Molecular cloning and characterization of HSP60 gene in domestic pigeons (Columba livia) and differential expression patterns under temperature stress

Heat shock protein 60 (HSP60) is a well-recognized multifunctional protein, playing a substantial role in protecting organisms from environmental stress. The domestic pigeon (Columba livia) is a promising model organism, with important economic and ecological value, and its health is susceptible to temperature stress. To explore the molecular characteristics, tissue expression profile, and response to temperature stress for HSP60 of Columba livia (ClHSP60), we firstly cloned and characterized the complete cDNA sequence and investigated its expression profile under optimal conditions and acute temperature stress. The cDNA of ClHSP60 contained 2257 nucleotides, consisting of 12 exons with length ranging from 65 to 590 bp. The open reading frame (ORF) encoded 573 amino acids with calculated molecular weight of 60.97 kDa that contained a number of structurally prominent domains or motifs. Under optimal temperature conditions, levels of ClHSP60 expression differed between all the tested tissues (the highest was noted in liver and the lowest in pectoralis major muscle). Under acute temperature stress, five patterns of change were detected in the tested tissues, suggesting that different tissues in domestic pigeons differentially responded to various temperature stress conditions. Upregulation of ClHSP60 expression was highest in the lung and pectoralis major muscle, reflecting the crucial role of these two tissues in temperature regulation. However, the crop, cerebrum, and heart showed little change or decreased ClHSP60 expression. The results indicate that ClHSP60 may be sensitive to and play pivotal roles in responding to acute temperature stress.Electronic supplementary materialThe online version of this article (10.1007/s12192-020-01160-7) contains supplementary material, which is available to authorized users.     

Retinoic acid causes MEK-dependent RAF phosphorylation through RARα plus RXR activation in HL-60 cells

Retinoic acid (RA) is known to cause the myeloid differentiation of HL-60 human myeloblastic leukemia cells in a process requiring MEK-dependent ERK2 activation. This RA-induced ERK2 activation appears after approximately 4 h and persists until the cells are differentiated and G0 arrested (Yen et al, 1998). This motivates the question of whether RA also activated RAF as part of a typical RAF/MEK/MAPK cascade. Retinoic acid is shown here to also increase the phosphorylation of RAF, but in an unusual way. Surprisingly, increased RAF phosphorylation is first detectable after 12 to 24 hours by phosphorylation-induced retardation of polyacrylamide gel electrophoretic mobility. The RA-induced increased RAF phosphorylation is still apparent after 72 hours of treatment when most cells are differentiated and G0 arrested. There is a progressive dose-response relationship with 10(-8), 10(-7), and 10(-6) M RA. The RA-induced RAF phosphorylation corresponds to increased in vitro kinase activity. Inhibition of MEK with a PD98059 dose which inhibits ERK2 phosphorylation and subsequent cell differentiation also inhibits RAF phosphorylation. RA-induced MEK-dependent RAF phosphorylation is not due to changes in the amount of cellular MEK. The induced RAF phosphorylation, as well as anteceding ERK2 activation, depends on ligand-induced activation of both an RARalpha receptor and an RXR receptor. This and the slow kinetics of activation suggest a need for prior RA-induced gene expression. In summary, RA induces a MEK-dependent prolonged RAF activation, whose slow onset occurs after ERK2 activation but still well before cell cycle arrest and cell differentiation. The RA-induced increased RAF phosphorylation thus differs from typical mitogenic growth factor signaling, features that may contribute to cell cycle arrest and differentiation instead of division as the cellular outcome.     

Ceramide kinase expression is altered during macrophage-like cell differentiation of the leukemia cell line HL-60

Ceramide kinase (CerK) has important roles in leukocyte functions, including the role in degranulation of mast cells and the phagocytosis of polymorphonuclear leukocytes, so its expression levels should be strictly regulated. Here, we report that the mRNA expression and enzyme activity of CerK were decreased during macrophage-like cell differentiation of the leukemia cell line HL-60, yet neither was altered during granulocytic differentiation of the same cells. Our findings demonstrate that HL-60 cells are useful for studying CerK functions in leukocyte differentiation, and they also suggest that CerK might have an important role in such differentiation.     

Caspase-3 antisense oligodeoxynucleotides inhibit apoptosis in γ-irradiated human leukemia HL-60 cells

To study the inhibitory effects of caspase-3 mRNA antisense oligodeoxynucleotides (ASODNs) on apoptosis, we designed four ASODNs targeting different regions of caspase-3 mRNA and transfected them into human leukemia HL-60 cells. The transfected cells were given 10 Gy γ-irradiation followed by incubation for 18 h and measurement of apoptosis and caspase-3 expression. Our results showed that ASODN-2 targeting the 5′ non-coding region of sites –62 to –46, and ASODN-3 targeting the 5′ coding region of sites –1 to 16, both reduced apoptosis measured by gel electrophoresis and flow cytometry. Hoechst 33258 staining and TUNEL assay revealed that apoptotic indexes in the ASODN-2 and ASODN-3 groups were significantly lower than those in the untransfected and mismatched oligodeoxynucleotide (MODN) groups. Immunocytochemistry, Western blotting and RT-PCR showed that expression levels of caspase-3 protein and mRNA in both ASODN-2 and ASODN-3 groups were decreased compared with those in the untransfected and MODN groups. In conclusion, caspase-3 mRNA ASODNs can inhibit γ-radiation-induced apoptosis of HL-60 cells and reduce expression of caspase-3 protein and mRNA. The results suggest that antisense approach may be useful for therapeutic treatment of certain neurodegenerative diseases in which apoptosis is involved. The work was supported by a grant from the National Natural Science Foundation of China (No. 39880008).     

Mathematical modeling and qualitative analysis of insulin therapies

Several insulin therapies are widely in clinical use with the basic strategy that mimics insulin secretion in a normal glucose-insulin endocrine metabolic regulatory system. In this paper, we model the insulin therapies using a delay differential equation model. We study the dynamics of the model both qualitatively and quantitatively. The analytical results show the existence and uniqueness of a stable periodic solution that corresponds to ultradian insulin secretion oscillations. Numerically we simulate the insulin administration based on our model. The numerical simulation results are in agreement with findings of clinical studies.     

Optimal harvesting and optimal vaccination

Two optimization problems are considered: Harvesting from a structured population with maximal gain subject to the condition of non-extinction, and vaccinating a population with prescribed reduction of the reproduction number of the disease at minimal costs. It is shown that these problems have a similar structure and can be treated by the same mathematical approach. The optimal solutions have a 'two-window' structure: Optimal harvesting and vaccination strategies or policies are concentrated on one or two preferred age classes. The results are first shown for a linear age structure problem and for an epidemic situation at the uninfected state (minimize costs for a given reduction of the reproduction number) and then extended to populations structured by size, to harvesting at Gurtin-MacCamy equilibria and to vaccination at infected equilibria.     

基于L-半胱氨酸修饰的Fe3O4@TiO2复合纳米颗粒体外光动力疗法灭活HL60细胞的试验研究

本文采用共沉淀法制备了L-半胱氨酸(L-Cys)修饰的Fe3O4包裹TiO2(Fe3O4@TiO2/L-Cys)复合纳米粒子。通过透射电子显微镜(TEM),X射线衍射(XRD)和傅立叶变换红外光谱仪(FTIR)对复合纳米粒子进行了表征,并讨论了复合纳米粒子对HL60细胞体外光动力疗法(PDT)灭活的影响。并对其PDT灭活机制进行了初步探索。试验表明,Fe3O4@TiO2/L-Cys复合纳米粒子分散性高,生物相容性好,对细胞的暗毒性更低,并可以有效增强靶向性,提高PDT灭活效率,在410nm波长的光激发下,光照剂量为18J/cm^2的情况下,当TiO2与Fe3O4的比例为1∶3时,整体PDT效率最高。PDT灭活效率可达69.36%。     

Erythrofordins D and E,two new cassaine-type diterpenes from Erythrophleum suaveolens

Two new cassaine-type diterpenoids, namely erythrofordins D (1) and E (2), sourced from a Cameroon collection of Erythrophleum suaveolens were isolated and assessed for anti-tumor activity. In the NCI-60 cancer cell assay, erythrofordins D (1) and E (2) were found to be cytotoxic in the low micro molar ranges with a mean GI₅₀ value of 2.45 and 0.71?µM, mean TGI value of 9.77 and 2.29?µM, and a mean LC₅₀ of 26.92 and 11.48?µM for 1 and 2 respectively. Using the COMPARE algorithm, the new compounds were found to have similar NCI-60 response profiles to the known cardiac glycosides hyrcanoside and strophanthin. In addition, in an assay examining the viability and contractile function in human cardiomyocytes derived from induced pluripotent stem-cells, erythrofordins showed cardiotoxicity effects at concentrations as low as 0.03?µg/mL.     

乙酰基转移酶Tip60(KAT5)的功能研究进展

Tip60(KAT5)属于MYST乙酰基转移酶家族,同时它也是进化上非常保守的Nu A4蛋白质复合体的重要成员.过去十几年的研究证实,Tip60一方面可以作为转录调控因子结合核受体(如雄激素受体,AR)或c-MYC、AICD/Fe65、NCo R、E2F等转录因子来激活或抑制下游基因的表达,另一方面,KAT5可以乙酰化一系列蛋白来调控这些蛋白质的活性及稳定性,进而调控DNA损伤修复反应、细胞周期进程、细胞周期检查点的激活、凋亡、代谢及自噬等重要细胞功能.此外,Tip60在肿瘤的发生发展及转移、胚胎发育等过程中也发挥着至关重要的作用.本文将主要对Tip60近几年的研究进展做一个综述.     

FAM60A,increased by Helicobacter pylori,promotes proliferation and suppresses apoptosis of gastric cancer cells by targeting the PI3K/AKT pathway

Helicobacter pylori (H. pylori) infection can promote the development of gastric cancer (GC); however, the underlying mechanism is not clear. FAM60A has been found showing high levels in some cancer cells, including lung cancer (A549), and pancreatic cancer (Capan-2) cell lines. Data in oncomine showed that FAM60A overexpression was an critical prognostic factor in GC. In this study, we showed that knockdown of FAM60A could revert the increase of proliferation and the decrease of apoptosis caused by H.pylori infection in HGC-27 and AGS cells. Conversely, FAM60A upregulation promoted proliferation and inhibited apoptosis in HGC-27 and AGS cells. We also found that the PI3K/AKT pathway inhibitor LY294002 could revert the changes caused by FAM60A upregulation in HGC-27 and AGS cells. Thus, our study provides evidence that FAM60A act as a carcinogen and suggests that H. pylori-induced upregulation of FAM60A may contribute to the development of gastric cancer.