Erratum: Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen [Phys. Rev. Lett. 127, 021101 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.127.021101.

Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen

We report the properties of sodium (Na) and aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV based on 0.46 million sodium and 0.51 million aluminum nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We found that Na and Al, together with nitrogen (N), belong to a distinct cosmic ray group. In this group, we observe that, similar to the N flux, both the Na flux and Al flux are well described by the sums of a primary cosmic ray component (proportional to the silicon flux) and a secondary cosmic ray component (proportional to the fluorine flux). The fraction of the primary component increases with rigidity for the N, Na, and Al fluxes and becomes dominant at the highest rigidities. The Na/Si and Al/Si abundance ratios at the source, 0.036±0.003 for Na/Si and 0.103±0.004 for Al/Si, are determined independent of cosmic ray propagation.

[Orexin-A inhibits γ-aminobutyric acid current of neonatal rat spinal cord ventral horn neurons by activating OX1R, OX2R and Ca2+-independent PKC]

OBJECTIVE

To investigate the effect of orexin-A on the functionality of ionotropic γ-aminobutyric acid (GABA) receptors in spinal cord ventral horn neurons and its mechanisms.

OBJECTIVE

The spinal cord containing the lumbosacral enlargement was isolated from neonatal SD rats (7-12 days old) and sliced. The slices were digested with papain (in 0.18 g/30 mL artificial cerebrospinal fluid) for 40-60 min, and the ventral horn neurons were separated acutely using fire-polished Pasteur pipettes. After the cells adhered to the bottom of Petri dishes, patch-clamp experiments combined with pharmacological methods were performed to test the effects of orexin-A on GABA currents of the neurons treated with SB334867 (a selective OX₁R antagonist), TCSOX229 (a selective OX₂R antagonist), Bis-Ⅳ (a PKC inhibitor), PMA (a PKC agonist), Rp-cAMP (a PKA inhibitor), or BAPTA (Ca²⁺ chelator).

OBJECTIVE

The isolated neurons maintained good morphologies with diverse shapes of cell body and long protrusions. Treatment with orexin-A significantly inhibited the amplitude of GABA-induced current (P < 0.001, n=49) with an inhibition rate of (67.48±12.50)%. SB334867 and TCSOX229, when applied simultaneously, completely abolished the suppressive effect of orexin-A on the GABA currents (P=0.93, n=6), and their separate use partially relieved the suppressive effect of orexin-A (P=0.001, n=8; P=0.02, n=8). The application of Bis-Ⅳ also abolished the suppressive effect of orexin-A on GABA currents (P=0.31, n=5). PMA mimicked the effect of orexin-A in these neurons and significantly inhibited GABA currents with an inhibition rate of (60.79±10.94)%, and the application of orexin-A did not cause further suppression of GABA currents in PMA-treated neurons (P=0.15, n=6). Orexin-A was still capable of suppressing GABA currents in Rp-cAMP-treated neurons (P=0.001, n=5). The extracellular Ca²⁺-free solution (P=0.004, n=8) or the presence of BAPTA (P=0.04, n=7) did not significantly affect the inhibitory effect of orexin-A on GABA currents.

OBJECTIVE

Orexin-A inhibits GABA currents in the ventral horn neurons of rat spinal cord probably by activating OX₁R, OX₂R and Ca²⁺-independent PKC.

POS0851 IDENTIFICATION OF HUB GENES AND PATHWAYS IN DERMATOMYOSITIS BY BIOINFORMATICS ANALYSIS

Background:

Dermatomyositis (DM) is a chronic systemic autoimmune disease characterized by inflammatory infiltrates in the skin and muscle1. The genes and pathways in the inflamed myopathies in patients with DM are poorly understood2.

Objectives:

To identify the key genes and pathways associated with DM and further discover its pathogenesis.

Methods:

Muscle tissue gene expression profile (GSE143323) were acquired from the GEO database, which included 39 DM samples and 20 normal samples. The differentially expressed genes (DEGs) in DM muscle tissue were screened by adopting the R software. Gene ontology (GO) and Kyoto Encyclopedia of Genome (KEGG) pathway enrichment analysis was performed by Metascape online analysis tool. A protein-protein interaction (PPI) network was then constructed by STRING software using the genes in significantly different pathways. Network of DEGs was analyzed by Cytoscape software. And degree of nodes was used to screen key genes.

Results:

Totally, 126 DEGs were obtained, which contained 122 up-regulated and 4 down-regulated. GO analysis revealed that most of the DEGs were significantly enriched in type I interferon signaling pathway, response to interferon-gamma, collagen-containing extracellular matrix, response to interferon-alpha and bacterium, positive regulation of cell death, leukocyte chemotaxis. KEGG pathway analysis showed that upregulated DEGs enhanced pathways associated with the hepatitis C, complement and coagulation cascades, p53 signaling pathway, RIG-I-like receptor signaling, Osteoclast differentiation, and AGE-RAGE signaling pathway. Ten hub genes were identified in DM, they were ISG15, IRF7, STAT1, MX1, OASL, OAS2, OAS1, OAS3, GBP1, and IRF9 according to the Cytoscape software and cytoHubba plugin.

Conclusion:

The findings from this bioinformatics network analysis study identified the key hub genes that might provide new molecular markers for its diagnosis and treatment.

References:

[1]Olazagasti JM, Niewold TB, Reed AM. Immunological biomarkers in dermatomyositis. Curr Rheumatol Rep 2015;17(11):68. doi: 10.1007/s11926-015-0543-y [published Online First: 2015/09/26].

[2]Chen LY, Cui ZL, Hua FC, et al. Bioinformatics analysis of gene expression profiles of dermatomyositis. Mol Med Rep 2016;14(4):3785-90. doi: 10.3892/mmr.2016.5703 [published Online First: 2016/09/08].

[3]Zhou Y, Zhou B, Pache L, et al. Metascape provides a biologist-oriented resource for the analysis of systems-level datasets. Nat Commun 2019;10(1):1523. doi: 10.1038/s41467-019-09234-6 [published Online First: 2019/04/05].

Acknowledgements:

This project was supported by National Science Foundation of China (82001740), Open Fund from the Key Laboratory of Cellular Physiology (Shanxi Medical University) (KLCP2019) and Innovation Plan for Postgraduate Education in Shanxi Province (2020BY078).

Disclosure of Interests:

None declared

POS0458 IDENTIFICATION OF HUB GENES AND MOLECULAR PATHWAYS IN PATIENTS WITH RHEUMATOID ARTHRITIS BY BIOINFORMATICS ANALYSIS

Background:

Rheumatoid arthritis (RA) is a chronic, inflammatory synovitis based systemic disease of unknown etiology1. The genes and pathways in the inflamed synovium of RA patients are poorly understood.

Objectives:

This study aims to identify differentially expressed genes (DEGs) associated with the progression of synovitis in RA using bioinformatics analysis and explore its pathogenesis2.

Methods:

RA expression profile microarray data GSE89408 were acquired from the public gene chip database (GEO), including 152 synovial tissue samples from RA and 28 healthy synovial tissue samples. The DEGs of RA synovial tissues were screened by adopting the R software. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. Protein-protein interaction (PPI) networks were assembled with Cytoscape software.

Results:

A total of 654 DEGs (268 up-regulated genes and 386 down-regulated genes) were obtained by the differential analysis. The GO enrichment results showed that the up-regulated genes were significantly enriched in the biological processes of myeloid leukocyte activation, cellular response to interferon-gamma and immune response-regulating signaling pathway, and the down-regulated genes were significantly enriched in the biological processes of extracellular matrix, retinoid metabolic process and regulation of lipid metabolic process. The KEGG annotation showed the up-regulated genes mainly participated in the staphylococcus aureus infection, chemokine signaling pathway, lysosome signaling pathway and the down-regulated genes mainly participated in the PPAR signaling pathway, AMPK signaling pathway, ECM-receptor interaction and so on. The 9 hub genes (PTPRC, TLR2, tyrobp, CTSS, CCL2, CCR5, B2M, fcgr1a and PPBP) were obtained based on the String database model by using the Cytoscape software and cytoHubba plugin3.

Conclusion:

The findings identified the molecular mechanisms and the key hub genes of pathogenesis and progression of RA.

References:

[1]Xiong Y, Mi BB, Liu MF, et al. Bioinformatics Analysis and Identification of Genes and Molecular Pathways Involved in Synovial Inflammation in Rheumatoid Arthritis. Med Sci Monit 2019;25:2246-56. doi: 10.12659/MSM.915451 [published Online First: 2019/03/28]

[2]Mun S, Lee J, Park A, et al. Proteomics Approach for the Discovery of Rheumatoid Arthritis Biomarkers Using Mass Spectrometry. Int J Mol Sci 2019;20(18) doi: 10.3390/ijms20184368 [published Online First: 2019/09/08]

[3]Zhu N, Hou J, Wu Y, et al. Identification of key genes in rheumatoid arthritis and osteoarthritis based on bioinformatics analysis. Medicine (Baltimore) 2018;97(22):e10997. doi: 10.1097/MD.0000000000010997 [published Online First: 2018/06/01]

Acknowledgements:

This project was supported by National Science Foundation of China (82001740), Open Fund from the Key Laboratory of Cellular Physiology (Shanxi Medical University) (KLCP2019) and Innovation Plan for Postgraduate Education in Shanxi Province (2020BY078).

Disclosure of Interests:

None declared

AB0005 IDENTIFICATION OF KEY GENES AND PATHWAYS FOR PSORIASIS BASED ON GEO DATABASES BY BIOINFORMATICS ANALYSIS

Background:

Psoriasis is an immune-mediated, genetic disease manifesting in the skin or joints or both, and also has a strong genetic predisposition and autoimmune pathogenic traits1. The hallmark of psoriasis is sustained inflammation that leads to uncontrolled keratinocyte proliferation and dysfunctional differentiation. And it’s also a chronic relapsing disease, which often necessitates a long-term therapy2.

Objectives:

To investigate the molecular mechanisms of psoriasis and find the potential gene targets for diagnosis and treating psoriasis.

Methods:

Total 334 gene expression data of patients with psoriasis research (GSE13355 GSE14905 and GSE30999) were obtained from the Gene Expression Omnibus database. After data preprocessing and screening of differentially expressed genes (DEGs) by R software. Online toll Metascape3 was used to analyze Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs. Interactions of proteins encoded by DEGs were discovered by Protein-protein interaction network (PPI) using STRING online software. Cytoscape software was utilized to visualize PPI and the degree of each DEGs was obtained by analyzing the topological structure of the PPI network.

Results:

A total of 611 DEGs were found to be differentially expressed in psoriasis. GO analysis revealed that up-regulated DEGs were mostly associated with defense and response to external stimulus while down-regulated DEGs were mostly associated with metabolism and synthesis of lipids. KEGG enrichment analysis suggested they were mainly enriched in IL-17 signaling, Toll-like receptor signaling and PPAR signaling pathways, Cytokine-cytokine receptor interaction and lipid metabolism. In addition, top 9 key genes (CXCL10, OASL, IFIT1, IFIT3, RSAD2, MX1, OAS1, IFI44 and OAS2) were identified through Cytoscape.

Conclusion:

DEGs of psoriasis may play an essential role in disease development and may be potential pathogeneses of psoriasis.

References:

[1]Boehncke WH, Schon MP. Psoriasis. Lancet 2015;386(9997):983-94. doi: 10.1016/S0140-6736(14)61909-7 [published Online First: 2015/05/31].

[2]Zhang YJ, Sun YZ, Gao XH, et al. Integrated bioinformatic analysis of differentially expressed genes and signaling pathways in plaque psoriasis. Mol Med Rep 2019;20(1):225-35. doi: 10.3892/mmr.2019.10241 [published Online First: 2019/05/23].

[3]Zhou Y, Zhou B, Pache L, et al. Metascape provides a biologist-oriented resource for the analysis of systems-level datasets. Nat Commun 2019;10(1):1523. doi: 10.1038/s41467-019-09234-6 [published Online First: 2019/04/05].

Acknowledgements:

This project was supported by National Science Foundation of China (82001740), Open Fund from the Key Laboratory of Cellular Physiology (Shanxi Medical University) (KLCP2019) and Innovation Plan for Postgraduate Education in Shanxi Province (2020BY078).

Disclosure of Interests:

None declared

POS0742 SCREENING AND BIOINFORMATICS ANALYSIS OF HUB GENES AND PATHWAYS FOR PRIMARY SJÖGREN’S SYNDROME BASED ON GEO DATABASE

Background:

Primary Sjögren’s syndrome (pSS) is an autoimmune disease that featured as lymphoplasmacytic infiltration of the exocrine glands leading to sicca symptoms1. However, its underlying molecular mechanisms remain elusive.

Objectives:

This study aims to identify differentially expressed genes (DEGs) and pathways associated with the progression of pSS using bioinformatics analysis and explore its pathogenesis.

Methods:

The pSS-associated gene chip data set GSE66795 was obtained from the Gene Expression Omnibus (GEO) database, which included 131 cases of fully-phenotyped pSS patients’ whole blood samples and 29 cases of control samples. DEGs were screened Using R software. Online tool Metascape2 was used to make Gene Ontology (GO) and KEGG pathway enrichment. The PPI network was performed using String database. Hub genes were identified by Cytoscape.

Results:

A total of 108 DEGs were captured, including 101 up-regulated genes and 7 down-regulated genes. GO enrichment showed that these DEGs were primarily enriched in defense response to virus, response to interferon-gamma, regulation of innate immune response, response to interferon-beta, double-stranded RNA binding, response to interferon-alpha. KEGG pathway enrichment analysis showed these DEGs were principally enriched in Influenza A, RIG-I-like receptor signaling pathway, necroptosis, Staphylococcus aureus infection. Finally, 9 hub genes (STAT1, IRF7, OAS2, GBP1, OAS1, IFIT3, IFIH1, OAS3, DDX60) had highest degree value.

Conclusion:

The findings identified molecular mechanisms and the key hub genes that may involve in the occurrence and development of pSS.

References:

[1]Francois H, Mariette X. Renal involvement in primary Sjogren syndrome. Nat Rev Nephrol 2016;12(2):82-93. doi: 10.1038/nrneph.2015.174 [published Online First: 2015/11/17].

[2]Zhou Y, Zhou B, Pache L, et al. Metascape provides a biologist-oriented resource for the analysis of systems-level datasets. Nat Commun 2019;10(1):1523. doi: 10.1038/s41467-019-09234-6 [published Online First: 2019/04/05].

Acknowledgements:

This project was supported by National Science Foundation of China (82001740), Open Fund from the Key Laboratory of Cellular Physiology (Shanxi Medical University) (KLCP2019) and Innovation Plan for Postgraduate Education in Shanxi Province (2020BY078).

Disclosure of Interests:

None declared

POS0848 IDENTIFICATION OF POTENTIAL CRUCIAL GENES AND KEY PATHWAYS IN PULMONARY ARTERIAL HYPERTENSION WITH SYSTEMIC SCLEROSIS BY BIOINFORMATIC ANALYSIS

Background:

Pulmonary arterial hypertension with systemic sclerosis (SSc-PAH) is the main cause of death in patients with SSc. Early diagnosis and timely treatment are very important to reduce the mortality of patients with SSc-PAH1. At present, there are not many sensitive markers for the diagnosis of SSc-PAH. Therefore, it is necessary to mine more sensitive markers as more accurate and practical predictors, which is of great significance for the diagnosis and treatment of SSc-PAH.

Objectives:

To discover the differentially expressed genes (DEGs) and activated signaling pathways in SSc-PAH.

Methods:

Fifty-five samples (27 SSc-PAH v.s 28 normal controls) in GSE33463 chip data obtained from Gene Expression Omnibus (GEO) were included in this study. DEGs in SSc-PAH patients were screened by R, key pathways and hub genes were discoved by Metascape2, STRING3 and Cytoscape.

Results:

Total 431 genes with large differences were identified, including 238 up-regulated genes and 193 down-regulated genes, after standardizing the data (|logFC| > 1; P < 0.05). GO analysis showed that the upregulated genes were mainly involved in defense response to virus, hemoglobin complex, platelet alpha granule membrane and cytokine binding. The downregulated genes were mainly characterized by positive regulation of cell death, regulation of MAPK cascade, regulation of DNA-binding transcription factor activity and transcription factor AP-1 complex. Several significant enriched pathways obtained in the KEGG pathway analysis were Influenza A, Hepatitis C, IL-17 signaling pathway, MAPK signaling pathway, Toll-like receptor signaling pathway. Finally, after the selected differential genes were introduced into STRING online software, the data information of protein interaction network was derived, and 12 core genes in the network were identified, they were CXCL8, PPBP, LPAR1, FPR2, GNG11, CXCL10, LPAR5, JUN, C3AR1, CCR2, CCR3, IRF2.

Conclusion:

The genes and signal pathways related to SSc-PAH discovered by bioinformatics methods could not only provided new molecular markers for its diagnosis and treatment, but also provided new ideas for its related biological research.

References:

[1]Zheng JN, Li Y, Yan YM, et al. Identification and Validation of Key Genes Associated With Systemic Sclerosis-Related Pulmonary Hypertension. Front Genet 2020;11:816. doi: 10.3389/fgene.2020.00816 [published Online First: 2020/08/15].

[2]Zhou Y, Zhou B, Pache L, et al. Metascape provides a biologist-oriented resource for the analysis of systems-level datasets. Nat Commun 2019;10(1):1523. doi: 10.1038/s41467-019-09234-6 [published Online First: 2019/04/05].

[3]Szklarczyk D, Gable AL, Lyon D, et al. STRING v11: protein-protein association networks with increased coverage, supporting functional discovery in genome-wide experimental datasets. Nucleic Acids Res 2019;47(D1):D607-D13. doi: 10.1093/nar/gky1131 [published Online First: 2018/11/27].

Acknowledgements:

This project was supported by National Science Foundation of China (82001740), Open Fund from the Key Laboratory of Cellular Physiology (Shanxi Medical University) (KLCP2019) and Innovation Plan for Postgraduate Education in Shanxi Province (2020BY078).

Disclosure of Interests:

None declared

[Contribution of sympathetic activation to antihypertrophic memory after regression of exercise-induced physiological myocardial hypertrophy in mice]

OBJECTIVE

To investigate whether anti-hypertrophic memory exists after regression of exercise-induced physiological myocardial hypertrophy (PMH) and explore the contribution of sympathetic activation to hypertrophic memory formation.

OBJECTIVE

Seventy-two mice were randomized equally into 6 groups, including sedentary sham-operated group, exercise hypertrophic preconditioning (EHP) + sham operation group, bisoprolol (an adrenergic β1 receptor blocker) + EHP + sham operation group (biso+Exe+Sham group), sedentary group with transverse aortic constriction (TAC) (Sed+TAC group), EHP+ TAC group (Exe+TAC group), and bisoprolol+EHP+TAC group (biso+Exe+TAC group). The mice in the EHP groups were subjected to 3 weeks of swimming training, and in the bisoprolol groups, bisoprolol was administered by gavage once daily from two days before till the end of the training. One week after the training, TAC or sham surgery was performed. Echocardiography and hemodynamic measurements were performed to evaluate cardiac function of the mice, and the myocardial tissues were examined histologically to detect cardiac remodeling.

OBJECTIVE

Compared with the sedentary group, the mice receiving 3 weeks of swimming training had significantly increased heart weight to body weight ratio (HW/BW), HW to tibia length ratio (HW/TL), and the cross-sectional area of the cardiomyocytes (P < 0.05). One week after the training, exercise-induced PMH rapidly diminished and both HW/BW and HW/TL recovered the baseline levels. Treatment with bisoprolol obviously prevented the occurrence of PMH. Four weeks after TAC, the left ventricular posterior wall thickness, HW/BW, HW/TL, left ventricular end diastolic pressure and cross-sectional area of cardiomyocytes were all significantly lower (P < 0.05) while the left ejection fraction and maximal change rate of left ventricular pressure were significantly higher (P < 0.05) in Exe + TAC group than in Sed + TAC group. No significant difference was found in these parameters between biso + Exe + TAC group and Sed + TAC group.

OBJECTIVE

Anti-hypertrophic memory exists even after the regression of exercise-induced PMH, which may be attributed to the activation of sympathetic nervous system during exercise.

The relationship between intestinal flora changes and osteoporosis in rats with inflammatory bowel disease and the improvement effect of probiotics

OBJECTIVE

The aim of this study was to investigate the relationship between the changes in intestinal flora and the occurrence of osteoporosis in rats with inflammatory bowel disease and the improvement effect of probiotics.

MATERIALS AND METHODS

A total of 100 Sprague Dawley (SD) model rats with colitis were selected as research objects. All rats were randomly divided into two groups, including: bowel disease group and osteoporosis group, with 50 rats in each group. Stool samples were collected from all rats, and Lactobacillus, Escherichia coli and Bifidobacteria were cultured and counted. The relationship between the occurrence of related osteoporosis and intestinal flora was analyzed as well. Thereafter, the rats in osteoporosis group were randomly divided into two subgroups, namely, control group (n=25) and observation group (n=25). Observation group was treated with probiotics by gastrogavage, while the control group was treated with the same volume of physiological saline. Next, the changes in serum osteoprotegerin (OPG), osteoprotegerin ligand [receptor activator of nuclear factor-kappa B ligand (RANKL)], procollagen type I carboxy-terminal propeptide (PICP), bone mineral density (BMD), bone alkaline phosphatase (BALP), tartrate-resistant acid phosphatase (TRACP), calcium concentration (Ca), and inflammatory cytokine levels were compared between the two groups after intervention.

RESULTS

Osteoporosis group had significantly more Escherichia coli and notably fewer Lactobacillus and Bifidobacteria than bowel disease group (p<0.05). Pearson correlation analysis revealed that the occurrence of osteoporosis in rats with inflammatory bowel disease was negatively correlated with the count of Escherichia coli, whereas was positively related to the counts of Lactobacillus and Bifidobacteria (p<0.05). Moreover, the levels of serum OPG, PICP, TRACP, and Ca in observation group were remarkably higher than those in the control group (p<0.05). However, the levels of serum RANKL, BALP, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (INF-γ) were markedly lower than those in the control group (p<0.05).

CONCLUSIONS

Osteoporosis in rats with inflammatory bowel disease has a negative association with the count of Escherichia coli, and a positive correlation with the counts of Lactobacillus and Bifidobacteria. In addition, treatment with probiotics can effectively alleviate osteoporosis symptoms in rats with inflammatory bowel disease by influencing the level of corresponding cytokines.

Accurate diagnosis of colorectal cancer based on histopathology images using artificial intelligence

BACKGROUND

Accurate and robust pathological image analysis for colorectal cancer (CRC) diagnosis is time-consuming and knowledge-intensive, but is essential for CRC patients' treatment. The current heavy workload of pathologists in clinics/hospitals may easily lead to unconscious misdiagnosis of CRC based on daily image analyses.

METHODS

Based on a state-of-the-art transfer-learned deep convolutional neural network in artificial intelligence (AI), we proposed a novel patch aggregation strategy for clinic CRC diagnosis using weakly labeled pathological whole-slide image (WSI) patches. This approach was trained and validated using an unprecedented and enormously large number of 170,099 patches, > 14,680 WSIs, from > 9631 subjects that covered diverse and representative clinical cases from multi-independent-sources across China, the USA, and Germany.

RESULTS

Our innovative AI tool consistently and nearly perfectly agreed with (average Kappa statistic 0.896) and even often better than most of the experienced expert pathologists when tested in diagnosing CRC WSIs from multicenters. The average area under the receiver operating characteristics curve (AUC) of AI was greater than that of the pathologists (0.988 vs 0.970) and achieved the best performance among the application of other AI methods to CRC diagnosis. Our AI-generated heatmap highlights the image regions of cancer tissue/cells.

CONCLUSIONS

This first-ever generalizable AI system can handle large amounts of WSIs consistently and robustly without potential bias due to fatigue commonly experienced by clinical pathologists. It will drastically alleviate the heavy clinical burden of daily pathology diagnosis and improve the treatment for CRC patients. This tool is generalizable to other cancer diagnosis based on image recognition.

G6PD activity contributes to the regulation of histone acetylation and gene expression in smooth muscle cells and to the pathogenesis of vascular diseases

We aimed to determine 1) the mechanism(s) that enables glucose-6-phosphate dehydrogenase (G6PD) to regulate serum response factor (SRF)- and myocardin (MYOCD)-driven smooth muscle cell (SMC)-restricted gene expression, a process that aids in the differentiation of SMCs, and 2) whether G6PD-mediated metabolic reprogramming contributes to the pathogenesis of vascular diseases in metabolic syndrome (MetS). Inhibition of G6PD activity increased (>30%) expression of SMC-restricted genes and concurrently decreased (40%) the growth of human and rat SMCs ex vivo. Expression of SMC-restricted genes decreased (>100-fold) across successive passages in primary cultures of SMCs isolated from mouse aorta. G6PD inhibition increased Myh11 (47%) while decreasing (>50%) Sca-1, a stem cell marker, in cells passaged seven times. Similarly, CRISPR-Cas9-mediated expression of the loss-of-function Mediterranean variant of G6PD (S188F; G6PDS188F) in rats promoted transcription of SMC-restricted genes. G6PD knockdown or inhibition decreased (48.5%) histone deacetylase (HDAC) activity, enriched (by 3-fold) H3K27ac on the Myocd promoter, and increased Myocd and Myh11 expression. Interestingly, G6PD activity was significantly higher in aortas from JCR rats with MetS than control Sprague-Dawley (SD) rats. Treating JCR rats with epiandrosterone (30 mg/kg/day), a G6PD inhibitor, increased expression of SMC-restricted genes, suppressed Serpine1 and Epha4, and reduced blood pressure. Moreover, feeding SD control (littermates) and G6PDS188F rats a high-fat diet for 4 mo increased Serpine1 and Epha4 expression and mean arterial pressure in SD but not G6PDS188F rats. Our findings demonstrate that G6PD downregulates transcription of SMC-restricted genes through HDAC-dependent deacetylation and potentially augments the severity of vascular diseases associated with MetS.NEW & NOTEWORTHY This study gives detailed mechanistic insight about the regulation of smooth muscle cell (SMC) phenotype by metabolic reprogramming and glucose-6-phosphate dehydrogenase (G6PD) in diabetes and metabolic syndrome. We demonstrate that G6PD controls the chromatin modifications by regulating histone deacetylase (HDAC) activity, which deacetylates histone 3-lysine 9 and 27. Notably, inhibition of G6PD decreases HDAC activity and enriches H3K27ac on myocardin gene promoter to enhance the expression of SMC-restricted genes. Also, we demonstrate for the first time that G6PD inhibitor treatment accentuates metabolic and transcriptomic reprogramming to reduce neointimal formation in coronary artery and large artery elastance in metabolic syndrome rats.

Properties of Heavy Secondary Fluorine Cosmic Rays: Results from the Alpha Magnetic Spectrometer

Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity R range 2.15 GV to 2.9 TV based on 0.29 million events collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The fluorine spectrum deviates from a single power law above 200 GV. The heavier secondary-to-primary F/Si flux ratio rigidity dependence is distinctly different from the lighter B/O (or B/C) rigidity dependence. In particular, above 10 GV, the F/Si/B/O ratio can be described by a power law R^{δ} with δ=0.052±0.007. This shows that the propagation properties of heavy cosmic rays, from F to Si, are different from those of light cosmic rays, from He to O, and that the secondary cosmic rays have two classes.

Properties of Iron Primary Cosmic Rays: Results from the Alpha Magnetic Spectrometer

We report the observation of new properties of primary iron (Fe) cosmic rays in the rigidity range 2.65 GV to 3.0 TV with 0.62×10^{6} iron nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. Above 80.5 GV the rigidity dependence of the cosmic ray Fe flux is identical to the rigidity dependence of the primary cosmic ray He, C, and O fluxes, with the Fe/O flux ratio being constant at 0.155±0.006. This shows that unexpectedly Fe and He, C, and O belong to the same class of primary cosmic rays which is different from the primary cosmic rays Ne, Mg, and Si class.

COX-2/PGE2 facilitates fracture healing by activating the Wnt/β-catenin signaling pathway

OBJECTIVE

The aim of this study was to explore the influence of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) on fracture healing by activating the Wnt/β-catenin signaling pathway.

MATERIALS AND METHODS

In this study, 36 adult Sprague-Dawley (SD) rats raised in our laboratory were selected as research objects. The rats were subjected to fracture surgery on the middle part of the right femoral shaft. Subsequently, they were randomly divided into the control group and experimental groups (including experimental group A and experimental group B). Rats in experimental group A were injected with PGE 2 or COX-2 selective inhibitor NS-398, while rats in experimental group B were injected with PGE2 (5 μmol/L). Meanwhile, rats in the control group were injected with the same amount of normal saline. After that, the transcriptional levels of PEG2, COX-2, vascular endothelial growth factor (VEGF) and β-catenin in rats of the experimental group A, experimental group B and control group were detected via fluorescence quantitative Polymerase Chain Reaction (PCR) assay. Enzyme-linked immunosorbent assay (ELISA) and Western blotting were conducted to determine the changes in protein levels of PEG2, COX-2, VEGF and β-catenin in rats of the experimental group A, experimental group B and control group. The expression level of VEGF in bone tissues at fracture ends of rats in the experimental group A, experimental group B and control group was observed through the hematoxylin-eosin (HE) staining. Furthermore, micro-computed tomography (CT) was employed to evaluate callus formation.

RESULTS

The transcriptional and translational levels of COX-2, β-catenin and VEGF in rats of experimental group A treated with COX-2 inhibitors were significantly down-regulated when compared with those of the control group, showing statistically significant differences (p<0.05). However, the levels of these genes were markedly elevated in the experimental group B treated with PGE2 in comparison with those in the control group, and the differences were statistically significant (p<0.05). After 6 weeks, HE staining showed that the expression level of VEGF in rats of the experimental group B was remarkably higher than that of the experimental group A (p<0.05). Micro-CT results revealed that the mean trabecular plate density (MTPD) of rats in the experimental group B (73.29±5.4) was markedly higher than the number of osteoblasts (49.6±3.9) in the experimental group A, showing a statistically significant difference (p<0.05).

CONCLUSIONS

COX-2/PGE2 facilitates fracture healing by activating the Wnt/β-catenin signaling pathway.

How despotic leadership jeopardizes employees' performance: the roles of quality of work life and work withdrawal

Purpose

This study contributes to the leadership literature by examining how and when despotic leadership jeopardizes employees' performance. Specifically, we examine whether employees' job performance could be harmed by despotic supervision through employees' work withdrawal behaviour. Moreover, we investigate whether the quality of work-life (QWL) helps in toning down the harmful effects of despotic supervision on work withdrawal.

Design/methodology/approach

We used a multi-wave research design with data collected from 195 employees and their supervisors working in Pakistan's manufacturing sector. At time 1, we measured the independent variable (i.e. despotic leadership) and moderator (QWL), whereas, at time-2, the mediator (work withdrawal) was tapped by the same respondent with a time interval of three weeks between them. At time 3, the outcome (supervisor-rated job performance) was assessed directly by the supervisors.

Findings

The results support the mediating effect between despotic leadership and employees' performance through an enhanced level of work withdrawal behaviour. The effect of despotic leadership on job performance via work withdrawal behaviour was found to be weaker among employees with a higher level of QWL.

Practical implications

For individuals, QWL serves as an enhancement of personal resources to deal with despotic leaders at the workplace; for organizations, our study results alert managers and leaders at the workplace to address employees' need for QWL as this positive resource may discourage work withdrawal behaviour and stimulate employees to perform well in their jobs despite facing despotic supervision.

Originality/value

This study contributes to the leadership literature by introducing work withdrawal as an underlying mechanism to explain the despotic leadership – job performance relationship. Further, we examined how the harmful effects of despotic leadership can be toned down through the moderating variable of QWL thus having practical implications for both employers and employees.

Donepezil markedly prevents the progression of chronic heart failure and renal dysfunction in renal artery stenosis-induced hypertensive rats

Introduction

Parasympathetic activation by donepezil has been shown to improve prognosis in chronic heart failure (CHF) rats following myocardial infarction. We examined whether donepezil is effective in the treatment of another CHF model complicated with renal artery stenosis (RAS)-induced hypertension.

Methods

RAS was created by ligating the left renal artery up to 50% in SD rats, at the same time, we implanted a blood pressure (BP) transmitter for confirming RAS-induced hypertension (7-week post-RAS: systolic BP = 154±7 mmHg; diastolic BP = 115±8 mmHg). In the 11th week after induction of RAS, surviving animals were randomly assigned to untreated (UT, n=10) or donepezil treated [DT, n=10, dissolved in drinking water (3mg/kg/day)] group. After a 6-week treatment, the effects of donepezil were evaluated by hemodynamics, blood levels of neurohumoral markers, and morphology.

Results

Compared with UT, DT significantly prevented the progression of the left kidney atrophy (2.38±0.13 vs. 1.51±0.34 g/kg, P&lt;0.05) and kidney fibrosis (left: −64%, P&lt;0.001; right: −55%, P&lt;0.01). DT also significantly prevented the progression of CHF, through suppressing cardiac hypertrophy (2.30±0.06 vs. 2.57±0.08 g/kg, P&lt;0.01), cardiac fibrosis (−70%, P&lt;0.01), and cardiac dysfunction [cardiac index: 102±3 vs. 86±3 ml/min/kg, P&lt;0.05; left ventricular (LV) end-diastolic pressure: 12±2 vs. 20±2 mmHg, P&lt;0.05; LV dp/dtmin: 5856±259 vs. 4924±227 mmHg/sec, P&lt;0.05]. DT not only decreased serum levels of creatinine (0.54±0.02 vs. 0.63±0.03 mg/dl, P&lt;0.05) and uric acid (1.4±0.2 vs. 1.9±0.2 mg/dl, P&lt;0.05); but also decreased plasma levels of norepinephrine (273±38 vs. 846±242, P&lt;0.01), AVP (2729±347 vs. 4783±695 pg/ml, P&lt;0.05), BNP (360±13 vs. 460±39 pg/ml, P&lt;0.05), angiotensin II and aldosteron, and suppressed the systemic inflammation.

Conclusions

Donepezil treatment markedly prevented the progression of CHF and renal dysfunction, and improved the neurohumoral markers in the CHF rat model complicated with RAS-induced hypertension, suggesting that donepezil may be used as a new pharmacotherapy for CHF patients complicated with RAS-induced hypertension.

Funding Acknowledgement

Type of funding source: None

Donepezil as a novel therapy for suppressing the progression of cardiovascular remodeling in obesity-induced hypertensive rats with reperfused myocardial infarction

Introduction

Acetylcholinesterase inhibition by donepezil has been shown to improve long-term survival in permanent myocardial infarction (MI)-induced chronic heart failure rats. This study examined whether donepezil is applicable to the treatment of obesity-induced hypertension with reperfused MI (RMI).

Methods

Four-week-old SD rats were fed a high-fat diet (57% kcal as fat) for 15 weeks. We implanted a blood pressure (BP) telemetry into the animals (8-week-old) for monitoring artery pressure. After a 1-week recovery, RMI was created by occluding the left coronary artery (30min) followed by reperfusion. Surviving animals were randomly assigned to untreated (UT, n=16) or donepezil treated (DT, n=16, 3 mg/kg/day) group. After a 10-week treatment, the effects of donepezil were evaluated by hemodynamics, blood biomarkers, immunohistochemistry, and morphology.

Results

The high-fat diet caused obesity and hypertension (9-week-old: systolic BP = 134±4 mmHg; diastolic BP = 92±2 mmHg) in the normal rats. Compared with UT, DT significantly decreased the heart rate (296±5 vs. 318±8 bpm, P&lt;0.05). DT significantly prevented the progression of cardiac remodeling and dysfunction [cardiac index: 91±4 vs. 73±9 ml/min/kg, P&lt;0.01; left ventricular (LV) end-diastolic pressure: 11±1 vs. 20±2 mmHg, P&lt;0.01; LV dp/dt max: 5347±206 vs. 3637±433 mmHg/sec, P&lt;0.01], through increasing capillary density (+120%/field, P&lt;0.001), reducing cardiac fibrosis (−50%, P&lt;0.01) and myocardial infarcted area (17±2 vs. 24±2%, P&lt;0.05), suppressing cardiac hypertrophy (2.35±0.04 vs. 2.70±0.14 g/kg, P&lt;0.01) and coronary artery remodeling (wall thickness: 30±1 vs. 37±2 mm, P&lt;0.01; media-to-lumen ratio: 2.3±0.2 vs. 6.2±1.6, P&lt;0.001). Additionally, DT not only decreased plasma levels of insulin, norepinephrine, BNP, angiotensin II, but also improved the systemic inflammation.

Conclusions

Donepezil treatment significantly suppressed the progression of cardiovascular remodeling and dysfunction following RMI in obesity-induced hypertensive rats, suggesting that donepezil may be used as a potential candidate for post-RMI therapy in obesity-induced hypertensive patients.

Funding Acknowledgement

Type of funding source: None

TRAF5 promotes the occurrence and development of colon cancer via the activation of PI3K/AKT/NF-κB signaling pathways

This study aimed to investigate the expression and biological functions of TRAF5 in colon cancer at tissue and cellular levels. Forty-two patients with colon cancer were included in the present study. Tumor tissues and tumor-adjacent tissues were collected from all patients. Bioinformatics was used to analyze how TRAF5 was related to metastasis and prognosis of colon cancer. Quantitative real-time polymerase chain reaction was carried out to determine the expression of mRNA. SW620 and SW480 cells were used to study the inhibition and overexpression of TRAF5, respectively. CCK-8 assay was used to examine cell proliferation. Flow cytometry was employed to investigate cell phase and apoptosis. Transwell assay was used to study migration and invasion of cells. Western blotting was utilized to test how TRAF5 expression affected the activities of PI3K/AKT/NF-κB signaling pathways. Bioinformatics showed that the expression of TRAF5 in colon cancer tissues was correlated with metastasis and prognosis of the tumor. TRAF5 mRNA expression was up-regulated in colon cancer tissues, and related to recurrence and metastasis of the cancer. In vitro experiments showed that TRAF5 expression promoted proliferation, migration, and invasion of colon cancer cells, but reduced apoptosis of the cells. Moreover, TRAF5 might exert its biological functions by activating PI3K/AKT/NF-κB signaling pathways in colon cancer cells. In conclusion, TRAF5 expression in colon cancer tissues is up-regulated and correlated with prognosis, lymphatic metastasis and clinical staging. TRAF5 promotes the occurrence and development of colon cancer by activating PI3K/ AKT/NF-κB signaling pathways, and acts as an oncogene.

miR-940 promotes spinal cord injury recovery by inhibiting TLR4/NF-κB pathway-mediated inflammation

OBJECTIVE

The aim of this study was to investigate the effects of miR-940 and Toll-like receptor 4/Nuclear Factor κB (TLR4/NF-κB) pathways on inflammatory responses and spinal cord injury (SCI).

MATERIALS AND METHODS

This study first established a model of spinal cord injury in mice. The grip force measurement was used to detect the recovery of the forelimb, left forelimb and right forelimb of SCI mice. The quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expression of miR-940 and macrophage receptor TLR4 in SCI mice. In addition, the protein levels of TLR4 and inducible nitric oxide synthase (iNOS) in SCI mice were detected by Western blot. MiR-940 mimic was injected into the injured area of SCI mice to explore the effect of miR-940 overexpression on TLR4 and myeloperoxidase (MPO) expression as well as the protein levels of TLR4, P65 and iNOS. Furthermore, the grip strength of SCI mice with double forelimb, left forelimb and right forelimb was detected by the grip force test after miR-940 overexpression.

RESULTS

Compared with the sham-operated mice, the grip strength of the forelimb, left forelimb, and right forelimb of the SCI group showed significant obstacles. Meanwhile, the expression of miR-940 was remarkably decreased in SCI mice along with significant elevation of the inflammatory response-related factors including TRL4 and iNOS. Then we injected SCI mice with miR-940 mimics into the spinal cord injury area and found that miR-940 overexpression decreased the expression levels of TLR4 and MPO. At the same time, the overexpression of miR-940 markedly decreased the protein levels of TLR4, P65, and iNOS in SCI mice. In addition, miR-940 overexpression improved the grip strength of the left and right forepaws and the simultaneous grip strength of the two claws of the SCI mice than those of the simple injury group.

CONCLUSIONS

High expression of miR-940 can promote the recovery of spinal cord injury by downregulating the TLR4/NF-κB signaling pathway and inhibiting inflammation.

Resveratrol promotes mammary cell proliferation and antioxidation capacity during pregnancy and lactation in mice

AIMS

Reproduction can induce maternal oxidative stress, and resveratrol is able to alleviate oxidative stress. This study aimed to investigate the protective effects of resveratrol supplementation in mice during pregnancy and lactation.

METHODS AND RESULTS

Pregnant mice were randomly divided into three groups: (i) Pure water (Con); (ii) Cellulose sodium dissolves with 20 mg kg^-1 resveratrol (R1) and (iii) Cellulose sodium dissolves with 40 mg kg^-1 resveratrol (R2). The experiment starts at pregnancy and ends at weaning. The results showed that resveratrol increased mammary cell proliferation and the mRNA expressions of UDP glucuronosyltransferase family 1 member A1 (UGT1A1) and cytochrome P450 proteins (CYP1A1), while decreased superoxide dismutase, extracellular (SOD3) in the mammary gland. Further study showed that resveratrol promoted the mRNA expressions of genes involved in mitophagy, such as transcription factor Eβ (Tfeβ), Bcl1lc3β, homosapiens microtubule-associated protein 1 light-chain 3 beta (Map1lc3β), Parkin, sequestosome1 (p62), autophagy-related protein (Atg5) and Beclin-1 (Becn1) in the mammary gland. Moreover, resveratrol increased the abundances of some intestinal microbial species. 40 mg kg^-1 resveratrol significantly increased the contents of Acidobacteri, unidentified acidbacteria, Bacilales, Staphylococcaceae and Staphylococcus at phylum, class, order, family and genus level respectively.

CONCLUSION

Our results indicate that resveratrol supplementation may promote mammary cell proliferation and antioxidant ability through mitophagy and regulating gut microbiota in pregnant mice.

SIGNIFICANCE AND IMPACT OF THE STUDY

Current study proved that resveratrol could affect mammary cell proliferation and antioxidation capacity during pregnancy and lactation in mice for the first time. The underlying mechanisms may be related to mitophagy and gut microbiota.

MicroRNA-23c inhibits articular cartilage damage recovery by regulating MSCs differentiation to chondrocytes via reducing FGF2

OBJECTIVE

The aim of the study was to explore the role of microRNA-23c in the differentiation of marrow stromal cells (MSCs) to chondrocytes and its potential mechanism.

MATERIALS AND METHODS

MSCs were first isolated from rat bone marrow for cell culture. Surface antigens of MSCs (CD29 and CD34) were identified by flow cytometry. MSCs were induced for chondrogenic differentiation in MCDM (Mesenchymal Stem Cell Chondrogenic Differentiation Medium) for 0, 3, and 7 days, respectively, followed by detection of RUNX2, microRNA-23c and FGF2 expressions by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Alcian blue staining was performed to access proteoglycan deposition in MSCs transfected with microRNA-23c mimics or inhibitor. Western blot was conducted to detect the protein expressions of ACAN and COL2A1 in MSCs. The binding condition between microRNA-23c and FGF2 was verified by dual-luciferase reporter gene assay. Finally, MSCs were co-transfected with microRNA-23c mimics and FGF2 overexpression plasmid for rescue experiments.

RESULTS

On the fourth day of MSCs isolation, MSCs were in an elongated shape. Flow cytometry results showed positive expression of CD29 and negative expression of CD34, which were consistent with MSCs phenotype. QRT-PCR data elucidated that the mRNA levels of RUNX2 and FGF2 gradually increased, whereas microRNA-23c expression decreased with the prolongation of chondrogenic differentiation. Transfection of microRNA-23c mimics in MSCs remarkably elevated microRNA-23c expression. Alcian blue staining showed that microRNA-23c overexpression results in less proteoglycan deposition in MSCs than that of controls. Both mRNA and protein expressions of ACAN and COL2A1 decreased after microRNA-23c overexpression. Dual-luciferase reporter gene assay confirmed that FGF2 binds to microRNA-23c. Further Western blot results demonstrated that FGF2 expression is negatively regulated by microRNA-23c. FGF2 overexpression reversed the inhibitory effects of microRNA-23c on proteoglycan deposition, as well as expressions of ACAN and COL2A1.

CONCLUSIONS

MicroRNA-23c expression decreases during chondrogenic differentiation of MSCs, which inhibits MSCs differentiation to chondrocytes by inhibiting FGF2.