Coronavirus disease 2019 (COVID-19): diagnosis and prognosis

Coronavirus disease 2019 (COVID-19) has become a global pandemic with a high rate of transmission. Currently, there is a lack of vaccines and specific drugs for this newly-emerged virus. Timely diagnosis and treatment, as well as isolation of patients and virus carriers, contribute to the effective prevention and control of this epidemic. This review focuses on early stage COVID-19 diagnosis methods and strategies, highlighting the guiding role of laboratory indicators on treatment strategy formulation, and prognosis assessments.     

Differential Responses of CO2 Assimilation,Carbohydrate Allocation and Gene Expression to NaCl Stress in Perennial Ryegrass with Different Salt Tolerance

Little is known about the effects of NaCl stress on perennial ryegrass (Lolium perenne L.) photosynthesis and carbohydrate flux. The objective of this study was to understand the carbohydrate metabolism and identify the gene expression affected by salinity stress. Seventy-four days old seedlings of two perennial ryegrass accessions (salt-sensitive ‘PI 538976’ and salt-tolerant ‘Overdrive’) were subjected to three levels of salinity stress for 5 days. Turf quality in all tissues (leaves, stems and roots) of both grass accessions negatively and significantly correlated with GFS (Glu+Fru+Suc) content, except for ‘Overdrive’ stems. Relative growth rate (RGR) in leaves negatively and significantly correlated with GFS content in ‘Overdrive’ (P<0.01) and ‘PI 538976’ (P<0.05) under salt stress. ‘Overdrive’ had higher CO₂ assimilation and F_v/F_m than ‘PI 538976’. Intercellular CO₂ concentration, however, was higher in ‘PI 538976’ treated with 400 mM NaCl relative to that with 200 mM NaCl. GFS content negatively and significantly correlated with RGR in ‘Overdrive’ and ‘PI 538976’ leaves and in ‘PI 538976’ stems and roots under salt stress. In leaves, carbohydrate allocation negatively and significantly correlated with RGR (r² = 0.83, P<0.01) and turf quality (r² = 0.88, P<0.01) in salt-tolerant ‘Overdrive’, however, the opposite trend for salt-sensitive ‘PI 538976’ (r² = 0.71, P<0.05 for RGR; r² = 0.62, P>0.05 for turf quality). A greater up-regulation in the expression of SPS, SS, SI, 6-SFT gene was observed in ‘Overdrive’ than ‘PI 538976’. A higher level of SPS and SS expression in leaves was found in ‘PI 538976’ relative to ‘Overdrive’. Accumulation of hexoses in roots, stems and leaves can induce a feedback repression to photosynthesis in salt-stressed perennial ryegrass and the salt tolerance may be changed with the carbohydrate allocation in leaves and stems.     

High content image analysis for human H4 neuroglioma cells exposed to CuO nanoparticles

Background  

High content screening (HCS)-based image analysis is becoming an important and widely used research tool. Capitalizing this technology, ample cellular information can be extracted from the high content cellular images. In this study, an automated, reliable and quantitative cellular image analysis system developed in house has been employed to quantify the toxic responses of human H4 neuroglioma cells exposed to metal oxide nanoparticles. This system has been proved to be an essential tool in our study.     

基于二元水循环的黄淮海平原耕地水源涵养功能研究

水源涵养功能是陆地生态系统的重要功能类型之一。黄淮海平原耕地数量巨大,耕地利用模式典型,研究其水源涵养功能,对于调控区域水资源,推动耕地可持续利用有重要作用。从耕地利用角度出发,基于整个系统二元水循环过程,构建了黄淮海平原耕地水源涵养功能研究基本框架,并应用SCS-CN模型,结合研究区耕地覆盖数据、气候数据、土壤数据对黄淮海平原耕地水源涵养功能进行了评价。研究结果表明:耕地利用过程中的耕地水源涵养功能认识,应从理想水源涵养能力、有效水源涵养能力和净水源涵养能力3个层次展开;黄淮海平原耕地水源涵养功能效应在上述各层级上均表现出正向性,耕地水源涵养能力分别为1890.74、1127.76、464.62亿m~3;空间上,黄淮海平原耕地水源涵养功能具有明显的空间分异性,北部和东南部地区耕地水源涵养能力较强,中部和西南部地区耕地水源涵养能力较弱。研究结果不仅为耕地生态功能理论研究提供新思考点,同时也为耕地水资源有效调控以及耕地生态补偿制定提供参考和支撑。     

Diosmetin inhibits osteoclast formation and differentiation and prevents LPS-induced osteolysis in mice

Osteolytic bone diseases are closely linked to the over-activation of osteoclasts and enhancement of bone resorption. It has become a major health issue in orthopedic practice worldwide. Inhibition of osteoclasts is proposed to be the main treatment for osteolytic disorders. Diosmetin (DIO) is a natural flavonoid with properties of antioxidant, anti-infection, and antishock. The effect of DIO on osteoclast differentiation is poorly understood. In this study project, we found that DIO could inhibit osteoclastic formation induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in a dose-dependent manner. The expression of the osteoclast differentiation marker genes, cathepsin K, nuclear factor of activated T-cells 1 (NFATc1), Acp5, Ctr, Atp6v0d2, and Mmp9 were also decreased by the treatment of DIO. In addition, DIO attenuated the formation of actin ring and the ability of bone resorption. Further, the western blotting showed that DIO inhibits the phosphorylation of the mitogen-activated protein kinases signaling pathway induced by RANKL, accompanied by the downregulation of NFATc1 and c-Fos expression. We also found that DIO could reduce the accumulation of reactive oxygen species (ROS) induced by RANKL. In vivo, the study revealed that DIO can significantly reduce LPS-induced osteolysis in mice. Collectively, our study shows that DIO can inhibit osteoclast formation and activation, and could serve as a potential therapeutic drug for osteolytic bone diseases.     

CYLD deficiency promotes pancreatic cancer development by causing mitotic defects

Successful treatment of pancreatic cancer, which has the highest mortality rate among all types of malignancies, has challenged oncologists for decades, and early detection would undoubtedly increase favorable patient outcomes. The identification of proteins involved in pancreatic cancer progression could lead to biomarkers for early detection of this disease. This study identifies one potential candidate, cylindromatosis (CYLD), a deubiquitinase and microtubule-binding protein that plays a suppressive role in pancreatic cancer development. In pancreatic cancer samples, downregulation of CYLD expression resulted from a loss in the copy number of the CYLD gene; additionally, reduced expression of CYLD negatively correlated with the clinicopathological parameters. Further study demonstrated that CYLD deficiency promoted colony formation in vitro and pancreatic cancer growth in vivo. Mechanistic studies revealed that CYLD is essential for spindle orientation and properly oriented cell division; CYLD deficiency resulted in a substantial increase in chromosome missegregation. Taken together, these data indicate a critical role for CYLD in suppressing pancreatic tumorigenesis, implicating its potential as a biomarker for early detection of pancreatic cancer and a prognostic indicator of patient outcomes.     

CYLD Regulates RhoA Activity by Modulating LARG Ubiquitination

Rho family guanosine triphosphatases (GTPases), such as RhoA, Cdc42, and Rac1, play a fundamental role in various cellular processes. The activation of Rho proteins is catalyzed by guanine nucleotide-exchange factors (GEFs), which promote the exchange of GDP for GTP. The precise mechanisms regulating the activation of Rho proteins are not fully understood. Herein, we demonstrate that RhoA activity is regulated by cylindromatosis (CYLD), a deubiquitinase harboring multiple functions. In addition, we find that RhoA-mediated cytoskeletal rearrangement, chromosome separation, and cell polarization are altered in CYLD-depleted cells. Mechanistically, CYLD does not interact with RhoA; instead, it interacts with and deubiquitinates leukemia-associated RhoGEF (LARG). Our data further show that CYLD-mediated deubiquitination of LARG enhances its ability to stimulate the GDP/GTP exchange on RhoA. These data thus identify LARG as a new substrate of CYLD and provide novel insights into the regulation of RhoA activation. Our results also suggest that the LARG-RhoA signaling pathway may play a role in diverse CYLD-mediated cellular events.     

Andrographolide prevents human nucleus pulposus cells against degeneration by inhibiting the NF-κB pathway

Intervertebral disc degeneration (IDD) is among the most common spinal disorders, pathologically characterized by excessive cell apoptosis and production of proinflammatory factors. Pharmacological targeting of nucleus pulposus (NP) degeneration may hold promise in IDD therapy, but it is limited by adverse side effects and nonspecificity of drugs. In this study, we used a natural compound, andrographolide (ANDRO), which has been widely used to intervene inflammatory and apoptotic diseases in the investigation of NP degeneration based on IDD-patients-derived NP cells by lipopolysaccharide (LPS) treatment for the preservation of degeneration. The results showed that LPS maintained the degeneration status of NP cells as evidenced by a high apoptosis rate and the expression of degenerative and inflammatory mediators after LPS treatment. ANDRO reversed the effects of LPS-caused degeneration of NP cells and maintained the phenotype of NP cells, as demonstrated by flow cytometry, degenerative mediators (ADAMTS4 and ADAMTS5), inflammatory factors (COX2, PGE2, MMP-13, and MMP-3), biomarkers of NP cells (SOX9, ACAN, and COL2A1) expressions, and glycosaminoglycan secretion. We also found the involvement of the nuclear factor kappa-light-chain-enhancer of the activated B cells (NF-κB) pathway in ANDRO treatment, indicating that ANDRO prevented the LPS-preserved degeneration of NP cells by inhibiting the NF-κB pathway. This study may provide a reference for clinic medication of IDD therapy.