Exploring potential SARS-CoV-2 Mpro non-covalent inhibitors through docking, pharmacophore profile matching, molecular dynamic simulation, and MM-GBSA.

CONTEXT: In the replication of SARS-CoV-2, the main protease (Mpro/3CLpro) is significant. It is conserved in a number of novel coronavirus variations, and no known human proteases share its cleavage sites. Therefore, 3CLpro is an ideal target. In the report, we screened five potential inhibitors (1543, 2308, 3717, 5606, and 9000) of SARS-CoV-2 Mpro through a workflow. The calculation of MM-GBSA binding free energy showed that three of the five potential inhibitors (1543, 2308, 5606) had similar inhibitor effects to X77 against Mpro of SARS-CoV-2. In conclusion, the manuscript lays the groundwork for the design of Mpro inhibitors. METHODS: In the virtual screening phase, we used structure-based virtual screening (Qvina2.1) and ligand-based virtual screening (AncPhore). In the molecular dynamic simulation part, we used the Amber14SB + GAFF force field to perform molecular dynamic simulation of the complex for 100 ns (Gromacs2021.5) and performed MM-GBSA binding free energy calculation according to the simulation trajectory.

Suppression of Cancer Cell Stemness and Drug Resistance via MYC Destabilization by Deubiquitinase USP45 Inhibition with a Natural Small Molecule.

Cancer stem cells (CSCs) play significant roles in cancer development, drug resistance and cancer recurrence. In cancer treatments based on the CSC characteristics and inducing factors, MYC is a promising target for therapeutic molecules. Although it has been regarded as an undrugable target, its stability tightly regulated by the ubiquitin-proteasome system offers a new direction for molecule targeting and cancer treatment. Herein we report our discoveries in this research area, and we have found that deubiquitinase USP45 can directly bind with MYC, resulting in its deubiquitination and stabilization. Further, USP45 overexpressing can upregulate MYC, and this overexpressing can significantly enhance cancer development, cancer cell stemness and drug resistance. Interestingly, without enhancing cancer development, MYC silencing with shRNA can only suppress USP45-induced stemness and drug resistance. Moreover, we have identified that USP45 can be specifically bound and inhibited by a natural small molecule (α-mangostin), in turn significantly suppressing USP45-induced stemness and drug resistance. Since USP45 is significantly expressed in cervical tumors, we have discovered that the combination of α-mangostin and doxorubicin can significantly inhibit USP45-induced cervical tumorigenesis in an animal model. In general, on the basis of our USP45 discoveries on its MYC deubiquitination and α-mangostin inhibition, suppressing USP45 has opened a new window for suppressing cancer development, stemness and drug resistance.

A chromosome-level genome assembly of Artocarpus nanchuanensis (Moraceae), an extremely endangered fruit tree.

Artocarpus nanchuanensis (Moraceae), which is naturally distributed in China, is a representative and extremely endangered tree species. In this study, we obtained a high-quality chromosome-scale genome assembly and annotation information for A. nanchuanensis using integrated approaches, including Illumina, Nanopore sequencing platform, and Hi-C. A total of 128.71 Gb of raw Nanopore reads were generated from 20-kb libraries, and 123.38 Gb of clean reads were obtained after filtration with 160.34× coverage depth and a 17.48-kb average read length. The final assembled A. nanchuanensis genome was 769.44 Mb with a 2.09 Mb contig N50, and 99.62% (766.50 Mb) of the assembled data was assigned to 28 pseudochromosomes. In total, 39,596 genes (95.10%, 39,596/41,636) were successfully annotated, and 129 metabolic pathways were detected. Plants disease resistance/insect resistance genes, plant-pathogen interaction metabolic pathways, and abundant biosynthesis pathways of vitamins, flavonoid, and gingerol were detected. Unigene reveals the basis of species-specific functions, and gene family in contraction and expansion generally implies strong functional differences in the evolution. Compared with other related species, a total of 512 unigenes, 309 gene families in contraction, and 559 gene families in expansion were detected in A. nanchuanensis. This A. nanchuanensis genome information provides an important resource to expand our understanding of the unique biological processes, nutritional and medicinal benefits, and evolutionary relationship of this species. The study of gene function and metabolic pathway in A. nanchuanensis may reveal the theoretical basis of a special trait in A. nanchuanensis and promote the study and utilization of its rare medicinal value.

DEFB126 polymorphisms and association with idiopathic asthenozoospermia in China.

Idiopathic asthenozoospermia, a common factor in male infertility, is characterized by altered sperm motility function in fresh ejaculate. Although the ß-defensin 126 (DEFB126) protein is associated with asthenozoospermia, DEFB126 gene polymorphisms have not been extensively studied. Therefore, the association between DEFB126 gene polymorphisms and asthenozoospermia requires further investigation. Screening was performed by semen analysis, karyotype analysis, and Y microdeletion detection, and 102 fertile men and 106 men with asthenozoospermia in Chengdu, China, were selected for DEFB126 gene sequence analyses. Seven nucleotide mutations and two nucleotide deletions in the DEFB126 gene were detected. rs11467417 (317-318 del/del), rs11467497 (163-166 wt/del), c.152T>C, and c.227A>G were significantly different between the control and asthenozoospermia groups, likely representing high-risk genetic factors for asthenozoospermia among males. DEFB126 expression was not observed in sperm with rs11467497 homozygous deletion and was unstable in sperm with rs11467417 homozygous deletion. The rs11467497 four-nucleotide deletion leads to truncation of DEFB126 at the carboxy-terminus, and the rs11467417 binucleotide deletion produces a non-stop messenger RNA (mRNA). The above deletions may be responsible for male hypofertility and infertility by reducing DEFB126 affinity to sperm surfaces. Based on in silico analysis, the amino acids 51M and 76K are located in the highly conserved domain; c.152T>C (M51T) and c.227A>G (K76R) are predicted to be damaging and capable of changing alternative splice, structural and posttranslational modification sites of the RNA, as well as the secondary structure, structural stability, and hydrophobicity of the protein, suggesting that these mutations are associated with asthenozoospermia.

The polymorphism analysis and epitope predicted of Alphapapillomavirus 9 E6 in Sichuan, China.

BACKGROUND: The Alphapapillomavirus 9 (α-9 HPV) is a member of the Alphapapillomavirus genus and Papillomaviridae family. These viruses are almost all carcinogenic HPV, which is closely related to 75% of invasive cervical cancer worldwide, and has a high prevalence in Sichuan. The carcinogenic function is mainly realized by its E6 oncoprotein. METHODS: Cell samples were collected by cervical scraped for HPV detecting and typing. HPV-16, HPV-31, HPV-33, HPV-52, HPV-58 5 α-9 genus HPV subtype positive samples were selected, their E6 gene was sequenced and analyzed. The positive selection sites of HPV E6 genes were estimated by PAML 4.8 server. The secondary and tertiary structure of E6 protein were predicted by PSIPred and Swiss-model. The T-cell antigen epitopes of E6 protein were predicted by IEDB. RESULTS: α-9 HPV has a high prevalence in Sichuan, China. From 2012 to 2017, 18,067 cell cervical samples were collected, and 3135 were detected with α-9 HPV infection. Among which, 250 cases HPV-16 E6, 96 cases HPV-31 E6, 216 cases HPV-33 E6, 288 cases HPV-52 E6 and 405 cases HPV-58 E6 were successfully amplified, 17, 6, 6, 13, and 4 non-synonymous nucleotide mutations were respectively detected in HPV-16, 31, 33, 52, and 58 E6, 7 positive selection sites of α-9 HPV E6 were selected out (D32E of HPV-16 E6, K35N, K93N and R145I of HPV-33 E6, K93R of HPV-52 E6, K93N and R145K of HPV-58 E6). The structure and antigen epitopes of E6 protein with amino acid substitution differ from those of wild-type E6 protein, especially for the mutation located in the E6 positive selection site. CONCLUSIONS: HPV E6 nucleotide non-synonymous mutation in the positive selection site influence the protein structure and decrease the antigen epitopes affinity of the E6 protein overall, making it more difficult for the HPV-infected cells to be detected by the immune system, and enhancing the HPV adaptability to the environment. Mutations influence the validity of HPV clinical diagnostic probes, the polymorphism analysis of α-9 HPV E6 enrich the data of HR-risk HPV in Sichuan China, and the detection probes designed with the polymorphism data in mind can improve the efficiency of clinical detection; Mutations influence epitopes affinity, the association of E6 polymorphism and epitope affinity can improve the design of therapeutic vaccine with good immunity and high generality antigen epitope; The above study all provide a good theoretical basis for the prevention and treatment of HPV-related diseases.

Neuron segmentation using 3D wavelet integrated encoder-decoder network.

MOTIVATION: 3D neuron segmentation is a key step for the neuron digital reconstruction, which is essential for exploring brain circuits and understanding brain functions. However, the fine line-shaped nerve fibers of neuron could spread in a large region, which brings great computational cost to the neuron segmentation. Meanwhile, the strong noises and disconnected nerve fibers bring great challenges to the task. RESULTS: In this article, we propose a 3D wavelet and deep learning-based 3D neuron segmentation method. The neuronal image is first partitioned into neuronal cubes to simplify the segmentation task. Then, we design 3D WaveUNet, the first 3D wavelet integrated encoder-decoder network, to segment the nerve fibers in the cubes; the wavelets could assist the deep networks in suppressing data noises and connecting the broken fibers. We also produce a Neuronal Cube Dataset (NeuCuDa) using the biggest available annotated neuronal image dataset, BigNeuron, to train 3D WaveUNet. Finally, the nerve fibers segmented in cubes are assembled to generate the complete neuron, which is digitally reconstructed using an available automatic tracing algorithm. The experimental results show that our neuron segmentation method could completely extract the target neuron in noisy neuronal images. The integrated 3D wavelets can efficiently improve the performance of 3D neuron segmentation and reconstruction. AVAILABILITYAND IMPLEMENTATION: The data and codes for this work are available at https://github.com/LiQiufu/3D-WaveUNet. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Human papillomavirus 68 prevalence and genetic variability based on E6/E7 genes in Sichuan.

HPV68 is a common HR-HPV, its persistent infection is closely related with the occurrence of cervical cancer. In this study, 2939 (27.60%, 2939/10650) positive samples were detected, and 174 (5.92%, 174/2939) were HPV68. 150 HPV68 E6-E7 were successful sequenced, 4 non-synonymous mutations were detected in E6, and E7 were 12. N133S non-synonymous mutations of HPV 68 E6 and C67G, T68 A/M of HPV68 E7 are E6, E7 positive selection sites, they all located in the key domains and major motifs of E6/E7 protein, the above amino-acid substitutions changed the protein structure, disturbed the interaction with other protein or cellular factors and make a difference in epitopes affinity, may affect the pathogenicity and adaptability of HPV68 to the environment. The enrichment of HPV68 data is of great significance for understanding the inherent geographical and biological differences of HPV68 in China.

WaveCNet: Wavelet Integrated CNNs to Suppress Aliasing Effect for Noise-Robust Image Classification.

Though widely used in image classification, convolutional neural networks (CNNs) are prone to noise interruptions, i.e. the CNN output can be drastically changed by small image noise. To improve the noise robustness, we try to integrate CNNs with wavelet by replacing the common down-sampling (max-pooling, strided-convolution, and average pooling) with discrete wavelet transform (DWT). We firstly propose general DWT and inverse DWT (IDWT) layers applicable to various orthogonal and biorthogonal discrete wavelets like Haar, Daubechies, and Cohen, etc., and then design wavelet integrated CNNs (WaveCNets) by integrating DWT into the commonly used CNNs (VGG, ResNets, and DenseNet). During the down-sampling, WaveCNets apply DWT to decompose the feature maps into the low-frequency and high-frequency components. Containing the main information including the basic object structures, the low-frequency component is transmitted into the following layers to generate robust high-level features. The high-frequency components are dropped to remove most of the data noises. The experimental results show that WaveCNets achieve higher accuracy on ImageNet than various vanilla CNNs. We have also tested the performance of WaveCNets on the noisy version of ImageNet, ImageNet-C and six adversarial attacks, the results suggest that the proposed DWT/IDWT layers could provide better noise-robustness and adversarial robustness. When applying WaveCNets as backbones, the performance of object detectors (i.e., faster R-CNN and RetinaNet) on COCO detection dataset are consistently improved. We believe that suppression of aliasing effect, i.e. separation of low frequency and high frequency information, is the main advantages of our approach. The code of our DWT/IDWT layer and different WaveCNets are available at https://github.com/CVI-SZU/WaveCNet.

The genetic variability, phylogeny and functional significance of E6, E7 and LCR in human papillomavirus type 52 isolates in Sichuan, China.

BACKGROUND: Variations in human papillomavirus (HPV) E6 and E7 have been shown to be closely related to the persistence of the virus and the occurrence and development of cervical cancer. Long control region (LCR) of HPV has been shown multiple functions on regulating viral transcription. In recent years, there have been reports on E6/E7/LCR of HPV-16 and HPV-58, but there are few studies on HPV-52, especially for LCR. In this study, we focused on gene polymorphism of the HPV-52 E6/E7/LCR sequences, assessed the effects of variations on the immune recognition of viral E6 and E7 antigens, predicted the effect of LCR variations on transcription factor binding sites and provided more basic date for further study of E6/E7/LCR in Chengdu, China. METHODS: LCR/E6/E7 of the HPV-52 were amplified and sequenced to do polymorphic and phylogenetic analysis. Sequences were aligned with the reference sequence by MEGA 7.0 to identify SNP. A neighbor-joining phylogenetic tree was constructed by MEGA 7.0, followed by the secondary structure prediction of the related proteins using PSIPRED 4.0. The selection pressure of E6 and E7 coding regions were estimated by Bayes empirical Bayes analysis of PAML 4.9. The HLA class-I and II binding peptides were predicted by the Immune Epitope Database server. The B cell epitopes were predicted by ABCpred server. Transcription factor binding sites in LCR were predicted by JASPAR database. RESULTS: 50 SNP sites (6 in E6, 10 in E7, 34 in LCR) were found. From the most variable to the least variable, the nucleotide variations were LCR > E7 > E6. Two deletions were found between the nucleotide sites 7387-7391 (TTATG) and 7698-7700 (CTT) in all samples. A deletion was found between the nucleotide sites 7287-7288 (TG) in 97.56% (40/41) of the samples. The combinations of all the SNP sites and deletions resulted in 12 unique sequences. As shown in the neighbor-joining phylogenetic tree, except for one belonging to sub-lineage C2, others sequences clustered into sub-lineage B2. No positive selection was observed in E6 and E7. 8 non-synonymous amino acid substitutions (including E3Q and K93R in the E6, and T37I, S52D, Y59D, H61Y, D64N and L99R in the E7) were potential affecting multiple putative epitopes for both CD4+ and CD8+ T-cells and B-cells. A7168G was the most variable site (100%) and the binding sites for transcription factor VAX1 in LCR. In addition, the prediction results showed that LCR had the high probability binding sites for transcription factors SOX9, FOS, RAX, HOXA5, VAX1 and SRY. CONCLUSION: This study provides basic data for understanding the relation among E6/E7/LCR mutations, lineages and carcinogenesis. Furthermore, it provides an insight into the intrinsic geographical relatedness and biological differences of the HPV-52 variants, and contributes to further research on the HPV-52 therapeutic vaccine development.

Genetic variability of human papillomavirus type 39 based on E6, E7 and L1 genes in Southwest China.

BACKGROUND: Human papillomavirus type 39 associated with genital intraepithelial neoplasia and invasive cancers, has a high prevalence in Southwest China. HPV E6, E7 are two main papillomavirus oncoproteins, closely relate to the function of HPV immortalization, cell transformation, and carcinogenesis. L1 is the major capsid protein, can reflect the replication status of the virus in cells and the progression of cervical lesions. The purpose of this study is to reveal the prevalence of HPV 39 and the genetic polymorphisms of HPV39 based on E6, E7 and L1 gene in southwest China. METHODS: Cell samples were collected by cervical scraped for HPV detecting and typing, and HPV39 positive samples were selected out. Important E6, E7 and L1 genes of HPV39 were sequenced and analyzed for the study of HPV39 genetic polymorphisms. Phylogenetic trees were constructed by Maximum-likelihood and Kimura 2-parameters methods in Molecular Evolutionary Genetics Analysis version 6.0. The selection pressures of E6, E7 and L1 genes were estimated by Datamonkey web server. The secondary and three-dimensional structure of HPV39 E6, E7 proteins were created by sopma server and SWISS-MODEL software. RESULTS: 344 HPV39 positive samples were selected from 5718 HPV positive cell samples. Among HPV39 E6-E7 sequences, 20 single nucleotide mutations were detected, including 10 non-synonymous and 10 synonymous mutations; 26 single nucleotide mutations were detected in HPV39 L1 sequences, including 7 non-synonymous and 19 synonymous mutations respectively. 11 novel variants of HPV39 E6-E7 (5 in E6 and 6 in E7) and 14 novel variants of HPV39 L1 were identified in this study. A-branch was the most frequent HPV39 lineage in southwest China during our investigation. Selective pressure analysis showed that codon sites 26, 87, 151 in E6 and 75, 180, 222, 272, 284, 346, 356 in L1 were positively selected sites, as well as codon sites 45, 138, 309, 381 were negative selection sites in L1 gene, E7 has neither positive selection sites nor negative selection sites. A certain degree of secondary and three-dimensional structure dislocation was existed due to the non-synonymous mutations. CONCLUSIONS: Amino acid substitution affected the secondary and three-dimensional structure of HPV39, and resulting in the differences of carcinogenic potential and biological functions as well as the immune response due to the antigen epitopes difference, the antigen epitopes with stronger adaptability in Southwest will be screened out based on the above research results for the later vaccine development. And gene polymorphism of HPV39 in Southwest China may improve the effectiveness of clinical test and vaccine design, specifically for women in Southwest China.

Deep learning based neuronal soma detection and counting for Alzheimer's disease analysis.

BACKGROUND AND OBJECTIVE: Alzheimer's Disease (AD) is associated with neuronal damage and decrease. Micro-Optical Sectioning Tomography (MOST) provides an approach to acquire high-resolution images for neuron analysis in the whole-brain. Application of this technique to AD mouse brain enables us to investigate neuron changes during the progression of AD pathology. However, how to deal with the huge amount of data becomes the bottleneck. METHODS: Using MOST technology, we acquired 3D whole-brain images of six AD mice, and sampled the imaging data of four regions in each mouse brain for AD progression analysis. To count the number of neurons, we proposed a deep learning based method by detecting neuronal soma in the neuronal images. In our method, the neuronal images were first cut into small cubes, then a Convolutional Neural Network (CNN) classifier was designed to detect the neuronal soma by classifying the cubes into three categories, "soma", "fiber", and "background". RESULTS: Compared with the manual method and currently available NeuroGPS software, our method demonstrates faster speed and higher accuracy in identifying neurons from the MOST images. By applying our method to various brain regions of 6-month-old and 12-month-old AD mice, we found that the amount of neurons in three brain regions (lateral entorhinal cortex, medial entorhinal cortex, and presubiculum) decreased slightly with the increase of age, which is consistent with the experimental results previously reported. CONCLUSION: This paper provides a new method to automatically handle the huge amounts of data and accurately identify neuronal soma from the MOST images. It also provides the potential possibility to construct a whole-brain neuron projection to reveal the impact of AD pathology on mouse brain.

3D Neuron Reconstruction in Tangled Neuronal Image With Deep Networks.

Digital reconstruction or tracing of 3D neuron is essential for understanding the brain functions. While existing automatic tracing algorithms work well for the clean neuronal image with a single neuron, they are not robust to trace the neuron surrounded by nerve fibers. We propose a 3D U-Net-based network, namely 3D U-Net Plus, to segment the neuron from the surrounding fibers before the application of tracing algorithms. All the images in BigNeuron, the biggest available neuronal image dataset, contain clean neurons with no interference of nerve fibers, which are not practical to train the segmentation network. Based upon the BigNeuron images, we synthesize a SYNethic TAngled NEuronal Image dataset (SYNTANEI) to train the proposed network, by fusing the neurons with extracted nerve fibers. Due to the adoption of dropout, àtrous convolution and Àtrous Spatial Pyramid Pooling (ASPP), experimental results on the synthetic and real tangled neuronal images show that the proposed 3D U-Net Plus network achieved very promising segmentation results. The neurons reconstructed by the tracing algorithm using the segmentation result match significantly better with the ground truth than that using the original images.

Generalization of SPIHT: Set Partition Coding System.

This paper constructs a set partition coding system (SPACS) to combine the advantages of different types of set partition coding algorithms. General tree (GT) is an important conception introduced in this paper, which can represent tree set and square set simultaneously. With the help of GT, SPIHT is generalized to construct degree- k SPIHT based on the analysis of two kinds of set partition operations. Using the same coding mechanism, SPACS (k,p) is constructed, aided with virtual subbands that are generated by recursive division on the LL band. SPACS belongs to tree-set partition coding algorithms if k and p take smaller values. In particular, SPACS(2,1) is the classical SPIHT. SPACS tends toward a block-set partition coding algorithm as k,p increases. Location bit, amplitude bit, and unnecessary bit are presented, which can be used to analyze the coding efficiency of SPACS. We compress 256 images with 512×512 using SPACS. The numerical results show SPACS achieves some improvements in coding efficiency over SPIHT, especially at very low bitrate. On average, to code every image, SPACS(3,1) (at an average of 3.93 bpp) needs 7792 more location bits but saves 10 218 unnecessary bits, compared with SPIHT (3.94 bpp).