Comparison of the replication and neutralization of different SARS-CoV-2 Omicron subvariants in vitro

Background:New Omicron subvariants are emerging rapidly from BA.1 to BA.4 and BA.5.Their pathogenicity has changed from that of wild-type(WH-09)and Omicron variants have over time become globally dominant.The spike proteins of BA.4 and BA.5 that serve as the target for vaccine-induced neutralizing antibodies have also changed compared to the previous subvariants,which is likely to cause immune es-cape and the reduction of the protective effect of the vaccine.Our study addresses the above issues and provides a basis for formulating relevant prevention and control strategies.Methods:We collected cellular supernatant and cell lysates and measured the viral titers,viral RNA loads,and E subgenomic RNA(E sgRNA)loads in different Omicron subvariants grown in Vero E6 cells,using WH-09 and Delta variants as a reference.Additionally,we evaluated the in vitro neutralizing activity of different Omicron sub-variants and compared it to the WH-09 and Delta variants using macaque sera with different types of immunity.Results:As the SARS-CoV-2 evolved into Omicron BA.1,the replication ability in vitro began to decrease.Then with the emergence of new subvariants,the replication ability gradually recovered and became stable in the BA.4 and BA.5 subvariants.In WH-09-inactivated vaccine sera,geometric mean titers of neutralization antibodies against different Omicron subvariants declined by 3.7~15.4-fold compared to those against WH-09.In Delta-inactivated vaccine sera,geometric mean titers of neutrali-zation antibodies against Omicron subvariants declined by 3.1~7.4-fold compared to those against Delta.Conclusion:According to the findings of this research,the replication efficiency of all Omicron subvariants declined compared with WH-09 and Delta variants,and was lower in BA.1 than in other Omicron subvariants.After two doses of inactivated(WH-09 or Delta)vaccine,cross-neutralizing activities against various Omicron subvariants were seen despite a decline in neutralizing titers.

PDMS/PEI膜渗透汽化分离正丁醇/乙醇/水的性能及渗透通量关联模型研究

采用聚二甲基硅氧烷/聚醚酰亚胺(PDMS/PEI)膜渗透汽化分离正丁醇/乙醇/水体系,考察进料温度、进料组成等条件对膜渗透汽化分离性能的影响;采用Arrhenius型半经验渗透通量关联模型描述PDMS-PEI膜分离正丁醇/乙醇/水体系膜通量变化。结果表明,当原料液中正丁醇质量分数分别为4.0%、4.5%和5.0%时,正丁醇/乙醇/水三元体系中正丁醇渗透通量分别至少提高14.2%、17.7%和23.4%。渗透通量关联模型能较好地描述PDMS-PEI膜分离正丁醇/乙醇/水体系膜渗透通量变化。

Mesenchymal stem cell-derived small extracellular vesicles in the treatment of human diseases:Progress and prospect

Mesenchymal stem cells(MSCs)are self-renewing,multipotent cells that could differentiate into multiple tissues.MSC-based therapy has become an attractive and promising strategy for treating human diseases through immune regulation and tissue repair.However,accumulating data have indicated that MSC-based therapeutic effects are mainly attributed to the properties of the MSC-sourced secretome,especially small extracellular vesicles(sEVs).sEVs are signaling vehicles in intercellular communication in normal or pathological conditions.sEVs contain natural contents,such as proteins,mRNA,and microRNAs,and transfer these functional contents to adjacent cells or distant cells through the circulatory system.MSC-sEVs have drawn much attention as attractive agents for treating multiple diseases.The properties of MSC-sEVs include stability in circulation,good biocompatibility,and low toxicity and immunogenicity.Moreover,emerging evidence has shown that MSC-sEVs have equal or even better treatment efficacies than MSCs in many kinds of disease.This review summarizes the current research efforts on the use of MSC-sEVs in the treatment of human diseases and the existing challenges in their application from lab to clinical practice that need to be considered.

Age-related rhesus macaque models of COVID-19

Background:Since December 2019,an outbreak of the Corona Virus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus(SARS-CoV-2)in Wuhan,China,has become a public health emergency of international concern.The high fatality of aged cases caused by SARS-CoV-2 was a need to explore the possible age-related phenomena with non-human primate models.Methods:Three 3-5 years old and two 15 years old rhesus macaques were intratracheally infected with SARS-CoV-2,and then analyzed by clinical signs,viral replication,chest X-ray,histopathological changes and immune response.Results:Viral replication of nasopharyngeal swabs,anal swabs and lung in old monkeys was more active than that in young monkeys for 14 days after SARS-CoV-2 challenge.Monkeys developed typical interstitial pneumonia characterized by thickened alveolar septum accompanied with inflammation and edema,notably,old monkeys exhibited diffuse severe interstitial pneumonia.Viral antigens were detected mainly in alveolar epithelial cells and macrophages.Conclusion:SARS-CoV-2 caused more severe interstitial pneumonia in old monkeys than that in young monkeys.Rhesus macaque models infected with SARS-CoV-2 provided insight into the pathogenic mechanism and facilitated the development of vaccines and therapeutics against SARS-CoV-2 infection.

HCCNet： an integrated network database of hepatocellular carcinoma

Dear Editor, As a complex disease, the development and progression of hepatocellular carcinoma （HCC） involves the interactions of multiple proteins, genes and miRNAs in various biological pathways, and it has been extensively studied with different high-throughput techniques. However, efforts to integrate multiple data sources at different levels, especially with regard to biological pathways and interaction networks, are still negligible in the HCC research field.

Sequentially immune-induced antibodies could cross-neutralize SARS-CoV-2 variants

Background:The Omicron(B.1.1.529)SARS-COV-2 variant has raised serious concerns because of its unprecedented rapid rate of spreading and the fact that there are 36 mutations in the spike protein.Since the vaccine-induced neutralizing antibody targets are the spike protein,this may lead to the possibility of vaccine-induced hu-moral immunity escape.Methods:We measured the neutralizing activity in vitro for Omicron and compared this with wild type(WH-09)and Delta variants in human and monkey sera from different types of immunity.The monkey sera samples were collected at 1 and 3 months post three-dose inactivated(PiCoVacc)and recombinant protein(ZF2001)vaccination.Human sera were collected from 1 month post three-dose inactivated vaccination.Results:In inactivated vaccine sera,at 1/3 months post three-dose,geometric mean titers(GMTs)of neutralization antibody(NAb)against the Omicron variant were 4.9/5.2-fold lower than those of the wild type.In recombinant protein vaccine sera,GMTs of NAb against Omicron were 15.7/8.9-fold lower than those of the wild type.In human sera,at 1 month post three-dose inactivated vaccination,GMTs of NAb against Omicron were 3.1-fold lower than those of the wild type.Conclusion:This study demonstrated that despite a reduction in neutralization titers,cross-neutralizing activity against Omicron and Delta variants was still observed after three doses of inactivated and recombinant protein vaccination.

Underlying mechanism of protection from hypoxic injury seen with n-butanol extract of Potentilla anserine L. in hippocampal neurons

The alcohol and n-butanol extract of Potentilla anserine L. significantly protects myocardium from acute ischemic injury. However, its effects on rat hippocampal neurons and the mechanism of protection remain unclear. In this study, primary cultured hippocampal neurons from neonatal rats were incubated in 95% N2 and 5% CO2 for 4 hours. Results indicated that hypoxic injury decreased the viability of neurons, increased the expression levels of caspase-9 and caspase-3 mRNA, as well as cytochrome c, Caspase-9, and Caspase-3 protein. Pretreatment with 0.25, 0.062 5, 0.015 6 mg/mL n-butanol extract of Potentilla anserine L. led to a significant increase in cell viability. Expression levels of caspase-9 and caspase-3 mRNA, as well as cytochrome c, Caspase-9, and Caspase-3 protein, were attenuated. The neuroprotective effect of n-butanol extract of Potentilla anserine L. was equivalent to tanshinone IIA. Our data suggest that the n-butanol extract of Potentilla anserine L. could protect primary hippocampal neurons from hypoxic injury by deactivating mitochondrial cell death.

Sensitivity of SARS-CoV-2 to different temperatures

This study was designed to investigate the sensitivity of SARS-CoV-2 to different temperatures,to provide basic data and a scientific basis for the control of COVID-19 epidemic.The virus was dispersed in 1 mL basal DMEM medium at a final concentration of 103.2 TCID 50/mL and then incubated at 4,22,30,35,37,38,39 and 40°C for up to 5 days.The infectivity of residual virus was titrated using the Vero E6 cell line.The results showed that the virus remained viable for 5 days at 4°C,and for 1 day only at 22 and 30°C.We found that the infectivity of the virus was completely lost after less than 12 hours at 37,38 and 39°C,while at 40°C,the inactivation time of the virus was rapidly reduced to 6 hours.We show that SARS-CoV-2 is sensitive to heat,is more stable at lower temperatures than higher temperature,remains viable for longer at lower temperatures,and loses viability rapidly at higher temperatures.

SARS-CoV-2 infection aggravates chronic comorbidities of cardiovascular diseases and diabetes in mice

Background:Cardiovascular diseases(CVDs)and diabetes mellitus(DM)are top two chronic comorbidities that increase the severity and mortality of COVID-19.However,how SARS-CoV-2 alters the progression of chronic diseases remain unclear.Methods:We used adenovirus to deliver h-ACE2 to lung to enable SARS-CoV-2 infection in mice.SARS-CoV-2’s impacts on pathogenesis of chronic diseases were studied through histopathological,virologic and molecular biology analysis.Results:Pre-existing CVDs resulted in viral invasion,ROS elevation and activation of apoptosis pathways contribute myocardial injury during SARS-CoV-2 infection.Viral infection increased fasting blood glucose and reduced insulin response in DM model.Bone mineral density decreased shortly after infection,which associated with impaired PI3K/AKT/mTOR signaling.Conclusion:We established mouse models mimicked the complex pathological symptoms of COVID-19 patients with chronic diseases.Pre-existing diseases could impair the inflammatory responses to SARS-CoV-2 infection,which further aggravated the pre-existing diseases.This work provided valuable information to better understand the interplay between the primary diseases and SARS-CoV-2 infection.

Mechanical Strain Regulates Osteoblast Proliferation Through Ca^(2+)-CaMK-CREB Signal Pathway

Objective To investigate the effects of mechanical strain on Ca^(2+)-calmodulin dependent kinase(CaMK)-cA MP response element binding protein(CREB) signal pathway and proliferation of osteoblasts. Methods Using a four-point bending device, MC3T3-E1 cells were exposed to mechanical tensile strains of 2500 μs and 5000 μs at 0.5 Hz respectively. The intracellular free Ca^(2+)([Ca^(2+)]i) concentration and calmodulin activity were assayed by fluorospectrophotometry, CaMK II β, CREB, and phosphorylated(activated) CREB(p-CREB) were assessed by Western blot, and cells proliferation was assayed with MTT. Pretreatment with verapamil was carried out to block Ca^(2+) channel, and inhibitor U73122 was used to inhibit phospholipase C(PLC). Results Mechanical strains of 2500 μs and 5000 μs for 1 to 10 minutes both increased [Ca^(2+)]i level of the cells. The 2500 μs strain, a periodicity of 1 h/d for 3 days, activated calmodulin, elevated protein levels of CaMK II β and p-CREB, and promoted cells proliferation, which were attenuated by pretreatment of verapamil or U73122. The effects of 5000 μs strain on calmodulin, CaMK II β, p-CREB and proliferation were contrary to 2500 μs strain. Conclusion The mechanical strain regulates osteoblasts proliferation through Ca^(2+)-Ca MK-CREB signal pathway via Ca^(2+) channel and PLC/IP_3 transduction cascades.

RIG-I,a novel DAMPs sensor for myoglobin,activates NF-κB/caspase-3 signaling in CS-AKI model

Background:Acute kidney injury(AKI)is the main life-threatening complication of crush syndrome(CS),and myoglobin is accepted as the main pathogenic factor.The pattern recognition receptor retinoicacid-inducible gene I(RIG-I)has been reported to exert anti-viral effects function in the innate immune response.However,it is not clear whether RIG-I plays a role in CS-AKI.The present research was carried out to explore the role of RIG-I in CS-AKI.Methods:Sprague-Dawley rats were randomly divided into two groups:the sham and CS groups(n=12).After administration of anesthesia,the double hind limbs of rats in the CS group were put under a pressure of 3 kg for 16 h to mimic crush conditions.The rats in both groups were denied access to food and water.Rats were sacrificed at 12 h or 36 h after pressure was relieved.The successful establishment of the CS-AKI model was confirmed by serum biochemical analysis and renal histological examination.In addition,RNA sequencing was performed on rat kidney tissue to identify molecular pathways involved in CS-AKI.Furthermore,NRK-52 E cells were treated with 200μmol/L ferrous myoglobin to mimic CS-AKI at the cellular level.The cells and cell supernatant samples were collected at 6 h or 24 h.Small interfering RNAs(siRNA)was used to knock down RIG-I expression.The relative expression levels of molecules involved in the RIG-I pathway in rat kidney or cells samples were measured by quantitative real-time PCR(qPCR),Western blotting analysis,and immunohistochemistry(IHC)staining.Tumor necrosis factor-α(TNF-α)was d etected by ELISA.Co-immunoprecipitation(Co-IP)assays were used to detect the interaction between RIG-I and myoglobin.Results:RNA sequencing of CS-AKI rat kidney tissue revealed that the different expression of RIG-I signaling pathway.qPCR,Western blotting,and IHC assays showed that RIG-I,nuclear factor kappa-B(NF-κB)P65,p-P65,and the a poptotic marker caspase-3 and cleaved caspase-3 were up-regulated in the CS group(P<0.05).However,the levels of interferon regulatory factor 3(IRF3),p-IRF3 and the antiviral factor interferon-beta(IFN-β)showed no significant c hanges between the sham and CS groups.Co-IP assays showed the interaction between RIG-I and myoglobin in the kidneys of the CS group.Depletion of RIG-I could alleviate the myoglobin induced expression of apoptosis-associated molecules via the NF-κB/caspase-3 axis.C onclusions:RIG-I is a novel damage-associated molecular patterns(DAMPs)sensor for myoglobin and participates in the NF-κB/caspase-3 signaling pathway in CS-AKI.In the development of CS-AKI,specific intervention in the RIG-I p athway might be a potential therapeutic strategy for CS-AKI.

The characteristics of hDPP4 transgenic mice subjected to aerosol MERS coronavirus infection via an animal nose-only exposure device

Background: Middle East respiratory syndrome coronavirus(MERS-Co V), which is not fully understood in regard to certain transmission routes and pathogenesis and lacks specific therapeutics and vaccines, poses a global threat to public health.Methods: To simulate the clinical aerosol transmission route, h DPP4 transgenic mice were infected with MERS-Co V by an animal nose-only exposure device and compared with instillation-inoculated mice. The challenged mice were observed for 14 consecutive days and necropsied on days 3, 5, 7, and 9 to analyze viral load, histopathology, viral antigen distribution, and cytokines in tissues.Results: MERS-Co V aerosol-infected mice with an incubation period of 5-7 days showed weight loss on days 7-11, obvious lung lesions on day 7, high viral loads in the lungs on days 3-9 and in the brain on days 7-9, and 60% survival. MERS-Co V instillation-inoculated mice exhibited clinical signs on day 1, obvious lung lesions on days 3-5, continuous weight loss, 0% survival by day 5, and high viral loads in the lungs and brain on days 3-5. Viral antigen and high levels of proinflammatory cytokines and chemokines were detected in the aerosol and instillation groups. Disease, lung lesion, and viral replication progressions were slower in the MERS-Co V aerosol-infected mice than in the MERS-Co V instillation-inoculated mice.Conclusion: h DPP4 transgenic mice were successfully infected with MERS-Co V aerosols via an animal nose-only exposure device, and aerosol-and instillation-infected mice simulated the clinical symptoms of moderate diffuse interstitial pneumonia. However, the transgenic mice exposed to aerosol MERS-Co V developed disease and lung pathology progressions that more closely resembled those observed in humans.

甲苯选择氧化制苯甲醛工艺及催化剂研究进展

介绍了当前甲苯选择氧化制苯甲醛的主要方法——液相氧化法、气相氧化法;重点综述了近年来相应催化剂的研究进展,并为研发高效绿色催化剂以及气相氧化法工艺工业化指明方向。

Infection with SARS-CoV-2 can cause pancreatic impairment

Evidence suggests associations between COVID-19 patients or vaccines and glycometabolic dysfunction and an even higher risk of the occurrence of diabetes.Herein,we retrospectively analyzed pancreatic lesions in autopsy tissues from 67 SARS-CoV-2 infected non-human primates(NHPs)models and 121 vaccinated and infected NHPs from 2020 to 2023 and COVID-19 patients.Multi-label immunofluorescence revealed direct infection of both exocrine and endocrine pancreatic cells by the virus in NHPs and humans.Minor and limited phenotypic and histopathological changes were observed in adult models.Systemic proteomics and metabolomics results indicated metabolic disorders,mainly enriched in insulin resistance pathways,in infected adult NHPs,along with elevated fasting C-peptide and C-peptide/glucose ratio levels.Furthermore,in elder COVID-19 NHPs,SARS-CoV-2 infection causes loss of beta(β)cells and lower expressed-insulin in situ characterized by islet amyloidosis and necrosis,activation ofα-SMA and aggravated fibrosis consisting of lower collagen in serum,an increase of pancreatic inflammation and stress markers,ICAM-1 and G3BP1,along with more severe glycometabolic dysfunction.In contrast,vaccination maintained glucose homeostasis by activating insulin receptorαand insulin receptorβ.Overall,the cumulative risk of diabetes post-COVID-19 is closely tied to age,suggesting more attention should be paid to blood sugar management in elderly COVID-19 patients.

The nodule-specific transcriptional repressor Top Hub 4 regulates nodule structure and nitrogen fixation capacity in soybean

Most leguminous plants establish symbiotic relationships with rhizobia to form root organs called nodules(Ferguson et al.,2010).Nodules are specialized organs containing bacterial symbionts,which can provide enormous amounts of fixed nitrogen to their plant hosts(Peoples et al.,2009).Soybean(Glycine max),an economically important grain and oil crop,forms symbiotic nitrogen-fixing nodules,which reduces the demand for chemical nitrogen fertilizers and promotes yield(Saito et al.,2014).Nodule development is spatiotemporally regulated by the action of a number of transcription factors(TFs).

Lonicerin targets EZH2 to alleviate ulcerative colitis by autophagy-mediated NLRP3 inflammasome inactivation

Aberrant activation of NLRP3 inflammasome in colonic macrophages strongly associates with the occurrence and progression of ulcerative colitis.Although targeting NLRP3 inflammasome has been considered to be a potential therapy,the underlying mechanism through which pathway the intestinal inflammation is modulated remains controversial.By focusing on the flavonoid lonicerin,one of the most abundant constituents existed in a long historical anti-inflammatory and anti-infectious herb Lonicera japonica Thunb.,here we report its therapeutic effect on intestinal inflammation by binding directly to enhancer of zeste homolog 2(EZH2)histone methyltransferase.EZH2-mediated modification of H3 K27 me3 promotes the expression of autophagy-related protein 5,which in turn leads to enhanced autophagy and accelerates autolysosome-mediated NLRP3 degradation.Mutations of EZH2 residues(His 129 and Arg685)indicated by the dynamic simulation study have found to greatly diminish the protective effect of lonicerin.More importantly,in vivo studies verify that lonicerin dose-dependently disrupts the NLRP3-ASC-pro-caspase-1 complex assembly and alleviates colitis,which is compromised by administration of EZH2 overexpression plasmid.Thus,these findings together put forth the stage for further considering lonicerin as an anti-inflammatory epigenetic agent and suggesting EZH2/ATG5/NLRP3 axis may serve as a novel strategy to prevent ulcerative colitis as well as other inflammatory diseases.

Repurposing carrimycin as an antiviral agent against human coronaviruses,including the currently pandemic SARS-CoV-2

COVID-19 pandemic caused by SARS-CoV-2 infection severely threatens global health and economic development.No effective antiviral drug is currently available to treat COVID-19 and any other human coronavirus infections.We report herein that a macrolide antibiotic,carrimycin,potently inhibited the cytopathic effects(CPE)and reduced the levels of viral protein and RNA in multiple cell types infected by human coronavirus 229 E,OC43,and SARS-CoV-2.Time-of-addition and pseudotype virus infection studies indicated that carrimycin inhibited one or multiple post-entry replication events of human coronavirus infection.In support of this notion,metabolic labelling studies showed that carrimycin significantly inhibited the synthesis of viral RNA.Our studies thus strongly suggest that carrimycin is an antiviral agent against a broad-spectrum of human coronaviruses and its therapeutic efficacy to COVID-19 is currently under clinical investigation.

SARS-CoV-2 crosses the blood-brain barrier accompanied with basement membrane disruption without tight junctions alteration

SARS-CoV-2 has been reported to show a capacity for invading the brains of humans and model animals.However,it remains undear whether and how SARS-CoV-2 crosses the blood-brain barrier(BBB).Herein,SARS-CoV-2 RNA was occasionally detected in the vascular wall and perivascular space,as well as in brain microvascular endothelial cells(BMECs)in the infected K18-hACE2 transgenic mice.Moreover,the permeability of the infected vessel was in creased.Furthermore,disin tegrity of BBB was discovered in the infected hamsters by administration of Evans blue.Interestingly,the expression of claudin5,ZO-1,occludin and the ultrastructure of tight junctions(TJs)showed unchanged,whereas,the basement membrane was disrupted in the infected animals.Using an in vitro BBB model that comprises primary BMECs with astrocytes,SARS-CoV-2 was found to infect and cross through the BMECs.Consistent with in vivo experiments,the expression of MMP9 was increased and collagen IV was decreased while the markers for TJs were not altered in the SARS-CoV-2-infected BMECs.Besides,inflammatory responses including vasculitis,glial activation,and upregulated inflammatory factors occurred after SARS-CoV-2 infection.Overall,our results provide evidence supporting that SARS-CoV-2 can cross the BBB in a transcellular pathway accompanied with basement membrane disrupted without obvious alteration of TJs.

Therapeutic efficacy of Pudilan Xiaoyan Oral Liquid(PDL)for COVID-19 in vitro and in vivo

Dear Editor,Coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus-2(SARS-CoV-2),has rapidly swept through the worldwide,with more than 3 million confirmed cases.Until now,no vaccine or effective therapeutic measures are provided to prevent the SARS-CoV-2 infection.Existing medicines have some strong advantages on pharmacokinetics,known side effects,safety and dosing regimens.1 Although remdesivir and chloroquine could effectively inhibit the replication of SARS-CoV-2 in vitro,2 no medicine candidates have been evaluated in vivo by using animal models with SARS-CoV-2 infection.

Sequential infection with H1N1 and SARS-CoV-2 aggravated COVID-19 pathogenesis in a mammalian model, and covaccination as an effective method of prevention of COVID-19 and influenza

Influenza A virus may circulate simultaneously with the SARS-CoV-2 virus,leading to more serious respiratory diseases during this winter.However,the influence of these viruses on disease outcome when both influenza A and SARS-CoV-2 are present in the host remains unclear.Using a mammalian model,sequential infection was performed in ferrets and in K18-MCE2 mice,with SARS-CoV-2 infection following H1N1.We found that co-infection with H1N1 and SARS-CoV-2 extended the duration of clinical manifestation of COVID-19,and enhanced pulmonary damage,but reduced viral shedding of throat swabs and viral loads in the lungs of ferrets.Moreover,mortality was increased in sequentially infected mice compared with single-infection mice.Compared with singlevaccine inoculation,co-inoculation of PiCoVacc(a SARS-CoV-2 vaccine)and the flu vaccine showed no significant differences in neutralizing antibody titers or virus-specific immune responses.Combined immunization effectively protected K18-MCE2 mice against both H1N1 and SARS-CoV-2 infection.Our findings indicated the development of systematic models of co-infection of H1N1 and SARS-CoV-2,which together notably enhanced pneumonia in ferrets and mice,as well as demonstrated that simultaneous vaccination against HINT and SARS-CoV-2 may be an effective prevention strategy for the coming winter.