The Evaluation and Prediction of Laminoplasty Surgery Outcome in Patients with Degenerative Cervical Myelopathy Using Diffusion Tensor MRI

BACKGROUND AND PURPOSE

DTI has been proved valuable for the diagnosis of degenerative cervical myelopathy, whereas its capacity for predicting the outcome of surgery is still under debate. Here we conduct a prospective cohort study to analyze the capacity of DTI for evaluating and predicting laminoplasty surgery outcome for degenerative cervical myelopathy.

MATERIALS AND METHODS

We recruited 55 patients with degenerative cervical myelopathy who underwent DTI before surgery and at 3- and 6-month follow-up stages, and 20 healthy subjects. For clinical assessment, the modified Japanese Orthopedic Association scale was recorded for each patient at different stages. DTI metrics were compared between patients before surgery and healthy subjects. Spearman correlation and receiver operating characteristic were used to analyze the evaluation and prediction capacity of DTI for the modified Japanese Orthopedic Association scale, respectively. We analyzed different vertebral levels: maximal compression level, average of all compression levels, and C2 level.

RESULTS

DTI metrics were significantly different between patients before surgery and healthy subjects. Before surgery, DTI for the maximal compression level or DTI for the average of all compression levels had no significant correlation with the modified Japanese Orthopedic Association scale. For all stages, DTI at the C2 level was correlated with the modified Japanese Orthopedic Association scale. DTI metrics at the C2 level before surgery were significantly correlated with the postoperative modified Japanese Orthopedic Association scale recovery rate. Receiver operating characteristic analysis demonstrated that fractional anisotropy at C2 was capable of predicting the postoperative modified Japanese Orthopedic Association scale recovery rate (P = .04).

CONCLUSIONS

The DTI metrics before laminoplasty surgery, especially fractional anisotropy at the C2 level, have the potential for evaluating and predicting the degenerative cervical myelopathy surgery outcome.

P55PIK Regulates P53-Dependent Apoptosis in Cancer Cells by Interacting with P53 DNA-Specific Domain

Purpose

Phosphatidylinositol 3-kinase (PI3K) plays an important role in tumorigenesis by cross-talking with several signaling pathways. p55PIK is a unique regulatory subunit of PI3K and contains an extra 24-residue N-terminal domain (N24). This study aimed to explore the interaction of p55PIK with p53 and the role of p55PIK in regulating p53-dependent apoptosis in cancer cells.

Materials and Methods

The expression of p55PIK was detected in cancer cells, and the interaction of p55PIK with p53 was examined by immunoprecipitation and pull-down assay. The expression of p53-dependent apoptosis-related genes was detected by PCR.

Results

N24 domain of p55PIK interacted with DNA-specific binding domain (DBD) of p53. The increase or decrease of p55PIK expression led to the change of the expression of p53 and p53-regulated genes in cancer cells. Moreover, N24 peptide led to the change of the expression of p53-regulated genes. Moreover, a membrane-permeable N24 peptide enhanced p53-dependent apoptosis induced by methyl methanesulfonate.

Conclusion

Our results reveal a novel mechanism that regulates p53-dependent apoptosis in cancer cells via p55PIK-p53 interaction.

Magnesium-Dependent Promotion of H2O2 Production Increases Ecological Competitiveness of Oral Commensal Streptococci

The pyruvate oxidase (SpxB)-dependent production of H₂O₂ is widely distributed among oral commensal streptococci. Several studies confirmed the ability of H₂O₂ to antagonize susceptible oral bacterial species, including caries-associated Streptococcus mutans as well as several periodontal pathobionts. Here we report a potential mechanism to bolster oral commensal streptococcal H₂O₂ production by magnesium (Mg²⁺) supplementation. Magnesium is a cofactor for SpxB catalytic activity, and supplementation increases the production of H₂O₂ in vitro. We demonstrate that Mg²⁺ affects spxB transcription and SpxB abundance in Streptococcus sanguinis and Streptococcus gordonii. The competitiveness of low-passage commensal streptococcal clinical isolates is positively influenced in antagonism assays against S. mutans. In growth conditions normally selective for S. mutans, Mg²⁺ supplementation is able to increase the abundance of S. sanguinis in dual-species biofilms. Using an in vivo biophotonic imaging platform, we further demonstrate that dietary Mg²⁺ supplementation significantly improves S. gordonii oral colonization in mice. In summary, our results support a role for Mg²⁺ supplementation as a potential prebiotic to promote establishment of oral health-associated commensal streptococci.

[Analysis on the efficacy and safety of fibrinolytic therapy in patients with acute ST-segment elevation myocardial infarction during the COVID-19 epidemic]

Objective: To evaluate the efficacy and safety of fibrinolysis strategy in patients with acute ST-segment elevation myocardial infarction (STEMI) during the COVID-19 epidemic, and to provide reference value for optimization of fibrinolytic process on the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff. Methods: The efficacy and safety of fibrinolysis were retrospectively analyzed in 7 patients with acute STEM, who hospitalized from February 29, 2020 to April 3, 2020 in the Department of Cardiology, Wuhan Union Hospital of Tongji Medical College, Huazhong University of Science and Technology. To optimize the fibrinolytic process on the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff, a full-time medical team in charge of fibrinolysis under third-grade protection was established. The acute STEMI patients were treated immediately in a fixed and isolated area in emergency department before receiving green channel fibrinolysis. Blood samples for complete blood count, COVID-19 antibody test and nasopharyngeal swab samples for COVID-19 nucleic acid test were made before fibrinolysis, while the chest CT examination was accomplished after fibrinolysis. By comparing differences of time from the first electrocardiogram (ECG) to fibrinolysis before and after the improvement of fibrinolytic process, the effect of optimization of the fibrinolytic process was evaluated. Results: In the present study, seven patients with acute STEMI received fibrinolysis therapy, 6 of them achieved reperfusion and no bleeding was observed in all of the patients. Five out of the 7 patients were hospitalized after fibrinolysis, and the hospitalization days were 19.6 days on average. By following up to April 14, 2020, none of the 7 patients died. The first 2 patients were treated according to the routine medical procedure and the time from the first ECG to fibrinolysis were 201 and 106 minutes, respectively. After the optimization of the fibrinolytic process, the time from the first ECG to fibrinolysis of the last 5 patients were 42, 46, 51, 43 and 54 minutes, respectively，which was significantly shorter than that before optimization. Conclusions: During the COVID-19 epidemic, fibrinolysis in patients with acute STEMI is safe, effective and easy to implement. Therefore, it is recommended as the top priority for the patients with acute STEMI with indications for fibrinolysis. On the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff, the duration of myocardial ischemia can be shortened by optimization of the fibrinolytic process.

[Effect of alprostadil in early wound healing of rats with deep partial-thickness scald]

Objective: To explore the effect of alprostadil in early wound healing of rats with deep partial-thickness scald. Methods: Ninety specific pathogen free healthy Sprague-Dawley rats (half males and half females) were divided into sham scald group, simple scald group, and alprostadil group using the random number table with 30 rats in each group. Rats in sham scald group were sham injured, and rats in the other 2 groups were inflicted with deep partial-thickness scald of 30% total body surface area on the back. Immediately after scald, rats in the 3 groups received anti-shock treatment. Two hours post scald, rats in sham scald group and simple scald group were injected intraperitoneally with 1 mL normal saline, and rats in alprostadil group were injected intraperitoneally with 1 mL alprostadil injection, once a day and continued for 14 days. On post scald day (PSD) 3, 7, and 14, 10 rats in each group were collected for observing the general wound conditions and the wound healing rates of rats in 2 scald groups were calculated, abdominal aortic blood of 2 mL from each rat were collected to detect serum thromboxane B2 by enzyme-linked immunosorbent assay, and wound tissue on the back was collected to examine pathomorphological change by hematoxylin-eosin staining and to detect wound microvessel density (MVD) by immunohistochemical staining. Data were statistically analyzed with analysis of variance of factorial design, t test, Kruskal-Wallis H test, Mann-Whitney U test, and Bonferroni correction. Results: (1) There was no scald wound in rats in sham scald group. On PSD 3, wounds of rats in simple scald group and alprostadil group formed dry eschar. On PSD 7 and 14, wound areas of rats in alprostadil group were significantly smaller than those of rats in simple scald group, and with less exudation. (2) On PSD 3, the wound healing rates of rats in simple scald group and alprostadil group were similar (t=1.167, P>0.05). On PSD 7 and 14, the wound healing rates of rats in alprostadil group were significantly higher than those in simple scald group (t=8.657, 33.050, P<0.01). (3) On PSD 3, 7, and 14, the levels of serum thromboxane B2 of rats in simple scald group and alprostadil group were (541±22), (607±47), (688±21), (326±25), (271±21), (135±27) pg/mL, significantly higher than (17±6), (16±4), (16±4) pg/mL of rats in sham scald group (t=72.977, 39.685, 102.076, 37.033, 37.253, 13.845, P<0.01). On PSD 3, 7, and 14, the levels of serum thromboxane B2 of rats in alprostadil group were significantly lower than those in simple scald group (t=20.637, 20.651, 51.680, P<0.01). (4) Normal epidermis and dermis were seen in rats in sham scald group. On PSD 3, a large number of necrotic tissue and inflammatory cells infiltration were seen in wounds of rats in simple scald group, while a little new epithelium formation and some inflammatory cells infiltration were seen in wounds of rats in alprostadil group. On PSD 7 and 14, the new epithelium of rats in alprostadil group was significantly thicker than that in simple scald group, and epidermis formed gradually in alprostadil group. (5) On PSD 3, 7, and 14, the wound MVD of rats in simple scald group and alprostadil group were significantly higher than those in sham scald group (Z=-3.780, -3.781, -3.780, -3.780, -3.781, -3.780, P<0.01). On PSD 3, the wound MVD of rats in simple scald group and alprostadil group were similar (Z=-1.965, P>0.05). On PSD 7 and 14, the wound MVD of rats in alprostadil group were significantly higher than those in simple scald group (Z=-3.780, -3.780, P<0.01). Conclusions: The early intervention with alprostadil can significantly improve microcirculation of deep partial-thickness scald wound, reduce inflammatory cell infiltration, promote the formation of new blood vessels, thus promoting wound healing.

Social exclusion influences conditioned fear acquisition and generalization: A mediating effect from the medial prefrontal cortex

Fear acquisition and generalization play key roles in promoting the survival of mammals and contribute to anxiety disorders. While previous research has provided much evidence for the repercussions of social exclusion on mental health, how social exclusion affects fear acquisition and generalization has received scant attention. In our study, participants were divided into two groups according to two Cyberball paradigm conditions (exclusion/inclusion). Both groups underwent a Pavlovian conditioning paradigm, functional near-infrared spectroscopy (fNIRS), and skin conductance response (SCR) assessments. We aimed to determine the effects of social exclusion on fear acquisition and generalization and whether modulation of the medial prefrontal cortex (mPFC) mediates this relationship. Our results showed that socially excluded participants featured significantly higher and lower shock risk scores to safety stimuli (conditioned stimulus, CS-) and threatening stimuli (CS+), respectively, than did socially included subjects during fear acquisition. The exclusion group had increased skin conductance responses (SCRs) to CS and exhibited heightened shock risk and increased SCRs to generalized stimuli compared with the inclusion group. The fNIRS results demonstrated that the CS ​+ ​evoked larger oxy-Hb changes in the mPFC in the inclusion group than in the exclusion group during fear acquisition. Furthermore, the oxy-Hb of left mPFC of CS ​+ ​mediated the effect on the association between social exclusion and perceived risk of CS+ in the fear acquisition. Our results indicate that social exclusion impairs fear acquisition and generalization via the mediation of the mPFC and that social exclusion increases susceptibility to anxiety disorders through bias processing of fear discrimination in fear acquisition and generalization. By studying the role of social relationship in fear acquisition and generalization, our research provides new insights into the pathological mechanisms of anxiety disorder.

Withdrawn: A Controllable Protein Translation Strategy for Exploring Cellular Signal Transduction Based on Reading through Premature Termination Codons

Withdrawal: Xiyao Cheng, Yongqi Huang, and Zhengding Su. A Controllable Protein Translation Strategy for Exploring Cellular Signal Transduction Based on Reading through Premature Termination Codons. The FASEB Journal. 34:s1. doi: 10.1096/fasebj.2020.34.s1.09195. The above abstract, published online on April 19, 2020, in Wiley Online Library (wileyonlinelibrary.com), has been withdrawn by agreement between the authors, FASEB, and Wiley Periodicals, Inc. The abstract has been withdrawn at the request of the authors.

CTXA hip: the effect of partial volume correction on volumetric bone mineral density data for cortical and trabecular bone

This study compares the results of computed tomography X-ray absorptiometry (CTXA) hip volumetric BMD (vBMD) analyses of cortical and trabecular bone with and without partial volume correction. For cortical bone in some circumstances, corrected cortical volumes were negative and corrected vBMD was very high. For trabecular bone, the correction effects are smaller. CTXA volumetric data should be interpreted with caution.

PURPOSE

Previous studies have reported concerns about the reliability of CTXA hip cortical vBMD measurements generated using partial volume (PV) correction (the "default" analysis, with cortical PV correction). To date, no studies have examined the results of the alternative ("new") analysis (with trabecular PV correction). This study presents in vivo and phantom data comparing the corrected and uncorrected data for cortical and trabecular bone respectively.

METHODS

We used the commercial QCTPro CTXA software to analyze CT scans of 129 elderly Chinese men and women and an anthropomorphic European Proximal Femur phantom (EPFP) and accessed data for two alternative scan analyses using the database dump utility. The CTXA software gives the user two methods of performing the PV correction: (1) a default analysis in which only cortical bone results are corrected; (2) a new analysis in which only trabecular bone results are corrected. Both methods are based on a numerical recalculation of vBMD values without any change in volume of interest (VOI) placement.

RESULT

In vivo, the results of the two analyses for integral bone were the same while cortical and trabecular results were different. PV correction of cortical bone led to a decrease of cortical volume for all four VOIs: total hip (TH), femoral neck (FN), trochanter (TR), and intertrochanter (IT) volumes were reduced on average by 7.8 cm³, 0.9 cm³, 2.5 cm³, and 4.3 cm³ respectively. For TR, where cortex was thinnest, average corrected cortical volume was negative (- 0.4± 1.3 cm³). Corrected cortical vBMD values were much larger than uncorrected ones for TH, FN, and IT. Scatter plots of corrected cortical vBMD against cortical bone thickness showed that elevated results correlated with thinner cortices. When trabecular bone was corrected for the PV effect, trabecular volumes of TH, FN, TR, and IT were reduced on average by 7.9 cm³, 0.8 cm³, 2.6 cm³, and 4.4 cm³ respectively, while vBMD measurements were increased correspondingly. The trabecular volume and vBMD measurements of the two datasets both had highly positive correlations. For the EPFP, the PV-corrected FN data deviated from the nominal phantom value, but was closer for the TR and IT VOIs. Both corrected and uncorrected data overestimated trabecular vBMD, with the corrected results showing greater deviation from nominal values.

CONCLUSION

The default and new CTXA analyses for volumetric data generate different results, both for cortical and trabecular bone. For cortical bone, the uncorrected results are subject to partial volume effects but the correction method of the default analysis overcorrects the effect leading to in part unreasonable results for cortical bone volume and BMD. For trabecular bone, the correction effects are smaller. CTXA volumetric data should be interpreted with caution.

Stable expression ratios of five pyroptosis-inducing cytokines in the spleen and thymus of mice showed potential immune regulation at the organ level

BACKGROUND

The immune system is one of the most complex regulatory systems in the body and is essential for the maintenance of homeostasis. Despite recent breakthroughs in immunology, the regulation of the immune system and the etiology of autoimmune diseases such as lupus remain unclear. Systemic lupus erythematosus is a systemic autoimmune disease with abnormally and inconsistently expressed pro-inflammatory cytokines. Pyroptosis is a pro-inflammatory form of programmed cell death that is associated with systemic lupus erythematosus. The thymus and spleen are important immune organs involved in systemic lupus erythematosus. Therefore, this study investigated the difference in expression of pyroptosis-inducing pro-inflammatory cytokines between the spleen and thymus in lupus model mice and in control mice, to describe immune regulation at the organ level.

OBJECTIVE

To investigate differences in the expression of pyroptosis-inducing cytokines in the spleen and thymus and to explore immune regulatory networks at the organ level.

METHODS

Two groups of lupus mice and two groups of control mice were utilized for this study. Using the thymus and spleen of experimental animals, mRNA expression levels of five pyroptosis-inducing cytokines (interleukin 1β, interleukin 18, NLRP3, caspase-1 and TNF-α) were determined via quantitative polymerase chain reaction. In addition, tissue distribution of these cytokines was investigated via immunohistochemistry.

RESULTS

All five pyroptosis-inducing inflammatory cytokines showed higher expression in the spleen than in the thymus (p < 0.05). Moreover, the spleen/thymus expression ratios of all five pyroptosis-inducing cytokines were not statistically different between the four experimental groups. Expression of all five cytokines exhibited a stable ratio (spleen/thymus ratios). This distinctive stable spleen/thymus ratio was consistent in all four experimental groups. The stable spleen/thymus ratios of the five inflammatory cytokines were as follows: interleukin 1β (2.02 ± 0.9), interleukin 18 (2.07 ± 1.06), caspase-1 (1.93 ± 0.66), NLRP3 (3.14 ± 1.61) and TNF-α (3.16 ± 1.36). Immunohistochemical analysis showed the cytokines were mainly expressed in the red pulp region of the spleen and the medullary region of the thymus, where immune-activated cells aggregated.

CONCLUSION

The stable spleen/thymus expression ratios of pyroptosis-inducing cytokines indicated that immune organs exhibit strictly regulated functions to maintain immune homeostasis and adapt to the environment.

High-efficiency Ni2+-NTA/PAA magnetic beads with specific separation on His-tagged protein

To effective capture and universal enrichment of His-tagged protein, polyacrylic acid (PAA) brushes were used to encapsulate Fe3O4 nanoparticles, connect NTA, and Ni2+ to prepare magnetic beads. These materials provide many advantages, such as excellent stability, tuneable particle size, and a surface for further functionalisation with biomolecules. His-tagged green fluorescence protein (GFP) was separated efficiently, and the binding capacity of Fe3O4/MPS@PAA/NTA-Ni2+ was 93.4 mg/g. Compared with High-Affinity Ni-NTA Resin and Ni-NTA Magnetic Agarose Beads, Fe3O4/MPS@PAA/NTA-Ni2+ nanocomposites exhibited higher separation efficiency and binding capacity towards His-tagged GFP. Moreover, the selectivity and recyclability of them for the target proteins were maintained well after six cycles. This study would widen the application of PAA in constructing multifunctional nanocomposites for biomedical fields.

MR Diffusional Kurtosis Imaging-Based Assessment of Brain Microstructural Changes in Patients with Moyamoya Disease before and after Revascularization

BACKGROUND AND PURPOSE

Conventional imaging examinations are insufficient to accurately assess brain damage in patients with Moyamoya disease. Our aim was to observe brain microstructural changes in patients with Moyamoya disease by diffusional kurtosis imaging and provide support data for application of this technique in individualized assessment of disease severity and surgical outcome among patients with Moyamoya disease.

MATERIALS AND METHODS

A total of 64 patients with Moyamoya disease and 15 healthy volunteers underwent diffusional kurtosis imaging, and a second scanning was offered to surgical patients 3-4 months after revascularization. The diffusional kurtosis imaging parameter maps were obtained for mean kurtosis, axial kurtosis, radial kurtosis, fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. The parameter values were measured in sensory pathway-related regions for all subjects. Differences in diffusional kurtosis imaging parameters of these brain regions were examined for healthy volunteers, patients without acroparesthesia, and asymptomatic and symptomatic sides of patients with acroparesthesia. Changes in diffusional kurtosis imaging parameters of patients with Moyamoya disease before and after revascularization were compared.

RESULTS

Compared with healthy volunteers, patients with Moyamoya disease showed decreased mean kurtosis, axial kurtosis, radial kurtosis, and fractional anisotropy in the corona radiata. Similarly, mean kurtosis, radial kurtosis, and fractional anisotropy decreased in the posterior limb of the internal capsule, whereas axial kurtosis decreased and radial kurtosis increased in the thalami of patients with Moyamoya disease compared with healthy volunteers. Compared with the asymptomatic contralateral hemisphere, the symptomatic group showed increased mean kurtosis in the contralateral primary somatosensory cortex, increased fractional anisotropy in the contralateral corona radiata and posterior limb of the internal capsule, and decreased axial kurtosis in the contralateral thalamus. Among patients with Moyamoya disease with acroparesthesia, mean kurtosis decreased in the primary somatosensory cortex on the operated side following revascularization.

CONCLUSIONS

The diffusional kurtosis imaging technique is applicable to patients with Moyamoya disease for detecting brain microstructural changes in white and gray matter before and after revascularization; this feature is useful in the assessment of disease severity and surgical outcome.

Circular RNA_LARP4 inhibits the progression of non-small-cell lung cancer by regulating the expression of SMAD7

OBJECTIVE

Researchers have uncovered the importance of circular RNAs (circ) in malignant tumors. Circ LARP4 has been found to serve as a tumor suppressor gene in gastric cancer. However, the exact function of circ LARP4 in non-small-cell lung cancer (NSCLC) has not been fully elucidated. The aim of this study was to uncover the role of circ LARP4 in the tumorigenesis of NSCLC.

PATIENTS AND METHODS

Expression level of circ LARP4 in NSCLC tissues was detected through Real Time-quantitative Polymerase Chain Reaction (RT-qPCR). Subsequently, the association between expression and patients' prognosis was analyzed. Circ LARP4 lentivirus was constructed and transfected into NSCLC cells. The effect of circ LARP4 on NSCLC cell migration and invasion was detected by function assays. Furthermore, Western blot was performed to analyze the expression of predicted protein of circ LARP4.

RESULTS

Compared with adjacent tissues, circ LARP4 was lowly expressed in NSCLC tissues. Meanwhile, expression of circ LARP4 was associated with the prognosis of NSCLC patients. Downregulated circ LARP4 was found in NSCLC cell lines as well. The migration and invasion abilities of NSCLC cells were significantly inhibited via overexpression of circ LARP4. SMAD7, the predicted protein of circ LARP4, increased remarkably via overexpression of circ LARP4.

CONCLUSIONS

Circ LARP4 could suppress the metastasis of NSCLC by up-regulating SMAD7.

Road network intersection density and childhood obesity risk in the US: a national longitudinal study

OBJECTIVES

Road intersection density is an important indicator of walkability. The objectives of this study were to examine the trends in intersection density in the US from 2007 to 2011 and assess the associations between intersection density and childhood obesity risk at the state level.

STUDY DESIGN

Longitudinal analyses were conducted to assess the spatial-temporal changes of population-weighted intersection density in relation to the risk of childhood obesity in the US.

METHODS

Road network data from the Topologically Integrated Geographic Encoding and Referencing (TIGER) (2007-2011), the prevalence of overweight and obesity data from the National Survey of Children's Health (NSCH) (2007-2011), and the American Community Survey (ACS) (2011) were used. Geographic information system (GIS) visualization and spatial and regression analyses were conducted. Mixed-effect models were fit to assess the longitudinal relationship between intersection density and childhood obesity.

RESULTS

Between 2007 and 2011, population-weighted intersection density remained relatively stable in most states. Low-intersection-density states were clustered in the Southeastern region in both 2007 and 2011. The high-intersection-density states were clustered in the Middle Atlantic Division. California and Nevada also were identified as high-intersection-density clusters in 2011. States with lower road intersection density corresponded with states with higher childhood obesity prevalence. Our mixed-effect model estimates suggested that increased intersection density was associated with decreased obesity prevalence.

CONCLUSIONS

This study provided empirical evidence for longitudinal associations between neighborhood intersection density and childhood obesity prevalence based on national data and offered a new perspective of the role that road network plays in childhood obesity prevention.

Polyamines Disrupt the KaiABC Oscillator by Inducing Protein Denaturation

Polyamines are positively charged small molecules ubiquitously existing in all living organisms, and they are considered as one kind of the most ancient cellular components. The most common polyamines are spermidine, spermine, and their precursor putrescine generated from ornithine. Polyamines play critical roles in cells by stabilizing chromatin structure, regulating DNA replication, modulating gene expression, etc., and they also affect the structure and function of proteins. A few studies have investigated the impact of polyamines on protein structure and function previously, but no reports have focused on a protein-based biological module with a dedicated function. In this report, we investigated the impact of polyamines (putrescine, spermidine, and spermine) on the cyanobacterial KaiABC circadian oscillator. Using an established in vitro reconstitution system, we noticed that polyamines could disrupt the robustness of the KaiABC oscillator by inducing the denaturation of the Kai proteins (KaiA, KaiB, and KaiC). Further experiments showed that the denaturation was likely due to the induced change of the thermal stability of the clock proteins. Our study revealed an intriguing role of polyamines as a component in complex cellular environments and would be of great importance for elucidating the biological function of polyamines in future.

The LEPR K109R and Q223R Might Contribute to the Risk of NAFLD: A Meta-Analysis

BACKGROUND

Leptin and insulin resistance have been pointed out to play a role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Increasing genes were shown to be associated with the risk of NAFLD.

OBJECTIVE

The study aimed to investigate the genetic association between two leptin receptor (LEPR) polymorphisms (Q223R and K109R) and the NAFLD risk.

METHODS

Studies were retrieved and included by using PubMed, Web of Science, the Cochrane Library databases, Chinese National Knowledge Infrastructure (CNKI) and EMBASE database. Genetic associations were assessed with pooled odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Five case-control studies with 1711 NAFLD patients and 1732 healthy controls were included in this meta-analysis. The K109R was significantly associated with NAFLD in allelic model in Southeast Asian subgroup (p=0.01, OR=0.59, 95% CI [0.39- 0.90]), but not in Chinese subgroup (p=0.24, OR=1.10, 95% CI [0.94-1.29]). The Q223R was significantly associated with NAFLD in both allelic and recessive models (allelic model: p<0.001, OR=0.57, 95% CI [0.50-0.65]; recessive model: p=0.001, OR=0.67, 95% CI [0.52-0.85]). However, subgroup analysis showed that the significant association between Q223R and NAFLD in allelic model cannot be found in Southeast Asians subgroup (p=0.07, OR=0.67, 95% CI [0.52-0.85]).

CONCLUSION

LEPR K109R might be a susceptible factor for NAFLD in Southeast Asian population. And LEPR Q223R might be a susceptible factor for NAFLD in Chinese population.

Tanshinones: First-in-Class Inhibitors of the Biogenesis of the Type 3 Secretion System Needle of Pseudomonas aeruginosa for Antibiotic Therapy

The type 3 secretion system (T3SS) found as cell-surface appendages of many pathogenic Gram-negative bacteria, although nonessential for bacterial survival, is an important therapeutic target for drug discovery and development aimed at inhibiting bacterial virulence without inducing antibiotic resistance. We designed a fluorescence-polarization-based assay for high-throughput screening as a mechanistically well-defined general strategy for antibiotic discovery targeting the T3SS and made a serendipitous discovery of a subset of tanshinones-natural herbal compounds in traditional Chinese medicine widely used for the treatment of cardiovascular and cerebrovascular diseases-as effective inhibitors of the biogenesis of the T3SS needle of multi-drug-resistant Pseudomonas aeruginosa. By inhibiting the T3SS needle assembly and, thus, cytotoxicity and pathogenicity, selected tanshinones reduced the secretion of bacterial virulence factors toxic to macrophages in vitro, and rescued experimental animals challenged with lethal doses of Pseudomonas aeruginosa in a murine model of acute pneumonia. As first-in-class inhibitors with a demonstrable safety profile in humans, tanshinones may be used directly to alleviate Pseudomonas-aeruginosa-associated pulmonary infections without inducing antibiotic resistance. Since the T3SS is highly conserved among Gram-negative bacteria, this antivirulence strategy may be applicable to the discovery and development of novel classes of antibiotics refractory to existing resistance mechanisms for the treatment of many bacterial infections.