Induction of apoptosis and autophagy by dichloromethane extract from Patrinia scabiosaefolia Fisch on acute myeloid leukemia cells.

Patrinia scabiosaefolia Fisch (PS), a perennial herb belonging to the genus Pinus in the family Pinnacle Sauce, has been previously known for its analgesic, anti-inflammatory, antibacterial, and antitumor properties. However, the specific mechanism behind its antileukemic effect remains unknown. This study focused on the cytotoxicity and potential modes of action of the dichloromethane extract from PS (DEPS) in acute myeloid leukemia (AML) cells. Our results demonstrated that DEPS reduced cell viability, arrested the cell cycle in the G2/M phase, disrupted the mitochondrial membrane potential, increased reactive oxygen species (ROS) production, and upregulated the expression of Bax/Bcl-2 and Cleaved caspase-3. However, the impact of DEPS on cell viability and the expression of apoptosis-associated proteins was reversed upon pretreatment with the caspase-3 inhibitor (Z-DEVD-FMK) in HL-60 cells, which demonstrated that DEPS could induce apoptosis through the mitochondria-associated apoptotic pathway. Interestingly, DEPS also influenced autophagy by upregulating the expression of LC3II/I, P62, and Beclin-1 proteins, and the autophagy inhibition chloroquine(CQ) could attenuate the apoptotic effects of DEPS in HL-60 cells. Furthermore, SMART 2.0 analysis predicted that the main components present in DEPS were likely terpenoids. In conclusion, DEPS possibly exerts antileukemic effects by downregulating the PI3K/AKT and ERK pathways, thereby promoting intracellular ROS production, activating the mitochondrial apoptotic pathway, and affecting autophagy, providing valuable insights for the potential future application of PS in the treatment of AML.

Diterpenoids with an unusual tricyclo[10.3.0.02,9]pentadecane skeleton from Pedilanthus tithymaloides as multidrug resistance modulators.

Three new diterpenoids with an unusual carbon skeleton, pedilanins A-C (1-3), and nine new jatrophane diterpenoids, pedilanins D-L (4-12), along with five known ones (13-17), were isolated from Pedilanthus tithymaloides. Compounds 1-3 characterize an unprecedented tricyclo[10.3.0.02,9]pentadecane skeleton. Compounds 4-8 are rare examples of the jatrophanes bearing a cyclic hemiketal substructure. Their structures were determined by an extensive analysis of HRESIMS, NMR, quantum-chemical calculation, DP4+ probability, and X-ray crystallographic data. In the bioassay, compounds 1-12 dramatically reversed multidrug resistance in cancer cells with the fold-reversals ranging from 17.9 to 396.8 at the noncytotoxic concentration of 10 µM. The mechanism results indicated that compounds 2 and 3 inhibited the P-glycoprotein (Pgp) transporter function, thus reversing the drug resistance.

[Effect of Dichloromethane Extraction Phase of Patrinia Scabiosaefolia Fisch. Stem on Proliferation and Differentiation of K562 Cells].

OBJECTIVE: To explore the effect of dichloromethane extraction phase of ethanol extract from stem of Patrinia scabiosaefolia Fisch.(DPSS) on proliferation and differentiation of K562 cells and its related mechanism. METHODS: MTT assay was used to detect the effects of DPSS at 0, 25, 50, 100 and 200 µg/ml on the proliferation of K562 cells at 24, 48 and 72 hours. Flow cytometry was used to analyze the changes of cell cycle and apoptosis at 24 and 48 hours. Wright-Giemsa staining was used to observe the morphological changes of K562 cells. The cell surface antigens CD33 and CD11b were detected by flow cytometry. RESULTS: The proliferation of K562 cells treated with different concentrations of DPSS was inhibited in a time-dose dependent manner (r=-0.96). Cell cycle analysis showed that with the increase of DPSS concentration, cells in G2/M phase increased (r=0.88), and cells were blocked in G2/M phase. Flow cytometry results showed that with the apoptosis rate of K562 cells was the highest when treated with 200 µg/ml DPSS for 48 h. Morphological observation showed that the K562 cell body increased, the amount of cytoplasm increased, the ratio of nucleus to cytoplasm decreased, and the nuclear chromatin was rough after DPSS treatment. Cell differentiation antigen, CD33 and CD11b, were positively expressed after treated with DPSS. CONCLUSION: DPSS can induce apoptosis through cell cycle arrest, inhibit the proliferation of K562 cells, and induce K562 cells to differentiate into monocytes, which has a potential anti-leukemia effect.

Atopomonas sediminilitoris sp. nov., isolated from beach sediment of Zhairuo Island, China.

A novel bacterium designated A3.4T was isolated from the beach sediment of Zhairuo Island, which is located in the East China Sea. Strain A3.4T was found to be Gram-stain negative, cream coloured, rod-shaped, aerobic and motile via a single monopolar flagellum. The isolate grows at 20-37 °C (optimum 25-30 °C), at pH 6.0-8.0 (optimum pH 7.0-8.0), and in the presence of 0-5.0% (w/v) NaCl (optimum 0.5-1%). A3.4T has catalase and oxidase activity. The predominant fatty acids (≥ 10%) of the strain were identified as C16:0, summed feature 3 (C16:1 ω7c /C16:1 ω6c) and summed feature 8 (C18:1 ω7c /C18:1 ω6c). Q-9 was identified as the major isoprenoid quinone, with trace levels of Q-8 present. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The draft genome size is 3.55 Mb, with a DNA G + C content of 57.7 mol%. Analysis of the 16S rRNA gene sequence of strain A3.4T indicates that it belongs to the genus Atopomonas and shares high sequence similarity with Atopomonas hussainii JCM 19513T (97.60%). This classification was also supported by phylogenetic analysis using rpoB and several core genes. The genome of strain A3.4T shows an average nucleotide identity of 82.3%, an amino acid identity of 83.0%, and a digital DNA-DNA hybridization value of 22.1% with A. hussainii. In addition, 20 conserved signature indels (CSIs) were identified to be specific for A3.4T and A. hussainii, demonstrating that the strain A3.4T is closely related to A. hussainii rather than other species of family Pseudomonadaceae. Hundreds of unique genes were identified in the genomes of A3.4T and A. hussainii, which may underly multiple phenotypic differences between these strains. Based on phenotypic, chemotaxonomic, phylogenetic, and genomic investigations, strain A3.4T is concluded to represent a novel species of the genus Atopomonas, for which the name Atopomonas sediminilitoris sp. nov. is proposed. The type strain is A3.4T (= LMG 32563T = MCCC 1K07166T).

Ancylobacter gelatini sp. nov., isolated from beach sediment of Zhairuo Island, China.

A Gram-negative, aerobic, non-motile, oxidase-positive, catalase-positive, methyl red-positive, and lipase-negative bacterium, designated A5.8T, was isolated from beach sediment of Zhairuo Island located in the East China Sea. Growth occurred at 10-40 °C (optimum, 30 °C), pH 5.5-9.5 (optimum, 7.5), and 0-2% NaCl (optimum, 1.5%). Based on 16S rRNA gene sequence analysis, strain A5.8T belongs to the genus Ancylobacter, sharing the highest similarity with Ancylobacter aquaticus JCM 20518T (98.0%). Its polar lipids mainly consist of phosphatidylethanolamine (PE) and phosphatidylcholine (PC). The predominant fatty acids are summed feature 8 (C18:1ω7c and/or C18:1ω6c, 91.0%), and the major respiratory quinone is Q-10. The DNA G + C content is 67.2 mol%. Based on above analysis, as well as digital DNA-DNA hybridization (22.5-22.9%) and average nucleotide identity (83.0-83.6%) of strain A5.8T with reference type strains of the genus Ancylobacter, strain A5.8T was suggested to represent a novel species of the genus Ancylobacter, for which the name Ancylobacter gelatini sp. nov. is proposed. The type strain is A5.8T (= MCCC 1K07167T = LMG 32566T).

Spectrins and human diseases.

Spectrin, as one of the major components of a plasma membrane-associated cytoskeleton, is a cytoskeletal protein composed of the modular structure of α and ß subunits. The spectrin-based skeleton is essential for preserving the integrity and mechanical characteristics of the cell membrane. Moreover, spectrin regulates a variety of cell processes including cell apoptosis, cell adhesion, cell spreading, and cell cycle. Dysfunction of spectrins is implicated in various human diseases including hemolytic anemia, neurodegenerative diseases, ataxia, heart diseases, and cancers. Here, we briefly discuss spectrins function as well as the clinical manifestations and currently known molecular mechanisms of human diseases related to spectrins, highlighting that strategies for targeting regulation of spectrins function may provide new avenues for therapeutic intervention for these diseases.

Uncovering Bleomycin-Induced Genomic Alterations and Underlying Mechanisms in the Yeast Saccharomyces cerevisiae.

Bleomycin (BLM) is a widely used chemotherapeutic drug. BLM-treated cells showed an elevated rate of mutations, but the underlying mechanisms remained unclear. In this study, the global genomic alterations in BLM-treated cells were explored in the yeast Saccharomyces cerevisiae. Using genetic assay and whole-genome sequencing, we found that the mutation rate could be greatly elevated in S. cerevisiae cells that underwent Zeocin (a BLM member) treatment. One-base deletion and T-to-G substitution at the 5'-GT-3' motif represented the most striking signature of Zeocin-induced mutations. This was mainly the result of translesion DNA synthesis involving Rev1 and polymerase ζ. Zeocin treatment led to the frequent loss of heterozygosity and chromosomal rearrangements in the diploid strains. The breakpoints of recombination events were significantly associated with certain chromosomal elements. Lastly, we identified multiple genomic alterations that contributed to BLM resistance in the Zeocin-treated mutants. Overall, this study provides new insights into the genotoxicity and evolutional effects of BLM. IMPORTANCE Bleomycin is an antitumor antibiotic that can mutate genomic DNA. Using yeast models in combination with genome sequencing, the mutational signatures of Zeocin (a member of the bleomycin family) are disclosed. Translesion-synthesis polymerases are crucial for the viability of Zeocin-treated yeast cells at the sacrifice of a higher mutation rate. We also confirmed that multiple genomic alterations were associated with the improved resistance to Zeocin, providing novel insights into how bleomycin resistance is developed in cells.

Acinetobacter sedimenti sp. nov., isolated from beach sediment.

A Gram-stain-negative, aerobic, non-motile, non-haemolytic, oxidase-negative, catalase-positive bacillus strain (A3.8T) was isolated from beach sediment from Zhairuo Island, PR China. The strain grew at pH 6.0-9.0 (optimum, 7.0), with 0-4.5 % NaCl (optimum, 2 %) and at 10-35 °C (optimum, 30 °C). Its whole-genome sequence was 2.5 Mb in size, with a DNA G+C content of 41.6 mol%. On the basis of the results of core genome phylogenetic analysis, A3.8T represents a separate branch within the clade formed by five species of the genus Acinetobacter with 'Acinetobacter marinus' as the most closely related species. The average nucleotide identity compared with the closely related species of the genus Acinetobacter was below 83.66 % and digital DNA-DNA hybridization values were less than 28.80 %. The predominant fatty acids included C18 : 1ω9c, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). Q-9 was the major respiratory quinone. The polar lipids are mainly composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two phospholipids, an aminolipid and four unknown lipids. A3.8T cannot assimilate dl-lactate and weakly utilizes l-glutamate, l-leucine, l-phenylalanine and l-tartrate, which distinguishes it from other species of the genus Acinetobacter. On the basis of the genotype, phenotype and biochemical data, strain A3.8T represents a novel species of the genus Acinetobacter, for which the name Acinetobacter sedimenti sp. nov. is proposed. The type strain is A3.8T (=MCCC 1K07161T=LMG 32568T).

A simple fluorescent probe for the determination of dissolved oxygen based on the catalytic activation of oxygen by iron(II) chelates.

This work aims at establishing a simple fluorescent probe for the determination of dissolved oxygen. It is found that iron(II) ions activate oxygen to produce reactive species being capable of oxidizing non-fluorescent coumarin to fluorescent 7-hydroxycoumarin. However, this process is not effective because the yield of the reactive species is very low in the presence of simple iron(II) salts alone. The addition of organic ligands such as oxalate results in the formation of complexes between iron(II) ions, which leads to considerable increase in the yield of reactive species (such as hydroxyl radicals) and then increase in the fluorescence intensity of 7-hydroxycoumarin to a significant level. It has been observed that in the mixture solution of iron(II) ions, ligand, coumarin, and dissolved oxygen, there is an excellent linear response between the fluorescence and dissolved oxygen. Therefore, a new spectrofluorimetric method has been proposed for the determination of dissolved oxygen by using catalytic activation of O(2) by iron(II) chelates. Under optimized conditions, a linear correlation (r=0.995) has been observed between the fluorescence intensity of 7-hydroxycoumarin at 456 nm and the concentration of dissolved oxygen over the range of 0.96-9.22 mg L(-1). The limit of detection for dissolved oxygen at a signal-to-noise ratio of 3 has been estimated to be 0.35 mg L(-1). The proposed method has been applied to determine the concentration of dissolved oxygen in practical water samples with results as satisfactory as that obtained by the standard iodometric method.