The impact of stroke on bone properties and muscle-bone relationship: a systematic review and meta-analysis

To systematically review available evidence related to the characteristics of bone changes post-stroke and the relationship between various aspects of muscle function (e.g., strength, spasticity) and bone properties after stroke onset. An extensive online database search was undertaken (last search in January 2019). Articles that examined the bone properties in stroke patients were included. The quality of the studies was evaluated with the National Institutes of Health (NIH) Study Quality Assessment Tools. Publication bias of meta-analyses was assessed using the Egger's regression asymmetry test. The selection and evaluation of the articles were conducted by two independent researchers. Fifty-nine studies were identified. In subacute and chronic stroke studies, the skeletal sites in the paretic limbs sustained a more pronounced decline in bone quality than did their counterparts in the non-paretic limbs. The rate of changes showed a decelerating trend as post-stroke duration increased, but the timing of achieving the steady rate differed across skeletal sites. The magnitude of bone changes in the paretic upper limb was more pronounced than the paretic lower limb. There was a strong relationship between muscle strength/mass and bone density/strength index. Muscle spasticity seemed to have a negative impact on bone integrity in the paretic upper limb, but its influence on bone properties in the paretic lower limb was uncertain. Substantial bone changes in the paretic limbs occurred particularly in the first few months after stroke onset. Early intervention, muscle strength training, and long-term management strategies may be important to enhance bone health post-stroke. This review has also revealed the knowledge gaps which should be addressed in future research.

Efficient base editing by RNA-guided cytidine base editors (CBEs) in pigs

Cytidine base editors (CBEs) have been demonstrated to be useful for precisely inducing C:G-to-T:A base mutations in various organisms. In this study, we showed that the BE4-Gam system induced the targeted C-to-T base conversion in porcine blastocysts at an efficiency of 66.7-71.4% via the injection of a single sgRNA targeting a xeno-antigen-related gene and BE4-Gam mRNA. Furthermore, the efficiency of simultaneous three gene base conversion via the injection of three targeting sgRNAs and BE4-Gam mRNA into porcine parthenogenetic embryos was 18.1%. We also obtained beta-1,4-N-acetyl-galactosaminyl transferase 2, alpha-1,3-galactosyltransferase, and cytidine monophosphate-N-acetylneuraminic acid hydroxylase deficient pig by somatic cell nuclear transfer, which exhibited significantly decreased activity. In addition, a new CBE version (termed AncBE4max) was used to edit genes in blastocysts and porcine fibroblasts (PFFs) for the first time. While this new version demonstrated a three genes base-editing rate of 71.4% at the porcine GGTA1, B4galNT2, and CMAH loci, it increased the frequency of bystander edits, which ranged from 17.8 to 71.4%. In this study, we efficiently and precisely mutated bases in porcine blastocysts and PFFs using CBEs and successfully generated C-to-T and C-to-G mutations in pigs. These results suggest that CBEs provide a more simple and efficient method for improving economic traits, reducing the breeding cycle, and increasing disease tolerance in pigs, thus aiding in the development of human disease models.

Dual roles of misshapen/NIK-related kinase (MINK1) in osteoarthritis subtypes through the activation of TGFβ signaling

OBJECTIVE

To identify the role of misshapen/NIK-related kinase (MINK1) in age-related Osteoarthritis (OA) and injury-induced OA, and the effects of enhanced TGFβ signaling in these progresses.

DESIGN

The effect of MINK1 was analyzed with MINK1 knock out (Mink1-/-) mice and C57BL/6J mice. OA progress was studied in age-related OA and instability-associated OA (destabilization of the medial meniscus, DMM) models. The murine knee joint was evaluated through histological staining, Osteoarthritis Research Society International (OARSI) scores, immunohistochemistry, and μCT analysis. Primary chondrocytes were isolated from wild type and Mink1-/- mice and subjected to osteogenic induction and Western blot analysis.

RESULTS

MINK1 is highly expressed during cartilage development and in normal cartilage. Mink1-/- mice displayed markedly lower OARSI scores, aggrecan degradation neoepitope positive cells and increased Safranin O and pSMAD2 staining in aging-related OA model. However, in injury-induced OA, loss of MINK1 accelerates extracellular matrix (ECM) destruction, osteophyte formation, and subchondral bone sclerosis. Accelerated subchondral bone remodeling in Mink1-/- mice was accompanied with increased numbers of nestin-positive mesenchymal stem cells (MSCs) and osterix-positive osteoprogenitors. pSMAD2 staining was increased in the subchondral bone marrow of Mink1-/- mice and overexpression of MINK1 inhibited SMAD2 phosphorylation in vitro.

CONCLUSIONS

This study shows for the first time that activation of TGFβ/SMAD2 by MINK1 deficiency plays opposite roles in aging-related and injury-induced OA. MINK1 deficiency protects cartilage from degeneration in aging joints through increased SMAD2 activation in chondrocytes, while accelerating OA progress in injury-induced model through enhanced osteogenesis of MSCs in the subchondral bone. These findings provide insights for developing precision OA therapeutics targeting TGFβ/SMAD2 signaling.

Generation of pRSAD2 gene knock-in pig via CRISPR/Cas9 technology

A wide range of endemic and epidemic viruses, including classic swine fever virus (CSFV), pseudorabies virus (PRV) and others, are among the most economically important pathogens in pigs and have severely affected the national economy, human health and animal welfare and productivity. The RSAD2 exhibits antiviral activity against various DNA and RNA viruses. In this study, we successfully accomplished site-specific insertion of the porcine RSAD2 gene (pRSAD2) at the porcine ROSA26 (pROSA26) locus, generating pRSAD2 gene knock-in (pRSAD2-KI) PK-15 cells and porcine foetal fibroblasts (PFFs) via CRISPR/Cas9 technology. Gene expression analysis confirmed that pRSAD2-KI cells stably and efficiently overexpressed the pRSAD2 gene. Furthermore, viral challenge studies in vitro indicated that site-specific integration of the pRSAD2 gene not only effectively reduced CSFV infection but also PRV infection. More importantly, we ultimately successfully produced a pRSAD2-KI pig that constitutively overexpressed the pRSAD2, viral challenge results indicated that fibroblasts isolated from the pRSAD2-KI pig reduced CSFV infection. Taken together, these results suggest that CRISPR/Cas9-mediated knock-in strategy can be used for producing pRSAD2-KI pigs.

Genotyping based on complete coding sequences of porcine circovirus type 3 is stable and reliable

Porcine circovirus type 3 (PCV3) is a newly identified virus, which is associated with PDNS-like clinical signs, reproductive failure, cardiac and multiorgan inflammation. However, the genotype of PCV3 is still controversial. Here, we reconstructed the phylogenies of 194 complete coding sequences of PCV3 using five different phylogenetic methods. The results showed five trees reconstructed using different methods displayed similar phylogenies, indicating genotyping based on complete coding sequences of PCV3 is stable and accurate.

Preparation of a new type 2 diabetic miniature pig model via the CRISPR/Cas9 system

Diabetes has become one of the major noninfectious diseases that seriously endanger public health. The formation of islet amyloid polypeptide (IAPP) affects the normal physiological functions of the body, such as glucose metabolism and lipid metabolism. The mature human IAPP protein (hIAPP) has a strong tendency to misfold and is considered to be one of the major causes of amyloid changes in islets. Deposition of hIAPP is considered to be one of the leading causes of type 2 diabetes mellitus (T2DM). Miniature pigs are experimental animal models that are well suited for research on gene function and human diabetes. In our study, we obtained IAPP gene-humanized miniature pigs via the CRISPR/Cas9 system and somatic cell nuclear transfer (SCNT) technology. The hIAPP pigs can be used to further study the pathogenesis and related complications of T2DM and to lay a solid foundation for the prevention and treatment of T2DM.

Expanded targeting scope and enhanced base editing efficiency in rabbit using optimized xCas9(3.7)

Evolved xCas9(3.7) variant with broad PAM compatibility has been reported in cell lines, while its editing efficiency was site-specific. Here, we show that xCas9(3.7) can recognize a broad PAMs including NGG, NGA, and NGT, in both embryos and Founder (F0) rabbits. Furthermore, the codon-optimized xCas9-derived base editors, exBE4 and exABE, can dramatically improve the base editing efficiencies in rabbit embryos. Our results demonstrated that the optimized xCas9 with expanded PAM compatibility and enhanced base editing efficiency could be used for precise gene modifications in organisms.

VEGFR2 and VEGF-C Suppresses the Epithelial-Mesenchymal Transition Via YAP in Retinal Pigment Epithelial Cells

BACKGROUND

Whereas retinal pigment epithelial (RPE) cells are known to secrete VEGF-A and VEGFR2, the functions of the autocrine VEGF signaling remain unclear. Meanwhile, anti-VEGF therapies have been applied routinely to treat ocular vascular diseases.

OBJECTIVE

The aim of this study was to determine the functions of the VEGF signaling in RPE cells and evaluate the consequences of its interruption.

METHODS

The genes involved in the VEGF and Hippo signal pathways were knocked down with siRNAs in both ARPE-19 cell line and human primary RPE cells via transient transfection whereas overexpression of VEGFR2 was mediated via adenovirus transduction. Expression of the epithelial-mesenchymal transition (EMT) markers and the downstream genes of YAP were determined by real-time PCR and Western Blot analysis. Immunofluorescence staining was utilized to determine gene expression in tissue and mouse samples.

RESULTS

Knockdown of VEGFR2 results in epithelial-mesenchymal transition in vitro and in vivo. Overexpression of VEGFR2 suppresses TGF β-mediated EMT in RPE cells. Loss of VEGF-C rather than VEGF-A induces EMT. Mechanistically, the VEGFR2 ablation-induced EMT in RPE cells is mediated by activation of YAP, an effector of the Hippo pathway. Finally, the immunohistochemical analysis of VEGFR2 and YAP in human proliferative vitreoretinopathy (PVR) membranes indicates a tendency of an inverse correlation between VEGFR2-positive and YAP-positive cells.

CONCLUSIONS

Our results disclose unexpected novel roles of VEGFR2 and VEGF-C in the process of EMT of RPE cells and in the Hippo pathway. The data shown here demonstrated that VEGFR2 and VEGF-C are important to maintain the normal physiological state of RPE cells.

Biomimetic Octopus-like Particles for Ultraspecific Capture and Detection of Pathogens

Infectious diseases caused by pathogenic bacteria (such as sepsis and meningitis) seriously threaten public health; therefore, rapid and accurate identification of the target bacteria is urgently needed to prevent and treat bacterial infections. Although technologies including plate-counting and polymerase chain reaction have been established to detect the pathogenic bacteria, they are either time-consuming or sophisticated. Herein, a biomimetic octopus-like structure integrating merits of multiarm and multivalent interaction is designed for ultraspecific capture and detection of pathogens. The flexible polymeric arms and multivalent ligands work together to mimic the arm-sucker coordination of an octopus to effectively grasp the target pathogens, leading to remarkably high capacity and specificity for the target capture (above 98%, 10 CFU mL^-1) without a nonspecific absorption of background pathogens. The captured bacteria can be identified as a point of care by the surface-enhanced Raman spectroscopy method with a detection limit of 10 cells mL^-1.

Porcine HMGCR Inhibits Porcine Circovirus Type 2 Infection by Directly Interacting with the Viral Proteins

Porcine circovirus type 2 (PCV2) is the etiological agent of porcine circovirus diseases and porcine circovirus-associated diseases (PCVDs/PCVADs). However, the pathogenesis of PCV2 is not fully understood. We previously found that 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) is negatively associated with PCV2 infection in vitro and in vivo. HMGCR inhibits the early stages of PCV2 infection, while PCV2 infection induces the phosphorylation of HMGCR to inactivate the protein. In this study, we investigated the possibility that adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK), and protein phosphatase 2 (PP2A) participate in HMGCR-mediated inhibition of PCV2 infection and the interaction of porcine HMGCR with PCV2 proteins. The results showed that AMPK activity fluctuated in cells during the early stage of PCV2 infection, while PP2A had little effect on PCV2 infection and HMGCR activity. Furthermore, PCV2 infection may enhance or maintain the level of phosphorylated HMGCR by directly interacting with the protein in PK-15 cells. These findings may provide a better understanding of PCV2 pathogenesis, and HMGCR may be a novel PCV2 antiviral target.

Data Mining and Validation of AMPK Pathway as a Novel Candidate Role Affecting Intramuscular Fat Content in Pigs

Simple Summary

Intramuscular fat (IMF) is increasingly being recognized as a key meat trait in the modern pork industry. The aims of this research were to identify potential signaling pathways associated with IMF content in the longissimus dorsi (LD) muscle of different pig breeds and investigate the gene expression levels in the screened signaling pathways. Our results indicated that the AMPK signaling pathway may be related to IMF deposition in the LD muscle of pigs. The results of qRT-PCR analysis showed that the expression of ten key hub genes (AMPK, ADIPOR1, ADIPOR2, LKB1, CAMKKβ, CPT1A, CPT1B, PGC-1α, CD36, and ACC1) differed between the LD muscle of Min and Large White pigs. The protein expression levels of AMPK, LKB1, CaMKK2, CPT1A, and ACC1 were similar to the genes expression patterns in the LD muscle of Large White pigs. The results of this study provide novel insights into the regulatory function of the AMPK signaling pathway in relation to the IMF content in the LD muscle of different pigs.

Abstract

Intramuscular fat (IMF) is an important economic trait for pork quality and a complex quantitative trait regulated by multiple genes. The objective of this work was to investigate the novel transcriptional effects of a multigene pathway on IMF deposition in the longissimus dorsi (LD) muscles of pigs. Potential signaling pathways were screened by mining data from three gene expression profiles in the Gene Expression Omnibus (GEO) database. We designed quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) arrays for the candidate signaling pathways to verify the results in the LD muscles of two pig breeds with different IMF contents (Large White and Min). Western blot analysis was used to detect the expression levels of several candidate proteins. Our results showed that the AMPK signaling pathway was screened via bioinformatics analysis. Ten key hub genes of this signaling pathway (AMPK, ADIPOR1, ADIPOR2, LKB1, CAMKKβ, CPT1A, CPT1B, PGC-1α, CD36, and ACC1) were differentially expressed between the Large White and Min pigs. Western blot analysis further confirmed that LKB1/CaMKK2-AMPK-ACC1-CPT1A axis dominates the activity of AMPK signaling pathway. Statistical analyses revealed that AMPK signaling pathway activity clearly varied among the two pig breeds. Based on these results, we concluded that the activation of the AMPK signaling pathway plays a positive role in reducing IMF deposition in pigs.

[Comparison of Imaging and Pathologic Findings of Retroperitoneal Dedifferentiated Liposarcoma]

Objective: To investigate the imaging appearance of CT and MRI in retroperitoneal dedifferentiated liposarcoma (DDL) based on pathological findings. Methods: Twelve patients with retroperitoneal DDL (13 lesions) who were surgically and pathologically confirmed were retrospectively collected in the Cancer Hospital of Chinese Academy of Medical Sciences. The correlation of CT and MRI features with histopathologic findings was analyzed. Results: The CT and MRI images of retroperitoneal DDLs were large, heterogeneous soft-tissue masses, mostly lobulated (30.8%, 4/13) or multinodular (46.2%, 6/13), invading adjacent anatomic structures (46.2%, 6/13). The lesions contained different proportions of fatty and non-fatty components, and usually with clear boundaries. The CT images of dedifferentiated components showed non-fatty masses of soft tissue density or mixed density, among which ground-glass nodules may be related to mucinous components. Occasionally calcification or ossification was seen (45.5%, 5/11). The contrast-enhanced CT and MRI images of non-fatty components commonly showed intense heterogeneous enhancement (84.6%, 11/13), central cystic changes and necrosis (61.5%, 8/13), pathologically corresponding to multiple types of soft tissue sarcomas without significant specificity. The well-differentiated components were fatty masses with irregular fibrous septa or soft tissue nodules, which is pathologically corresponding to well differentiated liposarcoma. Lymph node or distant metastasis was rare. Conclusions: The imaging manifestations of retroperitoneal DDLs are diverse and closely related to the proportion and distribution of different components. CT, MRI and contrast-enhanced imaging has a certain diagnostic value for retroperitoneal DDLs.

LMNA-mutated Rabbits: A Model of Premature Aging Syndrome with Muscular Dystrophy and Dilated Cardiomyopathy

Premature aging syndromes are rare genetic disorders mimicking clinical and molecular features of aging. Products of the LMNA gene, primarily lamin A and C, are major components of the nuclear lamina. A recently identified group of premature aging syndromes was related to mutations of the LMNA gene. Although LMNA disorders have been identified in premature aging syndromes, affect specifically the skeletal muscles, cardiac muscles, and lipodystrophy, understanding the pathogenic mechanisms still need to be elucidated. Here, to establish a rabbit knockout (KO) model of premature aging syndromes, we performed precise LMNA targeting in rabbits via co-injection of Cas9/sgRNA mRNA into zygotes. The LMNA-KO rabbits exhibited reduced locomotion activity with abnormal stiff walking posture and a shortened stature, all of them died within 22 days. In addition, cardiomyopathy, muscular dystrophy, bone and joint abnormalities, as well as lipodystrophy were observed in LMNA-KO rabbits. In conclusion, the novel rabbit LMNA-KO model, displayed typical features of histopathological defects that are observed in premature aging syndromes, and may be utilized as a valuable resource for understanding the pathophysiological mechanisms of premature aging syndromes and elucidating mysteries of the normal process of aging in humans.

CRISPR/Cas9-Mediated Hitchhike Expression of Functional shRNAs at the Porcine miR-17-92 Cluster

Successful RNAi applications depend on strategies allowing stable and persistent expression of minimal gene silencing triggers without perturbing endogenous gene expression. In this study, we proposed an endogenous microRNA (miRNA) cluster as a novel integration site for small hairpin RNAs (shRNAs). We successfully integrated exogenous shRNAs at the porcine miRNA-17-92 (pmiR-17-92) cluster via a CRISPR/Cas9-mediated knock-in strategy. The anti-EGFP or anti-CSFV shRNAs could be stably and effectively expressed at the control of the endogenous promoter of the pmiR-17-92 cluster. Importantly, we confirmed that hitchhike expression of anti- classical swine fever (CSFV) shRNA had no effect on cell growth, blastocyst development and endogenous pmiR-17-92 expression in selected transgene (TG) porcine fetal fibroblasts (PFFs) clones. Moreover, these TG PFFs could inhibit the replication of CSFV by half and could be further used for generation of transgenic pigs. Taken together, these results show that our RNA interference (RNAi) expression strategy benefits numerous applications, from miRNA, genome and transgenic research, to gene therapy.

Bioinspired hierarchically hairy particles for robust superhydrophobic coatings via a droplet dynamic template method

Bioinspired hierarchically hairy particles are prepared by using initiator droplets as dynamic templates to achieve a robust superhydrophobic coating.

Long Non-coding RNAs Contribute to the Inhibition of Proliferation and EMT by Pterostilbene in Human Breast Cancer

Background: There is increasing evidence that long non-coding RNAs (lncRNAs) are involved in the process of carcinogenesis and treatment using chemotherapy. Pterostilbene, a phytochemical agent with natural antioxidant and anti-inflammatory properties, has been shown to modulate oncogenic processes in many cancers. However, there has been limited research on the association between pterostilbene and the expression of lncRNAs.

Methods: MCF7 breast cancer cells were treated with various concentrations of pterostilbene and their gene expression profile was analyzed by quantitative real-time PCR, Western blotting and immunofluorescence.

Results: Treatment with pterostilbene inhibited cell proliferation and epithelial-to-mesenchymal transition (EMT), and increased cell apoptosis, autophagy and ER stress. The Akt/mTOR pathway was downregulated, but p38 MAPK/Erk signaling was activated in cells following treatment with pterostilbene. Pterostilbene increased the expression of the lncRNAs MEG3, TUG1, H19, and DICER1-AS1 whereas the expression of LINC01121, PTTG3P, and HOTAIR declined. Knockdown of lncRNA H19 resulted in a reduction of the cell invasion, with the cells becoming more sensitive to pterostilbene therapy.

Conclusions: These results suggest that efficient optimum disruption of lncRNA expression might possibly improve the anti-tumor effects of phytochemical agents, thus serving as a potential therapy for breast cancer.