Hydroxychloroquine-induced hyperpigmentation of the skin and bull's-eye maculopathy in rheumatic patients: a case report and literature review

Hydroxychloroquine (HCQ) is used as a traditional disease-modifying antirheumatic drugs (DMARDs), for the treatment of autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). However, it can cause serious adverse reactions, including hyperpigmentation of the skin and bull's-eye macular lesions. Here, we present a case of HCQ-induced hyperpigmentation of the skin and bull's-eye macular lesions in a patient who received HCQ for RA. A 65-year-old female patient developed blurred vision and hyperpigmentation of multiple areas of skin over the body for one month after 3 years of HCQ treatment for RA. Based on clinical presentation, ophthalmological examination and dermatopathological biopsy, a diagnosis of drug-induced cutaneous hyperpigmentation and bullous maculopathy of the right eye was made. After discontinuation of HCQ and treatment with iguratimod tablets, the hyperpigmentation of the patient 's skin was gradually reduced, and the symptoms of blurred vision were not significantly improved. We also reviewed the available literature on HCQ-induced cutaneous hyperpigmentation and bull's-eye macular lesions and described the clinical features of HCQ-induced cutaneous hyperpigmentation and bull's-eye macular lesions. In conclusion, clinicians should be aware of early cutaneous symptoms and HCQ-associated ophthalmotoxicity in patients with rheumatic diseases on HCQ sulphate and should actively monitor patients, have them undergo regular ophthalmological examinations and give appropriate treatment to prevent exacerbation of symptoms.

Ambient plasma treatment of pectin in aqueous solution to produce a polymer used in packaging

Water resistance, mechanical behavior and coloration of pectin needs to be tuned for packing utilization. Plasma was used for the treatment of natural products, but there is no research on its effect on the biomass in the presence of ammonia. Though the reaction of pectin (PE) and ammonia was known to impart the ammonolysis and de-esterification, the plasma treatment on PE solution containing ammonia was explored to exemplify the amination and polymerization of the carbohydrate at the ambient condition. The plasma treatment increased the coloration of the solution due to the deprotonation of PE for the production of more sp2 carbon. The film from the amination of PE showed higher hydrophobicity and water stability than the bare PE. The plasma treatment alone decreased the Young's modulus (4.3 MPa versus 22 MPa), while the nitrogen addition enhanced the Young's modulus to 160 MPa and increased the tensile strength (28.7 MPa versus 25.8 MPa of PE). The hydrogen bonds from the amine group induced a glass-to-rubber transition at 77.9 °C by the increasing the crosslinking. This work provided a facile way of aminating and conjugating the biomass in solution to produce polymer with improved mechanical properties using plasma and ammonia incorporation.

The combined effect of a novel formula of herbal extracts on bacterial infection and immune response in Micropterus salmoides

Herbal extracts have been considered as ideal alternative to antibiotics in aquaculture and application of combinatory effective extracts always can exhibit the enhanced bioactivity with high efficiency. In our study, a novel herbal extract combination GF-7, which is composed of Galla Chinensis, Mangosteen Shell extracts as well as the effective parts of Pomegranate peel and Scutellaria baicalensis Georgi extracts, was prepared and applied for the therapy of bacterial infection in aquaculture. The HPLC analysis of GF-7 was also investigated for quality control and chemical identification. In the bioassay, GF-7 had excellent antibacterial activity against various aquatic pathogenic bacteria in vitro, and the related MIC values were between 0.045 and 0.36 mg/mL. After feeding Micropterus salmoide with GF-7 (0.1, 0.3, and 0.6%, respectively) for 28 days, the activities of ACP, AKP, LZM, SOD, and CAT of the liver in each treatment group were significantly increased and the content of MDA was significantly decreased. Meanwhile, the hepatic expression of the immune regulators including IL-1β, TNF-α, and Myd88 at different times was up-regulated in varying degrees. The challenge results exhibited a good dose-dependent protective effect on M. salmoides infected with A. hydrophila, which was further confirmed by liver histopathology. Our results imply that the novel combination GF-7 is a potential natural medicine for the prevention and treatment of numerous aquatic pathogenic infectious diseases in aquaculture.

Clinical features of acute generalized exanthematous pustulosis caused by hydroxychloroquine in rheumatology patients and exploration of CARD14 gene mutations

Introduction

Acute generalized exanthematous pustulosis (AGEP) is a rare condition characterized by superficial pustules following drug ingestion or infection. Currently, there is no clear link between rheumatism and AGEP. It has been described that hydroxychloroquine (HCQ) is a rare cause of acute generalized epidermal necrolysis (AGEP). Presently, there are limited studies on HCQ-induced AGEP. We aimed to explore the clinical features and associated gene expression of AGEP induced after HCQ treatment exposure in rheumatology patients.

Methods

We assessed patients with HCQ-induced AGEP diagnosed at the Second Affiliated Hospital of Guizhou University of Chinese Medicine between January 1, 2017, and May 1, 2022. We also reviewed similar cases reported in specific databases.

Results

The study included five females (mean age, 40.2 years), and the mean time from initiation of HCQ treatment to symptom onset was 12.2 d. All patients received steroids and allergy medications after HCQ discontinuation, and the rash completely resolved within an average of 25.2 d. We performed whole exome sequencing and Sanger validation in our patient sample. CARD14 gene mutations were detected in three patients. Additionally, seven mutation sites were detected.

Discussion

HCQ-induced AGEP may have a longer latency period and regression time than AGEP induced by other drugs. Our patients all experienced CARD14 gene mutations. AGEP often resolves with topical therapy and drug discontinuation, although some cases require systemic steroid therapy. In the future, patients with rheumatism should pay attention to the effectiveness of HCQ during treatment and be aware of the associated skin toxicity.

Aqueous extract of Sanghuangporus baumii induces autophagy to inhibit cervical carcinoma growth

Sanghuangporus baumii, an edible fungus rich in heteropolysaccharides, has been found to have some anti-cervical cancer effects. In the current study, the effects of an aqueous extract of S. baumii on cervical cancer were investigated in a U14 cervical carcinoma cell implanted female Kunming mouse model. An aqueous extract of S. baumii (SHWE) was administered to tumor-bearing mice by gavage for 21 days. SHWE treatment significantly inhibited tumor growth by 67.4% at a dose of 400 mg per kg bodyweight. Transcriptomic results showed that the expression of key genes GABARAP, VMP1, VAMP8 and STX17 which are involved in the autophagy pathway was regulated after SHWE treatment, suggesting that SHWE may induce autophagy in tumors. The results were further confirmed by measuring the LC3II/LC3I ratio using western blotting. Moreover, some differentially expressed genes were involved in the insulin signaling pathway, implying that SHWE induced autophagy by disturbing glucose uptake and utilization in tumors. The analysis of the gut microbiota indicated that SHWE treatment stimulated the proliferation of Akkermansia, a well-known probiotic that presented benefits in metabolic regulation and cancer therapy. In conclusion, SHWE administration modified the gut microbiota, disturbed the glucose metabolism and induced autophagy in tumors, and then inhibited the development of cervical carcinoma in vivo.

Multiple joint dislocations and bone disintegration in rheumatoid arthritis: A case report

Rheumatoid arthritis (RA) is a chronic inflammatory disease, which typically affects the small joints of the hands and feet. Anti-rheumatism drugs should be promptly administered upon a diagnosis. Without standardized treatment, patients are prone to different degrees of deformities in the later stages of disease development, which negatively impact quality of life. We here report a case of a 52-year-old woman with an 18-year history of RA. After intermittent immunotherapy with anti-rheumatism drugs, the patient presented with multiple joint pain, dislocation, and disintegration of the bone. The interphalangeal joints of both hands were deformed to varying degrees and movement was significantly limited. After anti-rheumatism treatment, the patient experienced reduced joint pain. This case should enhance understanding and serve as a guide for patient management toward the prevention of joint deformities caused by RA.

The impact of major public health emergencies on Trust in Government: From SARS to COVID-19

Major public health emergencies always test the credibility of the government. The success of governments’ strategies relies on trust in government and broad acceptance of response measures. The profound experience of the epidemic often has a long-term impact on people’s cognition. We construct a difference-in-difference estimator by combining the variations of epidemic effects across cohorts and regions, and intend to evaluate the long-term effect of individuals’ early SARS experience on trust in government during the COVID-19 pandemic. We also use the instrumental variable method to overcome the endogenous problem caused by two-way causality. The results show that the impact of COVID-19 has significantly reduced trust in government of the groups who had not been exposed to the SARS epidemic (including groups who were in early childhood and the unborn during the SARS outbreak). While it has a positive impact on trust in government of people experienced SARS in adolescence, and only a little negative impact on trust in government of people experienced SARS in adulthood. We also find that the impact of COVID-19 mainly reduced the trust in government among groups socially vulnerable or without SARS experience (e.g., low income, low social status etc.). The results suggest that: (a) the trust created by governments’ successful anti-epidemic measures is long-lasting; (b) governments should pay more attention to their trust among socially vulnerable groups.

Time lagged investigation of entrepreneurship school innovation climate and students motivational outcomes: Moderating role of students’ attitude toward technology

Based on the reinforcement theory of motivation, the purpose of this research was to measure the effect of school innovation climate on students’ motivational outcomes, including behavioral engagement, academic self-efficacy, interest, and utility value. Furthermore, the conditional influence of students’ attitude toward technology on the link between school innovation climate and students’ motivating outcomes has been investigated and reported. Data were gathered from the 305 entrepreneurship program students of five different universities located in Wuhan, China. In the SamrtPLS 3.3.3 program, the analysis was carried out using SEM. Results revealed that the school innovation climate has a favorable impact on improving the motivating outcomes of students. Additionally, results also provided support for moderation hypotheses that “students’ attitude toward technology” moderated the relationship between “school innovation climate” and academic self-efficacy. On the contrary, “students’ attitudes about technology,” did not appear to be a significant moderator in terms of enhancing the influence of the “school innovation atmosphere” on the students’ behavioral engagement, interest, and utility value. This study provides key policy and theoretical and practical implications as well as future research avenues for entrepreneurial school managers and education scholars.

Evaluation of the protective efficacy of virus-like particles based on PCV 2b and 2d subtypes against mixed challenge in mice

Porcine circovirus type 2 (PCV2) is an economically important swine pathogen and, although small, it has the highest evolution rate among DNA viruses. Commercial PCV2 commercial vaccines are inactivated PCV2 isolates or a subunit vaccine based on the Cap protein of PCV2. Currently, PCV2 VLPs of individual subtype vaccines are available. Although the main prevalent genotype worldwide is PCV2b, the emerging subtype PCV2d subtype is also increasingly associated with PCV disease. The aim of the study was to evaluate the protective efficacy of VLP based on the PCV2b and 2d subtypes against the mixed challenge of two hypotype PCV2 in mice. Thirty-six female SPV Kunming mice were immunized twice with PCV2b and 2d VLPs, then challenged with PCV2b and PCV2d, to assess the immunogenicity and effectiveness of the VLPs. Vaccination of the mice with PCV2b and 2d VLPs elicited a robust antibody response specific for the PCV2. The virus load detected in the 2b and 2d spleen vaccine group was the lowest compared to other groups. Furthermore, there was no pathological damage in the HE stained sections of the 2b and 2d spleen vaccine, and no virus was detected in the immunohistochemical sections. Our data suggest that the mixed PCV2b and 2d VLP vaccine could protect mice from challenge with the mixed infection of PCV2b and PCV2d..

Electroencephalography Theta/Beta Ratio Decreases in Patients with Severe Obstructive Sleep Apnea

Purpose

Accumulating evidence suggests that theta/beta ratio (TBR), an electroencephalographic (EEG) frequency band parameter, might serve as an objective marker of executive cognitive control in healthy adults. Obstructive sleep apnea (OSA) has a detrimental impact on patients' behavior and cognitive performance while whether TBR is different in OSA population has not been reported. This study aimed to explore the difference in relative EEG spectral power and TBR during sleep between patients with severe OSA and non-OSA groups.

Patients and Methods

142 participants with in-laboratory nocturnal PSG recording were included, among which 100 participants suffered severe OSA (apnea hypopnea index, AHI > 30 events/hour; OSA group) and 42 participants had no OSA (AHI ≤ 5 events/h; control group). The fast Fourier transformation was used to compute the EEG power spectrum for total sleep duration within contiguous 30-second epochs of sleep. The demographic and polysomnographic characteristics, relative EEG spectral power and TBR of the two groups were compared.

Results

It was found that the beta band power during NREM sleep and total sleep was significantly higher in the OSA group than controls (p < 0.001, p = 0.012, respectively), and the theta band power during NREM sleep and total sleep was significantly lower in the OSA group than controls (p = 0.019, p = 0.014, respectively). TBR during NREM sleep, REM sleep and total sleep was significantly lower in the OSA group compared to the control group (p < 0.001 for NREM sleep and total sleep, p = 0.015 for REM sleep). TBR was negatively correlated with AHI during NREM sleep (r=-0.324, p < 0.001) and total sleep (r=-0. 312, p < 0.001).

Conclusion

TBR was significantly decreased in severe OSA patients compared to the controls, which was attributed to both increased beta power and decreased theta power. TBR may be a stable EEG-biomarker of OSA patients, which may accurately and reliably identify phenotype of patients.

Application of a recombinant replicase to localize the Trionyx sinensis hemorrhagic syndrome virus and evaluate its effects on antiviral genes of T. sinensis

Trionyx sinensis Hemorrhagic Syndrome Virus (TSHSV) is an arterivirus newly discovered in Chinese softshell turtles. Little is known about the effect of antibodies against the virus or the distribution of the virus in different organs of infected turtles. In this study, a partial protein of TSHSV-HP4 was produced using a prokaryotic expression system, and its polyclonal antibody was generated. The polyclonal antibody was confirmed by western blot and dot enzyme-linked immunosorbent assay (dot-ELISA). The distribution of TSHSV in different organs of T. sinensis was examined by immunohistochemistry (IHC) and the expression of immune-related genes was analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). The results indicated that the recombinant TSHSV-HP4 protein was successfully expressed, and the generated polyclonal antibody showed specific binding to viral particles in the lung tissues of infected turtles. The IHC assay indicated that the virus was highly localized in various cells, including intestinal lymphocytes, enterocytes, kidney epithelial cells, spleen cells, lung macrophages, and cardiomyocytes. The qRT-PCR analysis revealed that TSHSV was detected in all organs tested, including the lungs, liver, kidneys, spleen, and heart. The numbers of viral mRNA copies in lung and heart tissues were significantly higher in the virus-antibody group than in the virus group. The interferon-stimulated genes (ISGs), myxovirus resistance protein 2 (MX2) and radical S-adenosyl methionine domain containing 2 (RSAD2) were highly upregulated in all groups of infected turtles. Antibody-dependent enhancement (ADE) seemed to occur after stimulation by the polyclonal antibody, because significantly greater expression of the two genes was detected in the virus-antibody group than in the virus group. Overall, these results are important in understanding the cell localization of TSHSV and the immune response of infected turtles.

Mannose-Modified Liposome Co-Delivery of Human Papillomavirus Type 16 E7 Peptide and CpG Oligodeoxynucleotide Adjuvant Enhances Antitumor Activity Against Established Large TC-1 Grafted Tumors in Mice

Background

Previously, we demonstrated the therapeutic efficacy of a human papillomavirus (HPV) vaccine, including HPV16 E7 peptide and CpG oligodeoxynucleotides (CpG ODN), against small TC-1 grafted tumors. Here, we developed an HPV16 E7 peptide and CpG ODN vaccine delivered using liposomes modified with DC-targeting mannose, Lip E7/CpG, and determined its anti-tumor effects and influence on systemic immune responses and the tumor microenvironment (TME) in a mouse large TC-1 grafted tumor model.

Methods

L-alpha-phosphatidyl choline (SPC), cholesterol (CHOL), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol-2000)] (DSPE-PEG-2000), 1,2-dioleoyl-3-trimethylammonium-propane chloride salt (DOTAP) and Mannose-PEG-DSPE, loaded with HPV16 E7 peptide and CpG ODN, were used to construct the Lip E7/CpG vaccine. The anti-tumor effects and potential mechanism of Lip E7/CpG were assessed by assays of tumor growth inhibition, immune cells, in vivo cytotoxic T lymphocyte (CTL) responses and cytokines, chemokines, CD31, Ki67 and p53 expression in the TME. In addition, toxicity of Lip E7/CpG to major organs was evaluated.

Results

Lip E7/CpG had a diameter of 122.21±8.37 nm and remained stable at 4°C for 7 days. Co-delivery of HPV16 E7 peptide and CpG ODN by liposomes exerted potent anti-tumor effects in large (tumor volume ≥200mm³) TC-1 grafted tumor-bearing mice with inhibition rates of 80% and 78% relative to the control and Free E7/CpG groups, respectively. Vaccination significantly increased numbers of CD4+ and CD8+ T cells, and IFN-γ-producing cells in spleens and tumors and enhanced HPV-specific CTL responses, while reducing numbers of inhibitory cells including myeloid-derived suppressor cells and macrophages. Expression of cytokines and chemokines was altered and formation of tumor blood vessels was reduced in the Lip E7/CpG group, indicating possible modulation of the immunosuppressive TME to promote anti-tumor responses. Lip E7/CpG did not cause morphological changes in major organs.

Conclusion

Lip E7/CpG induced anti-tumor effects by enhancing cellular immunity and improving tumor-associated immunosuppression. Mannose-modified liposomes are the promising vaccine delivery strategy for cancer immunotherapy.

A Landscape of lncRNA Expression Profile and the Predictive Value of a Candidate lncRNA for Silica-Induced Pulmonary Fibrosis

Silicosis is the most common type of pneumoconiosis with the fastest progress and the most serious harm. At present, there is still a lack of effective treatment for silicosis, and the molecular mechanism of silicosis is very complex, which is not completely clear. This study aimed to identify crucial long noncoding RNA (lncRNA)-mRNA networks for silica-induced pulmonary fibrosis using microarray data from Gene Expression Omnibus database, including human lung epithelial cells Beas-2B and continuously exposed to 5 μg/mL amorphous silica nanoparticles for 40 passages. Differently expressed genes were calculated by "DESeq2" R package. Then we selected the differently expressed mRNAs (DEmRNAs) and differently expressed long noncoding RNAs (DElncRNAs) data construct lncRNA-mRNA coexpression network using weighted gene coexpression network analysis (WCGNA). A total of 1140 DEmRNA and 1406 DElncRNAs were identified, including 20 upregulated DEmRNAs, 1120 downregulated DEmRNAs as well as 213 upregulated DElncRNAs and 1193 downregulated DElncRNAs. Furthermore, we demonstrate that lncRNA AK131029 was specifically overexpressed in silicosis. Loss-of-function assay indicated that silencing AK131029 of inhibited cell proliferation in human lung fibroblast cells. In conclusion, this study preliminarily indicates that lncRNA AK131029 may play a role in pulmonary fibrosis.

Integrated renal metabolomic and metallomic profiling revealed protective effect and metabolic mechanism of Gushudan on glucocorticoid-induced osteoporotic rat based on GC-MS and ICP-MS

Based on the traditional Chinese medicine theory, kidney is considered to govern the bones and dominate the store of essence ('jing' in Chinese). Gushudan (GSD) is a traditional Chinese medicine prescription for the treatment osteoporosis in the clinic and is beneficial for improving kidney function and strengthening bone in vivo. This study aims to reveal the renal metabolic profiling of glucocorticoid-induced osteoporosis (GIOP) rats and the potential preventive effect of GSD based on an integrative metabolomic and metallomic approach. Gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma mass spectrometry (ICP-MS) were combined for the investigation of renal metabolomic and metallomic profiling. In the metabolomic analysis, 17 potential biomarkers were found to be related to GIOP, such as glucose, malate, γ-aminobutyric acid and arachidonic acid. And seven metallic elements, including Zn, Mn, Se, Fe, Mo, As and Ba, were identified in rat kidney tissue in the metallomic analysis. The major metabolic pathways included aerobic glycolysis, and neurotransmitter amino acids metabolism. It was worth mentioning that the levels of trace metal elements (Zn, Mn, Se, Fe, As and Ba) significantly reduced in the model group, while the contents of Zn, Mn, Se, Fe and As were elevated after administration of GSD. Finally, a correlation metabolic regulatory network and the metabolic pathways associated with trace metal elements were further investigated to illuminate the role of potential biomarkers and trace metal elements in GIOP rats. These variations of potential biomarkers and trace metal elements suggested the existence of kidney damage and metabolic disorder in GIOP rats, which indicated a close relationship between bone and kidney in vivo. Moreover, the integrated renal metabolomic and metallomic profiling could be as an effective supplementary measure to the plasma and urine metabolomic research, and it was helpful to further understand the holistic formation process of osetoporosis and the potential preventive effects of GSD on GIOP rats.

1H-NMR-based urinary metabolomic analysis for the preventive effects of gushudan on glucocorticoid-induced osteoporosis rats

Gushudan (GSD), a traditional Chinese medicine with a history of more than 15 years, has been shown to have anti-osteoporosis effects, but the specific therapeutic mechanism behind it is still unclear. To further elucidate the pathogenesis of osteoporosis and the preventive mechanism of GSD on glucocorticoid-induced osteoporosis (GIOP) rats, a rapid and comprehensive ¹H NMR metabolomics method was established to detect urinary metabolic profiles in the control group, model group and GSD treatment group in this study. The orthogonal partial least squares discriminant analysis (OPLS-DA) was performed to investigate changes in the metabolites, and related metabolic pathways were discovered using MetaboAnalyst platform. As a result, a total of 27 differential metabolites were identified. Of these, 17 metabolites such as formate, allantoin and l-threonate were newly discovered as GIOP potential biomarkers. Energy metabolism, intestinal flora metabolism, amino acid metabolism and oxidative stress response were significantly changed in the urinary profiles of GIOP rats, and GSD could play an anti-osteoporosis role by regulating these metabolic pathways. This study compliments the earlier LC-MS based urine metabolomics research, and helps further understand the pathogenesis of osteoporosis and the potential preventive effects of GSD on GIOP rats.

[Cytomegalovirus detoxification and associated factors among preschool children in Yi'nan County]

Objective: To investigate cytomegalovirus detoxification and associated factors among preschool children in Yinan County, Shandong Province. Methods: Two kindergartens were selected from the county and township of Yinan respectively. A total of 250 children were investigated in October 2018. Case information was obtained through the child's guardian. Saliva samples of children and their mothers were collected for cytomegalovirus realtime-PCR detection.The status of CMV detoxification of children was explored and the associated factors were analyzed. Results: A total of 242 preschool children were investigated, and the detoxification rate of cytomegalovirus among them was 22.31% (54/242, 95%CI: 17.0%-27.6%). Logistic regression analysis showed that the rate of detoxification was higher in children whose mothers were cytomegalovirus detoxified (OR=12.39, 95%CI:1.73-88.65)and whose school was located in the county (OR=3.58, 95%CI:1.34-9.55). Conclusions: The detoxification rate of cytomegalovirus in preschool children is high, and there is mutual transmission between children and mothers. Women of childbearing age should pay attention to prevent congenital cytomegalovirus infection when they come into contact with children.

Transcriptome profiling analysis of lung tissue of Chinese soft-shell turtle infected by Trionyx sinensis Hemorrhagic Syndrome Virus

Trionyx sinensis Hemorrhagic Syndrome Virus (TSHSV) is the firstly discovered aquatic arterivirus inducing high mortality of Trionyx sinensis. So far, the lack of genomic resources has hindered further research on revealing the immunological characteristics of T. sinensis in response to TSHSV. In the present study, we performed a transcriptome analysis from the lungs of T. sinensis challenged by TSHSV using Illumina-based RNA-Seq. The validity of transcriptomic data was confirmed with the gradual increase of TSHSV RNA copies detected in lung. A total of 103079339 clean reads were generated, and 58374764 unique mapped reads were analyzed. Assembly of the sequence data allowed identifying 16383 unigenes consisting of 36 significant differentially expressed genes (DEGs). These DEGs were categorized into 30 GO-enriched bioprocesses and 9 KEGG pathways. The combinational analysis of GO-enriched bioprocesses and KEGG pathways demonstrated that TSHSV modulated several immune genes of T. sinensis related to various biological processes, including virus recognition (RIG-I/MDA-5), immune initiation (IFIT-1 and IFIT-5), endocytosis (CUBN, ENPP2 and LRP2) and steroid metabolism (FCNIL and STAR). In summary, the finding of this study revealed several immune pathways and candidated genes involved in the immune response of T. sinensis against TSHSV-infection. These results will provide helpful information to investigate molecular mechanism of T. sinensis in response to TSHSV.

Isolation and characterization of a novel strain (YH01) of Micropterus salmoides rhabdovirus and expression of its glycoprotein by the baculovirus expression system

As one of the most important aquatic fish, Micropterus salmoides suffers lethal and epidemic disease caused by rhabdovirus at the juvenile stage. In this study, a new strain of M. salmoides rhabdovirus (MSRV) was isolated from Yuhang, Zhejiang Province, China, and named MSRV-YH01. The virus infected the grass carp ovary (GCO) cell line and displayed virion particles with atypical bullet shape, 300-500 nm in length and 100-200 nm in diameter under transmission electron microscopy. The complete genome sequence of this isolate was determined to include 11 526 nucleotides and to encode five classical structural proteins. The construction of the phylogenetic tree indicated that this new isolate is clustered into the Vesiculovirus genus and most closely related to the Siniperca chuatsi rhabdovirus. To explore the potential for a vaccine against MSRV, a glycoprotein (1-458 amino acid residues) of MSRV-YH01 was successfully amplified and cloned into the plasmid pFastBac1. The high-purity recombinant bacmid-glycoprotein was obtained from DH10Bac through screening and identification. Based on polymerase chain reaction (PCR), western blot, and immunofluorescence assay, recombinant virus, including the MSRV-YH01 glycoprotein gene, was produced by transfection of SF9 cells using the pFastBac1-gE2, and then repeatedly amplified to express the glycoprotein protein. We anticipate that this recombinant bacmid system could be used to challenge the silkworm and develop a corresponding oral vaccine for fish.

Detection of cyprinid herpesvirus 2 by loop-mediated isothermal amplification in combination with a lateral flow dipstick

We developed a convenient technique to detect Herpesviral haematopoietic necrosis attributed to cyprinid herpes virus 2 (CyHV-2), a serious disease of Crucian carp and goldfish related to high mortality. In the present study, we employed a lateral flow dipstick (LAMP-LFD) to present a loop-mediated isothermal amplification assay. The specificity was ascertained via other six viruses, and the sensitivity was compared using PCR method, which are the reaction conditions changes for the method improved. The results revealed that CyHV-2 performance was observable at 64 °C in a separated tube within 60 min, when the samples hybridized using an FITC-labeled probe. As the LAMP-LFD method's specificity was high, with its sensitivity identical to that of traditional PCR, the overall DNA collected revealed the lowest detection limit of 0.18 pg/μl from goldfish diseased by CyHV-2. In summary, the development of LAMP-LFD's method does not require expensive instruments, and it can be regarded as a fast, simple, and reliable method for CyHV-2 detection.

[Expression of nicotinamide adenine dinucleotide phosphate-reduced oxidase-4/reactive oxygen species and cystathionine-γ-lyase/hydrogen sulfide in patients with chronic obstructive pulmonary disease-related pulmonary hypertension]

Objective: To observe the levels of serum reactive oxygen species (ROS) and hydrogen sulfide(H(2)S) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and nicotinamide adenine dinucleotide phosphate-reduced (NADPH) oxidase 4 (NOX4) and cystathionine-γ-lyase (CSE) in lung tissue of patients with stable chronic obstructive pulmonary disease (COPD). Methods: (1) A total of 60 patients with AECOPD admitted to the Department of Respiratory Medicine at Ningxia Hui People's Hospital from November 2015 to December 2016 were recruited. According to the results of pulmonary function and echocardiography, the participants were divided into AECOPD-related pulmonary hypertension (PH) group(A) and AECOPD non-PH group (B).Other 30 healthy subjects were selected as the control group (C).Serum ROS and H(2)S of group A, B and C were detected by enzyme-linked immunosorbent assay (ELISA).(2)The lung tissues of patients undergoing lobectomy for lung cancer from November 2012 to April 2017 were collected, who were divided into COPD-related PH group (D), COPD non-PH group (E) and negative control (F). The expression of NOX4 and CSE protein in lung tissue was detected by immunohistochemistry and the thickness of pulmonary arteriole wall was measured. Results: (1)The serum ROS level in group A was higher than group B and C which were (613.52±69.66)IU/ml,(565.76±71.33)IU/ml, (294.63±60.39)IU/ml, respectively with that in group B higher than that in group C (P<0.05). Serum H(2)S level in group A was lower than group B and C, with that in group B lower than group C [(18.59±5.50) nmol/ml, (20.49±4.97) nmol/ml, (38.03±4.43) nmol/ml, respectively P<0.05]. ROS level was positively correlated with pulmonary systolic pressure (PASP) (r=0.59, P<0.05), H(2)S level was negatively correlated with PASP(r=-0.62, P<0.05).(2)The lung tissue expression of NOX4 in group D was higher than group E and F (P<0.05), which were 0.08±0.01,0.06±0.01,0.03±0.01, respectively,while the level of NOX4 in group E was higher than group F (P<0.05). The expression of CSE between group D, E and F were all significantly different (P<0.05),which were 0.03±0.01, 0.07±0.02,0.12±0.02, respectively.(3)Smooth muscle thickness of pulmonary arterioles as a percentage of vascular diameter (WT%) between group D, E and F was all different(P<0.05), which were (40.58±6.63)%,(36.87±5.60)%,(31.27±6.24)%, respectively; so was smooth muscle area of pulmonary arterioles as a percentage of total vascular area(WA%) with (32.33±6.27)%, (30.20±5.28)%, (25.20±4.31)%, respectively (P<0.05). (4)The expression of NOX4 was positively correlated with WT% and WA%, r was 0.81 and 0.66, respectively (P<0.05). The expression of CSE was negatively correlated with WT% and WA%, r was -0.55 and -0.39 respectively (P<0.05). Conclusions: NOX4/ROS and CSE/H(2)S signaling pathways may play an important role in the pathogenesis of COPD related PH.

Complete genome sequence and analysis of a new lethal arterivirus, Trionyx sinensis hemorrhagic syndrome virus (TSHSV), amplified from an infected Chinese softshell turtle

Trionyx sinensis hemorrhagic syndrome virus (TSHSV) is a newly discovered lethal arterivirus that causes serious disease in Trionyx sinensis in China. In this study, the complete genome sequence of TSHSV was determined by RACE cloning, and the functions of the predicted proteins were predicted. The complete genome of TSHSV was found to be 17,875 bp in length, and a 3'-end poly(A) tail was detected. Eight TSHSV hypothetical proteins (TSHSV-HPs) were predicted by gene model identification. TSHSV-HP2, 3 and 4 were associated with replicase activity, since papain-like protease (PLPs), serine-type endopeptidase, P-loop-containing nucleoside triphosphate hydrolase, and EndoU-like endoribonuclease motifs were detected. Phylogenetic analysis showed that TSHSV clusters with an arterivirus from a Chinese broad-headed pond turtle.

[Polysomnographic comparation between dexmedetomidine-induced sleep and natural sleep]

Objective: To compare the parameters of polysomnography (PSG) in sleep structure and respiratory events between dexmedetomidine-induced sleep and natural sleep. Methods: From April 2016 to September 2018, a total of 44 patients with obstructive sleep apnea (OSA) and 3 patients with simple snoring completed PSG monitor both in natural sleep and dexmedetomidine-induced sleep in Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tsinghua Changgung Hospital. The PSG parameters were statistically analysed with SPSS 22.0 software. Results: The average dose of dexmedetomidine was (104.60±27.93) μg, and there was no significant difference between the induced-sleep efficiency and the natural sleep efficiency (82.14%±16.66% vs. 86.50%±9.18%, t=-1.559, P>0.05). There was no rapid eye movement(REM) stages in all 47 subjects and only 1 case of them had non-rapid eye movement(NREM) stage 3 in induced sleep. The percentage of NREM1 in total sleep time was statistically different between the two groups (42.10%±26.71% vs. 17.47%±11.68%, t=5.997, P<0.001),but there was no significant difference in the percentage of NREM2 in total sleep time between the two groups (56.96%±26.0% vs. 62.95%±9.03%, t=-1.521, P=0.135). About respiratory events, there were significant differences in apnea hypopnea index ((46.29±20.23)/h vs. (39.67±25.41)/h), obstructive apnea index (25.20[10.50,45.40]/h vs. 16.20[3.30,35.20]/h) between induced-sleep and natural sleep (t=2.297, Z=-3.008, all P<0.05), these difference were more significant in mild-to-moderate OSA. There were no statistically significant differences in central apnea index (0.00[0.00,2.80]/h vs. 0.40[0.10,1.20]/h), mixed apnea index (0.00[0.00,6.20]/h vs. 0.00[0.00,3.40]/h, hypopnea index (4.20[0.00,3.30]/h vs. 12.00[5.20,17.40]/h), Z=-0.110,-0.508,-1.544, all P>0.05). There were statistical differences in the lowest oxygen saturation (84.77%±7. 59% vs. 80.21%±11.62%, t=2.558, P=0.014). Conclusions: There is no significant difference in sleep efficiency and NREM2 between dexmedetomidine induced sleep and natural sleep.NREM3 sleep is rare induced, but REM sleep is none of all. And dexmedetomidine induced sleep may aggravate obstructive sleep apnea, but not central apnea.

An available strategy based on accurate mass by ultra high performance liquid chromatography coupled to Fourier transform ion cyclotron resonance mass spectrometry technology to characterization of metabolic profile of palbociclib in rat urine, feces and bile

Palbociclib (named PD 0332991) is a novel highly selective cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitor, which has been approved by the Food and Drug Administration (FDA) for the treatment of hormone-receptor-positive advanced breast cancer. This present study developed a comprehensive strategy to investigate the metabolic profile of palbociclib in rat urine, feces and bile samples based on an ultra high performance liquid chromatography coupled to Fourier transform ion cyclotron resonance mass spectrometry (UHPLC-FT-ICR MS). A total of 29 metabolites, including 18 phase I metabolites and 11 phase II metabolites, were detected and identified. The metabolic pathways included hydroxylation, oxidation, dehydrogenation, N-dealkylation, carbonylation, oxidative deamination, acetylation, glucuronidation, sulphate conjugation as well as the crossover of multiple metabolic pathways in vivo, and 16 of these metabolites were proposed for the first time. This study showed an insight into the metabolism of palbociclib in vivo, which may provide relevant chemical information for subsequent studies in the future.

Development and validation of a hydrophilic interaction ultra-high-performance liquid chromatography-tandem mass spectrometry method for rapid simultaneous determination of 19 free amino acids in rat plasma and urine

Determination of amino acids in biofluids is a challenging task because of difficulties deriving from their high polarity and matrix interference. A simple, reliable and high-throughput hydrophilic interaction UHPLC-MS/MS method was developed and validated for the rapid simultaneous determination of 19 free amino acids in rat plasma and urine samples in this paper. Hydrophilic method with a Waters Acquity UPLC BEH Amide column (100 × 2.1 mm,1.7 μm) was used with a gradient mobile phase system of acetonitrile and water both containing 0.2% formic acid. The analysis was performed on a positive electrospray ionization mass spectrometer via multiple reaction monitoring. Samples of 10 μL plasma and 50 μL urine were spiked with three deuterated internal standards, pretreated with 250 μL acetonitrile for one-step protein precipitation and a final dilution of urine samples. Good linearities (r > 0.99) were obtained for all of the analytes with the lower limit of quantification from 0.1 to 1.2 μg/mL. The relative standard deviation of the intra-day and inter-day precisions were within 15.0% and the accuracy ranged from -12.8 to 12.7%. The hydrophilic interaction UHPLC-MS/MS method was rapid, accurate and high-throughput and exhibited better chromatography behaviors than the regular RPLC methods. It was further successfully applied to detect 19 free amino acids in biological matrix.

The Kynurenine 3-Monooxygenase Encoding Gene, BcKMO, Is Involved in the Growth, Development, and Pathogenicity of Botrytis cinerea

A pathogenic mutant, BCG183, was obtained by screening the T-DNA insertion library of Botrytis cinerea. A novel pathogenicity-related gene BcKMO, which encodes kynurenine 3-monooxygenase (KMO), was isolated and identified via thermal asymmetric interlaced PCR, bioinformatics analyses, and KMO activity measurement. The mutant BCG183 grew slowly, did not produce conidia and sclerotia, had slender hyphae, and presented enhanced pathogenicity. The phenotype and pathogenicity of the BcKMO-complementing mutant (BCG183/BcKMO) were similar to those of the wild-type (WT) strain. The activities of polymethylgalacturonase, polygalacturonase, and toxins were significantly higher, whereas acid production was significantly decreased in the mutant BCG183, when compared with those in the WT and BCG183/BcKMO. Moreover, the sensitivity of mutant BCG183 to NaCl and KCl was remarkably increased, whereas that to fluconazole, Congo Red, menadione, H₂O₂, and SQ22536 and U0126 [cAMP-dependent protein kinase (cAMP) and mitogen-activated protein kinase (MAPK) signaling pathways inhibitors, respectively] were significantly decreased compared with the other strains. Furthermore, the key genes involved in the cAMP and MAPK signaling pathways, Pka1, Pka2, PkaR, Bcg2, Bcg3, bmp1, and bmp3, were significantly upregulated or downregulated in the mutant BCG183. BcKMO expression levels were also upregulated or downregulated in the RNAi mutants of the key genes involved in the cAMP and MAPK signaling pathways. These findings indicated that BcKMO positively regulates growth and development, but negatively regulates pathogenicity of B. cinerea. Furthermore, BcKMO was found to be involved in controlling cell wall degrading enzymes activity, toxins activity, acid production, and cell wall integrity, and participate in cAMP and MAPK signaling pathways of B. cinerea.

Isolation and Characterization of a Novel Dicistrovirus Associated with Moralities of the Great Freshwater Prawn, Macrobrachium rosenbergii

The giant freshwater prawn, Macrobrachium rosenbergii, is an economically important crustacean and is farmed in many countries. Since 2009, a larval mortality syndrome of M. rosenbergii has broken out and spread widely in the main breeding area, including Zhejiang, Jiangsu, Guangxi, and Guangdong Provinces in mainland China. A novel virus, named Macrobrachium rosenbergii Taihu virus (MrTV), was isolated from the moribund larvae and was determined to be the causative agent of the M. rosenbergii larval mortality syndrome by experimental infection. Further genomic sequencing suggested that the MrTV genome is monopartite, 10,303 nt in length, and dicistronic with two non-overlapping open reading frames (ORFs) separated by an intergenic region (IGR) and flanked by untranslated regions (UTRs). Phylogenetic analysis using the full-length genomic sequence and the putative amino acid sequences of the capsid protein revealed that MrTV was more closely related to the taura syndrome virus (TSV) than to any other viruses. According to these molecular features, we proposed that MrTV is a new species in the genus Aparavirus, family Dicistroviridae. These results may shed light on controlling larval mortality syndrome in M. rosenbergii.

[Inactivated vaccine for hemorrhage of Grass carp up-regulates the expressions of major immune-related genes in spleen of Grass carp]

OBJECTIVE

To investigate the impact of the injection of inactivated vaccine for hemorrhage of Grass carp on the expressions of main immune-related genes in spleen including immunoglobulin M (IgM), major histocompatibility complexI(MHC I), interferon I(IFN1), complement 3 (C3), interleukin-1β (IL-1β) and intelectin genes.

METHODS

Ctenopharyngoden idellus kidney (CIK) cells were inoculated with Grass carp reovirus (GCRV). Then inactivated vaccine was prepared by inactivating virus suspension with formaldehyde. Vaccine was 50- and 100-times diluted with normal saline. The experiments included four groups: undiluted group, 50-times diluted group, 100-times diluted group and normal saline control group. Then healthy Grass carps with the average body mass (20 ± 5) g were intraperitoneally injected with vaccine or normal saline separately for each group. Spleens were collected at different time points after injection (0, 6, 12, 24, 72 hours) and total RNA extraction was performed immediately. Real-time quantitative PCR (qRT-PCR) was used to detect mRNA expressions of the six immune-related genes.

RESULTS

Compared with normal saline control group, inactivated vaccine injection increased mRNA expressions of the six immune-related genes in the spleen of Grass carp, indicating that the vaccine stimulated the Grass carp to generate non-specific and specific immune responses. In the immunized groups, relative expressions of the genes intelectin, MHCI, IL-1β, C3 were all up-regulated at first and then declined as time went on. Relative expression of IFNIgene reached the peak at 6 hours post-injection and then decreased gradually to the normal level. Differently, relative expression of IgM gene increased continuously within 0-72 hours post-injection.

CONCLUSION

The expressions of the six major immune-related genes were all up-regulated in the spleen of Grass carp injected with different doses of inactivated vaccine for hemorrhage of Grass carp.

Functional up-regulation of P2X3 receptors in dorsal root ganglion in a rat model of bone cancer pain

BACKGROUND

Cancer-induced bone pain remains a clinical challenge due to the poor understanding of the mechanisms. Recent study revealed extracellular adenosine triphosphate (ATP) and P2X receptors may be implicated in nociceptive signalling under cancer pain state. Therefore, here we investigated the potential role of P2X(3) receptor in a rat model of bone cancer pain.

METHODS

Walker 256 tumour cells were inoculated into the left tibia of Wistar rats. The model was verified by X-ray imaging, pathology and behaviour examinations. The expression of P2X(3) receptors in dorsal root ganglia (DRG) was examined. Functional significance of altered P2X(3) receptors was investigated by measuring influx upon α,β-meATP stimulation in acutely dissociated DRG neurons. Moreover, A-317491, an antagonist of P2X(3) receptors, was administrated intrathecally or locally to evaluate its analgesia effect in the cancer pain animals.

RESULTS

The P2X(3) receptor was up-regulated for about 50% in DRG neurons in rats with bone cancer at both protein and mRNA levels and correlated with the pain behaviour in bone cancer rats. A 51.9% increase of α,β-me ATP (10 μM, for 4 s) evoked transient response currents and a higher percentage of neurons responsive to the application of α,β-me ATP was detected in bone cancer rats. Intrathecal or local injection of A-317491 significantly attenuated pain behaviour induced by bone cancer.

CONCLUSIONS

These results suggest that the P2X(3) receptor is functionally up-regulated in DRG in cancer rats. P2X(3) receptor is a promising target for therapeutic intervention in cancer patients for pain management.

Antigenic analysis of classical swine fever virus E2 glycoprotein using pig antibodies identifies residues contributing to antigenic variation of the vaccine C-strain and group 2 strains circulating in China

Background

Glycoprotein E2, the immunodominant protein of classical swine fever virus (CSFV), can induce neutralizing antibodies and confer protective immunity in pigs. Our previous phylogenetic analysis showed that subgroup 2.1 viruses branched away from subgroup 1.1, the vaccine C-strain lineage, and became dominant in China. The E2 glycoproteins of CSFV C-strain and recent subgroup 2.1 field isolates are genetically different. However, it has not been clearly demonstrated how this diversity affects antigenicity of the protein.

Results

Antigenic variation of glycoprotein E2 was observed not only between CSFV vaccine C-strain and subgroup 2.1 strains, but also among strains of the same subgroup 2.1 as determined by ELISA-based binding assay using pig antisera to the C-strain and a representative subgroup 2.1 strain QZ-07 currently circulating in China. Antigenic incompatibility of E2 proteins markedly reduced neutralization efficiency against heterologous strains. Single amino acid substitutions of D705N, L709P, G713E, N723S, and S779A on C-strain recombinant E2 (rE2) proteins significantly increased heterologous binding to anti-QZ-07 serum, suggesting that these residues may be responsible for the antigenic variation between the C-strain and subgroup 2.1 strains. Notably, a G713E substitution caused the most dramatic enhancement of binding of the variant C-strain rE2 protein to anti-QZ-07 serum. Multiple sequence alignment revealed that the glutamic acid residue at this position is conserved within group 2 strains, while the glycine residue is invariant among the vaccine strains, highlighting the role of the residue at this position as a major determinant of antigenic variation of E2. A variant Simpson's index analysis showed that both codons and amino acids of the residues contributing to antigenic variation have undergone similar diversification.

Conclusions

These results demonstrate that CSFV vaccine C-strain and group 2 strains circulating in China differ in the antigenicity of their E2 glycoproteins. Systematic site-directed mutagenesis of the antigenic units has revealed residues that limit cross-reactivity. Our findings may be useful for the development of serological differential assays and improvement of immunogenicity of novel classical swine fever vaccines.

Genetic characterization of E2 gene of classical swine fever virus by restriction fragment length polymorphism and phylogenetic analysis

An RT-nested PCR (RT-nPCR)-based restriction fragment length polymorphism (RFLP) analyses of the E2 gene were developed for genetic subtyping and differentiation of vaccinated and infected classical swine fever virus (CSFV) strains. RT-nPCR identified 96 CSFV-positive samples from 321 clinical specimens from southeastern China during 2003-2008. The PCR products of positive samples were further differentiated using MspI digestion, 23 were identified as the C-strain, 62 as field strains, and 11 as mixture of the vaccine strain and field ones. RFLP with BglI, DdeI, DraI, and PstI were then used for subtyping of the field CSFV isolates. Thirty-eight field isolates phylogenetically classified as subgroup 2.1 based on E2 were divided into 11 subtypes by this RFLP scheme. Both RFLP profiling and sequence-based phylogenetic analysis revealed genetic diversity of CSFV in the field. Three novel substitutions at amino acid positions 17, 93, and 286 were identified in the predominant subtype VI strains isolated in 2008 as compared to other strains including historical subtype VI strains. These results suggest that CSFV in China experienced gradual variations and evolutionary accumulation progress. Thus, the RFLP methods targeting on the CSFV E2 gene are suitable for epidemiological survey in endemic area where the C-strain is applied for vaccination. Combination of the RFLP schemes with sequence-based phylogenetic analysis could provide more detailed information on transmission of CSFV in the region or even its evolution.

Effects of full-length borealin on the composition and protein-protein interaction activity of a binary chromosomal passenger complex

The chromosomal passenger complex (CPC) comprises at least four protein components and functions at various cellular localizations during different mitotic stages to ensure correct chromosome segregation and completion of cytokinesis. Borealin, the most recently identified member of the CPC, is an intrinsically unstructured protein of low solubility and stability. Recent reports have demonstrated the formation of binary or ternary CPC subcomplexes incorporating short Borealin fragments in vitro. Using isothermal titration calorimetry, we show that full-length Borealin, instead of a Borealin fragment possessing the complete Survivin and INCENP recognition sequence, is required for the composition of a Borealin-Survivin complex competent to interact with INCENP. In addition, we show evidence that full-length Borealin, which forms high-order oligomers in its isolated form, is a monomer in the Borealin-Survivin CPC subcomplex.

Deconstructing Survivin: comprehensive genetic analysis of Survivin function by conditional knockout in a vertebrate cell line

Survivin is a key cellular protein thought to function in apoptotic regulation, mitotic progression, or possibly both. In this study, we describe the isolation of two conditional knockouts of the survivin gene in chicken DT40 cells. DT40 cells lacking Survivin die in interphase after failing to complete cytokinesis. However, these cells show normal sensitivity to the chemotherapeutic agent etoposide. Expression of Survivin mutants against a null background to reassess the role of several key residues reveals that DT40 cells can grow normally if their sole Survivin is missing a widely studied cyclin-dependent kinase phosphorylation site or sites reportedly essential for binding to Smac or aurora B. Mutations in the nuclear export sequence or dimerization interface render cells temperature sensitive for growth. As an important caveat for other studies in which protein function is studied by transient transfection, three of the Survivin mutants fail to localize in the presence of the wild-type protein but do localize and indeed support life in its absence.

Conformational changes in the AAA ATPase p97-p47 adaptor complex

The AAA+ATPase p97/VCP, helped by adaptor proteins, exerts its essential role in cellular events such as endoplasmic reticulum-associated protein degradation or the reassembly of Golgi, ER and the nuclear envelope after mitosis. Here, we report the three-dimensional cryo-electron microscopy structures at approximately 20 Angstroms resolution in two nucleotide states of the endogenous hexameric p97 in complex with a recombinant p47 trimer, one of the major p97 adaptor proteins involved in membrane fusion. Depending on the nucleotide state, we observe the p47 trimer to be in two distinct arrangements on top of the p97 hexamer. By combining the EM data with NMR and other biophysical measurements, we propose a model of ATP-dependent p97(N) domain motions that lead to a rearrangement of p47 domains, which could result in the disassembly of target protein complexes.

Structure, dynamics and interactions of p47, a major adaptor of the AAA ATPase, p97

p47 is a major adaptor molecule of the cytosolic AAA ATPase p97. The principal role of the p97-p47 complex is in regulation of membrane fusion events. Mono-ubiquitin recognition by p47 has also been shown to be crucial in the p97-p47-mediated Golgi membrane fusion events. Here, we describe the high-resolution solution structures of the N-terminal UBA domain and the central domain (SEP) from p47. The p47 UBA domain has the characteristic three-helix bundle fold and forms a highly stable complex with ubiquitin. We report the interaction surfaces of the two proteins and present a structure for the p47 UBA-ubiquitin complex. The p47 SEP domain adopts a novel fold with a betabetabetaalphaalphabeta secondary structure arrangement, where beta4 pairs in a parallel fashion to beta1. Based on biophysical studies, we demonstrate a clear propensity for the self-association of p47. Furthermore, p97 N binding abolishes p47 self-association, revealing the potential interaction surfaces for recognition of other domains within p97 or the substrate.

Solution Structure of the Third TB Domain from LTBP1 Provides Insight into Assembly of the Large Latent Complex that Sequesters Latent TGF-β

Almost all TGF-beta is secreted as part of a large latent complex. This complex is formed from three molecules, a latent transforming growth factor-beta binding protein (LTBP), which plays roles in targeting and activation, a latency associated peptide (LAP), which regulates latency, and the TGF-beta cytokine. LAP is the TGF-beta pro-peptide that is cleaved intracellularly prior to secretion, and TGF-beta binds non-covalently to LAP. Formation of the large latent complex is important for the efficient secretion of TGF-beta. Previous studies have revealed that the LTBP-LAP interaction is mediated by intracellular exchange of a single disulphide bond within the third, and only the third, TB domain (TB3) with LAP. We have previously reported the structure of a homologous TB domain from fibrillin-1. However, TB3 contains a two amino acid insertion, not found in fibrillin-1 TB domains, which is not amenable to molecular modelling. In order to clarify the basis of TB domain function, we have determined the solution NMR structure of TB3(LTBP1). Comparison with the fibrillin-1 TB domain reveals that the two-residue insertion is associated with a significant increase in solvent accessibility of one of the disulphide bonds (linking the second and sixth cysteine residues). Site-directed mutagenesis and NMR studies indicate that this is the only disulphide bond that can be removed without perturbing the TB domain fold. Furthermore, a ring of negatively charged residues has been identified that surrounds this disulphide bond. Homology modelling suggests that the surface properties of TB3 domains from different LTBP isoforms correlate with binding activities. This research provides testable hypotheses regarding the molecular basis of complex formation between LTBPs and LAPs.

Solution structure and RNA interactions of the RNA recognition motif from eukaryotic translation initiation factor 4B

Eukaryotic initiation factor 4B (eIF4B) is a multidomain protein with a range of activities that serves primarily to promote association of messenger RNA to the 40S ribosomal subunit during translation initiation. We report here the solution structure of the eIF4B RNA recognition motif (RRM) domain. It adopts a classical RRM fold, with a beta alpha beta beta alpha beta topology. The most striking difference with other RRM structures is in the disposition of loop 3, which connects the beta 2 and beta 3 strands and is implicated in RNA recognition. This loop folds down against the body of the RRM and exhibits restricted motion on a milli- to microsecond time scale. Although it contributes to a large basic patch on the RNA binding surface, it does not protrude out from the domain as observed in other RRM structures, possibly implying a different mode of RNA binding. On its own, the core RRM domain provides only a relative weak interaction with RNA targets and appears to require extensions at the N- and C-terminus for high-affinity binding.

Effects of the N2144S mutation on backbone dynamics of a TB-cbEGF domain pair from human fibrillin-1

The calcium-binding epidermal growth factor-like (cbEGF) module and the transforming growth factor beta-binding protein-like (TB) module are the two major structural motifs found in fibrillin-1, the extracellular matrix (ECM) protein defective in the Marfan syndrome (MFS). An MFS-causing mutation, N2144S, which removes a calcium ligand in cbEGF32, does not detectably affect fibrillin-1 biosynthesis, rate of secretion, processing, or deposition of reducible fibrillin-1 into the ECM. Since the residue at position 2144 is normally engaged in calcium ligation, it is unable to mediate intermolecular interactions. We have shown previously that this mutation does not affect the folding properties of the TB or cbEGF domains in vitro, but does decrease calcium-binding in cbEGF and TB-cbEGF domain constructs. Here, we use NMR spectroscopy to probe the effects of the N2144S mutation on backbone dynamic properties of TB6-cbEGF32. Analysis of the backbone (15)N relaxation data of wild-type TB6-cbEGF32 has revealed a flexible inter-domain linkage. Parallel dynamics analysis of the N2144S mutant has shown increased flexibility in the region joining the two domains as well as in the calcium-binding site at the N terminus of cbEGF32. This research demonstrates that a small change in peptide backbone flexibility, which does not enhance proteolytic susceptibility of the domain pair, is associated with an MFS phenotype. Flexibility of the TB-cbEGF linkage is likely to contribute to the biomechanical properties of fibrillin-rich connective tissue microfibrils, and may play a role in the microfibril assembly process.

Chemical shift mapping of RNA interactions with the polypyrimidine tract binding protein

The polypyrimidine tract binding protein (PTB), a homodimer that contains four RRM-type RNA binding domains per monomer, plays important roles in both the regulation of alternative splicing and the stimulation of translation initiation as directed by the internal ribosome entry sites of certain picornaviruses. We have used chemical shift mapping experiments to probe the interactions between PTB-34, a recombinant fragment that contains the third and fourth RRM domains of the protein, and a number of short pyrimidine-rich RNA oligonucleotides. The results confirm that the RNAs interact primarily with the beta-sheet surface of PTB-34, but also reveal roles for the two long flexible linkers within the protein fragment, a result that is supported by mutagenesis experiments. The mapping indicates distinct binding preferences for RRM3 and RRM4 with the former making a particularly specific interaction with the sequence UCUUC.

Transdifferentiation of neoplastic cells

Transdifferentiation is a process in which a stable cell's phenotype changes to that of a distinctly different cell type. It occurs during certain physiological processes and leads to transition of tumor cell phenotypes. The latter process includes neoplastic epithelial-epithelial transition, neoplastic epithelial-mesenchymal transition, neoplastic mesenchymal-epithelial transition and transition between non-neural and neural neoplastic cell. This phonomenon is exemplified in some origin-debated tumors, such as carcinosarcoma, pleomorphic adenoma, synovial sarcoma, Ewing's/pPNET, and malignant fibrohistiocytoma. We propose that differentiation disturbance of cancer cells should include not only undifferentiation and dedifferentiation, but also transdifferentiation as well. Tumor cell transdifferentiation may be influenced or determined by cellular genetic instabilities, proliferation and apoptosis, as well as by extracellular matrix and growth factors.

Transdifferentiation in neoplastic development and its pathological implication

Transdifferentiation is a process in which a cell committed to a particular specialization changes to another quite distinct type. It occurs during embryological development and some pathological processes, and causes the tumor cells to express a phenotype different from that of their normal progenitors. Neoplastic transdifferentiation involves pathogenesis of cancer subtype, transition between neoplastic epithelia and neuroendocrine cell, transition between neoplastic epithelia and mesenchyme, as well as transition between non-neuroectodermal and neuroectodermal cells. We propose that differentiation disturbance of cancer cells should include not only lower-, un-, or de-differentiation, but also transdifferentiation. Tumor cell transdifferentiation results from genetic instabilities. In some type of neoplastic transition, the initiation may be induced by extracellular matrix and growth factors.

Apoptotic death of inflammatory cells in human atheroma

Although the accumulation of cholesterol and other lipidic material is unquestionably important in atherogenesis, the reasons why this material progressively accumulates, rather than being effectively cleared by phagocytic cells such as macrophages, are not completely understood. We hypothesize that atheromatous lesions may represent "death zones" that contain toxic materials such as oxysterols and in which monocytes/macrophages become dysfunctional and apoptotic. Indeed, cathepsins B and L, normally confined to the lysosomal compartment, are present in the cytoplasm and nuclei of apoptotic (caspase-3-positive) macrophages within human atheroma. The possible involvement of oxysterols is suggested by experiments in which cultured U937 and THP-1 cells exposed to 7-oxysterols similarly undergo marked lysosomal destabilization, caspase-3 activation, and apoptosis. Like macrophages within atheroma, intralysosomal cathepsins B and L are normally present in the cytoplasm and nuclei of these oxysterol-exposed cells. Lysosomal destabilization, cathepsin release, and apoptosis may be causally related, because inhibitors of cathepsins B and L suppress oxysterol-induced apoptosis. Thus, toxic materials such as 7-oxysterols in atheroma may impair the clearance of cholesterol and other lipidic material by fostering the apoptotic death of phagocytic cells, thereby contributing to further development of atherosclerotic lesions.

Lysosomal destabilization during macrophage damage induced by cholesterol oxidation products

We have previously shown that oxidized low-density lipoprotein (LDL) induces damage to the macrophage lysosomal membranes, with ensuing leakage of lysosomal contents and macrophage cell death. Cholesterol oxidation products (ChOx) have been reported to be the major cytotoxic components of oxidized LDL/LDL- and also to stimulate cholesterol accumulation in vascular cells. In the present study, we characterized the initial events during macrophage damage induced by cholesterol oxidation products (ChOx). Within 24 h of exposure, ChOx caused lysosomal destabilization, release to the cytosol of the lysosomal marker-enzyme cathepsin D, apoptosis, and postapoptotic necrosis. Enhanced autophagocytosis and chromatin margination was found 12 h after the exposure to ChOx, whereas apoptosis and postapoptotic necrosis was pronounced 24 and 48 h after the exposure. Some lysosomal vacuoles were then filled with degraded cellular organelles, indicating phagocytosis of apoptotic bodies by surviving cells. Because caspase-3 activation was detected in the ChOx-exposed cells, lysosomal destabilization may associate with the leakage of lysosomal enzymes, and activation of the caspase cascade. MnSOD mRNA levels were markedly increased after 24 h of exposure to ChOx, suggesting associated induction of mitochondrial protection repair or turnover. We conclude that ChOx-induced damage to lysosomes and mitochondria are sequelae to the cascade of oxysterol cytotoxic events. The early disruption of lysosomes induced by ChOx, with resultant autophagocytosis may be a critical event in apoptosis and/or necrosis of macrophages/foam cells during the development of atherosclerotic lesions.

Apoptotic macrophage-derived foam cells of human atheromas are rich in iron and ferritin, suggesting iron-catalysed reactions to be involved in apoptosis

We investigated the presence of low-molecular-weight iron and ferritin in human atheromas, and their possible relation to the apoptotic process. Arterial wall segments with fatty streaks were collected from coronary arteries and thoracic aortas of 12 clinical autopsy cases with general atherosclerosis. Normal appearing regions from the same cases together with normal coronary arteries from seven young forensic autopsy cases, without any sign of atherosclerosis, were used for comparison. Anti-CD68 (macrophage marker) and anti-ferritin antibodies were applied to serial sections of the arterial wall segments, fixed in formadehyde and embedded in paraffin wax, using an avidin-biotin complex (ABC) technique. Similarly, apoptotic cells were assayed by the TUNEL technique, while low-molecular-weight iron was cytochemically detected by autometallography. Cell counting and computerised image analysis were performed to compare the distribution of macrophages, ferritin- and iron-rich cells, and apoptotic cells in the intima, media, and adventitia of the arteries. Pronounced ferritin accumulation, occurrence of lysosomal low-molecular-weight iron, and apoptosis mainly concerned CD68-positive cells (macrophages) in the atherosclerotic lesions. No ferritin- or CD68-positivity was found in normal coronary arteries from the young forensic-autopsy cases, while a moderate number of such cells were observed in the intima of normal looking vessel areas from the control cases. In the intima, cytosolic ferritin and low-molecular-weight iron with a lysosomal type distribution were found in many CD68-positive macrophages which frequently were surrounded by erythrocytes. A substantial number of apoptotic cells within the intima, media, and adventitia were registered in all atherosclerotic lesions examined, although mainly in the vulnerable macrophage-enriched areas of the atheroma shoulder. We suggest that iron may occur within the cytosol, mainly bound in ferritin, but also in low-molecular weight, redox-active form within the acidic vacuolar apparatus of macrophages and macrophage-derived foam cells following erythrophagocytosis or phagocytosis of apoptotic cells. Low-molecular-weight iron within lysosomes, present due to degradation of iron-containing structures, such as ferritin, may partially become exocytosed and contribute to cell-mediated LDL-oxidation. Moreover, such lysosomal iron may also sensitise lysosomes to oxidative stress and induce apoptosis of macrophage/foam-cells that may result in instability and rupture of atherosclerotic plaques.