Genetic diversity and natural selection on the thrombospondin-related adhesive protein (TRAP) gene of Plasmodium falciparum on Bioko Island, Equatorial Guinea and global comparative analysis.

BACKGROUND: Thrombospondin-related adhesive protein (TRAP) is a transmembrane protein that plays a crucial role during the invasion of Plasmodium falciparum into liver cells. As a potential malaria vaccine candidate, the genetic diversity and natural selection of PfTRAP was assessed and the global PfTRAP polymorphism pattern was described. METHODS: 153 blood spot samples from Bioko malaria patients were collected during 2016-2018 and the target TRAP gene was amplified. Together with the sequences from database, nucleotide diversity and natural selection analysis, and the structural prediction were preformed using bioinformatical tools. RESULTS: A total of 119 Bioko PfTRAP sequences were amplified successfully. On Bioko Island, PfTRAP shows its high degree of genetic diversity and heterogeneity, with π value for 0.01046 and Hd for 0.99. The value of dN-dS (6.2231, p < 0.05) hinted at natural selection of PfTRAP on Bioko Island. Globally, the African PfTRAPs showed more diverse than the Asian ones, and significant genetic differentiation was discovered by the fixation index between African and Asian countries (Fst > 0.15, p < 0.05). 667 Asian isolates clustered in 136 haplotypes and 739 African isolates clustered in 528 haplotypes by network analysis. The mutations I116T, L221I, Y128F, G228V and P299S were predicted as probably damaging by PolyPhen online service, while mutations L49V, R285G, R285S, P299S and K421N would lead to a significant increase of free energy difference (ΔΔG > 1) indicated a destabilization of protein structure. CONCLUSIONS: Evidences in the present investigation supported that PfTRAP gene from Bioko Island and other malaria endemic countries is highly polymorphic (especially at T cell epitopes), which provided the genetic information background for developing an PfTRAP-based universal effective vaccine. Moreover, some mutations have been shown to be detrimental to the protein structure or function and deserve further study and continuous monitoring.

Genetic polymorphism of Plasmodium falciparum circumsporozoite protein on Bioko Island, Equatorial Guinea and global comparative analysis.

BACKGROUND: Plasmodium falciparum circumsporozoite protein (PfCSP) is a potential malaria vaccine candidate, but various polymorphisms of the pfcsp gene among global P. falciparum population become the major barrier to the effectiveness of vaccines. This study aimed to investigate the genetic polymorphisms and natural selection of pfcsp in Bioko and the comparison among global P. falciparum population. METHODS: From January 2011 to December 2018, 148 blood samples were collected from P. falciparum infected Bioko patients and 96 monoclonal sequences of them were successfully acquired and analysed with 2200 global pfcsp sequences mined from MalariaGEN Pf3k Database and NCBI. RESULTS: In Bioko, the N-terminus of pfcsp showed limited genetic variations and the numbers of repetitive sequences (NANP/NVDP) were mainly found as 40 (35%) and 41 (34%) in central region. Most polymorphic characters were found in Th2R/Th3R region, where natural selection (p > 0.05) and recombination occurred. The overall pattern of Bioko pfcsp gene had no obvious deviation from African mainland pfcsp (Fst = 0.00878, p < 0.05). The comparative analysis of Bioko and global pfcsp displayed the various mutation patterns and obvious geographic differentiation among populations from four continents (p < 0.05). The global pfcsp C-terminal sequences were clustered into 138 different haplotypes (H_1 to H_138). Only 3.35% of sequences matched 3D7 strain haplotype (H_1). CONCLUSIONS: The genetic polymorphism phenomena of pfcsp were found universal in Bioko and global isolates and the majority mutations located at T cell epitopes. Global genetic polymorphism and geographical characteristics were recommended to be considered for future improvement of malaria vaccine design.

Involvement of PML-I in reformation of PML nuclear bodies in acute promyelocytic leukemia cells by leptomycin B.

Acute promyelocytic leukemia (APL) is characterized by a reciprocal translocation between chromosomes 15 and 17, t(15;17), resulting in the expression of PML-RARα fusion protein, which disrupts the normal PML nuclear bodies (PML-NBs) to micro-speckled pattern, leading to loss of their original functions. Moreover, reformation of PML-NBs in APL by arsenic is considered as one of the important step for APL treatment. Leptomycin B (LMB), a nuclear export inhibitor, is commonly used to inhibit the proteins exporting from the nucleus to the cytoplasm. In the present study, we found that LMB could induce the reformation of PML-NBs in leukemia NB4 cells as well as in APL blast cells from the patients, implying that nuclear shuttle proteins might be involved in the reformation of PML-NBs. Herein, we further found that LMB totally lost the ability to induce PML-NBs reformation when the endogenous PML gene was knocked out, indicating that endogenous PML protein is probably involved in the reformation of PML-NBs. More interestingly, among all PML isoforms (i.e., seven isoforms), reformation of PML-NBs was only observed when co-transfection of PML-RARα with PML-I after LMB treatment. Similarly, deletion of nuclear export signal (NES) of PML-I could also reform PML-NBs, suggesting that the protein level of endogenous PML-I in nucleus is important for the reformation of PML-NBs that interfered by PML-RARα fusion protein. Additionally, LMB has synergistic effect with iAsIII on enhancing PML-RARα fusion protein degradation, and it might provide new insight into APL treatment at clinical level in the near future.

Biosorption of copper ions from aqueous solution using rape straw powders: Optimization, equilibrium and kinetic studies.

In this paper, the adsorption behaviors of Cu(II) from the aqueous solution using rape straw powders were studied. The effects of initial Cu(II) concentration, pH range and absorbent dosage on the adsorption efficiency of Cu(II) by rape straw powder were investigated by Box-Behnken Design based on response surface methodology. The values of coefficient constant of the nonlinear models were 0.9997, 0.9984 and 0.9944 for removal Cu(II) from aqueous solution using rape straw shell, seed pods and straw pith core, respectively, which could navigate the design space for various factors on effects of biosorption Cu(II) from aqueous solution. The various factors of pH and biosorbents dosage were the key factors that affecting the removal efficiency of Cu(II) from aqueous solution. The biosorption equilibrium data presented its favorable monolayer adsorption Cu(II) onto shell, seed pods and straw pith core, respectively. The pseudo-second order kinetic model was the proper approach to determine the adsorption kinetics. The biosorption of Cu(II) onto surfaces of rape straw powders were confirmed and ion-exchanged in the adsorption process by energy dispersive spectrometer. The critical groups, -OH, -CH, -NH3+, -CH3, -NH and -C-O, exhibited by the infrared spectra results, changed to suggest that these groups played critical roles, especially -CH3 in the adsorption of copper ions onto rape straw powders. The study provided evidences that rape straw powders can be used for removing Cu(II) from aqueous water.

1/2 order subharmonic waves of two cavitation bubbles.

In the work, the 1/2 order subharmonic wave of two coupling cavitation bubbles is investigated numerically via Fourier spectrum analysis. By analyzing the dynamics of bubble, we find that the mutual interaction between bubbles can affect the appearance of 1/2 order subharmonic. The results of parameter dependence show that the intensity of 1/2 order subharmonic would be promoted or inhibited with the increase of mutual interaction. The higher the driving amplitude or the smaller the distance between bubbles, the stronger the mutual interaction is, and also the greater the promotion or suppression of the 1/2 order subharmonic is. Moreover, while the 1/2 order subharmonic occurs, the energy of bubble would alternate between two different peaks, and the temperature inside bubble has a similar fluctuation while the bubble collapses. This qualitative analysis suggests that the bubble's dynamics for multi-bubble case is complex. Understanding the generation of subharmonic of bubble's dynamics is of great significance for helpful applying of cavitation bubble.

A highly specific and ultrasensitive approach to detect Prymnesium parvum based on RPA-CRISPR-LbaCas12a-LFD system.

BACKGROUND: Harmful algal blooms (HABs), caused by the rapid proliferation or aggregation of microorganisms, are catastrophic for the environment. The Prymnesium parvum is a haptophyte algal species that is found worldwide and is responsible for extensive blooms and death of larval amphibians and bivalves, causing serious negative impacts on the ecological environment. For the prevention and management of environmental pollution, it is crucial to explore and develop early detection strategies for HABs on-site using simple methods. The major challenge related to early detection is the accurate and sensitive detection of algae present in low abundance. RESULTS: Herein, recombinase polymerase amplification (RPA) was combined with clustered regularly interspaced short palindromic repeats and Cas12a protein (CRISPR-LbaCas12a) systems, and the lateral flow dipstick (LFD) was used for the first time for early detection of P. parvum. The internal transcribed spacer (ITS) of P. parvum was selected as the target sequence, and the concentration of single-strand DNA reporters, buffer liquid system, reaction time, and amount of gold particles were optimized. The RPA-CRISPR-LbaCas12a-LFD approach demonstrated highly specificity during experimental testing, with no cross-reaction against different microalgae used as controls. In addition, the lowest detection limit was 10,000 times better than the lowest detection limit of the standalone RPA approach. The feasibility and robustness of this approach were further verified by using the different environmental samples. It also observed that P. parvum are widely distributed in Chinese Sea, but the cell density of P. parvum is relatively low (<0.1 cells/mL). SIGNIFICANCE: The developed approach has an excellent specificity and offers 10,000 times better sensitivity than the standalone RPA approach. These advantages make this approach suitable for early warning detection and prevention of HAB events in environmental water. Also, the outcomes of this study could promote a shift from traditional laboratory-based detection to on-site monitoring, facilitating early warning against HABs.

Molecular mechanism of a coastal cyanobacterium Synechococcus sp. PCC 7002 adapting to changing phosphate concentrations.

Phosphorus concentration on the surface of seawater varies greatly with different environments, especially in coastal. The molecular mechanism by which cyanobacteria adapt to fluctuating phosphorus bioavailability is still unclear. In this study, transcriptomes and gene knockouts were used to investigate the adaptive molecular mechanism of a model coastal cyanobacterium Synechococcus sp. PCC 7002 during periods of phosphorus starvation and phosphorus recovery (adding sufficient phosphorus after phosphorus starvation). The findings indicated that phosphorus deficiency affected the photosynthesis, ribosome synthesis, and bacterial motility pathways, which recommenced after phosphorus was resupplied. Even more, most of the metabolic pathways of cyanobacteria were enhanced after phosphorus recovery compared to the control which was kept in continuous phosphorus replete conditions. Based on transcriptome, 54 genes potentially related to phosphorus-deficiency adaptation were selected and knocked out individually or in combination. It was found that five mutants showed weak growth phenotype under phosphorus deficiency, indicating the importance of the genes (A0076, A0549-50, A1094, A1320, A1895) in the adaptation of phosphorus deficiency. Three mutants were found to grow better than the wild type under phosphorus deficiency, suggesting that the products of these genes (A0079, A0340, A2284-86) might influence the adaptation to phosphorus deficiency. Bioinformatics analysis revealed that cyanobacteria exposed to highly fluctuating phosphorus concentrations have more sophisticated phosphorus acquisition strategies. These results elucidated that Synechococcus sp. PCC 7002 have variable phosphorus response mechanisms to adapt to fluctuating phosphorus concentration, providing a novel perspective of how cyanobacteria may respond to the complex and dynamic environments. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-024-00244-y.

RT-RPA-PfAgo detection platform for one-tube simultaneous typing diagnosis of human respiratory syncytial virus.

Human respiratory syncytial virus (HRSV) is the most prevalent pathogen contributing to acute respiratory tract infections (ARTI) in infants and young children and can lead to significant financial and medical costs. Here, we developed a simultaneous, dual-gene and ultrasensitive detection system for typing HRSV within 60 minutes that needs only minimum laboratory support. Briefly, multiplex integrating reverse transcription-recombinase polymerase amplification (RT-RPA) was performed with viral RNA extracted from nasopharyngeal swabs as a template for the amplification of the specific regions of subtypes A (HRSVA) and B (HRSVB) of HRSV. Next, the Pyrococcus furiosus Argonaute (PfAgo) protein utilizes small 5'-phosphorylated DNA guides to cleave target sequences and produce fluorophore signals (FAM and ROX). Compared with the traditional gold standard (RT-qPCR) and direct immunofluorescence assay (DFA), this method has the additional advantages of easy operation, efficiency and sensitivity, with a limit of detection (LOD) of 1 copy/µL. In terms of clinical sample validation, the diagnostic accuracy of the method for determining the HRSVA and HRSVB infection was greater than 95%. This technique provides a reliable point-of-care (POC) testing for the diagnosis of HRSV-induced ARTI in children and for outbreak management, especially in resource-limited settings.

Decorating diruthenium compounds with Fréchet dendrons via the click reaction.

A series of dendronized-Ru(2) compounds were prepared using the Cu(I)-catalyzed 1,3-dipolar cycloaddition (click reaction) between the terminal azides of azidopoly(benzyl ether) dendrons ([D(n)]-N(3), n = 0-3) and Ru(2) units bearing one or two terminal ethynes, Ru(2)(D(3,5-Cl(2)Ph)F)(4-m)(DMBA-4-C(2)H)(m)Cl with m = 1 and 2, and D(3,5-Cl(2)Ph)F and DMBA-4-C(2)H as N,N'-bis(3,5-dichloro-phenyl)formamidinate and N,N'-dimethyl-4-ethynylbenzamidinate, respectively. The resultant Ru(2)(D(3,5-Cl(2)Ph)F)(4-m)(DMBA-D(n))(m)Cl compounds were further functionalized by the axial ligand displacement of Cl by -C(2)Ph to yield new compounds Ru(2)(D(3,5-Cl(2)Ph)F)(4-m)(DMBA-D(n))(m)(C(2)Ph)(2) (where m = 1 and 2; n = 0 and 1). All Ru(2) compounds reported herein were analyzed via mass spectrometry, voltammetry, and UV-visible and fluorescence spectroscopy. Density-functional theory (DFT) calculations were performed on a model compound to gain more insight into the molecular orbital energy levels possibly associated with the photophysical data obtained and presented herein.

[Progress of transcranial magnetic stimulation-motor evoked potential and its forensic application].

Transcranial magnetic stimulation-motor evoked potential (TMS-MEP) test is one of the electrophysiological examination methods to evaluate the function of central nervous system. The value of the TMS-MEP has been recognized by some clinical forensic workers recently. This article reviews the principle and advantages of TMS-MEP and its application in functional evaluation of central nervous system and clinical treatment. The value of TMS-MEP in forensic medicine, especially in objective assessment of muscle strength after injury of central nervous system is also discussed.

Apolipoprotein A-I inhibits chemotaxis, adhesion, activation of THP-1 cells and improves the plasma HDL inflammatory index.

The anti-inflammatory effects of high density lipoprotein (HDL) are well described, however, such effects of Apolipoprotein A-I (ApoA-I) are less studied. Building on our previous study, we further explored the mechanism of anti-inflammatory effects of ApoA-I, and focused especially on the interaction between monocyte and endothelial cells and plasma HDL inflammatory index in LPS-challenged rabbits. Our results show that ApoA-I significantly decreased LPS-induced MCP-1 release from THP-1 cells and ox-LDL-induced THP-1 migration ratio (P<0.01, respectively). ApoA-I significantly decreased sL-selectin, sICAM-1 and sVCAM-1 release (P<0.01, P<0.01, P<0.05, respectively) from LPS-stimulated THP-1 cells. Furthermore, ApoA-I significantly inhibited LPS-induced CD11b and VCAM-1 expression on THP-1 cells (P<0.01, P<0.05, respectively). ApoA-I diminished LPS-induced mCD14 expression (P<0.01) and NFkappaB nuclear translocation in THP-1 cells. After single dose treatment of ApoA-I, the value of plasma HDL inflammatory index in LPS-challenged rabbits was improved significantly (P<0.05). These results suggest that ApoA-I can inhibit chemotaxis, adhesion and activation of human monocytes and improve plasma HDL inflammatory index with presenting beneficial anti-inflammatory effects.

[Effect of estrogen receptor alpha gene polymorphism on the variations of T lymphocyte subsets and its related cell factors in female patients with primary cholestasis cirrhosis].

OBJECTIVE: To study the effects of estrogen receptor (ER) alpha gene polymorphism on the migration of T lymphocyte subsets and related cytokines in the female patients with primary biliary cirrhosis(PBC). METHODS: This study was conducted with sixty female PBC patients without treatment as the study group and fifty-two healthy people wtih sex and age met the requirements of the study as the control group. The polymorphism of restriction enzyme cutting site of Xba I and Pvu II in intron 1 of ERa gene was detected by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). CD4+, CD8+, CD4+CD25+ and CD4+CD28- T lymphocytes in peripheral blood were quantitatively detected by flow cytometry. RT-PCR method was used to detect the expression of TNFa, IL-2, IFNgamma, IL-4, IL-6 and IL-10 in peripheral mononuclear cells. RESULTS: The positive rate of Pp in ERa gene Pvu II enzyme gene subtypes of female PBC patients was significantly greater than that of the control group, and the positive rate of pp gene subtype was significantly smaller than that of the control group (X2 = 7.2880, P = 0.0261). The difference of Xba I genotype and allele frequency between the female PBC patients group and the control group was not of statistical significance (X2 = 6.5382, P = 0.5833). The proportion of CD4+ T in T lymphocytes of PBC patients was increased to 45.31%+/-5.26%, compared with 33.81%+/-3.87% in the control group; and the proportion of CD8+ T lymphocytes was decreased to 27.78%+/-1.43 % from 31.83%+/-1.73% in the control group. In comparison with the control group, the proportion of CD4+CD25+ T lymphocytes decreased significantly, while that of CD4+CD28- T lymphocytes rose significantly. The expression levels of TNFa, IL-2 and IFNgamma mRNA were 0.59+/-0.19, 0.71+/-0.29 and 0.67+/-0.21 respectively, which were significantly higher than that in the control group (0.22+/-0.13, 0.31+/-0.14, 0.27+/-0.13) (t = 6.93, 5.07, 7.01, P value less than 0.01); the expression level of IL-6 mRNA was increased to 0.45+/-0.21 from 0.34+/-0.16 in the control group (t = 1.84, P value less than 0.05); and the difference of the expression levels of IL-4 and IL-10 mRNA between two groups was not of statistical significance. CONCLUSION: Pp of gene Pvu II was a genetically susceptible genotype in female PBC patients, and the allele p was a susceptible gene. Th1 cell subsets and related cytokines were dominant in peripheral blood of PBC patients. As a background of genetic susceptibility, ERa gene polymorphism could affect the shift of T lymphocyte subsets and the expression of the related cytokines in PBC patients.

[The association of hepatitis B virus genotype and the basal core promoter mutation in Qidong, China].

OBJECTIVES: To investigate the prevalence of hepatitis B virus (HBV) genotypes and the association with hepatocellular carcinoma (HCC) or basal core promoter (BCP) mutation in Qidong, China. METHODS: The whole genome of HBV or X gene sequences were obtained from serum samples of HBV infected patients by using PCR and direct sequencing methods. Phylogenetic tree was constructed to determine the genotypes or subgenotypes of HBV. RESULTS: According to the phylogenetic tree constructed from full-length sequence of HBV, genotype C2 was predominant in Qidong area. It was prevalent in 44 out of the 48 cases (91.7%), whereas genotype B2 only existed in 4 cases (8.3%). No other genotypes or recombinant types were found in Qidong patients. The result of genotyping based on X gene sequence confirmed the above observation. In a total of 182 samples, 169 (92.9%) showed genotype C2 and 10 (5.5%) showed genotype B2. There were 3 (1.6%) patients showed a coinfection with C2 and B2. The infection rate of genotype C in Qidong was significantly higher than that in neighboring city Shanghai (chi(2) = 12.252, P less than 0.01). There was no significant difference of genotype distribution between HCC and chronic hepatitis groups (P is more than 0.05). The frequency of T1762/A1764 double mutation in genotype C2 (70.3%) was significantly higher than that in genotype B2 (30.8%, P less than 0.05). The other two types of point mutation which also occurred in BCP, i.e. T1766 and A1768, were only seen in genotype C2. CONCLUSION: (1) Genotype C2 is the predominant genotype in Qidong, China. (2) There is no association between genotype C and HCC in Qidong. (3) Genotype C has a higher prevalence of BCP mutation than genotype B.

Recent Advances on Dynamical Behaviors of Coupled Neural Networks With and Without Reaction-Diffusion Terms.

Recently, the dynamical behaviors of coupled neural networks (CNNs) with and without reaction-diffusion terms have been widely researched due to their successful applications in different fields. This article introduces some important and interesting results on this topic. First, synchronization, passivity, and stability analysis results for various CNNs with and without reaction-diffusion terms are summarized, including the results for impulsive, time-varying, time-invariant, uncertain, fuzzy, and stochastic network models. In addition, some control methods, such as sampled-data control, pinning control, impulsive control, state feedback control, and adaptive control, have been used to realize the desired dynamical behaviors in CNNs with and without reaction-diffusion terms. In this article, these methods are summarized. Finally, some challenging and interesting problems deserving of further investigation are discussed.

Trends in Molecular Markers Associated with Resistance to Sulfadoxine-Pyrimethamine (SP) Among Plasmodium falciparum Isolates on Bioko Island, Equatorial Guinea: 2011-2017.

PURPOSE: Antimalarial drug resistance is one of the major challenges in global efforts to control and eliminate malaria. In 2006, sulfadoxine-pyrimethamine (SP) replaced with artemisinin-based combination therapy (ACT) on Bioko Island, Equatorial Guinea, in response to increasing SP resistance, which is associated with mutations in the dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes. PATIENTS AND METHODS: To evaluate the trend of molecular markers associated with SP resistance on Bioko Island from 2011 to 2017, 179 samples collected during active case detection were analysed by PCR and DNA sequencing. RESULTS: Pfdhfr and Pfdhps gene sequences were obtained for 90.5% (162/179) and 77.1% (138/179) of the samples, respectively. For Pfdhfr, 97.5% (158/162), 95.7% (155/162) and 98.1% (159/162) of the samples contained N51I, C59R and S108N mutant alleles, respectively. And Pfdhps S436A, A437G, K540E, A581G, and A613S mutations were observed in 25.4% (35/138), 88.4% (122/138), 5.1% (7/138), 1.4% (2/138), and 7.2% (10/138) of the samples, respectively. Two classes of previously described Pfdhfr-Pfdhps haplotypes associated with SP resistance and their frequencies were identified: partial (IRNI-SGKAA, 59.4%) and full (IRNI-SGEAA, 5.5%) resistance. Although no significant difference was observed in different time periods (p>0.05), our study confirmed a slowly increasing trend of the frequencies of these SP-resistance markers in Bioko parasites over the 7 years investigated. CONCLUSION: The findings reveal the general existence of SP-resistance markers on Bioko Island even after the replacement of SP as a first-line treatment for uncomplicated malaria. Continuous molecular monitoring and additional control efforts in the region are urgently needed.

Evidence of positively selected G6PD A- allele reduces risk of Plasmodium falciparum infection in African population on Bioko Island.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) is an essential enzyme that protects red blood cells from oxidative damage. Although G6PD-deficient alleles appear to confer a protective effect of malaria, the link with clinical protection against Plasmodium infection is conflicting. METHODS: A case-control study was conducted on Bioko Island, Equatorial Guinea and further genotyping analysis used to detect natural selection of the G6PD A- allele. RESULTS: Our results showed G6PD A- allele could significantly reduce the risk of Plasmodium falciparum infection in male individuals (adjusted odds ratio [AOR], 0.43; 95% confidence interval [CI], 0.20-0.93; p < .05) and homozygous female individuals (AOR, 0.11; 95% CI, 0.01-0.84; p < .05). Additionally, the parasite densities were significantly different in the individuals with different G6PD A- alleles and individual levels of G6PD enzyme activity. The pattern of linkage disequilibrium and results of the long-range haplotype test revealed a strong selective signature in the region encompassing the G6PD A- allele over the past 6,250 years. The network of inferred haplotypes suggested a single origin of the G6PD A- allele in Africans. CONCLUSION: Our findings demonstrate that glucose-6-phosphate dehydrogenase (G6PD) A- allele could reduce the risk of P. falciparum infection in the African population and indicate that malaria has a recent positive selection on G6PD A- allele.

Irreversibility of arsenic trioxide induced PML/RARα fusion protein solubility changes.

Arsenic trioxide (As2O3) is one of the most effective drugs for the treatment of acute promyelocytic leukemia (APL), and induces the degradation of chimeric oncoprotein PML/RARα (P/R) and APL cell differentiation. Recent evidence has suggested that P/R fusion protein degradation by arsenic occurs through two steps, namely, rapid solubility change/shift of the P/R fusion protein following arsenic treatment (i.e., transfer of P/R protein from the soluble fraction to the insoluble pellet fraction), and subsequent degradation of these insoluble proteins. However, there is little information regarding the reversibility of arsenic induced P/R fusion protein solubility change as well as protein degradation in the insoluble fraction after removing arsenic. In this study, we used APL cell line NB4 or P/R and PML over-expressed 293T cells as well as HeLa cells to reveal the solubility change of P/R and PML by arsenic exposure, and further determined the fate of these insoluble proteins after the removal of arsenic. Here, for the first time, we found that arsenic induced P/R or PML protein solubility change is an irreversible process. Once arsenic induces a P/R or PML protein solubility change, these insoluble proteins could be degraded by the proteasomal pathway even without continuous arsenic treatment. However, PML and P/R proteins can be newly synthesized after the removal of arsenic, suggesting that great caution should be taken in the clinical therapy of APL patients before ending arsenic treatment.

RNA interference targeting the platelet-derived growth factor receptor beta subunit ameliorates experimental hepatic fibrosis in rats.

BACKGROUND/AIMS: Platelet-derived growth factor (PDGF) is the strongest stimulator of the proliferation of hepatic stellate cells (HSCs). PDGF receptor beta subunit (PDGFR-beta) is acquired on HSCs proliferation induced by PDGF. In this study, we aim to investigate the effect of PDGFR-beta small interference RNA (siRNA) on experimental hepatic fibrosis. METHODS: We constructed a PDGFR-beta siRNA expression plasmid and investigated its effect on the activation of HSCs. Bromodeoxyuridine incorporation was performed to investigate the effect of PDGFR-beta siRNA on HSCs proliferation. A hydrodynamics-based transfection method was used to deliver PDGFR-beta siRNA to rats with hepatic fibrosis. The distribution of transgenes in the liver was observed by immunofluorescence. The antifibrogenic effect of PDGFR-beta siRNA was investigated pathologically. RESULTS: Platelet-derived growth factor receptor-beta subunit siRNA could significantly downregulate PDGFR-beta expression, suppress HSCs activation, block the mitogen-activated protein kinase signalling pathway and inhibit HSCs proliferation in vitro. PDGFR-beta siRNA expression plasmid could be delivered into activated HSCs by the hydrodynamics-based transfection method, and remarkably improve the liver function of the rat model induced by dimethylnitrosamine and bile duct ligation. Furthermore, the progression of fibrosis in the liver was significantly suppressed by PDGFR-beta siRNA in both animal models. CONCLUSIONS: Platelet-derived growth factor receptor-beta subunit siRNA may be presented as an effective antifibrogenic gene therapeutic method for hepatic fibrosis.

[The expression of scavenger receptor class A in the lung in mice with acute lung injury induced by lipopolysaccharide].

OBJECTIVE: To investigate the expression of scavenger receptor class A (SR-A) in lung tissue and alveolar macrophage (AM) in mice with acute lung injury (ALI) induced by lipopolysaccharide (LPS). METHODS: The model of ALI was reproduced by intraperitoneal (ip) injection of LPS (5 mg/kg), and the expression of SR-A was observed in lung tissue and AM, and the expression and distribution of J774 A.1 were also studied by using mouse macrophage line. RESULTS: Partial pressure of oxygen in artery (PaO(2)) of lung tissue in LPS groups was significantly lower while wet/dry weight (W/D) ratio was higher than those in normal saline control group (both P<0.01). SR-A was widely expressed in murine lung, including AM, pulmonary vascular endothelial cells, vascular smooth muscle cells, lung epithelial cells and polymorphonuclear neutrophils. Immunohistochemical staining showed that, during the course of development of ALI in mice, the expression of SR-A was gradually down-regulated with the elapse of time after ip injection of LPS, The same result was seen in the isolated AM, and especially marked in group 4 hours and group 8 hours. In vitro, the expression of SR-A on J774 A.1 cells decreased was also down-regulated when treated with LPS. CONCLUSION: SR-A was widely expressed in murine lung. During the course of ALI, the expression of SR-A in the murine lung and AM is down-regulated, which may be induced by LPS.

[The value of antimitochondrial antibody and its subtypes in the diagnosis of primary biliary cirrhosis].

OBJECTIVE: A study on the value of antimitochondrial antibody (AMA) and its subtypes anti-M2, anti-M4, and anti-M9 in diagnosing primary biliary cirrhosis (PBC). METHODS: Antimitochondrial antibody was detected by indirect immunofluorescence and anti-M2, anti-M4 and anti-M9 by Western blotting. AMA and anti-M2 of 78 PBC patients, of 35 non-PBC hepato-biliary disease patients and 20 healthy controls were studied and anti-M2, anti-M4 and anti-M9 were studied in 30 of the 78 PBC patients. RESULTS: 96.2% (75/78) of PBC patients were AMA positive and 94.9% (74/78) of PBC patients were anti-M2 positive. Only three among the 35 non-PBC patients were positive for AMA (one with very low titre). None of the 35 non-PBC patients was anti-M2 positive. AMA and anti-M2 were negative in all the healthy controls. Among the 30 anti-M2 positive patients, 16 patients were anti-M4 positive (16/30, 53.3%) and 4 patients were anti-M9 positive (4/30, 13.3%). CONCLUSION: AMA and its subtypes (special anti-M2) are important sero-immunological markers for the diagnosis of PBC.