant production of MC-RR. The LD50 of the extracted MC-RR administered by oral route to mice is (12.10 ± 1.35) mg/kg of body weight, and liver is the target organ of MC-RR. The existence and potential risk of MC-RR in China cannot be ignored.

[The influence of microcystin-LR on monocytes and lymphocytes of mice].

OBJECTIVE: To investigate the influence of microcystin-LR (MC-LR) on monocytes and lymphocytes in blood of mice and to find a sensitive index of toxic effects. METHODS: Specific pathogen free Kunming male mice, aging 1 month-old,were randomly divided into 5 groups by weights, 7 mice for each group. The mice in 5 groups were exposed to MC-LR through intraperitoneal injection at 0, 3.125,6.250, 12.500 and 25.000 µg/kg respectively for 7 days. Then cytokine levels in the serum were measured by radioimmunoassay, DNA-protein crosslinks (DPC) was measured by the SDS/KCl precipitation technique, and the phagocytosis and ROS of leukocytes were detected by flow cytometry. RESULTS: The levels of interleukin 6 in the 6.250, 12.500 and 25.000 µg·kg(-1)·d(-1) dose groups were (346.837 ± 25.536), (360.847 ± 37.886) and (434.245 ± 35.858)pg/ml respectively, which were significantly higher than those in the control group which the value was (232.775 ± 32.816) pg/ml (t values were -7.258, -6.760 and -10.966 respectively, P values were all < 0.05).While the level of tumor necrosis factor-alpha was(10.782 ± 0.966) fmol/ml in 25 µg·kg(-1)·d(-1) dose group was statistically lower than it in the control group which the value was (16.878 ± 3.378) fmol/ml (t value was 4.591, P < 0.05). The DPC levels of lymphocytes in 6.250, 12.500 µg·kg(-1)·d(-1) dose group were (242.576 ± 7.545),(241.472 ± 2.793) ng/ml,higher than it in the control group while the value was (228.657 ± 4.130) ng/ml (t value was -4.282, -6.801, P values were all <0.05). The fluorescence intensity of DCF in lymphocytes in the 4 treated groups were separately 3299.37 ± 120.54, 3281.38 ± 58.34, 3308.06 ± 136.12 and 3346.92 ± 108.69, all significantly lower than 3770.81 ± 131.39 in the control group (t values were 6.995, 9.007, 6.472 and 6.577 respectively, and P values were all <0.05). The fluorescence intensity of DCF in monocytes in the 4 treated groups (3271.51 ± 140.79, 3270.05 ± 117.92, 3326.90 ± 114.39 and 3292.49 ± 145.97 respectively) were also significantly lower than the value in the control group was 3841.72 ± 130.92 (t values were 7.847, 8.584, 7.835 and 7.411 respectively, P values were all <0.05). There was no significant difference in other index among the four experiment groups and the control group. CONCLUSION: The MC-LR administered via intraperitoneal injection to mice induced the alterations of some cytokines of monocytes and lymphocytes in blood. By comparison, the ROS of leukocyte was the most sensitive index.

[Purification and identification of microcystin-RR].

An effective method based on the combination of solid phase extraction and gel chromatography to extract and purify microcystin-RR (MC-RR) from natural cyanobacteria bloom was developed. Thirty five gram natural cyanobacterial bloom scum was extracted with 70% aqueous methanol. After the methanol in the crude extract was removed by a rotary evaporator, the solid phase extraction was used for preliminary purification and concentration. And then 7.5 mL eluent was concentrated to 2 mL and loaded onto a Sephadex LH-20 gel chromatographic column for further purification. The eluate was collected by tubes and detected at 238 nm. The elution curve was plotted by tube numbers as X-axis and the absorbance at 238 nm as Y-axis. The purity and the spectral characteristics of the final extract were identified with high performance liquid chromatograph (HPLC) and spectrophotometer, respectively. A total of 3.65 mg of MC-RR with a final yield of 74. 1% was obtained, and the purity was more than 90% with characteristic UV absorption spectra at 238 nm.

Comparison of response indices to toxic microcystin-LR in blood of mice.

In order to investigate the response indices to toxic microcystin-LR (MC-LR) in blood of mice, concentrations of free and total MC-LR in blood and tissues, accompanied by serous parameters in series including some enzymatic activities, hematology and the function of leukocytes, were determined in mice exposed to the toxin ranging from 3.125 to 25.000 µg kg(-1)day(-1) by intraperitoneal injection for 7 days. On the 7th day, the ratios of mass of free MC-LR in serum to the mass of MC-LR in given dose were 3.843-4.555%, while the ratios of total MC-LR in liver were 34.465-38.567%. Comparing the overall experimental results, the three most sensitive indices are total MC-LR in the liver, the phagocytic index and reactive oxygen species (ROS) which have shown significant differences between the lowest dose group and the control group. Alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and lactate dehydrogenase had proportional correlations with the MC-LR exposure doses, and the hematology of the majority of blood cells and the volume of erythrocytes were also influenced by the toxin. The alterations of some cytokines and the ROS of leukocytes were observed. The results of the studies suggest that measurement of MC-LR in blood is powerful and clear evidence to indicate that subjects have been exposed to MC-LR and can be used to discriminate from other causes leading to hepatic lesions although it is not as sensitive as other indices that are usually as useful complements to reflect the liver function.

[The establishment and application of the method with virus concentration and detection in drinking water].

OBJECTIVE: This study aimed to construct an effective method to concentrate and detect virus in drinking water, and human adenovirus pollution status in actual water samples was monitored by constructed method. METHODS: The concentration efficient of NanoCeram filter for the first concentration with source water and drinking water and the concentration efficient of the different concentrations of PEG 8000 for the second concentration were assessed by spiking f2 bacteriophage into water samples. The standard of human adenovirus for real-time PCR was constructed by T-A clone. The plasmid obtained was identified through sequence analyzing and consistency check comparing to target gene fragment was conducted by using blast algorithm. Then, real-time PCR was constructed to quantify the concentration of human adenovirus using the plasmid as standard. Water samples were concentrated by using NanoCeram filter on the spot and then concentrated for the second time by PEG/NaCl in 2011. The DNA of concentrated samples were extracted for the quantification of human adenovirus in real-time PCR subsequently to monitor the pollution of human adenovirus in water. RESULTS: For the first concentration by NanoCeram filter, the recovery rates were (51.63 ± 26.60)% in source water and (50.27 ± 14.35)% in treated water, respectively. For the second concentration, the highest recovery rate was reached to (90.09 ± 10.50)% at the concentration of 0.13 kg/L of PEG 8000. The sequence identity score of standard of adenovirus for real time PCR and adenovirus gene was 99%, implying that it can be successfully used to quantification with human adenovirus. The levels of human adenovirus in the water samples sampled in 2011 ranged from 4.13×10³ to 2.20×106 copies/L in source water, while range from 5.57×10² to 7.52×105 copies/L in treated water and the removal efficiency range was (75.49 ± 11.71)%. CONCLUSION: NanoCeram filers combined with PEG/NaCl was an effective method to concentrate virus in aquatic environment. There was a large number of human adenovirus in source water, and it is not sufficient to remove them thoroughly through conventional water treatment processes.