Mslar: Microbial synthetic lethal and rescue database.

Synthetic lethality (SL) occurs when mutations in two genes together lead to cell or organism death, while a single mutation in either gene does not have a significant impact. This concept can also be extended to three or more genes for SL. Computational and experimental methods have been developed to predict and verify SL gene pairs, especially for yeast and Escherichia coli. However, there is currently a lack of a specialized platform to collect microbial SL gene pairs. Therefore, we designed a synthetic interaction database for microbial genetics that collects 13,313 SL and 2,994 Synthetic Rescue (SR) gene pairs that are reported in the literature, as well as 86,981 putative SL pairs got through homologous transfer method in 281 bacterial genomes. Our database website provides multiple functions such as search, browse, visualization, and Blast. Based on the SL interaction data in the S. cerevisiae, we review the issue of duplications' essentiality and observed that the duplicated genes and singletons have a similar ratio of being essential when we consider both individual and SL. The Microbial Synthetic Lethal and Rescue Database (Mslar) is expected to be a useful reference resource for researchers interested in the SL and SR genes of microorganisms. Mslar is open freely to everyone and available on the web at http://guolab.whu.edu.cn/Mslar/.

Prediction of protein-coding small ORFs in multi-species using integrated sequence-derived features and the random forest model.

Proteins encoded by small open reading frames (sORFs) can serve as functional elements playing important roles in vivo. Such sORFs also constitute the potential pool for facilitating the de novo gene birth, driving evolutionary innovation and species diversity. Therefore, their theoretical and experimental identification has become a critical issue. Herein, we proposed a protein-coding sORFs prediction method merely based on integrative sequence-derived features. Our prediction performance is better or comparable compared with other nine prevalent methods, which shows that our method can provide a relatively reliable research tool for the prediction of protein-coding sORFs. Our method allows users to estimate the potential expression of a queried sORF, which has been demonstrated by the correlation analysis between our possibility estimation and codon adaption index (CAI). Based on the features that we used, we demonstrated that the sequence features of the protein-coding sORFs in the two domains have significant differences implying that it might be a relatively hard task in terms of cross-domain prediction, hence domain-specific models were developed, which allowed users to predict protein-coding sORFs both in eukaryotes and prokaryotes. Finally, a web-server was developed and provided to boost and facilitate the study of the related field, which is freely available at http://guolab.whu.edu.cn/codingCapacity/index.html.

CHD6 promotes broad nucleosome eviction for transcriptional activation in prostate cancer cells.

Despite being a member of the chromodomain helicase DNA-binding protein family, little is known about the exact role of CHD6 in chromatin remodeling or cancer disease. Here we show that CHD6 binds to chromatin to promote broad nucleosome eviction for transcriptional activation of many cancer pathways. By integrating multiple patient cohorts for bioinformatics analysis of over a thousand prostate cancer datasets, we found CHD6 expression elevated in prostate cancer and associated with poor prognosis. Further comprehensive experiments demonstrated that CHD6 regulates oncogenicity of prostate cancer cells and tumor development in a murine xenograft model. ChIP-Seq for CHD6, along with MNase-Seq and RNA-Seq, revealed that CHD6 binds on chromatin to evict nucleosomes from promoters and gene bodies for transcriptional activation of oncogenic pathways. These results demonstrated a key function of CHD6 in evicting nucleosomes from chromatin for transcriptional activation of prostate cancer pathways.

Dynamic fecal microenvironment properties enable predictions and understanding of peripartum blood oxidative status and nonesterified fatty acids in dairy cows.

The transition period in dairy cows is a critical stage and peripartum oxidative status, negative energy balance (NEB), and inflammation are highly prevalent. Fecal microbial metabolism is closely associated with blood oxidative status and nonesterified fatty acids (NEFA) levels. Here, we investigated dynamic changes in total oxidative status markers and NEFA in blood, fecal microbiome, and metabolome of 30 dairy cows during transition (-21, -7, +7, +21 d relative to calving). Then the Bayesian network and 9 machine-learning algorithms were applied to dismantle their relationship. Our results show that the oxidative status indicator (OSI) of -21, -7, +7 d was higher than +21 d. The plasma concentration of NEFA peaked on +7 d. For fecal microenvironment, a decline in bacterial α diversity was observed at postpartum and in bacterial interactions at +7 d. Conversely, microbial metabolites involved in carbohydrate, lipid, and energy metabolism increased on +7 d. A correlation analysis revealed that 11 and 10 microbial metabolites contributed to OSI and NEFA variations, respectively (arc strength >0.5). The support vector machine (SVM) radial model showed the highest average predictive accuracy (100% and 88.9% in the test and external data sets) for OSI using 1 metabolite and 3 microbiota. The SVM radial model also showed the highest average diagnostic accuracy (100% and 91% in the test and external data sets) for NEFA with 2 metabolites and 3 microbiota. Our results reveal a relationship between variation in the fecal microenvironment and indicators of oxidative status, NEB, and inflammation, which provide a theoretical basis for the prevention and precise regulation of peripartum oxidative status and NEB.

[Molding law of traditional Chinese medicine gel plaster based on physicochemical properties of raw materials and intermediates].

This paper aims to study the correlation between the physicochemical properties of raw materials and intermediates and the molding quality and law of traditional Chinese medicine(TCM) gel plaster by using TCM slices and powder as raw materials. 48 TCM compounds are selected as model prescriptions to prepare gel plasters. The rotational rheometer is used to determine the rheological parameters of the plaster, including storage modulus(G'), loss modulus(G″), yield stress(τ), and creep compliance [J(t)]. The molding quality of the prepared TCM gel plaster is evaluated by subjective and objective measures. Clustering and principal component analysis are conducted to evaluate the physical properties of the plaster. By measuring the rheological properties of the plaster, the molding quality of the TCM gel plaster can be predicted, with an accuracy of 83.72% after seven days of modeling and 88.37% after 30 days of modeling. When the parameters such as G' and G″ of the plaster are large, and the [J(t)] is small, the molding quality of the plaster is better. When the plaster coating point is no less than 3, it is difficult to be coated. In addition, when the proportion of metal ions in the prescription is higher, the 30-day forming quality of the plaster is mainly affected, and the viscosity of the plaster is poor. If the prescription contains many acidic chemical components, the 7-day forming quality of the plaster is mainly affected, with many residuals. The results suggest that the rheological properties of the plaster can be used to predict the molding quality of TCM slice and powder gel plaster. It can provide a reference for the development of TCM gel plaster prescriptions.

HKDC1 upregulation promotes glycolysis and disease progression, and confers chemoresistance onto gastric cancer.

There is increasing evidence that hexokinase is involved in cell proliferation and migration. However, the function of the hexokinase domain containing protein-1 (HKDC1) in gastric cancer (GC) remains unclear. Immunohistochemistry analysis and big data mining were used to evaluate the correlation between HKDC1 expression and clinical features in GC. In addition, the biological function and molecular mechanism of HKDC1 in GC were studied by in vitro and in vivo assays. Our study indicated that HKDC1 expression was upregulated in GC tissues compared with adjacent nontumor tissues. High expression of HKDC1 was associated with worse prognosis. Functional experiments demonstrated that HKDC1 upregulation promoted glycolysis, cell proliferation, and tumorigenesis. In addition, HKDC1 could enhance GC invasion and metastasis by inducing epithelial-mesenchymal transition (EMT). Abrogation of HKDC1 could effectively attenuate its oncogenic and metastatic function. Moreover, HKDC1 promoted GC proliferation and migration in vivo. HKDC1 overexpression conferred chemoresistance to cisplatin, oxaliplatin, and 5-fluorouracil (5-Fu) onto GC cells. Furthermore, nuclear factor kappa-B (NF-κB) inhibitor PS-341 could attenuate tumorigenesis, metastasis, and drug resistance ability induced by HKDC1 overexpression in GC cells. Our results highlight a critical role of HKDC1 in promoting glycolysis, tumorigenesis, and EMT of GC cells via activating the NF-κB pathway. In addition, HKDC1-mediated drug resistance was associated with DNA damage repair, which further activated NF-κB signaling. HKDC1 upregulation may be used as a potential indicator for choosing an effective chemotherapy regimen for GC patients undergoing chemotherapy.

Three-Dimensional Reduced Graphene Oxide Hybrid Nano-Silver Scaffolds with High Antibacterial Properties.

In recent years, hazardous wastewater treatment has been a complex and global problem. In this work, by considering the antimicrobial activity of Ag nanoparticles (AgNPs) and reduced graphene oxide (rGO), we constructed an antibacterial device (G-AgNP) with AgNPs conformably deposited onto a 3D scaffold of reduced graphene oxide in situ. The major limitation, which is difficult to recycle, of two-dimensional graphene-silver composite materials in previous studies is improved. Characterization techniques, SEM, TEM, XRD, and XPS, confirmed the synthesis of nanocomposites. Attributed to its larger specific area, more active sites, and synergistic enhancement, the G-AgNP device demonstrated the best bacterial removal capacity, with an antibacterial rate for both E. coli and S. aureus as high as 100% at quite low AgNP contents. The reported G-AgNP has potential application as a wearable sewage treatment device and for the protection of wearable sensors as a promising sterilizing candidate based on its high and stable antibacterial efficiency.

Prognostic significance and function of MCM10 in human hepatocellular carcinoma.

Aim: To investigate the role of MCM10, a conserved replication factor, in hepatocellular carcinoma (HCC). Methods: We used data from 364 HCC patients in the Cancer Genome Atlas database and conducted in vitro experiments to confirm the role of MCM10. Results: High MCM10 expression correlated with poor HCC patient outcome and was an independent prognosticator for HCC. Time-dependent receiver operating characteristic curve analysis found that the sequential trend of MCM10 for survival was not inferior to that of the tumor node metastasis stage. The MCM10 model had a higher C-index than the non-MCM10 model, indicating that incorporating MCM10 into a multivariate model improves the model's prognostic accuracy for HCC. Genetic alterations of MCM10 prominently correlated with an unfavorable HCC outcome. Conclusion: Our findings strongly suggest using the MCM10 gene as a prognostic indicator in HCC.

Lay abstract Hepatocellular carcinoma is one of the most aggressive malignant cancers globally. Our study investigated the role of a conserved replication factor, MCM10, in hepatocellular carcinoma. We performed some bioinformatics analysis and in vitro experiments, and successfully found that MCM10 has a good predictive value for survival in patients with hepatocellular carcinoma.

Diagnostic and prognostic value of HOXC family members in gastric cancer.

Aims: HOX clusters encode proteins that play pivotal roles in regulating transcription factors and many other proteins during embryogenesis. However, little is known about the diagnostic and prognostic values of HOXC family members in gastric cancer (GC). Materials and methods: The authors evaluated the data in patients with GC based on bioinformatics analysis. Results: HOXC6/8/9/10/11/13 were overexpressed in GC and associated with a poor prognosis. HOXC4/5 were downregulated in GC tissues. Receiver operating characteristic curve analysis demonstrated that they have high diagnostic value. In addition, HOXC4/5/6/9/10/11/13 were negatively correlated with DNA methylation level. The gene set enrichment analysis results implied that they play essential roles in multiple biological processes underlying tumorigenesis. Conclusion: HOXC family members are potential targets for diagnosis and may work as prognostic biomarkers of GC.

Lay abstracts Gastric cancer (GC) remains one of the most common malignant tumors of the digestive system and the third most common cause of death from cancer. Since GC is usually diagnosed at an advanced stage, despite advances in comprehensive treatment strategies, its mortality rate is still very high. GC is a disease that is highly heterogeneous in terms of genotype and phenotype. Therefore, a more complete understanding of the molecular mechanism of GC carcinogenesis and identification of reliable molecular targets for the diagnosis and prognosis of GC are highly valued. It is well known that the HOXC gene family expression is upregulated in most solid tumor types, such as lung cancer, colon cancer and prostate cancer. The authors explore the role of the HOXC gene family in GC. Results demonstrated that HOXC family members are potential targets for diagnosis and may work as prognostic biomarkers of GC.

HOTAIR plays an oncogenic role in gastric cancer through microRNA and SNP.

HOX transcript antisense intergenic RNA (HOTAIR) is a lncRNA with a length of 2,158 nucleotides and its two terminal domains could combine with different complexes to function at the level of transcription and translation. It overexpresses in many cancers including gastric cancer. HOTAIR could play an oncogenic role in the initiation and progression of gastric cancer through interaction with microRNAs, such as miR-330/618/126 in the PI3K/Akt signaling pathways. HOTAIR single nucleotide polymorphisms (SNPs) may have genotype-function and allele-specific effect on gastric cancer by a mechanism that specific SNP could give rise to a variation of HOTAIR and alter the binding site of microRNAs. Both rs920778 T allele and rs4759314 G allele will enhance the susceptibility to gastric cancer in the Chinese populations. In a word, the suppression of HOTAIR and overexpression of downstream microRNAs may be potential therapeutic strategies of gastric cancer related to HOTAIR.

Guidance Point Generation-Based Cooperative UGV Teleoperation in Unstructured Environment.

Teleoperation is widely used for unmanned ground vehicle (UGV) navigation in military and civilian fields. However, the human operator has to limit speed to ensure the handling stability because of the low resolution of video, limited field of view and time delay in the control loop. In this paper, we propose a novel guidance point generation method that is well suited for human-machine cooperative UGV teleoperation in unstructured environments without a predefined goal position. The key novelty of this method is that the guidance points used for navigation can be generated with only the local perception information of the UGV. Firstly, the locally occupied grid map (OGM) was generated utilizing a probabilistic grid state description method, and converted into binary image to constructed the convex hull of obstacle area. Secondly, we proposed an improved thinning algorithm to extract skeletons of navigable regions from binary images, and find out the target skeleton related to the position of the UGV utilizing the k-nearest neighbor (kNN) algorithm. The target skeleton was reconstructed at the midline position of the navigable region using the decreasing gradient algorithm in order to obtain the appropriate skeleton end points for use as candidate guidance points. For visually presenting the driving trend of the UGV and convenient touch screen operation, we transformed guidance point selection into trajectory selection by generating the predicted trajectory correlative to candidate guidance points based on the differential equation of motion. Experimental results show that the proposed method significantly increases the speed of teleoperated UGV.

[Establishment of prediction model for personalized water-paste pills based on classification of traditional Chinese medicine materials].

The purpose of the present study was to investigate the relationship of the classification of traditional Chinese medicine(TCM) materials with the suitable binder concentration and dosage in the preparation of personalized water-paste pills and establish a model for predicting the binder concentration and dosage. Five representative TCM materials were selected, followed by mixture uniform design. The water-paste pills were prepared by extrusion and spheronization with hypromellose E5(HPMC E5) as the binder. The quality of intermediates and final products was evaluated, and the resulting data were subjected to multivariate statistical analysis. The prediction models for binder concentration and dosage were established as follows: binder concentration: Y_1=0.378 6 + 0.570 1X_A + 2.271 2X_B-0.894 5X_C-0.458 2X_D-1.145 4X_E(when Y_1 < 0, 10% HPMC E5 was required; when Y_1 > 0, 20% HPMC E5 was required), with the accuracy reaching up to 100%; binder dosage: Y_2=32.38 + 0.25X_A + 1.85X_B-0.013X_B~2-0.002 5X_C~2(R~2=0.932 6, P < 0.001). The results showed that the binder concentration and dosage were correlated positively with the proportion of fiber material but negatively with the proportions of sugar material and brittle material. Then the validation experiments were conducted with the prediction models and all the prescriptions could be successfully prepared at one time. These demonstrated that following the classification of TCM materials and the calculation of their proportions in the prescription, the established mathematical model could be adopted for predicting the binder concentration and dosage required in the preparation of personalized water-paste pills, which contributed to reducing the pre-formulation research and guiding the actual production of personalized water-paste pills.

Urban-Rural Differences in Bone Mineral Density and its Association with Reproductive and Menstrual Factors Among Older Women.

PURPOSE: This study aimed to compare the bone mineral density (BMD) of older women living in rural and urban areas, and evaluate the potential factors affecting the risk of osteoporosis. METHODS: We recruited 574 women aged 65 years or older from rural areas and 496 from urban areas in Shanghai, China. The BMD values of the lumbar vertebrae and total left hip were measured by a dual energy X-ray absorptiometry densitometer. We also recorded information about education level, family income, medications, reproductive and menstrual history, diet, smoking, and alcohol consumption. RESULTS: Women in urban areas had significantly higher BMD in their lumbar spine, and there was a dramatic increase in the proportion of women with osteoporosis in rural areas. The age at menarche was significantly higher among women living in rural areas, and there were more years from menarche to menopause among urban women. Rural women had significantly higher numbers of both pregnancies and parity, and a significantly lower age at first parity. In multiple linear regression analyses, years from menarche to menopause was independently related to high lumbar spine BMD, while age at menarche and parity was independently related to low lumbar spine BMD. CONCLUSION: More older women in rural areas had osteoporosis. Later menarche, less years from menarche to menopause and higher parity might partially contribute to decreased BMD among women in rural areas. More attention should be paid to women in rural areas to prevent bone loss and further bone and health impairment.

A comparison between the low back pain scales for patients with lumbar disc herniation: validity, reliability, and responsiveness.

BACKGROUND: Although the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ), Numerical Pain Rating Scale (NPRS), Oswestry Disability Index (ODI), Roland Morris Disability Questionnaire (RMDQ), and Short Form 36 Health Survey (SF-36) has shown a preferable psychometric properties in patients with low back pain (LBP), but no study has yet determined these in conservative treatment of patients with lumbar disc herniation (LDH). Thus the current study aimed to compare those scales in LDH patients receiving conservative treatment to select the better option to assess the severity of disease. METHODS: LDH patients were invited to complete the JOABPEQ, NPRS, ODI, RMDQ, and SF-36 twice. The internal consistency was evaluated by the Cronbach's α. Test-retest reliability was tested by the intraclass correlation coefficient (ICC). The relationships of these scales were evaluated by the Pearson correlation coefficients (r). The responsiveness was operationalised using the receiver operating characteristic (ROC) curve, as well as the comparison of smallest detectable change (SDC), minimum important change (MIC). RESULTS: A total of 353 LDH patients were enrolled. Four subscales of the Chinese JOABPEQ were over 0.70, then the ICCs for the test-retest reliability were over 0.75. For functional status, remarked negative correlations could be seen between JOABPEQ Q2-Q4 and ODI, as well as RMDQ (r = - 0.634 to - 0.752). For general health status, remarkable positive correlations could also be seen between Q5 Mental health and SF-36 PCS (r = 0.724) as well as SF-36 MCS (r = 0.736). Besides, the area under of the curves (AUC) of the JOABPEQ ranged from 0.743 to 0.827, indicating acceptale responsiveness, as well as the NPRS, ODI, and RMDQ. CONCLUSION: NPRS, and ODI or RMDQ is recommended in studies related to LDH patients, while if the quality of life also is needed to observe, the NPRS, and JOABPEQ would be more appropriate rather than SF-36.

Polycomb group proteins EZH2 and EED directly regulate androgen receptor in advanced prostate cancer.

Polycomb group proteins are important epigenetic regulators for cell proliferation and differentiation, organ development, as well as initiation and progression of lethal diseases, including cancer. Upregulated Polycomb group proteins, including Enhancer of zeste homolog 2 (EZH2), promote proliferation, migration, invasion and metastasis of cancer cells, as well as self-renewal of cancer stem cells. In our study, we report that EZH2 and embryonic ectoderm development (EED) indicate respective direct interaction with androgen receptor (AR). In the context of AR-positive prostate cancer, EZH2 and EED regulate AR expression levels and AR downstream targets. More importantly, we demonstrate that targeting EZH2 with the small-molecule inhibitor astemizole in cancer significantly represses the EZH2 and AR expression as well as the neoplastic capacities. These results collectively suggest that pharmacologically targeting EZH2 might be a promising strategy for advanced prostate cancer.

Loss of myocardial retinoic acid receptor α induces diastolic dysfunction by promoting intracellular oxidative stress and calcium mishandling in adult mice.

Retinoic acid receptor (RAR) has been implicated in pathological stimuli-induced cardiac remodeling. To determine whether the impairment of RARα signaling directly contributes to the development of heart dysfunction and the involved mechanisms, tamoxifen-induced myocardial specific RARα deletion (RARαKO) mice were utilized. Echocardiographic and cardiac catheterization studies showed significant diastolic dysfunction after 16wks of gene deletion. However, no significant differences were observed in left ventricular ejection fraction (LVEF), between RARαKO and wild type (WT) control mice. DHE staining showed increased intracellular reactive oxygen species (ROS) generation in the hearts of RARαKO mice. Significantly increased NOX2 (NADPH oxidase 2) and NOX4 levels and decreased SOD1 and SOD2 levels were observed in RARαKO mouse hearts, which were rescued by overexpression of RARα in cardiomyocytes. Decreased SERCA2a expression and phosphorylation of phospholamban (PLB), along with decreased phosphorylation of Akt and Ca2+/calmodulin-dependent protein kinase II δ (CaMKII δ) was observed in RARαKO mouse hearts. Ca2+ reuptake and cardiomyocyte relaxation were delayed by RARα deletion. Overexpression of RARα or inhibition of ROS generation or NOX activation prevented RARα deletion-induced decrease in SERCA2a expression/activation and delayed Ca2+ reuptake. Moreover, the gene and protein expression of RARα was significantly decreased in aged or metabolic stressed mouse hearts. RARα deletion accelerated the development of diastolic dysfunction in streptozotocin (STZ)-induced type 1 diabetic mice or in high fat diet fed mice. In conclusion, myocardial RARα deletion promoted diastolic dysfunction, with a relative preserved LVEF. Increased oxidative stress have an important role in the decreased expression/activation of SERCA2a and Ca2+ mishandling in RARαKO mice, which are major contributing factors in the development of diastolic dysfunction. These data suggest that impairment of cardiac RARα signaling may be a novel mechanism that is directly linked to pathological stimuli-induced diastolic dysfunction.

Overexpression of NKX6.1 is closely associated with progressive features and predicts unfavorable prognosis in human primary hepatocellular carcinoma.

The homeobox gene NKX6.1 was recently identified in cervical tumors. This study was designed to explore the clinical and prognostic significance of NKX6.1 further in patients with primary hepatocellular carcinoma (HCC). The expression levels of NKX6.1 were examined using real-time PCR, Western blotting, and immunohistochemistry in HCC cell lines and HCC tissues. The invasion capability of cell lines following silencing or overexpression of NKX6.1 was investigated by Transwell assay. Cells proliferation was tested by MTT assays. Epithelial-mesenchymal transition (EMT) marker expression levels were detected in relation to NKX6.1 expression. Correlation between NKX6.1 immunohistochemical staining, clinicopathologic parameters, and follow-up data of HCC patients was analyzed statistically. NKX6.1 expression was higher in HCC tissues compared to the adjacent noncancerous tissue. NKX6.1 overexpression was significantly correlated with tumor size, tumor differentiation, clinical stage, metastasis, and relapse. Kaplan-Meier analysis revealed that NKX6.1 overexpression was related to unfavorable 5-year disease-free survival and overall survival. Importantly, multivariate analysis indicated that NKX6.1 overexpression was an independent unfavorable marker for overall survival. Moreover, a significant relationship was observed between NKX6.1 and EMT marker expression levels, and NKX6.1 knockdown inhibited cell invasion, and overexpression of NKX6.1 promotes cell proliferation in vitro. NKX6.1 is upregulated in HCC and is a reliable prognostic marker for patients with HCC.

Low expression of BARX2 in human primary hepatocellular carcinoma correlates with metastasis and predicts poor prognosis.

AIM: The homeobox gene Barx2 was recently identified as a regulator of ovarian and breast cancer; however, the expression level of BARX2 and its significance in hepatocellular carcinoma (HCC) remain unknown. METHODS: Protein and mRNA expression levels of Barx2 were examined using Western blotting and real-time PCR respectively, in paired HCC tissue and matched adjacent non-cancerous tissue from 12 patients. The expression levels of epithelial-mesenchymal transition (EMT) markers were also detected in relation to BARX2 expression. Lastly, immunohistochemistry for BARX2 was also performed on a tissue microarray containing 231 HCC tissue samples. RESULTS: We observed that BARX2 expression was lower in HCC tissues compared to matching adjacent non-cancerous tissue. The low expression level of BARX2 was significantly correlated with metrics of tumor size, tumor differentiation, clinical stage, metastasis and relapse. Furthermore, the patients with low BARX2 expression had adverse survival outcomes. Importantly, multivariate Cox regression analysis revealed that low BARX2 expression was an independent marker for lower overall survival (P = 0.007). Moreover, a significant negative relationship was observed between the expression of BARX2 and markers of EMT. CONCLUSION: These findings provide evidence that the low expression level of BARX2 in HCC is significantly correlated with tumor metastasis, and that BARX2 may be an independent prognostic biomarker for patients with HCC.

Protein Phosphatase 2C of Toxoplasma Gondii Interacts with Human SSRP1 and Negatively Regulates Cell Apoptosis.

OBJECTIVE: The protozoan Toxoplasma gondii expresses large amounts of a 37 kDa Type 2C serine-threonine phosphatase, the so-called TgPP2C which has been suggested to contribute to parasite growth regulation. Ectopic expression in mammalian cells also indicated that the enzyme could regulate growth and survival. In this study, we aimed to investigate the interaction of TgPP2C with human SSRP1 (structure-specific recognition protein 1) and the effects of TgPP2C on cell viability. METHODS: The yeast two hybrid system, His-tag pull-down and co-immunoprecipitation assays were used to confirm the interaction of TgPP2C with SSRP1 and determine the binding domain on SSRP1. The evaluation of cell apoptosis was performed using cleaved caspase-3 antibody and Annexin-V/PI kit combined with flow cytometry. RESULTS: We identified human SSRP1 as an interacting partner of TgPP2C. The C-terminal region of SSRP1 including the amino acids 471 to 538 was specifically mapped as the region responsible for interaction with TgPP2C. The overexpression of TgPP2C down-regulated cell apoptosis and negatively regulated apoptosis induced by DRB, casein kinase II (CKII) inhibitor, through enhanced interaction with SSRP1. CONCLUSION: TgPP2C may be a parasitic factor capable of promoting cell survival through interaction with the host protein SSRP1, thereby creating a favorable environment for parasite growth.

Neopterin mediates sleep deprivation-induced microglial activation resulting in neuronal damage by affecting YY1/HDAC1/TOP1/IL-6 signaling.

INTRODUCTION: Sleep deprivation (SD) is a common disorder in modern society. Hippocampus is an important region of the brain for learning, memory, and emotions. Dysfunction of hippocampus can lead to severe learning and memory disorder, significantly affecting quality of life. SD is accompanied by hippocampal microglia activation and a surge in inflammatory factors, but the precise mechanism remains unclear. Moreover, the ongoing unknown persists regarding how activated microglia in SD lead to neuronal damage. Topoisomerase 1 (TOP1) plays an essential role in the inflammatory process, including the tumor system and viral infection. In this study, we observed a significant elevation in TOP1 levels in the hippocampus of mice subjected to SD. Therefore, we hypothesize that TOP1 may be implicated in SD-induced microglia activation and neuronal damage. OBJECTIVES: To investigate the role of TOP1 in SD-induced microglial activation, neuronal damage, and neurobehavioral impairments, and the molecular basis of SD-induced elevated TOP1 levels. METHODS: TOP1-specific knockout mice in microglia were used to study the effects of TOP1 on microglial activation and neuronal damage. Transcription factor prediction, RNA interference, ChIP-qPCR, ChIP-seq database analysis, and luciferase reporter assays were performed to explore the molecular mechanisms of YY1 transcriptional activation. Untargeted metabolic profiling was employed to investigate the material basis of YY1 transcriptional activation. RESULTS: Knockdown of TOP1 in hippocampal microglia ameliorates SD-induced microglial activation, inflammatory response, and neuronal damage. Mechanistically, TOP1 mediates the release of IL-6 from microglia, which consequently leads to neuronal dysfunction. Moreover, elevated TOP1 due to SD were associated with neopterin, which was attributed to its promotion of elevated levels of H3K27ac in the TOP1 promoter region by disrupting the binding of YY1 and HDAC1. CONCLUSION: The present study reveals that TOP1-mediated microglial activation is critical for SD induced hippocampal neuronal damage and behavioral impairments.