Independent and combined associations of upper and lower limb strength with all-cause mortality in community-based older adults: findings from the Chinese Longitudinal Healthy Longevity Survey

OBJECTIVE

With the acceleration of aging progress, China is projected to have the largest older population globally. This study aimed to examine the association of upper limb strength (ULS) and lower limb strength (LLS) with all-cause mortality based on the Chinese Longitudinal Healthy Longevity Survey (2012-2018).

STUDY DESIGN

This is a prospective cohort study.

METHODS

Participants were 2442 older adults (aged 84.98 ± 11.94 years) recruited from eight longevity areas in China. Limb muscle strength was evaluated using handgrip strength and objective physical examinations. Cox proportional hazards regression was used to analyze the association of limb muscle strength with all-cause mortality. Demographic characteristics, health status, and biological markers were included as confounders.

RESULTS

Over a median follow-up period of 42.2 months, 993 older people died. After adjusting for all covariates, low ULS was associated with higher mortality risk (hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 1.25-1.84), and the association of low LLS with all-cause mortality was only significant in women (HR = 1.36, 95% CI = 1.04-1.79). Participants with combined low ULS and low LLS had the highest risk of mortality than those with normal limb muscle strength (hazard ratio = 2.06, 95% confidence interval = 1.61-2.63). The combined association of ULS and LLS with mortality was robust in subgroup and sensitivity analyses.

CONCLUSION

Low ULS and low LLS were independently and synergistically associated with higher all-cause mortality risk. Considering the high prevalence of limb muscle weakness among Chinese older adults, especially the oldest-old, limb strength could be considered as a potential doable mortality predictor for community health care.

Discovery and characterization of a novel cGAS covalent inhibitor for the treatment of inflammatory bowel disease

Cyclic GMP-AMP synthase (cGAS), a cytosolic DNA sensor, acts as a nucleotidyl transferase that catalyzes ATP and GTP to form cyclic GMP-AMP (cGAMP) and plays a critical role in innate immunity. Hyperactivation of cGAS-STING signaling contributes to hyperinflammatory responses. Therefore, cGAS is considered a promising target for the treatment of inflammatory diseases. Herein, we report the discovery and identification of several novel types of cGAS inhibitors by pyrophosphatase (PPiase)-coupled activity assays. Among these inhibitors, 1-(1-phenyl-3,4-dihydro-1H-pyrrolo[1,2-a]pyrazin-2-yl)prop-2-yn-1-one (compound 3) displayed the highest potency and selectivity at the cellular level. Compound 3 exhibited better inhibitory activity and pathway selectivity than RU.521, which is a selective cGAS inhibitor with anti-inflammatory effects in vitro and in vivo. Thermostability analysis, nuclear magnetic resonance and isothermal titration calorimetry assays confirmed that compound 3 directly binds to the cGAS protein. Mass spectrometry and mutation analysis revealed that compound 3 covalently binds to Cys419 of cGAS. Notably, compound 3 demonstrated promising therapeutic efficacy in a dextran sulfate sodium (DSS)-induced mouse colitis model. These results collectively suggest that compound 3 will be useful for understanding the biological function of cGAS and has the potential to be further developed for inflammatory disease therapies.

Major depressive disorder is correlated with the mitochondrial ND1 T3394C mutation in two Han Chinese families: Two case reports

BACKGROUND

Major depressive disorder (MDD) is the most frequent reason of disabled people in the world, as reported by the World Health Organization. However, the diagnosis of MDD is mainly based on clinical symptoms.

CASE SUMMARY

The clinical, genetic, and molecular characteristics of two Chinese families with MDD are described in this study. There were variable ages of onset and severity in depression among the families. Both Chinese families had a very low pre-valence of MDD. The mitochondrial genomes of these pedigrees were sequenced and indicated a homoplasmic T3394C (Y30H) mutation, with the polymorphism located at a highly conserved tyrosine at position 30 of ND1. The analysis also revealed unique sets of mitochondrial DNA (mtDNA) polymorphisms orig-inating from haplogroups M9a3 and M9a.

CONCLUSION

This finding of the T3394C mutation in two unrelated depressed patients provides strong evidence that this mutation may have a part in the etiology of MDD. However, In these two Chinese families having the T3394C mutation, no functional mtDNA mutation was observed. Therefore, T3394C mutations are related with MDD, and the phenotypic manifestation of these mutations may be affected by changes in nuclear genes or environmental factors.

The purine metabolite inosine monophosphate accelerates myelopoiesis and acute pancreatitis progression

Hyperglycemia-induced myelopoiesis and atherosclerotic progression occur in mice with type I diabetes. However, less is known about the effects of metabolites on myelopoesis in type 2 diabetes. Here, we use fluorescence-activated cell sorting to analyze the proliferation of granulocyte/monocyte progenitors (GMP) in db/db mice. Using targeted metabolomics, we identify an increase in inosine monophosphate (IMP) in GMP cells of 24-week-old mice. We show that IMP treatment stimulates cKit expression, ribosomal S6 activation, GMP proliferation, and Gr-1⁺ granulocyte production in vitro. IMP activates pAkt in non-GMP cells. In vivo, using an established murine acute pancreatitis (AP) model, administration of IMP-treated bone marrow cells enhances the severity of AP. This effect is abolished in the presence of a pAkt inhibitor. Targeted metabolomics show that plasma levels of guanosine monophosphate are significantly higher in diabetic patients with AP. These findings provid a potential therapeutic target for the control of vascular complications in diabetes.

Metabolomics analysis reveals that inosine monophosphate, a purine metabolite, promotes myelopoiesis and contributes to severe acute pancreatitis in db/db mice.

[Mechanism of Tibetan medicine Ershiwuwei Shanhu Pills on scopolamine-induced learning and memory impairment in mice based on Keap1/Nrf2/HO-1 signaling pathway]

This study aims to investigate the mechanism of the Tibetan medicine Ershiwuwei Shanhu Pills(ESP) in improving scopolamine-induced learning and memory impairment in mice based on Keap1/Nrf2/HO-1 signaling pathway. ICR mice were randomized into blank group, model group, low-dose(200 mg·kg~(-1)), medium-dose(400 mg·kg~(-1)), and high-dose(800 mg·kg~(-1)) ESP groups, and donepezil hydrochloride group. The learning and memory impairment was induced in mice by intraperitoneal injection of scopola-mine. The learning and memory abilities of mice were detected by Morris water maze test, and the damage of hippocampal neurons and cortical neurons was detected based on Nissl staining. The expression of neuron specific nuclear protein(NeuN) in hippocampus and cortex of mice was determined by immunofluorescence assay, and the content of acetylcholine(Ach) and the activity of acetylcholines-terase(AchE) in hippocampus of mice by kits. Moreover, the content of superoxide dismutase(SOD), malondialdehyde(MDA), catalase(CAT), and total antioxidant capacity(T-AOC) in serum of mice was detected. The content of Kelch-like ECH-associated protein 1(Keap1), nuclear factor erythroid 2-related factor 2(Nrf2), and heme oxygenase 1(HO-1) in hippocampus was determined by Western blot. The results showed that there were significant differences in the trajectory map of mice among different groups in the behavioral experiment. Moreover, the latency of ESP groups decreased significantly compared with that in the model group. The hippocampal neurons in the high-dose ESP group were significantly more than those in the model group and the cortical neurons in the high-dose and medium-dose ESP groups were significantly more than those in the model group. The expression of NeuN in the model group was significantly decreased compared with that in the blank group, and the expression in the ESP groups was significantly higher than that in the model group. The AchE activity and MDA level were significantly decreased, and Ach content and levels of SOD, CAT, and T-AOC in the ESP groups were significantly increased in the ESP groups compared with those in the model group. The expression of Keap1 in the model group was significantly increased compared with that in the blank group, and the Keap1 expression increased insignificantly in ESP groups compared with that in the model group. The expression of Nrf2 and HO-1 was significantly lower in the model group than in the blank group, and the expression was significantly higher in the medium-dose ESP group than in the model group. In conclusion, ESP protected mice against the scopolamine-induced learning and memory impairment by regulating the Keap1/Nrf2/HO-1 signaling pathway.

[Ershiwuwei Shanhu Pills regulate Akt/mTOR/GSK-3β signaling pathway to alleviate Alzheimer's disease mice]

The present study investigated the mechanism of the Tibetan patent medicine Ershiwuwei Shanhu Pills(ESP) in alleviating Alzheimer's disease in mice via Akt/mTOR/GSK-3β signaling pathway. BALB/c mice were randomly assigned into a blank control group, a model group, low(200 mg·kg~(-1)), medium(400 mg·kg~(-1)) and high(800 mg·kg~(-1)) dose groups of ESP, and donepezil hydrochloride group. Except the blank control group, the other groups were given 20 mg·kg~(-1) aluminum chloride by gavage and 120 mg·kg~(-1) D-galactose by intraperitoneal injection for 56 days to establish Alzheimer's disease model. Morris water maze was used to detect the learning and memory ability of mice. The level of p-tau protein in mouse hippocampus and the levels of superoxide dismutase(SOD), malondialdehyde(MDA), catalase(CAT), and total antioxidant capacity(T-AOC) in hippocampus and serum were detected. Hematoxylin-eosin staining and Nissl staining were performed for the pathological observation of whole brain in mice. TdT-mediated dUTP nick-end labeling(TUNEL) staining was employed for the observation of apoptosis in mouse cortex. Western blot was adopted to detect the protein levels of p-mTOR, p-Akt, and GSK-3β in the hippocampus. Compared with the model group, the ESP groups showcased alleviated pathological damage of the whole brain, decreased TUNEL positive cells, reduced level of p-tau protein in hippocampus, and risen SOD, CAT, and T-AOC levels and declined MDA level in hippocampus and serum. Furthermore, the ESP groups had up-regulated protein levels of p-mTOR and p-Akt while down-regulated protein level of GSK-3β in hippocampus. Therefore, ESP can alleviate the learning and memory decline and oxidative damage in mice with Alzheimer's disease induced by D-galactose combined with aluminum chloride, which may be related to Akt/mTOR/GSK-3β signaling pathway.

[Research progress on precious Tibetan medicine formula in prevention and treatment of central nervous system diseases]

Precious Tibetan medicine formula is a characteristic type of medicine commonly used in the clinical treatment of central nervous system diseases. Through the summary of modern research on the precious Tibetan medicine formulas such as Ratnasampil, Ershiwuwei Zhenzhu Pills, Ershiwewei Shanhu Pills, and Ruyi Zhenbao Pills, it is found that they have obvious advantages in the treatment of stroke, Alzheimer's disease, epilepsy, angioneurotic headache, and vascular dementia. Modern pharmacological studies have shown that the mechanisms of precious Tibetan medicine formulas in improving central nervous system diseases are that they promote microcirculation of brain tissue, regulate the permeability of the blood-brain barrier, alleviate inflammation, relieve oxidative stress damage, and inhibit nerve cell apoptosis. This review summarizes the clinical and pharmacological studies on precious Tibetan medicine formulas in prevention and treatment of central nervous system diseases, aiming to provide a reference for future in-depth research and innovative discovery of Tibetan medicine against central nervous diseases.

[Mechanism of Tibetan medicine Ershiwuwei Songshi Pills against liver injury induced by acetaminophen in mice based on Keap1/Nrf2 and TLR4/NF-κB p65 signaling pathways]

The present study investigated the mechanism of the Tibetan medicine Ershiwuwei Songshi Pills(ESP) against the liver injury induced by acetaminophen(APAP) in mice based on the kelch-like ECH-associated protein 1(Keap1)/nuclear transcription factor E2 related factor 2(Nrf2) and Toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB) p65 signaling pathways. Kunming mice were randomly divided into a blank control group, a model group, an N-acetyl-L-cysteine(NAC) group, and high-(400 mg·kg~(-1)), medium-(200 mg·kg~(-1)), and low-dose(100 mg·kg~(-1)) ESP groups. After 14 days of continuous administration, except for those in the control group, the mice were intraperitoneally injected with 200 mg·kg~(-1) APAP. After 12 h, the serum and liver tissues of mice were collected. Hematoxylin-eosin(HE) staining was performed on pathological sections of the liver, and the levels of aspartate aminotransferase(AST) and alanine aminotransferase(ALT) in the serum and the levels of glutathione(GSH), malondialdehyde(MDA), superoxide dismutase(SOD), catalase(CAT), myeloperoxidase(MPO), and total antioxidant capacity(T-AOC) in liver tissue homogenate were detected to observe and analyze the protective effect of ESP on APAP-induced liver injury in mice. The serum levels of tumor necrosis factor-alpha(TNF-α), interleukin-1 beta(IL-1β), and interleukin-6(IL-6) were determined by enzyme-linked immunosorbent assay(ELISA). The protein expression of Nrf2, Keap1, TLR4, and NF-κB p65 in the liver was determined by Western blot. Quantitative real-time was used to determine the mRNA expression of glutamate-cysteine ligase catalytic subunit(GCLC), glutamate-cysteine ligase regulatory subunit(GCLM), heme oxygenase-1(HO-1), and NAD(P)H dehydrogenase quinone 1(NQO-1) in the liver to explore the mechanism of ESP in improving APAP-induced liver damage in mice. As revealed by results, compared with the model group, the ESP groups showed improved liver pathological damage, decreased ALT and AST levels in the serum and MDA and MPO content in the liver, increased GSH, SOD, CAT, and T-AOC in the liver, reduced TNF-α and IL-6 levels in the serum, down-regulated expression of Keap1 in the liver cytoplasm and NF-κB p65 in the liver nucleus, up-regulated expression of Nrf2 in the liver nucleus, insignificant change in TLR4 expression, and elevated relative mRNA expression levels of antioxidant genes GCLC, GCLM, HO-1, and NQO-1. ESP can reduce the oxidative damage and inflammation caused by APAP, and the mechanism may be related to the Keap1/Nrf2 signaling pathway and the signal transduction factors on the TLR4/NF-κB p65 pathway.

[A retrospective safety study on screening of the samples in the clinical biobank of Beijing Hospital]

To investigate whether the laboratory specimens preserved in Beijing Hospital Biobank during a specific period had been contaminated by SARS-Cov-2 through a cross-sectional study, and to establish a retrospective biobank safety screening system. Laboratory specimens were collected from the Department of Respiratory and Critical Care Medicine and the Fever Clinic of Beijing Hospital from November 1, 2019 to January 22, 2020, nucleic acid and serological antibody testing were performed for SARS-CoV-2 in these specimens (including 79 serum, 20 urine, 42 feces and 21 bronchoalveolar lavage fluid specimens). The safety of the stored samples during this period was defined by negative and positive results. Both the nucleic acid test and serological antibody test showed negative for SARS-CoV-2, indicating that these specimens were safely stored in the biobank. High-risk specimens collected in our hospital during the early stage of the COVID-19 outbreak are free of SARS-CoV-2, and a safety screening strategy for the clinical biobank is established to ensure the biosafety of these samples.

Crystallography-guided discovery of carbazole-based retinoic acid-related orphan receptor gamma-t (RORγt) modulators: insights into different protein behaviors with "short" and "long" inverse agonists

A series of 6-substituted carbazole-based retinoic acid-related orphan receptor gamma-t (RORγt) modulators were discovered through 6-position modification guided by insights from the crystallographic profiles of the "short" inverse agonist 6. With the increase in the size of the 6-position substituents, the "short" inverse agonist 6 first reversed its function to agonists and then to "long" inverse agonists. The cocrystal structures of RORγt complexed with the representative "short" inverse agonist 6 (PDB: 6LOB), the agonist 7d (PDB: 6LOA) and the "long" inverse agonist 7h (PDB: 6LO9) were revealed by X-ray analysis. However, minor differences were found in the binding modes of "short" inverse agonist 6 and "long" inverse agonist 7h. To further reveal the molecular mechanisms of different RORγt inverse agonists, we performed molecular dynamics simulations and found that "short" or "long" inverse agonists led to different behaviors of helixes H11, H11', and H12 of RORγt. The "short" inverse agonist 6 destabilizes H11' and dislocates H12, while the "long" inverse agonist 7h separates H11 and unwinds H12. The results indicate that the two types of inverse agonists may behave differently in downstream signaling, which may help identify novel inverse agonists with different regulatory mechanisms.

Nanomedicine for the treatment of diabetes-associated cardiovascular diseases and fibrosis

Cardiomyopathy and fibrosis are the main causes of heart failure in diabetes patients. For therapeutic purposes, a delivery system is required to enhance antidiabetic drug efficacy and specifically target profibrotic pathways in cardiomyocytes. Nanoparticles (NPs) have distinct advantages, including biocompatibility, bioavailability, targeting efficiency, and minimal toxicity, which make them ideal for antidiabetic treatment. In this review, we overview the latest information on the pathogenesis of cardiomyopathy and fibrosis in diabetes patients. We summarize how NP applications improve insulin and liraglutide efficacy and their sustained release upon oral administration. We provide a comprehensive review of the results of NP clinical trials in diabetes patients and of animal studies investigating the effects of NP-mediated anti-fibrotic treatments. Collectively, the application of advanced NP delivery systems in the treatment of cardiomyopathy and fibrosis in diabetes patients is a promising and innovative therapeutic strategy.

Association between periodontitis and systemic lupus erythematosus: a meta-analysis

OBJECTIVE

The objective of this study was to explore the association between periodontitis and systemic lupus erythematosus (SLE).

METHODS

To identify eligible studies, the PubMed, EMBASE and Web of Science databases were searched from inception to 19 September 2019. Associations of periodontitis, and other periodontal parameters, with SLE were assessed.

RESULTS

Ten studies involving 80,633 subjects were included in this meta-analysis. Pooled data showed a significant association between periodontitis and SLE (odds ratio=5.32, 95% confidence interval (CI) 1.69-16.78, p = 0.004). In addition, SLE patients had a higher prevalence of bleeding on probing (mean difference = 0.03, 95% CI 0.00-0.06, p = 0.02) and higher mean clinical attachment loss (mean difference = 0.69, 95% CI 0.39-1.00, p < 0.001). However, there were no significant differences between SLE and reference subjects in mean plaque index, gingival index, pocket depth or decayed, missing or filled teeth.

CONCLUSIONS

This study demonstrates a significant association between periodontitis and SLE, which indicates that avoidance of periodontitis by maintaining oral health may be a simple and economical way to prevent SLE.

Roles of Hematopoietic Stem and Progenitor Cells in Ischemic Cardiovascular Disease

Macrophage proliferation and skewed myelopoiesis-induced monocytosis, as well as neutrophils, enhance the generation of atherogenic inflammatory cells in a lesion area, leading to plaque formation and Cardiovascular Disease (CVD). Among all risk factors, accumulated data have shown that hyperlipidemia activates Hematopoietic Stem/Progenitor Cells (HSPCs) in the Bone Marrow (BM) niche. Recently, proliferation of Granulocyte-Monocyte Progenitors (GMPs) has been demonstrated to drive skewed myelopoiesis, while HSPCs remain quiescent. In this review, we discuss how HSPCs and GMPs participate in atherosclerosis of mice in terms of proliferation and cell mobilization from BM to peripheral blood and the lesion area. We also describe how the spleen, an extramedullary organ, is involved in skewed myelopoiesis and inflammation in atherosclerosis. We further summarize the clinical evidence of the relationship of HSPCs with coronary stenoses in patients with CVD. Ultimately, this review facilitates understanding the pathological roles of HSPCs and GMPs in atherosclerosis for future treatments.

New triterpenoids from Staphylea bumalda flower buds and their neuroprotective activity against H2O2-induced injury in vitro

Four new acylated triterpene glycosides with aliphatic chains (4-7) as well as five known triterpenoids were isolated from the flower buds of Staphylea bumalda with bioassay guidance. Their structures were determined on the basis of spectral techniques, including IR, 1D and 2D NMR, and HR-APCI-MS. Most compounds (except 8) were isolated from S. bumalda for the first time. Additionally, the neuroprotective effects of 1 and 4-9 on suckling rat primary cultured hippocampal neurons against H₂O₂-induced injury were evaluated in vitro. The four new triterpenoids (4-7) showed neuroprotective effects, which increased the cell viability to over 74% at different concentrations, which was higher than the negative control (59%), while compounds 1 and 8-9 exhibited cytotoxic activity.

Effects of Tai Chi Exercise on Cancer-Related Fatigue in Patients With Nasopharyngeal Carcinoma Undergoing Chemoradiotherapy: A Randomized Controlled Trial

CONTEXT

Tai Chi exercise has been shown to improve cancer-related fatigue (CRF) and autonomic nervous system (ANS) balance in some cancer patients or survivors; however, such effects are yet to be verified in nasopharyngeal carcinoma (NPC) patients undergoing chemoradiotherapy.

OBJECTIVES

To explore the effects of Tai Chi exercise on CRF in NPC patients undergoing chemoradiotherapy and then to evaluate ANS information indicated by heart rate variability parameters and their association with CRF.

METHODS

A randomized controlled trial of Tai Chi exercise was conducted from January 2014 to August 2015. Participants in the Tai Chi group practiced Tai Chi a one-hour session, five sessions/week during chemoradiotherapy. Participants in the control group received usual care. The primary end points were scores of the multidimensional fatigue symptom inventory-short form (MFSI-SF). Secondary end points were heart rate variability parameters, including normalized low-frequency (nLF) power, normalized high-frequency (nHF) power, and the nLF/nHF ratio, and their association with CRF.

RESULTS

One hundred fourteen patients were recruited in this study, and 83 patients completed the trial. The Tai Chi group and the control group had comparable baseline characteristics. After chemoradiotherapy, the Tai Chi group exhibited lower MFSI-SF total score and three negative subscale (general, physical, and emotional fatigue) scores and higher vigor score compared with the control group (P < 0.01 for all). The nLF/nHF ratio was significantly lower in the Tai Chi group compared to the control group after chemoradiotherapy. The MFSI-SF total score was markedly correlated with the nLF/nHF ratio.

CONCLUSION

Tai Chi exercise is conducive to alleviate CRF in NPC patients undergoing chemoradiotherapy. The improvement in ANS balance might fit into the process of Tai Chi for CRF management in this population.

Selective HDAC6 inhibition decreases early stage of lupus nephritis by down-regulating both innate and adaptive immune responses

We have demonstrated previously that histone deacetylase (HDAC6) expression is increased in animal models of systemic lupus erythematosus (SLE) and that inhibition of HDAC6 decreased disease. In our current studies, we tested if an orally active selective HDAC6 inhibitor would decrease disease pathogenesis in a lupus mouse model with established early disease. Additionally, we sought to delineate the cellular and molecular mechanism(s) of action of a selective HDAC6 inhibitor in SLE. We treated 20-week-old (early-disease) New Zealand Black (NZB)/White F₁ female mice with two different doses of the selective HDAC6 inhibitor (ACY-738) for 5 weeks. As the mice aged, we determined autoantibody production and cytokine levels by enzyme-linked immunosorbent assay (ELISA) and renal function by measuring proteinuria. At the termination of the study, we performed a comprehensive analysis on B cells, T cells and innate immune cells using flow cytometry and examined renal tissue for immune-mediated pathogenesis using immunohistochemistry and immunofluorescence. Our results showed a reduced germinal centre B cell response, decreased T follicular helper cells and diminished interferon (IFN)-γ production from T helper cells in splenic tissue. Additionally, we found the IFN-α-producing ability of plasmacytoid dendritic cells was decreased along with immunoglobulin isotype switching and the generation of pathogenic autoantibodies. Renal tissue showed decreased immunoglobulin deposition and reduced inflammation as judged by glomerular and interstitial inflammation. Taken together, these studies show selective HDAC6 inhibition decreased several parameters of disease pathogenesis in lupus-prone mice. The decrease was due in part to inhibition of B cell development and response.

In Silico Prediction of Chemical Toxicity Profile Using Local Lazy Learning

BACKGROUND

Chemical toxicity is an important reason for late-stage failure in drug R&D. However, it is time-consuming and expensive to identify the multiple toxicities of compounds using the traditional experiments. Thus, it is attractive to build an accurate prediction model for the toxicity profile of compounds.

MATERIALS AND METHODS

In this study, we carried out a research on six types of toxicities: (I) Acute Toxicity; (II) Mutagenicity; (III) Tumorigenicity; (IV) Skin and Eye Irritation; (V) Reproductive Effects; (VI) Multiple Dose Effects, using local lazy learning (LLL) method for multi-label learning. 17,120 compounds were split into the training set and the test set as a ratio of 4:1 by using the Kennard-Stone algorithm. Four types of properties, including molecular fingerprints (ECFP_4 and FCFP_4), descriptors, and chemical-chemical-interactions, were adopted for model building.

RESULTS

The model 'ECFP_4+LLL' yielded the best performance for the test set, while balanced accuracy (BACC) reached 0.692, 0.691, 0.666, 0.680, 0.631, 0.599 for six types of toxicities, respectively. Furthermore, some essential toxicophores for six types of toxicities were identified by using the Laplacian-modified Bayesian model.

CONCLUSION

The accurate prediction model and the chemical toxicophores can provide some guidance for designing drugs with low toxicity.

Renal-infiltrating CD11c+ cells are pathogenic in murine lupus nephritis through promoting CD4+ T cell responses

Lupus nephritis (LN) is a major manifestation of systemic lupus erythematosus (SLE), causing morbidity and mortality in 40-60% of SLE patients. The pathogenic mechanisms of LN are not completely understood. Recent studies have demonstrated the presence of various immune cell populations in lupus nephritic kidneys of both SLE patients and lupus-prone mice. These cells may play important pathogenic or regulatory roles in situ to promote or sustain LN. Here, using lupus-prone mouse models, we showed the pathogenic role of a kidney-infiltrating CD11c⁺ myeloid cell population in LN. These CD11c⁺ cells accumulated in the kidneys of lupus-prone mice as LN progressed. Surface markers of this population suggest their dendritic cell identity and differentiation from lymphocyte antigen 6 complex (Ly6C)^low mature monocytes. The cytokine/chemokine profile of these renal-infiltrating CD11c⁺ cells suggests their roles in promoting LN, which was confirmed further in a loss-of-function in-vivo study by using an antibody-drug conjugate (ADC) strategy targeting CX₃ CR1, a chemokine receptor expressed highly on these CD11c⁺ cells. However, CX₃ CR1 was dispensable for the homing of CD11c⁺ cells into lupus nephritic kidneys. Finally, we found that these CD11c⁺ cells co-localized with infiltrating T cells in the kidney. Using an ex- vivo co-culture system, we showed that renal-infiltrating CD11c⁺ cells promoted the survival, proliferation and interferon-γ production of renal-infiltrating CD4⁺ T cells, suggesting a T cell-dependent mechanism by which these CD11c⁺ cells promote LN. Together, our results identify a pathogenic kidney-infiltrating CD11c⁺ cell population promoting LN progression, which could be a new therapeutic target for the treatment of LN.

[Population-based study on infection and genotype distribution of high-risk human among women in rural areas of China, 2014]

Objective: To explore the epidemiologic characterization of high-risk human papillomavirus (HR-HPV) infection and genotype distribution of HR-HPV among women in rural areas of China. Methods: This study used multiple layers of stratified cluster random sampling method. During January to December in 2014, 117 counties of 27 provinces were selected as the HPV test screening pilot project counties. The women aged 35-64 years with rural areas Hukou in these project counties were selected as the study subjects. A total 457 799 women received HPV DNA test. Among them, 118 237 women from 32 counties in 11 provinces received qualified HPV DNA test by fluorescent PCR to detect HPV genotypes. Results: Among 118 237 rural women, the overall HR-HPV positive infection rate was 7.8% (9 249/118 237). The infection rate increased with age and reached an infection peak at the 60-64 age groups (9.9%, 831/8 394). The HR-HPV positive infection rate in western regions (6.9%, 2 144/31 130) was statistical significantly lower than in central regions (8.2%, 1 894/23 023) and eastern regions (8.1%, 5 211/64 084) (χ(2)=51.46, P<0.001). Among 9 249 women with specific genotypes of HR-HPV, 6 496 (97.6%) cases were infected with single HR-HPV type, and 163 cases (2.4% ) were infected with multiple types. HR-HPV type 52, 16 and 58 were the most common infection types in rural areas of China. The single infection rates were 20.9% (1 355/6 496), 18.7% (1 215/6 496), and 11.2% (725/6 496), respectively. The multiple infection rates were 47.2% (77/163), 17.8% (29/163), and 18.4% (30/163), respectively. Conclusion: The HR-HPV positive infection rate in rural areas of Chinese woman was 7.8%, western region has lower infection rate compared with central and eastern regions. HPV 52 was first of the most common genotypes in rural areas of China.

Identification and biochemical characterization of DC07090 as a novel potent small molecule inhibitor against human enterovirus 71 3C protease by structure-based virtual screening

Hand, foot and mouth disease (HFMD) is a serious, highly contagious disease. HFMD caused by Enterovirus 71 (EV71), results in severe complications and even death. The pivotal role of EV71 3Cpro in the viral life cycle makes it an attractive target for drug discovery and development to treat HFMD. In this study, we identified novel EV71 3Cpro inhibitors by docking-based virtual screening. Totally 50 compounds were selected to test their inhibitory activity against EV71 3Cpro. The best inhibitor DC07090 exhibited the inhibition potency with an IC50 value of 21.72 ± 0.95 μM without apparent toxicity (CC50 > 200 μM). To explore structure-activity relationship of DC07090, 15 new derivatives were designed, synthesized and evaluated in vitro enzyme assay accordingly. Interestingly, four compounds showed inhibitory activities against EV71 3Cpro and only DC07090 inhibited EV71 replication with an EC50 value of 22.09 ± 1.07 μM. Enzyme inhibition kinetic experiments showed that the compound was a reversible and competitive inhibitor. The Ki value was determined to be 23.29 ± 12.08 μM. Further molecular docking, MD simulation and mutagenesis studies confirmed the binding mode of DC07090 and EV71 3Cpro. Besides, DC07090 could also inhibit coxsackievirus A16 (CVA16) replication with an EC50 value of 27.76 ± 0.88 μM. Therefore, DC07090 represents a new non-peptidyl small molecule inhibitor for further development of antiviral therapy against EV71 or other picornaviruses.

Fine structure characterization of martensite/austenite constituent in low-carbon low-alloy steel by transmission electron forward scatter diffraction

Transmission electron forward scatter diffraction and other characterization techniques were used to investigate the fine structure and the variant relationship of the martensite/austenite (M/A) constituent of the granular bainite in low-carbon low-alloy steel. The results demonstrated that the M/A constituents were distributed in clusters throughout the bainitic ferrite. Lath martensite was the main component of the M/A constituent, where the relationship between the martensite variants was consistent with the Nishiyama-Wassermann orientation relationship and only three variants were found in the M/A constituent, suggesting that the variants had formed in the M/A constituent according to a specific mechanism. Furthermore, the Σ3 boundaries in the M/A constituent were much longer than their counterparts in the bainitic ferrite region. The results indicate that transmission electron forward scatter diffraction is an effective method of crystallographic analysis for nanolaths in M/A constituents.

ANAC005 is a membrane-associated transcription factor and regulates vascular development in Arabidopsis

Vascular tissues are very important for providing both mechanical strength and long-distance transport. The molecular mechanisms of regulation of vascular tissue development are still not fully understood. In this study we identified ANAC005 as a membrane-associated NAC family transcription factor that regulates vascular tissue development. Reporter gene assays showed that ANAC005 was expressed mainly in the vascular tissues. Increased expression of ANAC005 protein in transgenic Arabidopsis caused dwarf phenotype, reduced xylem differentiation, decreased lignin content, repression of a lignin biosynthetic gene and genes related to cambium and primary wall, but activation of genes related to the secondary wall. Expression of a dominant repressor fusion of ANAC005 had overall the opposite effects on vascular tissue differentiation and lignin synthetic gene expression. The ANAC005-GFP fusion protein was localized at the plasma membrane, whereas deletion of the last 20 amino acids, which are mostly basic, caused its nuclear localization. These results indicate that ANAC005 is a cell membrane-associated transcription factor that inhibits xylem tissue development in Arabidopsis.

[Clinical characteristics of orthostatic hypertension with hemodynamic response of vasovagal syncope and postural orthostatic tachycardia syndrome in children and adolescents]

OBJECTIVE

To analyze the clinical characteristics of orthostatic hypertension (OHT) with hemodynamic response of vasovagal syncope (VVS) and postural orthostatic tachycardia syndrome (POTS) in children and adolescents.

METHOD

Children and adolescents admitted to the Second Xiangya Hospital from July 2008 to April 2015 were included, and divided into three groups according to the results of head-up tilt test (HUTT): OHT group, OHT+ VVS group, OHT+ POTS group. The clinical characteristics were analyzed.

RESULT

Totally 629 cases were included, 300 cases in OHT group, 264 cases in OHT+ VVS group and 65 cases in OHT+ POTS group. Syncope and dizziness were the main symptoms of the three groups, and the proportion of patients complaining syncope in OHT+ VVS group was higher than that in OHT group (49.6% vs. 35.7%, χ(2)=11.211, P<0.05) and in OHT+ POTS group (49.6% vs. 27.7%, χ(2)=10.123, P<0.05). Baseline heart rate (HR)((78±14) beat/min vs. (77±12) beat/min, t=2.570, P<0.05), HUTT 3 min HR ((100±14) beat/min vs. (94±13) beat/min, t=17.464, P<0.05) and ΔHR ((22±12) beat/min vs. (17±9) beat/min, t=19.303, P<0.05) were higher in OHT+ VVS group than in OHT group. When compared with OHT group, baseline systolic blood pressure (SBP) ((105±10) mmHg(1 mmHg=0.133 kPa) vs. (103±10) mmHg, t=4.918, P<0.05), HUTT 3 min SBP((114±10) mmHg vs. (113±11) mmHg, t=4.046, P<0.05), baseline diastolic blood pressure (DBP)((64±6) mmHg vs. (63±7) mmHg, t=2.618, P<0.05), HUTT 3 min DBP((78±8) mmHg vs. (77±8) mmHg, t=3.302, P<0.05), HUTT 3 min HR ((107±14) beat/min vs. (94±13) beat/min, t=24.229, P<0.05) and ΔHR ((32±11) beat/min vs. (17±9) beat/min, t=39.146, P<0.05) in OHT+ POTS group were significantly higher, and baseline HR((75±14) beat/min vs. (77±12) beat/min, t=-4.221, P<0.05)in OHT+ POTS group was lower.

CONCLUSION

OHT with higher supine HR, upright HR and HR change is more susceptible to being complicated with VVS, while OHT with higher supine and upright SBP, higher supine and upright DBP and lower supine HR is more susceptible to being accompanied by POTS.

Cloning and characterization of up-regulated HbSINA4 gene induced by drought stress in Tibetan hulless barley

Hulless barley is an important crop cereal in Tibetan, China. Drought is a major abiotic stress in barley production. In this study, we cloned the drought-related HbSINA4 gene from the variety 'Himalaya 10' and analyzed its expression patterns under different drought and rehydration conditions. The cDNA of HbSINA4 was 1052 bp long, including an open reading frame of 771 bp that encoded a protein of 256 amino acids. The molecular weight of HbSINA4 protein was predicted to be 29.53 kDa and the theoretical pI was 8.32. Bioinformatic analysis showed that the HbSINA4 gene contained a protein kinase domain profile family signature motif, with high similarity to that of Oryza sativa and Brachypodium distachyon. Real-time polymerase chain reaction (PCR) assays revealed that gene expression declined rapidly with increasing drought stress; in contrast, its expression increased after rehydration treatment. Therefore, the HbSINA4 gene responds to the drought stress and plays an important role in barely drought resistance. Furthermore, our results provide information which may be useful in other temperate crop studies and in aiding resistance to drought.

In vitro pharmacological characterization of TKI-28, a broad-spectrum tyrosine kinase inhibitor with anti-tumor and anti-angiogenic effects

Tyrosine kinases are used as important biomarkers in many tumor types. Preclinical and clinical anti-tumor studies have shown that broadly acting tyrosine kinase inhibitors may be more useful than specific inhibitors, since the former might overcome redundancies and crosstalk in tumor cell growth signaling pathways. Here, we aim to identify a novel potent tyrosine kinase inhibitor. Computer modeling of the pyrido-pyrimidine class compound, TKI-28(6-(2,6-dichlorophenyl)-8-methyl-2-phenylamino-8H-pyrido[2,3-d]pyrimidine-7-one), predicted that the compound would dock well in the ATP pocket of the ErbB-2 tyrosine kinase, yielding a high binding affinity for ErbB receptors. Biochemical studies revealed that TKI-28 potently inhibited the activities of tyrosine kinases such as ErbB-2, EGFR, KDR, PDGFRbeta, c-kit and c-Src, but had little effect on Flt-1 in cell-free system. TKI-28 also efficiently blocked autophosphorylation of the listed receptor tyrosine kinases, and subsequently downregulated phosphorylation of many downstream signaling proteins at the cellular level. TKI-28 exhibited a more potent anti-proliferative activity against EGF- and neuregulin-stimulated SK-OV-3 cells versus serum-stimulated cells, accompanied by apparent induction of apoptosis. Finally, TKI-28 was found to possess anti-angiogenic effects, characterized by inhibition of cell proliferation driven by EGF, VEGF and PDGF, as well as decreased cell migration and tube formation in HMECs. These results collectively highlight the pharmacological characteristics of TKI-28 as a broad-spectrum tyrosine kinase inhibitor, suggesting that it has great potential as an anti-cancer and anti-angiogenesis agent.

Genetic diversity and relationship of chicory (Cichorium intybus L.) using sequence-related amplified polymorphism markers

Chicory is a crop with economically important roles and is cultivated worldwide. The genetic diversity and relationship of 80 accessions of chicories and endives were evaluated by sequence-related amplified polymorphism (SRAP) markers to provide a theoretical basis for future breeding programs in China. The polymorphic rate was 96.83%, and the average polymorphic information content was 0.323, suggesting the rich genetic diversity of chicory. The genetic diversity degree of chicory was higher (GS = 0.677) than that of endive (GS = 0.701). The accessions with the highest genetic diversity (effective number of alleles, NE = 1.609; Nei's genetic diversity, H = 0.372; Shannon information index, I = 0.556) were from Italy. The richest genetic diversity was revealed in a chicory line (NE = 1.478, H = 0.289, I = 0.443) among the 3 types (line, wild, and cultivar). The chicory genetic structure of 8 geographical groups showed that the genetic differentiation coefficient (GST) was 14.20% and the number of immigrants per generation (Nm) was 3.020. A GST of 6.80% and an Nm of 6.853 were obtained from different types. This observation suggests that these chicory lines, especially those from the Mediterranean region, have potential for providing rich genetic resources for further breeding programs, that the chicory genetic structure among different countries obviously differs with a certain amount of gene flow, and that SRAP markers could be applied to analyze genetic relationships and classifications of Cichorium intybus and C. endivia.

Animal models of gastrointestinal inflammation and cancer

Inflammation and cancer are the two major disorders in the gastrointestinal tract. They are causally related in their pathogenesis. It is important to study animal models' causal relationship and, in particular, to discover new therapeutic agents for such diseases. There are several criteria for these models in order to make them useful in better understanding the etiology and treatment of the said diseases in humans. In this regard, animal models should be similar as possible to human diseases and also be easy to produce and reproducible and also economic to allow a continuous replication in different laboratories. In this review, we summarize the various animal models for inflammatory and cancerous disorders in the upper and lower gastrointestinal tract. Experimental approaches are as simple as by giving a single oral dose of alcohol or other noxious agents or by injections of multiple dosages of ulcer inducing agents or by parenteral administration or in drinking water of carcinogens or by modifying the genetic makeups of animals to produce relatively long-term pathological changes in particular organs. With these methods they could induce consistent inflammatory responses or tumorigenesis in the gastrointestinal mucosa. These animal models are widely used in laboratories in understanding the pathogenesis as well as the mechanisms of action for therapeutic agents in the treatment of gastrointestinal inflammation and cancer.

How often are ineffective interventions still used in clinical practice? A cross-sectional survey of 6,272 clinicians in China

Background

The World Health Organization reported in 2011that irrational use of medicines was a serious global problem that is wasteful and harmful. The worst is use of ineffective or harmful interventions which should not be used at all. However, little is known about the changes that 20 years of evidence-based medicine has made particularly in reducing use of ineffective interventions. We surveyed clinicians in China to show how often ineffective interventions were still used in practice.

Methods

3,246 clinicians from 24 tertiary hospitals were surveyed in person and another 3,063 through an online survey between 2006–2007. The main outcomes are prescription by a clinician, and use in a patient of, an ineffective intervention and of a matched effective intervention in patients with the same disease. 129 ineffective interventions for 68 diseases were identified from the BMJ Clinical Evidence and included in the survey. One effective intervention was identified for each disease and a total of 68 effective interventions were thus also included. The frequency of use of effective interventions was used as a reference for that of ineffective intervention.

Results

The mean prescription rate by clinicians is 59.0% (95% confidence interval (95% CI): 58.6% to 59.4%) and 81.0% (95% CI: 80.6% to 81.4%) respectively for ineffective and effective interventions. The mean frequency of use in patients is 31.2% (95% CI: 30.8% to 31.6%) and 56.4% (95% CI: 56.0% to 56.8%) for ineffective and effective interventions respectively. The relative reduction in use of ineffective interventions as compared with that of matched effective interventions is 27.2% (95% CI: 27.0% to 27.4%) and 44.7% (95% CI: 44.3% to 45.1%) for clinician's prescription and use in patients respectively. 8.6% ineffective interventions were still routinely used in practice.

Conclusions

Ineffective interventions were still commonly used. Efforts are necessary to further reduce and eventually eliminate ineffective interventions from practice.

BZS1, a B-box protein, promotes photomorphogenesis downstream of both brassinosteroid and light signaling pathways

Photomorphogenesis is controlled by multiple signaling pathways, including the light and brassinosteroid (BR) pathways. BR signaling activates the BZR1 transcription factor, which is required for suppressing photomorphogenesis in the dark. We identified a suppressor of the BR hypersensitive mutant bzr1-1D and named it bzr1-1D suppressor1-Dominant (bzs1-D). The bzs1-D mutation was caused by overexpression of a B-box zinc finger protein BZS1, which is transcriptionally repressed by BZR1. Overexpression of BZS1 causes de-etiolation in the dark, short hypocotyls in the light, reduced sensitivity to BR treatment, and repression of many BR-activated genes. Knockdown of BZS1 by co-suppression partly suppressed the short hypocotyl phenotypes of BR-deficient or insensitive mutants. These results support that BZS1 is a negative regulator of BR response. BZS1 overexpressors are hypersensitive to different wavelengths of light and loss of function of BZS1 reduces plant sensitivity to light and partly suppresses the constitutive photomorphogenesis 1 (cop1) mutant in the dark, suggesting a positive role in light response. BZS1 protein accumulates at an increased level after light treatment of dark-grown BZS1-OX plants and in the cop1 mutants, and BZS1 interacts with COP1 in vitro, suggesting that light regulates BZS1 through COP1-mediated ubiquitination and proteasomal degradation. These results demonstrate that BZS1 mediates the crosstalk between BR and light pathways.

Characteristics of patients with fluid extravasation during retrograde ureteroscopic holmium laser lithotripsy for renal calculi

OBJECTIVE

To explore the risk factors of fluid extravasation during retrograde ureteroscopic holmium laser lithotripsy for renal calculi.

METHODS

Three hundred and twenty-seven patients with renal calculi ranging 10 to 20 mm received retrograde ureteroscopic holmium laser lithotripsy at Renmin Hospital of Wuhan University, Wuhan, China from January 2004 to December 2010. The clinical records were reviewed, and the correlation was studied between various clinical factors and fluid extravasation complications during operation. The clinical factors to be tested included patients' gender and age (<30, 30-50, and >50 years), hydronephrosis degree, previous intervention for renal calculi (none, shock-wave lithotripsy, and open surgery), upper urinary tract infection, ureteral access sheath placement, and procedure duration (<60, 60-120, and >120 mins). The data were processed by SPSS Version 16.0 statistical software, x2 test, and binary logistic regression were used for analysis.

RESULTS

Fluid extravasation complications appeared in 35 patients. Patients` gender, age, and hydronephrosis degree were irrelevant to the occurrence of fluid extravasation, while having previous open surgery for renal calculi, without ureteral access sheath placement, upper urinary tract infection, and long procedure duration were all responsible for higher incidence of the complications.

CONCLUSION

Reasonable selection of patients, effective control of upper urinary tract infection, routine ureteral access sheath placement, and controlling procedure duration help to decrease the incidence of fluid extravasation complications in retrograde ureteroscopic holmium laser lithotripsy for renal calculi.

Integration of light- and brassinosteroid-signaling pathways by a GATA transcription factor in Arabidopsis

Light and brassinosteroid (BR) antagonistically regulate the developmental switch from etiolation in the dark to photomorphogenesis in the light in plants. Here, we identify GATA2 as a key transcriptional regulator that mediates the crosstalk between BR- and light-signaling pathways. Overexpression of GATA2 causes constitutive photomorphogenesis in the dark, whereas suppression of GATA2 reduces photomorphogenesis caused by light, BR deficiency, or the constitutive photomorphogenesis mutant cop1. Genome profiling and chromatin immunoprecipitation experiments show that GATA2 directly regulates genes that respond to both light and BR. BR represses GATA2 transcription through the BR-activated transcription factor BZR1, whereas light causes accumulation of GATA2 protein and feedback inhibition of GATA2 transcription. Dark-induced proteasomal degradation of GATA2 is dependent on the COP1 E3 ubiquitin ligase, and COP1 can ubiquitinate GATA2 in vitro. This study illustrates a molecular framework for antagonistic regulation of gene expression and seedling photomorphogenesis by BR and light.

Calponin expression in laryngeal myoepithelial carcinoma and its prognostic implications: a case report and literature review

A case report of laryngeal myoepithelial carcinoma (MEC) is presented and the literature concerning prognostic factors in MEC is reviewed. A 61-year old man was admitted to hospital with hoarseness and progressive dyspnoea. On examination, both vocal cords were fixed in the midline with a glottic fissure of only 3 mm. No tumour was seen, but the subglottis was not completely visible. A computed tomography scan showed a soft mass below the right vocal cord obstructing two-thirds of the larynx. On suspension laryngoscopy, a dull mass (1.5 x 1.5 cm) was seen below the right vocal cord, which was malignant on frozen biopsy. A total laryngectomy was performed and the patient received radiotherapy. He died of recurrence 25 months later. The tumour was positive for cytokeratin 14, S-100 protein and calponin. MEC of the larynx is extremely rare. The clinical behaviour of MEC is variable and prognostic factors have been poorly analysed. Calponin expression may be a prognostic factor, but other factors also affect the outcome in MEC.

Prognosis and Expression of Lambda Light Chains in Solitary Extramedullary Plasmacytoma of the Head and Neck: Two Case Reports and a Literature Review

Two cases of extramedullary plasmacytoma (EMP) of the head and neck, an uncommon plasma cell neoplasm, were studied. Both patients had good outcomes and have been followed for 17 and 12 years without recurrence or systemic disease. In these two cases, the tumours measured were 4 cm and 0.3 cm, and both cases were positive for lambda light chain restriction on immunohistochemistry. Prognostic factors were considered, based on a review of EMP of the head and neck, including published reports and the authors' clinical experience. Of all plasma cell tumours, EMP has the best prognosis, especially when located in the head and neck region. Variation in the biological behaviour of EMP and the limited number of documented cases make it difficult to determine prognostic factors. Some series have found that age, tumour size, site of origin (extramedullary versus bone), grade, M-protein, light chains and radiotherapy dose all influence the outcome in EMP patients.

Establishment of the active catalytic domain of human PDGFRβ tyrosine kinase-based ELISA assay for inhibitor screening

Tyrosine kinases are emerging as frequent targets of primary oncogenic events and therefore represent an optimal focus of therapeutic intervention. In an effort towards therapeutic PDGFR inactivation, we expressed the catalytic domain of PDGFRbeta as a soluble active kinase using Bac-to-Bac expression system, and studied the correlations between PDGFRbeta activity and enzyme concentration, ATP concentration, substrate concentration and divalent cation type. And a convenient, effective and non-radioactive ELISA screening model is then established for identification of the potential inhibitors targeting PDGFRbeta kinase. Of 500 RTK target-based compounds, TKI-30 was identified as a small molecule potential inhibitor of PDGFRbeta (IC(50)=0.34 microM). Further studies indicated that TKI-30 blocked PDGF-BB-induced autophosphorylation of PDGFRbeta in a dose-dependent manner in Swiss 3T3 cells and human umbilical vein smooth muscle cells (HUVSMCs). Moreover, it dose-dependently suppressed the PDGF-BB-induced proliferation in HUVSMCs and tube formation of HUVEC. Our data collectively indicated that PDGFRbeta-based ELISA assay is a new method available for screening inhibitors targeting PDGFRbeta kinase and TKI-30 is a potential novel anti-cancer agent worthy of being further investigated.

The Role of NGX6 and Its Deletion Mutants in the Proliferation, Adhesion and Migration of Nasopharyngeal Carcinoma 5-8F Cells

OBJECTIVE

To demonstrate the subcellular localization of nasopharyngeal carcinoma (NPC)-associated gene 6 (NGX6) and its basic structure and function.

METHODS

The deletion mutants of NGX6 were constructed by one-step PCR and transfected into NPC cell line 5-8F. The subcellular location of NGX6 or its mutants was detected by immunofluorescence staining of cytoplasm (CYTO) and nuclear protein, and immunoelectron-microscopic analysis. The role of NGX6 and its mutants in the proliferation, adhesion and migration of NPC 5-8F cells was detected using the following assays: growth curve, colony formation in soft agar, cell adhesion, in vitro Matrigel invasion, and in vitro scratch wound healing.

RESULTS AND CONCLUSIONS

NGX6 and its mutants were distributed on the plasma membrane, nuclear membrane, endoplasmic reticulum membrane, and other membrane structures in the cytosol. The deleted domains did not affect its distribution in 5-8F cells. NGX6 could increase the adhesion but inhibited the proliferation, growth and migration of 5-8F cells. The epidermal growth factor-like domain and CYTO region were found to be important for NGX6 to modulate cell adhesion, and CYTO was found to be essential for NGX6 involved in the regulation of growth, proliferation, and migration of 5-8F cells.

Design, synthesis, antitumor evaluations and molecular modeling studies of novel 3,5-substituted indolin-2-one derivatives

AIM

To design and synthesize a novel class of antitumor agents, featuring the 3, 5-substituted indolin-2-one framework.

METHODS

Based on enzyme binding features of (Z)-SU5402, introducing a beta-pyrrole group at the 3-position of the indolin- 2-one core, a series of novel 3,5-substituted indolin-2-ones were designed and synthesized. Four human carcinoma cell lines of A-431, A-549, MDA-MB-468, and Autosomal Dominant Polycystic Kidney disease were chosen for the cell proliferation assay.

RESULTS

Twenty new compounds (1a-t) with E configuration have been designed, synthesized and bioassayed. Their structural features were determined by nuclear magnetic resonance (NMR) spectra, low- and high-resolution mass spectra, and confirmed by X-ray crystallography. Although the enzyme assay showed a weak inhibition effect against the epidermal growth factor receptor, vascular endothelial growth factor receptor, fibroblast growth factor receptor and platelet-derived growth factor receptor tyrosine kinases, the cell-based antitumor activity was promising. Compounds 1 g and 1 h showed higher inhibitory activity toward the A-549 and MDA-MB-468 cell lines with IC(50 ) of 0.065-9.4 micromol/L.

CONCLUSION

This study provides a new template for further development of potent antitumor drugs.

Gene expression profiling of nasopharyngeal carcinoma reveals the abnormally regulated Wnt signaling pathway

Nasopharyngeal carcinoma (NPC) is a particularly common malignant disease in areas of south China and Southeast Asia. To characterize the gene expression profiling of NPC, we detected the gene expression profiles in 22 NPC and 10 nontumor nasopharyngeal epithelial tissues by complementary DNA microarray. We identified 503 genes that were significantly (P < .001) differentially regulated between NPC and nontumor nasopharyngeal epithelial tissues. The differentially expressed genes are involved in many signaling pathways, such as the Wnt, transforming growth factor-beta, and mitogen-activated protein kinase signaling pathways. The aberrant expression of the Wnt signaling pathway components, such as wingless-type MMTV integration site family, member 5A, Frizzled homolog 7, casein kinase IIbeta, beta-catenin, CREB-binding protein, and Dishevelled-associated activator of morphogenesis 2 was validated on the NPC tissue microarrays. The data suggest that the Wnt signaling pathway may be abnormally regulated in NPC, which provides insight into the molecular mechanisms of NPC.

Utilization of 3′-carboxy-containing tyrosine derivatives as a new class of phosphotyrosyl mimetics in the preparation of novel non-phosphorylated cyclic peptide inhibitors of the Grb2–SH2 domain

A new class of phosphotyrosyl (pTyr) mimetics, distinct from the conventional pTyr mimetic design of adding non-hydrolyzable acidic functionalities to the 4'-position of phenylalanine, was created by introducing carboxy-containing groups to the 3'-position of tyrosine. The effect of the chain length of the carboxy substituent was examined. Reported herein is the chiral pool synthesis of the new pTyr mimetics, and their first use in a novel non-phosphorylated Grb2-SH2 domain binding motif with the 5-amino-acid sequence Xx1-Leu-(3'-substituted-Tyr)-Ac6c-Asn. The highest affinity was exhibited by the 3-L-(2-carboxyethyl)tyrosine-containing sulfoxide-cyclized peptide , with an IC50 = 1.1 microM, providing a promising new template for further development of potent Grb2-SH2 domain inhibitors with reduced charge and peptidic nature, but improved selectivity and bioavailability.

Expression and purification of the catalytic domain of human vascular endothelial growth factor receptor 2 for inhibitor screening

Vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, can act in tumor-induced angiogenesis by binding to specific receptors on the surface of endothelial cells. One such receptor, VEGFR-2/KDR, plays a key role in VEGF-induced angiogenesis. Here, we expressed the catalytic domain of VEGFR-2 as a soluble active kinase using Bac-to-Bac expression system, and investigated correlations between VEGFR-2 activity and enzyme concentration, ATP concentration, substrate concentration and divalent cation type. We used these data to establish a convenient, effective and non-radioactive ELISA screening technique for the identification and evaluation of potential inhibitors for VEGFR-2 kinase. We screened 200 RTK target-based compounds and identified one (TKI-31) that potently inhibited VEGFR-2 kinase activity (IC50=0.596 microM). Treatment of NIH3T3/KDR cells with TKI-31 blocked VEGF-induced phosphorylation of KDR in a dose-dependent manner. Moreover, TKI-31 dose-dependently suppressed HUVEC tube formation. Thus, we herein report a novel, efficient method for identifying VEGFR-2 kinase inhibitors and introduce one, TKI-31, that may prove to be a useful new angiogenesis inhibitor.

Conformational flexibility of beta-secretase: molecular dynamics simulation and essential dynamics analysis

AIM

Based on the structural analysis to reveal the mechanism of ligand binding to beta-secretase and the specificity of each binding sub-site.

METHODS

Molecular dynamics was used to simulate on the ligand free beta-secretase and ligand bound beta-secretase. The trajectories were analyzed using the essential dynamics, and the significant conformational change was illustrated employing the DynDom program.

RESULTS

The essential dynamics and DynDom analyses clearly showed that the beta-secretase experienced a large conformational change upon the substrate or inhibitor binding. The flap structure adopted a swing motion, gradually covering the active site to facilitate the ligand binding process. Residues Ser86 and Ile87 served as the hinge point. Inhibitor-enzyme interaction analysis revealed that residues at P2, P1, and P1' positions of the inhibitor were very important for the binding, and residues at P2' and P3' positions may be modified to improve the binding specificity. S3 subsite of the enzyme still had space to modify the inhibitors in increasing the binding affinity.

CONCLUSION

The information presented here is valuable and could be used to identify small molecular inhibitors of beta-secretase.

A 3D model of SARS_CoV 3CL proteinase and its inhibitors design by virtual screening

AIM

To constructed a three-dimensional (3D) model for the 3C like (3CL) proteinase of SARS coronavirus (SARS-CoV), and to design inhibitors of the 3CL proteinase based on the 3D model.

METHODS

Bioinformatics analyses were performed to search the homologous proteins of the SARS-CoV 3CL proteinase from the GenBank and PDB database. A 3D model of the proteinase was constructed by using homology modeling technique. Targeting to the 3D model and its X-ray crystal structure of the main proteinase (Mpro) of transmissible gastroenteritis virus (TGEV), virtual screening was performed employing molecular docking method to identify possible 3CL proteinase inhibitors from small molecular databases.

RESULTS

Sequence alignment indicated that the SARS-CoV 3CL proteinase was extremely homologous to TGEV Mpro, especially the substrate-binding pocket (active site). Accordingly, a 3D model for the SARS-CoV 3CL proteinase was constructed based on the crystal structure of TGEV Mpro. The 3D model adopts a similar fold of the TGEV Mpro, its structure and binding pocket feature are almost as same as that of TGEV Mpro. The tested virtual screening indicated that 73 available proteinase inhibitors in the MDDR database might dock into both the binding pockets of the TGEV Mpro and the SARS-CoV 3CL proteinase.

CONCLUSIONS

Either the 3D model of the SARS-CoV 3CL proteinase or the X-ray crystal structure of the TGEV Mpro may be used as a starting point for design anti-SARS drugs. Screening the known proteinase inhibitors may be an appreciated shortcut to discover anti-SARS drugs.

Putative hAPN receptor binding sites in SARS_CoV spike protein

AIM

To obtain the information of ligand-receptor binding between the S protein of SARS-CoV and CD13, identify the possible interacting domains or motifs related to binding sites, and provide clues for studying the functions of SARS proteins and designing anti-SARS drugs and vaccines.

METHODS

On the basis of comparative genomics, the homology search, phylogenetic analyses, and multi-sequence alignment were used to predict CD13 related interacting domains and binding sites in the S protein of SARS-CoV. Molecular modeling and docking simulation methods were employed to address the interaction feature between CD13 and S protein of SARS-CoV in validating the bioinformatics predictions.

RESULTS

Possible binding sites in the SARS-CoV S protein to CD13 have been mapped out by using bioinformatics analysis tools. The binding for one protein-protein interaction pair (D757-R761 motif of the SARS-CoV S protein to P585-A653 domain of CD13) has been simulated by molecular modeling and docking simulation methods.

CONCLUSION

CD13 may be a possible receptor of the SARS-CoV S protein, which may be associated with the SARS infection. This study also provides a possible strategy for mapping the possible binding receptors of the proteins in a genome.

Identification of probable genomic packaging signal sequence from SARS-CoV genome by bioinformatics analysis

AIM

To predict the probable genomic packaging signal of SARS-CoV by bioinformatics analysis. The derived packaging signal may be used to design antisense RNA and RNA interfere (RNAi) drugs treating SARS.

METHODS

Based on the studies about the genomic packaging signals of MHV and BCoV, especially the information about primary and secondary structures, the putative genomic packaging signal of SARS-CoV were analyzed by using bioinformatic tools. Multi-alignment for the genomic sequences was performed among SARS-CoV, MHV, BCoV, PEDV and HCoV 229E. Secondary structures of RNA sequences were also predicted for the identification of the possible genomic packaging signals. Meanwhile, the N and M proteins of all five viruses were analyzed to study the evolutionary relationship with genomic packaging signals.

RESULTS

The putative genomic packaging signal of SARS-CoV locates at the 3' end of ORF1b near that of MHV and BCoV, where is the most variable region of this gene. The RNA secondary structure of SARS-CoV genomic packaging signal is very similar to that of MHV and BCoV. The same result was also obtained in studying the genomic packaging signals of PEDV and HCoV 229E. Further more, the genomic sequence multi-alignment indicated that the locations of packaging signals of SARS-CoV, PEDV, and HCoV overlaped each other. It seems that the mutation rate of packaging signal sequences is much higher than the N protein, while only subtle variations for the M protein.

CONCLUSIONS

The probable genomic packaging signal of SARS-CoV is analogous to that of MHV and BCoV, with the corresponding secondary RNA structure locating at the similar region of ORF1b. The positions where genomic packaging signals exist have suffered rounds of mutations, which may influence the primary structures of the N and M proteins consequently.

Small envelope protein E of SARS: cloning, expression, purification, CD determination, and bioinformatics analysis

AIM

To obtain the pure sample of SARS small envelope E protein (SARS E protein), study its properties and analyze its possible functions.

METHODS

The plasmid of SARS E protein was constructed by the polymerase chain reaction (PCR), and the protein was expressed in the E coli strain. The secondary structure feature of the protein was determined by circular dichroism (CD) technique. The possible functions of this protein were annotated by bioinformatics methods, and its possible three-dimensional model was constructed by molecular modeling.

RESULTS

The pure sample of SARS E protein was obtained. The secondary structure feature derived from CD determination is similar to that from the secondary structure prediction. Bioinformatics analysis indicated that the key residues of SARS E protein were much conserved compared to the E proteins of other coronaviruses. In particular, the primary amino acid sequence of SARS E protein is much more similar to that of murine hepatitis virus (MHV) and other mammal coronaviruses. The transmembrane (TM) segment of the SARS E protein is relatively more conserved in the whole protein than other regions.

CONCLUSION

The success of expressing the SARS E protein is a good starting point for investigating the structure and functions of this protein and SARS coronavirus itself as well. The SARS E protein may fold in water solution in a similar way as it in membrane-water mixed environment. It is possible that beta-sheet I of the SARS E protein interacts with the membrane surface via hydrogen bonding, this beta-sheet may uncoil to a random structure in water solution.

Chicken keel cartilage as a source of chondroitin sulfate

Chondroitin sulfate is used extensively as a treatment for osteoarthritis. This study was conducted to evaluate whether chondroitin sulfate could be isolated from chicken keel cartilage in sufficient quantities and of requisite quality to make it a feasible source of chondroitin sulfate. Proteoglycans were extracted from chicken keel cartilage obtained immediately after slaughter by using 3 M MgCl2 at room temperature. The extract was then dialyzed and digested with papain to remove proteins. Glycosaminoglycans were obtained by ethanol precipitation, lyophilized, and characterized by using gel filtration on Sepharose CL-6B columns. Guanidine-HCI extraction was also used as a control to investigate the efficiency of extraction using MgCl2. Results showed that, from every gram of wet or non-lyophilized keel cartilage, 32.9 +/- 4.8 mg (dry weight) of glycosaminoglycans could be obtained following MgCl2 extraction. Analyses revealed that 75.5 +/- 4.2% of these glycosaminoglycans were chondroitin sulfate. Chromatographic analyses showed a single symmetrical peak, which could be almost entirely removed by prior digestion with chondroitinase ABC, indicating that the material in the peak was in fact chondroitin sulfate. The average molecular weight (also called relative molecular mass, Mr) of the glycosaminoglycans was also estimated (Mr 48,500). Characterization using polyacrylamide or agarose gel electrophoresis showed diffuse bands containing chondroitin sulfate, which could be entirely removed by prior digestion with chondroitinase ABC. This study shows that chicken keel cartilage is a readily available source of chondroitin sulfate.

[In vitro culture of modified neonatal pig islets]

A cell-isolation-and-cell-culture-in-vitro method which can produce a mass of new-born pig islet-like clusters was introduced. The new-born pig pancreas were incubated in V-type collagenase (0.5-1.0 mg.ml-1) for 8-12 minutes, and then cultured in vitro for 7 days before large amount of highly purified porcine islets were produced. The neonatal pig islets had good insulin secretion and normal sub-cell structure. The results suggest that the neonatal pig islets are probably a fine donor source for clinical xenotransplantation of islets.