Onion (Allium cepa L.) Flavonoid Extract Ameliorates Osteoporosis in Rats Facilitating Osteoblast Proliferation and Differentiation in MG-63 Cells and Inhibiting RANKL-Induced Osteoclastogenesis in RAW 264.7 Cells.

Osteoporosis, a prevalent chronic health issue among the elderly, is a global bone metabolic disease. Flavonoids, natural active compounds widely present in vegetables, fruits, beans, and cereals, have been reported for their anti-osteoporotic properties. Onion is a commonly consumed vegetable rich in flavonoids with diverse pharmacological activities. In this study, the trabecular structure was enhanced and bone mineral density (BMD) exhibited a twofold increase following oral administration of onion flavonoid extract (OFE). The levels of estradiol (E2), calcium (Ca), and phosphorus (P) in serum were significantly increased in ovariectomized (OVX) rats, with effects equal to alendronate sodium (ALN). Alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) levels in rat serum were reduced by 35.7% and 36.9%, respectively, compared to the OVX group. In addition, the effects of OFE on bone health were assessed using human osteoblast-like cells MG-63 and osteoclast precursor RAW 264.7 cells in vitro as well. Proliferation and mineralization of MG-63 cells were promoted by OFE treatment, along with increased ALP activity and mRNA expression of osteoprotegerin (OPG)/receptor activator of nuclear factor-kappaB ligand (RANKL). Additionally, RANKL-induced osteoclastogenesis and osteoclast activity were inhibited by OFE treatment through decreased TRAP activity and down-regulation of mRNA expression-related enzymes in RAW 264.7 cells. Overall findings suggest that OFE holds promise as a natural functional component for alleviating osteoporosis.

Combined fabrication of zeolitic imidazolate framework-8 and lanthanide towards coordination polymers: A dual-signal fluorescent probe for sensing Cu2+ based on synergistic effect of aggregation-induced emission and antenna effect.

Copper ion (Cu2+) detection remains an important task for monitoring water quality because of its specific toxicity. Herein, a new dual-signal fluorescent probe was developed by combining zeolitic imidazolate framework-8 (ZIF-8) and lanthanide for the detection of Cu2+ for the first time. The lanthanide coordination polymer (guanosine monophosphate and Eu3+, GMP/Eu) was initially incorporated into ZIF-8 to yield ZIF-8/GMP/Eu nanomaterials with extremely weak single emission fluorescence at 618 nm. It was found that the resulted nanomaterials could display a dual emission fluorescence at 515 nm and 618 nm after the introduction of tetracycline (TC) due to the synergistic effect of aggregation-induced emission effect (AIE, TC induced by ZIF-8) and antenna effect (AE, between TC and GMP/Eu). Interestingly, in the presence of Cu2+, the AIE of TC was destroyed because of the interaction of Cu2+ with ZIF-8 and TC. The AE between TC and GMP/Eu disappeared due to the formation of complex between TC and Cu2+. A dual-signal fluorescent probe of ZIF-8/GMP/Eu/TC was thereby established for sensing Cu2+ in the range of 0.5-100 µM. Such a dual-signal response strategy that intelligently utilized the "ON"/"OFF" of AIE and AE can not only eliminate the background interference, but also ensure the improved selectivity of Cu2+ sensing. Subsequently, the dual-signal fluorimetric strategy was applied for the detection of Cu2+ in environmental water samples, indicating the potential feasibility of applications for water quality monitoring.

Selenite Ameliorates Cadmium-induced Cytotoxicity Through Downregulation of ROS Levels and Upregulation of Selenoprotein Thioredoxin Reductase 1 in SH-SY5Y Cells.

Cadmium (Cd) as a ubiquitous toxic heavy metal in the environment, causes severe hazards to human health, such as cellular stress and organ injury. Selenium (Se) was reported to reduce Cd toxicity and the mechanisms have been intensively studied so far. However, it is not yet crystal clear whether the protective effect of Se against Cd-induced cytotoxicity is related to selenoproteins in nerve cells or not. In this study, we found that Cd inhibited selenoprotein thioredoxin reductase 1 (TrxR1; TXNRD1) and decreased the expression level of TrxR1, resulting in cellular oxidative stress, and Se supplements ameliorated Cd-induced cytotoxicity in SH-SY5Y cells. Mechanistically, the detoxification of Se against Cd is attributed to the increase of the cellular TrxR activity and upregulated TrxR1 protein level, culminating in strengthened antioxidant capacity. Results showed that Se supplements attenuated the ROS production and apoptosis in SH-SY5Y cells, and significantly mitigated Cd-induced SH-SY5Y cell death. This study may be a valuable reference for shedding light on the mechanism of Cd-induced cytotoxicity and the role of TrxR1 in Se-mitigated cytotoxicity of Cd in neuroblast cells, which may be helpful for understanding the therapeutic potential of Cd and Se in treating or preventing neurodegenerative diseases, like Alzheimer's disease (AD) and Parkinson's disease (PD).

Nursing Countermeasures of Continuous Renal Replacement Treatment in End-Stage Renal Disease with Refractory Hypotension in the Context of Smart Health.

This work is aimed at exploring the nursing strategies and effects of continuous renal replacement therapy (CRRT) for end-stage renal disease (ESRD) with refractory hypotension under the background of smart health. 40 ESRD patients with refractory hypotension who received CRRT treatment were enrolled as the research objects and were randomly rolled into the intervention group and the control group, with 20 cases in each group. Patients in the control group received routine nursing, and those in the intervention group received individualized nursing. The incidence of hypotension, dry body weight, serous cavity effusion, renal function indicators (blood urea nitrogen (BUN) and creatinine (Cre)), and patient satisfaction were compared between the two groups. The results showed that the probability of hypotension in the intervention group was 9.38%, which was lower than that in the control group (34.38%). The probability of early termination of dialysis in the intervention group was 0%, which was lower than that in the control group (18.75%), and the difference was statistically significant (P < 0.05). The decreases of BUN and Cre in the intervention group were significantly greater than those in the control group, and the differences were statistically significant (P < 0.05). The proportion of water growth less than 10% during dialysis in the intervention group was 98.44%, which was greater than that in the control group (93.45%), and the difference was statistically significant (P < 0.05). The ultrafiltration volume after dialysis in the intervention group was 2850 ± 400 mL, which was greater than that in the control group 2350 ± 350 mL. After intervention, the proportion of patients with pleural effusion in the intervention group was 10% less than that in the control group (20%), and the difference was statistically significant (P < 0.05). The satisfaction rate of the intervention group was 97.66%, which was higher than that of the control group (65.63%). In conclusion, individualized nursing was more helpful to the recovery of ESRD patients with refractory hypotension treated with CRRT than routine nursing.

Integration of DSF and Temperature Signals for RpfC/RpfG Two-Component System Modulating Protease Production in Stenotrophomonas maltophilia FF11.

Two-component signal system (TCS) is the predominant bacterial sense-and-response machinery. RpfC/RpfG TCS involved in quorum sensing molecule Diffuse Signal Factor (DSF) signal perception and transduction was well studied in many bacteria. However, whether other environmental factors participating in the signal perception and transduction of RpfC/RpfG was still unclear. Here, we showed that RpfC/RpfG could integrate temperature and DSF signal partially controlling the production of the temperature-dependent protease (SmtP) in S. maltophilia FF11, a strain isolated from frozen Antarctic krill, exhibited spoilage potential due to secret more protease at low temperatures involving in protein degradation. qRT-PCR analysis revealed rpf system mediating approximately 60% transcription activity of Clp, a critical transcription factor linking with LotS/LotR, consisting a signal network controlling completely the SmtP production in previous study. Protease production was partially reduced in rpfF (coding DSF synthetase) mutant strains at 15 °C or 25 °C, not be increased through addition DSF or overexpression RpfF in WT at 37 °C, indicating that DSF was effective for protease production only at low temperatures in S. maltophilia. Additionally, biochemical analysis revealed the enzymatic activity of RpfG from strain FF11 cultured at 37 °C or DSF-deficient strains grown at 25 °C was significantly reduced compared to that of RpfG from strain FF11 cultured at 25 °C. These findings outline an interplay mechanism that allows S. maltophilia to integrate quorum sensing and temperature cues controlling protease production, and imply a potential relationship between two distinct systems of RpfC/RpfG and LotS/LotR.

Thioredoxin reductase 1 inhibitor shikonin promotes cell necroptosis via SecTRAPs generation and oxygen-coupled redox cycling.

Shikonin, a naturally occurring naphthoquinone with potent anti-tumor activity, has been reported to induce cancer cell death via targeting selenoenzyme thioredoxin reductase 1 (TrxR1; TXNRD1). However, the interaction between shikonin and TrxR1 remains unclear, and the roles of the cellular antioxidant system in shikonin induced cell death are obscure. Here, we found that shikonin modified the Sec498 residue of TrxR1 to fully inhibit its antioxidant activity, however, the shikonin-modified TrxR1 still remained intrinsic NADPH oxidase activity, which promotes superoxide anions production. Besides, TrxR1 efficiently reduced shikonin in both selenocysteine dependent and selenocysteine independent manners, and the oxygen-coupled redox cycling of shikonin also generates excessive superoxide anions. The inhibitory effects and the redox cycling of shikonin towards TrxR1 caused cancer cell ROS-dependent necroptosis. Interestingly, as we evaluated, some cancer cell lines were insensitive to shikonin, especially kelch-like ECH associated protein 1 (KEAP1)-mutant non-small cell lung cancer (NSCLC) cells, which harbor constitutive activation of the nuclear factor-erythroid 2-related factor 2 (NRF2). NADPH bankruptcy caused by glucose starvation or glucose limitation (inhibiting glucose transporter 1 by BAY-876) could efficiently overcome the resistance of KEAP1-mutant NSCLC cells to shikonin. Glucose-6-phosphate dehydrogenase (G6PD), was known as a rate-limiting enzyme in the pentose phosphate pathway, however, the pharmacological inhibition of G6PD by 6-aminonicotinamide (6-AN), enhanced the shikonin-induced cytotoxicity but has no selectivity on KEAP1-mutant NSCLC cells. This study will be helpful in applying shikonin for potential chemotherapy, and in combinational treatment of KEAP1-mutant NSCLC.

Plumbagin reduction by thioredoxin reductase 1 possesses synergy effects with GLUT1 inhibitor on KEAP1-mutant NSCLC cells.

Thioredoxin reductase 1 (TrxR1 or TXNRD1) is a major enzyme in cellular redox regulation and is considered as a drug target for cancer therapy. Previous studies have reported that plumbagin caused reactive oxygen species (ROS)-dependent apoptosis via inhibiting TrxR1 activity or being reduced by TrxR1, leading to selectively cancer cell death. However, the mechanism of TrxR1-mediated redox cycling of plumbagin is obscure and the evidence for plumbagin targeting TrxR1 is still lacking. Herein, we demonstrated that TrxR1 catalyzed plumbagin reduction in both selenocysteine (Sec)-dependent and independent manners, and its activity relied on the intact N-terminal motif of TrxR1, but a high-efficiency reduction was supported by the C-terminal thiols. During the redox cycling of plumbagin, excessive ROS production was observed coupled with oxygen. Using LC-MS and TrxR1 mutants, we found that the Sec residue of TrxR1 was modified by plumbagin, which converted the enzyme from antioxidant to pro-oxidant. Furthermore, we evaluated the therapeutic potential of plumbagin in non-small cell lung cancer (NSCLC), and found that Kelch-like ECH-associated protein 1 (KEAP1)-mutant NSCLC cells, which possess constitutive nuclear factor erythroid 2-related factor 2 (NRF2) activity, were insensitive to plumbagin; however, inhibition of glucose transporter 1 (GLUT1) by small-molecule BAY-876 or inhibiting glucose-6-phosphate dehydrogenase (G6PD) by 6-aminonicotinamide (6-AN) overcame the plumbagin-resistance of KEAP1-mutant NSCLC cells. Taken together, this study elucidated the pharmacological mechanism of plumbagin by targeting TrxR1 and revealed the synergy effect of plumbagin and BAY-876, which may be helpful for applying naphthoquinone compounds to chemotherapy, particularly for treating KEAP1-mutant NSCLC cells.

Chlorophyllin Inhibits Mammalian Thioredoxin Reductase 1 and Triggers Cancer Cell Death.

Food colorants are widely used by humans in food production and preparation; however, their potential toxicity requires an in-depth analysis. In this study, five out of 15 commercial food colorants, namely, lutein, betanin, caramel, crocin and chlorophyll, significantly inhibited wild type selenoprotein thioredoxin reductase 1 (TrxR1, TXNRD1) in vitro. The hyperactive Sec498 residue of TrxR1 was targeted by those five colorants, which was confirmed by the site-directed mutagenesis of TrxR1. Furthermore, two colorants, chlorophyll and betanin, triggered the oligomerization of TrxR1. A chlorophyll-derived compound, chlorophyllin, irreversibly inhibited the 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) reducing activity of TrxR1 with Kinact = 6.96 × 10-3 ± 0.49 × 10-3 µM-1 min-1. Moreover, chlorophyllin reduced the cellular TrxR activity, leading to reactive oxygen species (ROS) accumulation and, subsequently, promoting cancer cell death. In conclusion, this study might contribute to understand the food safety of commercial colorants and provide chemotherapeutic compounds by targeting TrxR1.

TMEM120A contains a specific coenzyme A-binding site and might not mediate poking- or stretch-induced channel activities in cells.

TMEM120A, a member of the transmembrane protein 120 (TMEM120) family, has a pivotal function in adipocyte differentiation and metabolism, and may also contribute to sensing mechanical pain by functioning as an ion channel named TACAN. Here we report that expression of TMEM120A is not sufficient in mediating poking- or stretch-induced currents in cells and have solved cryo-electron microscopy (cryo-EM) structures of human TMEM120A (HsTMEM120A) in complex with an endogenous metabolic cofactor (coenzyme A, CoASH) and in the apo form. HsTMEM120A forms a symmetrical homodimer with each monomer containing an amino-terminal coiled-coil motif followed by a transmembrane domain with six membrane-spanning helices. Within the transmembrane domain, a CoASH molecule is hosted in a deep cavity and forms specific interactions with nearby amino acid residues. Mutation of a central tryptophan residue involved in binding CoASH dramatically reduced the binding affinity of HsTMEM120A with CoASH. HsTMEM120A exhibits distinct conformations at the states with or without CoASH bound. Our results suggest that TMEM120A may have alternative functional roles potentially involved in CoASH transport, sensing, or metabolism.

The effect of psychological nursing on the short- and long-term negative emotions and quality of life of cervical cancer patients undergoing postoperative chemotherapy.

OBJECTIVE: The purpose of this study was to analyze the effect of psychological nursing intervention on the short- and long-term negative emotions and changes in the quality of life in patients with cervical cancer who underwent postoperative chemotherapy. METHODS: 141 patients with cervical cancer who received postoperative chemotherapy in our hospital were recruited as the study cohort. They were divided into the study group (80 cases) and the control group (61 cases) according to the different nursing methods each underwent. The patients in the control group underwent routine nursing, and the study group also underwent psychological nursing. The changes in the quality of life and the negative emotions of the patients in the two groups before and after the intervention were compared, and the correlation between the quality of life and the negative emotions were explored. RESULTS: The patients' Quality of Life Questionnaire (EROTC-QLQ-C30) and Self-rating Anxiety Scale (SAS) scores in the two groups before the intervention were not significantly different (P > 0.05). A re-evaluation at the end of the 90 day-intervention showed that the EROTC-QLQ-C30 scores in the study group were significantly higher than they were in the control group (P < 0.05). A dynamic evaluation showed that the proportion of patients with mild anxiety in the study group was higher than it was in the control group at 30, 60, and 90 days of intervention (P < 0.05). A Spearman correlation analysis showed that the SAS scale and EROTC-QLQ-C30 scores were negatively correlated (r=-0.4438, P < 0.05). CONCLUSION: The implementation of psychological intervention can help alleviate the short- and long-term negative emotions of cervical cancer patients who underwent postoperative chemotherapy, and it is feasible and conducive to the patients' quality of life. We recommend carrying out the clinical promotion and application of this psychological intervention.

Enhancing the understanding of hydrological responses induced by ecological water replenishment using improved machine learning models: A case study in Yongding River.

The ecological water replenishment (EWR) of Yongding River has been an important project implemented in response to the Development of an Ecological Civilization policy in China since 2016. A reasonable amount of EWR requires a systematic understanding of the relationship among the surface water, groundwater, ecology and economy. However, studying surface water-groundwater interactions still remains an important issue. Thus, a coupled model integrating a Muskingum method-based open channel flow model and machine learning-based groundwater model is developed to describe the dynamic changes in streamflow and groundwater level in response to the EWR of Yongding River. The model is calibrated using observed streamflow data as well as groundwater level data on a daily scale for the spring EWR in 2020. The simulated results match well with the observed data and suggest that significant groundwater level increases occur only around the main channel of Yongding River. Fifteen scenarios under different EWR schemes are set to obtain reasonable streamflow during EWR, and then the responses of streamflow and groundwater level changes are simulated. Reasonable streamflow at the Guanting Reservoir need to be above 65 m3/s to ensure the streamflow can pass through Beijing and significant groundwater level recoveries of 170 million m3 through EWR. The developed models can improve the understanding of the interaction between surface water and groundwater and provide a quick assessment of the factors influencing the different EWR schemes and thus aid in effective EWR project management.

Cryo-electron microscopy structure of CLHM1 ion channel from Caenorhabditis elegans.

Calcium homeostasis modulators (CALHMs/CLHMs) comprise a family of pore-forming protein complexes assembling into voltage-gated, Ca2+ -sensitive, nonselective channels. These complexes contain an ion-conduction pore sufficiently wide to permit the passing of ATP molecules serving as neurotransmitters. While their function and structure information is accumulating, the precise mechanisms of these channel complexes remain to be full understood. Here, we present the structure of the Caenorhabditis elegans CLHM1 channel in its open state solved through single-particle cryo-electron microscopy at 3.7-Å resolution. The transmembrane region of the channel structure of the dominant class shows an assembly of 10-fold rotational symmetry in one layer, and its cytoplasmic region is involved in additional twofold symmetrical packing in a tail-to-tail manner. Furthermore, we identified a series of amino acid residues critical for the regulation of CeCLHM1 channel using functional assays, electrophysiological analyses as well as structural-based analysis. Our structure and function analyses provide new insights into the mechanisms of CALHM channels.

Highly pathogenic H5N6 avian influenza virus outbreak in Pavo cristatus in Jiangxi Province, China.

Highly pathogenic avian influenza (HPAI) is a persistent threat to poultry, wild birds, humans, and other mammals. The continually evolving HPAI H5N6 virus has induced great losses in breeding industries in growing regions around the world. In this study, we confirmed an outbreak of the HPAI H5N6 virus in captive Pavo cristatus in Jiangxi Province, China. The causative agents H5N6 viruses were isolated and designated JS01, JS02, and K10. Animal experiments showed that all three isolates exhibited high pathogenicity to chickens, but they need adaption to effectively infect mice. A phylogenetic analysis showed that all three isolates were clustered in H5 clade 2.3.4.4c. No novel genetic reassortant was found in JS01, JS02, and K10 viruses. It was estimated that JS01, JS02, and K10 H5N6 viruses were direct descendants of the H5N6 virus circulating in South of China. The estimated divergence time from tMRCAs was anywhere between May 2014 to June 2016. Although the number of outbreaks of avian influenza decreased significantly in 2018, the threat from avian influenza to public health remains serious. Enhanced active surveillance is required to monitor the transmission and evolution of H5 influenza viruses.

Imaging and Inhibiting: A Dual Function Molecular Flare for Cancer Cells.

The Wnt pathway is dysregulated and activated in many human malignancies. More than 90% of colon cancers have variations in the Wnt pathway. Sulindac, a drug that targets protein Dvl of the Wnt/Dvl/ß-catenin pathway, which regulates cancer gene expression, has been reported to significantly reduce the incidence and the risk of death from colorectal cancer and other types of cancer. Herein, a dual functional compound (SLN) containing Sulindac and a linked fluorophore is first reported, combining the functions of lighting up colon cancer cells as a flare and inhibiting colon tumors as a drug. SLN can not only mark the Dvl protein in the Wnt pathway to recognize tumors layer by layer but also achieve effective inhibition of colon cancer, providing a promising reagent for chemotherapy and a fluorescent indicator for surgery during the removal the colon tumors in situ.

Functional daidzein enhances the anticancer effect of topotecan and reverses BCRP-mediated drug resistance in breast cancer.

Topotecan (TPT), a semisynthetic derivative of camptothecin, has been used in cancer chemotherapy, but side effects and drug resistance limit its clinical application. Daidzein (DAI), a natural isoflavone and bioactive food component widely existing in fruits, nuts, soybeans and soy-based products, is a type of phytoestrogen. Combination treatment with DAI and TPT showed a strong synergistic effect on tumor cells, with a 0.10˜0.66 combined index, by increasing TPT inhibition on Topo Ⅰ, resulting in more cells arresting at the G2/M phase and inducing more cells to undergo apoptosis. In addition, the resistance of MCF7/ADR cells to TPT was reversed (the resistance index decreased from 7.17 to 0.77) by inhibiting the expression of ERα and BCRP to increase TPT accumulation intracellularly. Moreover, the combination of DAI and TPT showed a stronger inhibitory effect (P < 0.01) on tumor growth in both MCF7 and MCF7/ADR xenograft models than the 9 mg/kg TPT monotherapy group. Our results may provide a reasonable, new approach to develop safe and efficient nutrition components from foods for breast cancer combination treatment.

[Clinical Efficacy of Modified BU/CY as Conditioning Regimen Combined with Autologous Peripheral Blood Hematopoietic Stem Cell Transplantation in Young Acute Myeloid Leukemia Patients with Low or Intermediate Risk].

OBJECTIVE: To investigate the safety and efficacy of autologous peripheral blood hematopoietic stem cell transplantation (auto-PBHSCT) using modified BU/CY conditioning regimen for young AML patients of low and middle risk in the first complete remission (CR1). METHODS: Ten young AML patients of low and middle risk who did not want to accept allogeneic hematopoietic stem cell transplantation（allo-HSCT）and underwent auto-PBHSCT in CR1 during May 2013 to December 2016 were retrospectively analyzed. From 3 months after auto-PBHSCT, the maintenance therapy with interleukin-2 (IL-2) or IL-2 combined with histamine dihydrochloride was performed for these patients in the next 18 months. The side effects of the conditioning regimen, hematopoietic recovery time, transplant-related mortality (TRM) within 100 days and 1 year after auto-PBHSCT, relapse rate, leukemia-free survival (LFS) rate at 2 years and 3 years, overall survival (OS) were evaluated at 3 years and 4 years. RESULTS: Gastrointestinal side effects were the major non-hematologic toxicity reaction, among which, 7 cases relatively mild and 3 cases displayed moderate, just one case suffered from severe reaction. In 4 cases, the mild liver damage occurred, but no hemorrhagic cystitis occurred. All the patients experienced different kinds of infection, including 5 cases of bloodstream infection, 2 cases of gastrointestinal infection, 3 cases of crissum infection and 2 cases of oral infection. The myeloablative effect occurred in all ten patients. The median times for absolute neutrophil count (ANC)<0.5×109/L and for platelet count <20.0×109/L were 1.5 (0-3) days and 3 (2-5) days after transplantation, respectively. The patients achieved ANC>0.5×109/L at 10 to 19 days, median was 13 days after auto-PBHSCT. The patients achieved platelet count >20×109/L at 10 to 72 days; median was 32 days after auto-PBHSCT. The TRM within 100 days and 1 year after transplantation was 0. The relapse occurred in 2 cases at 6 and 14 months after auto-PBHSCT raspectively. The median follow-up time was 48.1 months, and the median survival time was 54.7 months after transplantation. The 2-year and 3-year LFS were 100% (10 cases) and 80% (8 cases), respectively. The 3-year and 4-year OS were 80% (8 cases) and 70% (7 cases), respectively. CONCLUSION: Modified BU/CY as conditioning regimen for auto-PBHSCT can achieve the myeloablative effect without raising TRM and obtain good LFS and OS. As for young AML patients without high risk, it is a valuable therapeutic option, especially for those lacking the chance of allo-HSCT.

Pifithrin-α enhancing anticancer effect of topotecan on p53-expressing cancer cells.

p53 is generally known as an effective anti-cancer molecular, but it is lost or mutated in more than 50% of human tumors. It is still a controversial issue whether the activity of p53 really benefits for treating cancers, we wondered what would happen if the endogenous p53 was inhibited before treated with topotecan (TPT) on p53 positive tumor cells. In this study, pifithrin-α (PFTα), a p53 inhibitor, was used 2 h before treated with TPT on three kinds of cancer cell lines including MCF7, BGC823 and HepG2 cells. The IC50s of TPT for MCF7, BGC823 and HepG2 cells after 10 µΜ PFTα pretreated, was 4.8 to 14.4 folds lower than the effect of TPT alone. It was demonstrated that PFTα decreases the p-p53 levels and p-p53 activity, not affects p53 expression in p53 positive tumor cells. PFTα enhanced anticancer effect of TPT on cells was found mainly by two ways. Firstly, it increased the TPT accumulation in cells and nucleus and promoted the inhibition of TPT on activity of Topo I, and induced more DNA damage. Secondly, PFTα decreased formation of p53/mdm2 complex responsible for p53 degradation by inhibiting the protein expression of mdm2, so p53 degradation was decreased in cytoplasm and p53 accumulation was increased in nucleus, which induced more cells undergo apoptosis. So, the crosstalk between p53 and TPT played a pivotal role for enhancing anticancer effects of PFTα and TPT on p53 positive cancer cells. These findings provide a new idea for drug design and combination chemotherapy of cancers.

LotS/LotR/Clp, a novel signal pathway responding to temperature, modulating protease expression via c-di-GMP mediated manner in Stenotrophomonas maltophilia FF11.

Stenotrophomonas maltophilia as one of increasing food spoilage bacteria and fish pathogens has become a threat to aquiculture industry. A major factor contributing to the success of bacterium is its outstanding ability to secrete protease at low temperatures. Here, a cAMP receptor like protein (Clp) shows a positive regulation on this protease, named S. maltophilia temperature-response protease (SmtP). Interestingly, a two-component system, comprising of LotS sensor and LotR regulator, for low-temperature response is also confirmed to modulate SmtP expression with similar effect to Clp. Evidence is presented that LotS/LotR modulates smtP (coding SmtP) expression via Clp: clp promoter activity was reduced significantly at low temperatures and protease activity was partially restored by Clp overexpressed in lotS or lotR deletion strain. Furthermore, as a Clp negative effector, the binding ability of c-di-GMP with Clp is not impacted by temperature. c-di-GMP level was increased in S. maltophilia growing at high temperature, but not exhibited significantly in lotR deleted strain, these indicate that LotR is required for temperature modulating c-di-GMP level, although the synthesis or degradation activity of c-di-GMP by LotR was not detected. These findings suggest that LotS/LotR/Clp play an important role in responding to temperature stimuli via c-di-GMP mediated manner.

Monitoring of clonal evolution of double C-KIT exon 17 mutations by Droplet Digital PCR in patients with core-binding factor acute myeloid leukemia.

C-KIT gene mutations result in the constitutive activation of tyrosine kinase activity, and greatly affect the pathogenesis and prognosis of core-binding factor acute myeloid leukemia (CBF-AML). C-KIT mutations are often found as single point mutations. However, the rate of double mutations has recently increased in AML patients. In this study, we detected six cases (18.8%) harboring double C-KIT exon17 mutations in 75 patients with CBF-AML. The clone composition and dynamic evolution were analyzed by sequencing and droplet digital PCR (ddPCR). Results revealed that these double mutations can be occurred in either the same or different clones. Different clones of double mutations may result in different sensitivity to the treatment of CBF-AML. The clones with N822 mutation responded better to treatment as compared to those with D816 mutation. Moreover, D816 clone was readily transformed into a predominant clone at relapse. Meanwhile, the predominant clones in the same patient may change during the progression of disease. The emerging mutation can originate from a small quantity of clones at diagnosis or newly acquired during the course of disease. Furthermore, patients with double mutations had better overall survival (OS) and event-free survival (EFS) than those with single mutation, but the differences did not reach statistical significance (P > 0.05). The ddPCR is an effective method for monitoring clonal evolution in patients with CBF-AML.

Ion- and water-binding sites inside an occluded hourglass pore of a trimeric intracellular cation (TRIC) channel.

BACKGROUND: Trimeric intracellular cation (TRIC) channels are crucial for Ca2+ handling in eukaryotes and are involved in K+ uptake in prokaryotes. Recent studies on the representative members of eukaryotic and prokaryotic TRIC channels demonstrated that they form homotrimeric units with the ion-conducting pores contained within each individual monomer. RESULTS: Here we report detailed insights into the ion- and water-binding sites inside the pore of a TRIC channel from Sulfolobus solfataricus (SsTRIC). Like the mammalian TRIC channels, SsTRIC is permeable to both K+ and Na+ with a slight preference for K+, and is nearly impermeable to Ca2+, Mg2+, or Cl-. In the 2.2-Å resolution K+-bound structure of SsTRIC, ion/water densities have been well resolved inside the pore. At the central region, a filter-like structure is shaped by the kinks on the second and fifth transmembrane helices and two nearby phenylalanine residues. Below the filter, the cytoplasmic vestibule is occluded by a plug-like motif attached to an array of pore-lining charged residues. CONCLUSIONS: The asymmetric filter-like structure at the pore center of SsTRIC might serve as the basis for the channel to bind and select monovalent cations. A Velcro-like plug-pore interacting model has been proposed and suggests a unified framework accounting for the gating mechanisms of prokaryotic and eukaryotic TRIC channels.