Thrombosis and inflammation are primary contributors to the onset and progression of ischemic stroke.The contact-kinin pathway,initiated by plasma kallikrein(PK)and activated factor XII(FXIIa),functions bidirectionall...Thrombosis and inflammation are primary contributors to the onset and progression of ischemic stroke.The contact-kinin pathway,initiated by plasma kallikrein(PK)and activated factor XII(FXIIa),functions bidirectionally with the coagulation and inflammation cascades,providing a novel target for therapeutic drug development in ischemic stroke.In this study,we identified a bat-derived oligopeptide from Myotis myotis(Borkhausen,1797),designated LE6(Leu-Ser-Glu-Glu-Pro-Glu,702 Da),with considerable potential in stroke therapy due to its effects on the contact kinin pathway.Notably,LE6 demonstrated significant inhibitory effects on PK and FXIIa,with inhibition constants of 43.97μmol/L and 6.37μmol/L,respectively.In vitro analyses revealed that LE6 prolonged plasma recalcification time and activated partial thromboplastin time.In murine models,LE6 effectively inhibited carrageenan-induced mouse tail thrombosis,FeCl3-induced carotid artery thrombosis,and photochemically induced intracerebral thrombosis.Furthermore,LE6 significantly decreased inflammation and stroke injury in transient middle cerebral artery occlusion models.Notably,the low toxicity,hemolytic activity,and bleeding risk of LE6,along with its synthetic simplicity,underscore its clinical applicability.In conclusion,as an inhibitor of FXIIa and PK,LE6 offers potential therapeutic benefits in stroke treatment by mitigating inflammation and preventing thrombus formation.展开更多
Prof.Yun Zhang was born on 9 July 1963 in Kunming,Yunnan,China,during a tumultuous period which he often referenced.Throughout his life,he harbored a steadfast belief in using knowledge to unravel the mysteries of hum...Prof.Yun Zhang was born on 9 July 1963 in Kunming,Yunnan,China,during a tumultuous period which he often referenced.Throughout his life,he harbored a steadfast belief in using knowledge to unravel the mysteries of human diseases.His educational journey was marked by frequent changes in schools due to his parents’occupational relocations.However,despite these challenges,he consistently displayed diligence and was admitted to the East China University of Science and Technology,Shanghai,after completing high school in 1980.He remained an active and loyal member of the School of Biotechnology at the university.展开更多
The recalcitrance of pathogens to traditional antibiotics has made treating and eradicating bacterial infections more difficult.In this regard,developing new antimicrobial agents to combat antibiotic-resistant strains...The recalcitrance of pathogens to traditional antibiotics has made treating and eradicating bacterial infections more difficult.In this regard,developing new antimicrobial agents to combat antibiotic-resistant strains has become a top priority.Antimicrobial peptides(AMPs),a ubiquitous class of naturally occurring compounds with broadspectrum antipathogenic activity,hold significant promise as an effective solution to the current antimicrobial resistance(AMR)crisis.Several AMPs have been identified and evaluated for their therapeutic application,with many already in the drug development pipeline.Their distinct properties,such as high target specificity,potency,and ability to bypass microbial resistance mechanisms,make AMPs a promising alternative to traditional antibiotics.Nonetheless,several challenges,such as high toxicity,lability to proteolytic degradation,low stability,poor pharmacokinetics,and high production costs,continue to hamper their clinical applicability.Therefore,recent research has focused on optimizing the properties of AMPs to improve their performance.By understanding the physicochemical properties of AMPs that correspond to their activity,such as amphipathicity,hydrophobicity,structural conformation,amino acid distribution,and composition,researchers can design AMPs with desired and improved performance.In this review,we highlight some of the key strategies used to optimize the performance of AMPs,including rational design and de novo synthesis.We also discuss the growing role of predictive computational tools,utilizing artificial intelligence and machine learning,in the design and synthesis of highly efficacious lead drug candidates.展开更多
The discovery of antibiotics marked a golden age in the revolution of human medicine. However,decades later, bacterial infections remain a global healthcare threat, and a return to the pre-antibiotic era seems inevita...The discovery of antibiotics marked a golden age in the revolution of human medicine. However,decades later, bacterial infections remain a global healthcare threat, and a return to the pre-antibiotic era seems inevitable if stringent measures are not adopted to curb the rapid emergence and spread of multidrug resistance and the indiscriminate use of antibiotics. In hospital settings, multidrug resistant(MDR) pathogens, including carbapenem-resistant Pseudomonas aeruginosa, vancomycin-resistant enterococci(VRE), methicillin-resistant Staphylococcus aureus(MRSA), and extendedspectrum β-lactamases(ESBL) bearing Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae are amongst the most problematic due to the paucity of treatment options,increased hospital stay, and exorbitant medical costs. Antimicrobial peptides(AMPs) provide an excellent potential strategy for combating these threats. Compared to empirical antibiotics, they show low tendency to select for resistance, rapid killing action, broad-spectrum activity, and extraordinary clinical efficacy against several MDR strains. Therefore, this review highlights multidrug resistance among nosocomial bacterial pathogens and its implications and reiterates the importance of AMPs as next-generation antibiotics for combating MDR superbugs.展开更多
Protease inhibitors have been reported rarely from the leech Hirudinaria manillensis.In this study,we purified a novel protease inhibitor(bdellin-HM-2)with anticoagulant properties from H.manillensis.With a molecular ...Protease inhibitors have been reported rarely from the leech Hirudinaria manillensis.In this study,we purified a novel protease inhibitor(bdellin-HM-2)with anticoagulant properties from H.manillensis.With a molecular weight of 1.4x104,bdellin-HM-2 was also characterized with three intra?molecular disulfide bridges at the N-terminus and multiple HHXDD and HXDD motifs at theC-terminus.cDNAcloning revealed that the putative nucleotide-encoding protein of bdellin-HM-2 contained 132 ami no acids and was encoded by a 399 bp open reading frame(ORF).Sequence alignment showed that bdellin-HM-2 shared similarity with the“non-classical"Kazal-type serine protease inhibitors,but had no inhibitory effect on trypsin,elastase,chymotrypsin,kallikrein,factor Xlla(FXIIa),factor Xia(FXIa),factor Xa(FXa),thrombin,or plasmin.Bdellin-HM-2 showed anticoagulant effects by proIonging the activated partial thromboplastin time(aPTT),indicating a role in enabling H.manillensis to obtain a blood meal from its host.Our results suggest that bdellin-HM丒2 may play a crucial role in blood-sucking in this leech species and may be a pote ntial can didate for the development of clinical anti-thrombotic drugs.展开更多
Endosymbionts influence many aspects of their hosts’ health conditions, including physiology, development, immunity, metabolism, etc. Tree shrews(Tupaia belangeri chinensis) have attracted increasing attention in mod...Endosymbionts influence many aspects of their hosts’ health conditions, including physiology, development, immunity, metabolism, etc. Tree shrews(Tupaia belangeri chinensis) have attracted increasing attention in modeling human diseases and therapeutic responses due to their close relationship with primates. To clarify the situation of symbiotic bacteria from their body surface, oral cavity, and anus, 12 wild and 12 the third generation of captive tree shrews were examined. Based on morphological and cultural characteristics, physiological and biochemical tests, as well as the 16 S rDNA full sequence analysis, 12 bacteria strains were isolated and identified from the wild tree shrews: body surface: Bacillus subtilis(detection rate 42%), Pseudomonas aeruginosa(25%), Staphlococcus aureus(33%), S. Epidermidis(75%), Micrococcus luteus(25%), Kurthia gibsonii(17%); oral cavity: Neisseria mucosa(58%), Streptococcus pneumonia(17%); anus: Enterococcus faecalis(17%), Lactococus lactis(33%), Escherichia coli(92%), Salmonella typhosa(17%); whereas, four were indentified from the third generation captive tree shrews: body surface: S. epidermidis(75%); oral cavity: N.mucosa(67%); anus: L. lactis(33%), E. coli(100%). These results indicate that S. epidermidis, N. mucosa, L. lactis and E. coli were major bacteria in tree shrews, whereas, S. aureus, M. luteus, K. gibsonii, E. faecalis and S. typhosa were species-specific flora. This study facilitates the future use of tree shrews as a standard experimental animal and improves our understanding of the relationship between endosymbionts and their hosts.展开更多
As a group of intestinal hormones and neurotransmitters, cholecystokinins（CCKs） regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally...As a group of intestinal hormones and neurotransmitters, cholecystokinins（CCKs） regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally contain a DYMGWMDFG sequence at the C-terminus. Many CCKs have been reported in mammals. However, only a few have been reported in amphibians, such as Hyla nigrovittata, Xenopus laevis, and Rana catesbeiana, with none reported in urodele amphibians like newts and salamanders. Here, a CCK called CCK-TV was identified and characterized from the skin of the salamander Tylototriton verrucosus. This CCK contained an amino acid sequence of DYMGWMDF-NH2 as seen in other CCKs. A c DNA encoding the CCK precursor containing 129 amino acid residues was cloned from the c DNA library of T. verrucosus skin. The CCK-TV had the potential to induce the contraction of smooth muscle strips isolated from porcine gallbladder, eliciting contraction at a concentration of 5.0x10-11 mol/L and inducing maximal contraction at a concentration of 2.0x10-6 mol/L. The EC50 was 13.6 nmol/L. To the best of our knowledge, this is the first report to identify the presence of a CCK in an urodele amphibian.展开更多
The global outbreak of coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),as of 8 May 2021,has surpassed 150700000 infections and 3279000 deaths worldwide...The global outbreak of coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),as of 8 May 2021,has surpassed 150700000 infections and 3279000 deaths worldwide.Evidence indicates that SARS-CoV-2 RNA can be detected on particulate matter(PM),and COVID-19 cases are correlated with levels of air pollutants.However,the mechanisms of PM involvement in the spread of SARS-CoV-2 remain poorly understood.Here,we found that PM exposure increased the expression level of angiotensin-converting enzyme 2(ACE2)and transmembrane serine protease 2(TMPRSS2)in several epithelial cells and increased the adsorption of the SARS-CoV-2 spike protein.Instillation of PM in a hACE2 mouse model significantly increased the expression of ACE2 and Tmprss2 and viral replication in the lungs.Furthermore,PM exacerbated the pulmonary lesions caused by SARS-CoV-2 infection in the hACE2 mice.In conclusion,our study demonstrated that PM is an epidemiological factor of COVID-19,emphasizing the necessity of wearing anti-PM masks to cope with this global pandemic.展开更多
Various bio-active substances in amphibian skins play important roles in survival of the amphibians.Many protease inhibitor peptides have been identified from amphibian skins,which are supposed to negatively modulate ...Various bio-active substances in amphibian skins play important roles in survival of the amphibians.Many protease inhibitor peptides have been identified from amphibian skins,which are supposed to negatively modulate the activity of proteases to avoid premature degradation or release of skin peptides,or to inhibit extracellular proteases produced by invading bacteria.However,there is no information on the proteinase inhibitors from the frog Lepidobatrachus laevis which is unique in South America.In this work,a cDNA encoding a novel trypsin inhibitor-like(TIL)cysteine-rich peptide was identified from the skin cDNA library of L.laevis.The 240-bp coding region encodes an 80-amino acid residue precursor protein containing 10 half-cysteines.By sequence comparison and signal peptide prediction,the precursor was predicted to release a 55-amino acid mature peptide with amino acid sequence,IRCPKDKIYKFCGSPCPPSCKDLTPNCIAVCKKGCFCRDGTVDNNHGKCVKKENC.The mature peptide was named LL-TIL.LL-TIL shares significant domain similarity with the peptides from the TIL supper family.Antimicrobial and trypsin-inhibitory abilities of recombinant LL-TIL were tested.Recombinant LL-TIL showed no antimicrobial activity,while it had trypsin-inhibiting activity with aKi of 16.5178 lM.These results suggested there was TIL peptide with proteinase-inhibiting activity in the skin of frog L.laevis.To the best of our knowledge,this is the first report of TIL peptide from frog skin.展开更多
Cathelicidin Pc-CATH1 is a cathelicidin-derived myeloid antimicrobial peptide identified from Phasianus colchicus with strong antimicrobial activity against most of bacteria and fungi tested,including the clinically i...Cathelicidin Pc-CATH1 is a cathelicidin-derived myeloid antimicrobial peptide identified from Phasianus colchicus with strong antimicrobial activity against most of bacteria and fungi tested,including the clinically isolated(IS)drug-resistant strains.Considering the uniform distribution of net positive charge in both C-and N-terminus sequence of cathelicidin Pc-CATH1 and most of hydrophobic amino acid(aa)residues positioned in middle of the sequence,the antimicrobial peptide was used to investigate the structure-function relationship by truncating gradually N-or C-terminus amino acid residue.More than 10 modified peptide homo-logues(20-26 aa length)of cathelicidin Pc-CATH1 were found to keep strong antimicrobial abilities.The possible relationships between bioactivities including antimicrobial and hemolytic abilities,components of secondary structure,hydrophobicity,amphipathicity,net charge,and sequence length were investigated.The current work provided suggestions for structural and functional modification of linear,α-helical antimicrobial peptides containing no disulfided bridges.展开更多
Cross-talks (e.g., host-driven iron withdrawal and microbial iron uptake between host gastrointestinal tract and commensal microbes) regulate immunotolerance and intestinal homeostasis. However, underlying mechanisms ...Cross-talks (e.g., host-driven iron withdrawal and microbial iron uptake between host gastrointestinal tract and commensal microbes) regulate immunotolerance and intestinal homeostasis. However, underlying mechanisms that regulate the cross-talks remain poorly understood. Here, we show that bacterial products up-regulate iron-transporter transferrin and transferrin acts as an immunosuppressor by interacting with cluster of differentiation 14 (CD14) to inhibit pattern recognition receptor (PRR) signaling and induce host immunotolerance. Decreased intestinal transferrin is found in germ-free mice and human patients with ulcerative colitis, which are characterized by impaired intestinal immunotolerance. Intestinal transferrin and host immunotolerance are returned to normal when germ-free mice get normal microbial commensalism, suggesting an association between microbial commensalism, transferrin, and host immunotolerance. Mouse colitis models show that transferrin shortage impairs host’s tolerogenic responses, while its supplementation promotes immunotolerance. Designed peptide blocking transferrin–CD14 interaction inhibits immunosuppressive effects of transferrin. In monkeys with idiopathic chronic diarrhea, transferrin shows comparable or even better therapeutic effects than hydrocortisone. Our findings reveal that by up-regulating host transferrin to silence PRR signaling, commensal bacteria counteract immune activation induced by themselves to shape host immunity and contribute for intestinal tolerance.展开更多
Bacterial DNA(bacDNA) is frequently found in serum of patient with ulcerative colitis(UC) and Crohn's disease, even blood bacterial culture is negative. How bacDNA evades immune elimination and is translocated int...Bacterial DNA(bacDNA) is frequently found in serum of patient with ulcerative colitis(UC) and Crohn's disease, even blood bacterial culture is negative. How bacDNA evades immune elimination and is translocated into blood remain unclear. Here, we showed that bacDNA avoids elimination and disables bacteriakilling function of antimicrobial peptide LL-37(Cramp in mice) by forming complex with LL-37, which is inducible after culture with bacteria or bacterial products. Elevated LL-37-bacDNA complex was found in plasma and lesions of patients with UC. LL-37-bacDNA promoted inflammation by inducing Th1, Th2 and Th17 differentiation and activating toll-like receptor-9(TLR9). The complex also increased paracellular permeability, which possibly combines its inflammatory effects to promote local damage and bacDNA translocation into blood. Cramp-bacDNA aggravated mouse colitis severity while interference with the complex ameliorated the disease. The study identifies that inflammatogenic bacDNA utilizes LL-37 as a vehicle for blood translocation and to evade immune elimination. Additionally, bacteria may make a milieu by releasing bacDNA to utilize and resist host antimicrobial peptides as a ‘trojan horse'.展开更多
Dear Editor,The Ras superfamily of GTPases are conserved in eukary?otes from yeast to humans,and play essential roles in the regulation of a variety of key cellular processes,including cell differentiation and prolife...Dear Editor,The Ras superfamily of GTPases are conserved in eukary?otes from yeast to humans,and play essential roles in the regulation of a variety of key cellular processes,including cell differentiation and proliferation,membrane trafficking,nuclear import and export,cytoskeletal remodeling and mitogenic signaling(Karnoub and Weinberg,2008).Notably,numerous studies have shown that many members of the Ras-related small GTPases are involved in diverse aspects of tumorigenesis and tumor progress!on(Chen et al.,2014;Liu et al.,2017).展开更多
Unlike healthy, non-transformed cells, the proteostasis network of cancer cells is taxed to produce proteins involved in tumor development. Cancer cells have a higher dependency on molecular chaperones to maintain pro...Unlike healthy, non-transformed cells, the proteostasis network of cancer cells is taxed to produce proteins involved in tumor development. Cancer cells have a higher dependency on molecular chaperones to maintain proteostasis. The chaperonin T-complex protein ring complex(TRiC) contains eight paralogous subunits(CCT1-8), and assists the folding of as many as 10% of cytosolic proteome.TRiC is essential for the progression of some cancers, but the roles of TRiC subunits in osteosarcoma remain to be explored. Here, we show that CCT4/TRiC is significantly correlated in human osteosarcoma,and plays a critical role in osteosarcoma cell survival. We identify a compound anticarin-β that can specifically bind to and inhibit CCT4. Anticarin-β shows higher selectivity in cancer cells than in normal cells. Mechanistically, anticarin-β potently impedes CCT4-mediated STAT3 maturation. Anticarin-β displays remarkable antitumor efficacy in orthotopic and patient-derived xenograft models of osteosarcoma.Collectively, our data uncover a key role of CCT4 in osteosarcoma, and propose a promising treatment strategy for osteosarcoma by disrupting CCT4 and proteostasis.展开更多
Dear editor,To date,a number of clinically approved drugs have been evaluated for potential to treat coronavirus disease 2019(COVID-19),such as lopinavir/ritonavir,hydroxychloroquine,cobicistat,and darunavir.Some of t...Dear editor,To date,a number of clinically approved drugs have been evaluated for potential to treat coronavirus disease 2019(COVID-19),such as lopinavir/ritonavir,hydroxychloroquine,cobicistat,and darunavir.Some of these drugs have been proven to be effective in vitro;however,clinical trials showed that none of these compounds led to a significant improvement in symptoms or length of hospitalization.Thus,it is essential and more reliable to start from a defined target to ide ntify can didate drugs.展开更多
基金supported by the National Natural Science Foundation of China(32200397,23SWAQ09,and 31930015)Yunnan Province Grant(202302AA310032,202302AA310035,and 202003AD150008)+5 种基金Ministry of Science and Technology of China(2018YFA0801403)Chinese Academy of Sciences(SAJC202103 and KFJ-BRP-008-003)New Cornerstone Investigator Program(NCI202238)Kunming Science and Technology Bureau(2022SCP007)Priority Union Foundation of Yunnan Provincial Science and Technology Department and Kunming Medical University(202101AC070461)Basic Research Program of Yunnan Province Science and Technology Department(202301AT070083)。
文摘Thrombosis and inflammation are primary contributors to the onset and progression of ischemic stroke.The contact-kinin pathway,initiated by plasma kallikrein(PK)and activated factor XII(FXIIa),functions bidirectionally with the coagulation and inflammation cascades,providing a novel target for therapeutic drug development in ischemic stroke.In this study,we identified a bat-derived oligopeptide from Myotis myotis(Borkhausen,1797),designated LE6(Leu-Ser-Glu-Glu-Pro-Glu,702 Da),with considerable potential in stroke therapy due to its effects on the contact kinin pathway.Notably,LE6 demonstrated significant inhibitory effects on PK and FXIIa,with inhibition constants of 43.97μmol/L and 6.37μmol/L,respectively.In vitro analyses revealed that LE6 prolonged plasma recalcification time and activated partial thromboplastin time.In murine models,LE6 effectively inhibited carrageenan-induced mouse tail thrombosis,FeCl3-induced carotid artery thrombosis,and photochemically induced intracerebral thrombosis.Furthermore,LE6 significantly decreased inflammation and stroke injury in transient middle cerebral artery occlusion models.Notably,the low toxicity,hemolytic activity,and bleeding risk of LE6,along with its synthetic simplicity,underscore its clinical applicability.In conclusion,as an inhibitor of FXIIa and PK,LE6 offers potential therapeutic benefits in stroke treatment by mitigating inflammation and preventing thrombus formation.
文摘Prof.Yun Zhang was born on 9 July 1963 in Kunming,Yunnan,China,during a tumultuous period which he often referenced.Throughout his life,he harbored a steadfast belief in using knowledge to unravel the mysteries of human diseases.His educational journey was marked by frequent changes in schools due to his parents’occupational relocations.However,despite these challenges,he consistently displayed diligence and was admitted to the East China University of Science and Technology,Shanghai,after completing high school in 1980.He remained an active and loyal member of the School of Biotechnology at the university.
基金This work was supported by the National Natural Science Foundation of China(31930015,32200397)Ministry of Science and Technology of China(2018YFA0801403)+3 种基金Chinese Academy of Sciences(XDB31000000,KFJ-BRP-008-003)Yunnan Province Grant(202003AD150008,202002AA100007)Kunming Science and Technology Bureau(2023SCP001)New Cornerstone Investigator Program。
文摘The recalcitrance of pathogens to traditional antibiotics has made treating and eradicating bacterial infections more difficult.In this regard,developing new antimicrobial agents to combat antibiotic-resistant strains has become a top priority.Antimicrobial peptides(AMPs),a ubiquitous class of naturally occurring compounds with broadspectrum antipathogenic activity,hold significant promise as an effective solution to the current antimicrobial resistance(AMR)crisis.Several AMPs have been identified and evaluated for their therapeutic application,with many already in the drug development pipeline.Their distinct properties,such as high target specificity,potency,and ability to bypass microbial resistance mechanisms,make AMPs a promising alternative to traditional antibiotics.Nonetheless,several challenges,such as high toxicity,lability to proteolytic degradation,low stability,poor pharmacokinetics,and high production costs,continue to hamper their clinical applicability.Therefore,recent research has focused on optimizing the properties of AMPs to improve their performance.By understanding the physicochemical properties of AMPs that correspond to their activity,such as amphipathicity,hydrophobicity,structural conformation,amino acid distribution,and composition,researchers can design AMPs with desired and improved performance.In this review,we highlight some of the key strategies used to optimize the performance of AMPs,including rational design and de novo synthesis.We also discuss the growing role of predictive computational tools,utilizing artificial intelligence and machine learning,in the design and synthesis of highly efficacious lead drug candidates.
基金supported by the National Natural Science Foundation of China(21761142002 and 31801975)Chinese Academy of Sciences(XDB31000000,SAJC201606,KFZD-SW-219-2,KFJ-BRP-008,and KGFZD-135-17-011)Yunnan Province Grant(2015HA023)
文摘The discovery of antibiotics marked a golden age in the revolution of human medicine. However,decades later, bacterial infections remain a global healthcare threat, and a return to the pre-antibiotic era seems inevitable if stringent measures are not adopted to curb the rapid emergence and spread of multidrug resistance and the indiscriminate use of antibiotics. In hospital settings, multidrug resistant(MDR) pathogens, including carbapenem-resistant Pseudomonas aeruginosa, vancomycin-resistant enterococci(VRE), methicillin-resistant Staphylococcus aureus(MRSA), and extendedspectrum β-lactamases(ESBL) bearing Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae are amongst the most problematic due to the paucity of treatment options,increased hospital stay, and exorbitant medical costs. Antimicrobial peptides(AMPs) provide an excellent potential strategy for combating these threats. Compared to empirical antibiotics, they show low tendency to select for resistance, rapid killing action, broad-spectrum activity, and extraordinary clinical efficacy against several MDR strains. Therefore, this review highlights multidrug resistance among nosocomial bacterial pathogens and its implications and reiterates the importance of AMPs as next-generation antibiotics for combating MDR superbugs.
基金supported by the National Natural Science Foundation of China(21761142002,81770464)Ministry of Science and Technology of China(2018ZX09301043-003)+3 种基金Chinese Academy of Sciences(QYZDJ-SSW-SMC012,SAJC201606)West Light FoundationYouth Innovation Promotion Association(2017432)Yunnan Provincial Science and Technology Department(2017FB038,2015BC005)
文摘Protease inhibitors have been reported rarely from the leech Hirudinaria manillensis.In this study,we purified a novel protease inhibitor(bdellin-HM-2)with anticoagulant properties from H.manillensis.With a molecular weight of 1.4x104,bdellin-HM-2 was also characterized with three intra?molecular disulfide bridges at the N-terminus and multiple HHXDD and HXDD motifs at theC-terminus.cDNAcloning revealed that the putative nucleotide-encoding protein of bdellin-HM-2 contained 132 ami no acids and was encoded by a 399 bp open reading frame(ORF).Sequence alignment showed that bdellin-HM-2 shared similarity with the“non-classical"Kazal-type serine protease inhibitors,but had no inhibitory effect on trypsin,elastase,chymotrypsin,kallikrein,factor Xlla(FXIIa),factor Xia(FXIa),factor Xa(FXa),thrombin,or plasmin.Bdellin-HM-2 showed anticoagulant effects by proIonging the activated partial thromboplastin time(aPTT),indicating a role in enabling H.manillensis to obtain a blood meal from its host.Our results suggest that bdellin-HM丒2 may play a crucial role in blood-sucking in this leech species and may be a pote ntial can didate for the development of clinical anti-thrombotic drugs.
基金This study was supported by the National 863 Project of China （2012AA021801） and the Project of Frontier Study of Foundation, CAS （KSCX2-EW-R-11, KSCX2-EW-J-23）
文摘Endosymbionts influence many aspects of their hosts’ health conditions, including physiology, development, immunity, metabolism, etc. Tree shrews(Tupaia belangeri chinensis) have attracted increasing attention in modeling human diseases and therapeutic responses due to their close relationship with primates. To clarify the situation of symbiotic bacteria from their body surface, oral cavity, and anus, 12 wild and 12 the third generation of captive tree shrews were examined. Based on morphological and cultural characteristics, physiological and biochemical tests, as well as the 16 S rDNA full sequence analysis, 12 bacteria strains were isolated and identified from the wild tree shrews: body surface: Bacillus subtilis(detection rate 42%), Pseudomonas aeruginosa(25%), Staphlococcus aureus(33%), S. Epidermidis(75%), Micrococcus luteus(25%), Kurthia gibsonii(17%); oral cavity: Neisseria mucosa(58%), Streptococcus pneumonia(17%); anus: Enterococcus faecalis(17%), Lactococus lactis(33%), Escherichia coli(92%), Salmonella typhosa(17%); whereas, four were indentified from the third generation captive tree shrews: body surface: S. epidermidis(75%); oral cavity: N.mucosa(67%); anus: L. lactis(33%), E. coli(100%). These results indicate that S. epidermidis, N. mucosa, L. lactis and E. coli were major bacteria in tree shrews, whereas, S. aureus, M. luteus, K. gibsonii, E. faecalis and S. typhosa were species-specific flora. This study facilitates the future use of tree shrews as a standard experimental animal and improves our understanding of the relationship between endosymbionts and their hosts.
基金supported by the National Basic Research Program of China（973 Program）（2013CB911300）National Natural Science Foundation of China（U1132601）the Chinese Academy of Sciences（SAJC201308）
文摘As a group of intestinal hormones and neurotransmitters, cholecystokinins（CCKs） regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally contain a DYMGWMDFG sequence at the C-terminus. Many CCKs have been reported in mammals. However, only a few have been reported in amphibians, such as Hyla nigrovittata, Xenopus laevis, and Rana catesbeiana, with none reported in urodele amphibians like newts and salamanders. Here, a CCK called CCK-TV was identified and characterized from the skin of the salamander Tylototriton verrucosus. This CCK contained an amino acid sequence of DYMGWMDF-NH2 as seen in other CCKs. A c DNA encoding the CCK precursor containing 129 amino acid residues was cloned from the c DNA library of T. verrucosus skin. The CCK-TV had the potential to induce the contraction of smooth muscle strips isolated from porcine gallbladder, eliciting contraction at a concentration of 5.0x10-11 mol/L and inducing maximal contraction at a concentration of 2.0x10-6 mol/L. The EC50 was 13.6 nmol/L. To the best of our knowledge, this is the first report to identify the presence of a CCK in an urodele amphibian.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(31900331,32070444)Science and Technology Department of Yunnan Province(202001AW070019)+2 种基金Chinese Academy of Sciences“Light of West China”Program and Youth Innovation Promotion Association(2019378)to L.J.and the NSFC(21761142002)Chinese Academy of Sciences(XDB31000000,SAJC201606 and KGFZD-135-17-011)Yunnan Province(2019-YT-053 and 2019ZF003)to R.L.and the NSFC(91643206)to W.J.D。
文摘The global outbreak of coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),as of 8 May 2021,has surpassed 150700000 infections and 3279000 deaths worldwide.Evidence indicates that SARS-CoV-2 RNA can be detected on particulate matter(PM),and COVID-19 cases are correlated with levels of air pollutants.However,the mechanisms of PM involvement in the spread of SARS-CoV-2 remain poorly understood.Here,we found that PM exposure increased the expression level of angiotensin-converting enzyme 2(ACE2)and transmembrane serine protease 2(TMPRSS2)in several epithelial cells and increased the adsorption of the SARS-CoV-2 spike protein.Instillation of PM in a hACE2 mouse model significantly increased the expression of ACE2 and Tmprss2 and viral replication in the lungs.Furthermore,PM exacerbated the pulmonary lesions caused by SARS-CoV-2 infection in the hACE2 mice.In conclusion,our study demonstrated that PM is an epidemiological factor of COVID-19,emphasizing the necessity of wearing anti-PM masks to cope with this global pandemic.
基金the China National Natural Science Foundation of Young Scientists(No.31201717)Special Foundation for Young Scientists of Jiangsu Province(No.BK2012365)Jiangsu Province Science and Technology Support Project(No.BE2012748).
文摘Various bio-active substances in amphibian skins play important roles in survival of the amphibians.Many protease inhibitor peptides have been identified from amphibian skins,which are supposed to negatively modulate the activity of proteases to avoid premature degradation or release of skin peptides,or to inhibit extracellular proteases produced by invading bacteria.However,there is no information on the proteinase inhibitors from the frog Lepidobatrachus laevis which is unique in South America.In this work,a cDNA encoding a novel trypsin inhibitor-like(TIL)cysteine-rich peptide was identified from the skin cDNA library of L.laevis.The 240-bp coding region encodes an 80-amino acid residue precursor protein containing 10 half-cysteines.By sequence comparison and signal peptide prediction,the precursor was predicted to release a 55-amino acid mature peptide with amino acid sequence,IRCPKDKIYKFCGSPCPPSCKDLTPNCIAVCKKGCFCRDGTVDNNHGKCVKKENC.The mature peptide was named LL-TIL.LL-TIL shares significant domain similarity with the peptides from the TIL supper family.Antimicrobial and trypsin-inhibitory abilities of recombinant LL-TIL were tested.Recombinant LL-TIL showed no antimicrobial activity,while it had trypsin-inhibiting activity with aKi of 16.5178 lM.These results suggested there was TIL peptide with proteinase-inhibiting activity in the skin of frog L.laevis.To the best of our knowledge,this is the first report of TIL peptide from frog skin.
基金supported by Chinese National Natural Science Foundation(31070701,31000962,31025025,30730026)the Program of Shanghai Subject Chief Scientist(NO.09XD1405100)+1 种基金the Ministry of Science and Technology(2010CB529800,2009ZX09103-1/091,2011ZX09102-002-10)the Ministry of Agriculture(2009ZX08009-159B).
文摘Cathelicidin Pc-CATH1 is a cathelicidin-derived myeloid antimicrobial peptide identified from Phasianus colchicus with strong antimicrobial activity against most of bacteria and fungi tested,including the clinically isolated(IS)drug-resistant strains.Considering the uniform distribution of net positive charge in both C-and N-terminus sequence of cathelicidin Pc-CATH1 and most of hydrophobic amino acid(aa)residues positioned in middle of the sequence,the antimicrobial peptide was used to investigate the structure-function relationship by truncating gradually N-or C-terminus amino acid residue.More than 10 modified peptide homo-logues(20-26 aa length)of cathelicidin Pc-CATH1 were found to keep strong antimicrobial abilities.The possible relationships between bioactivities including antimicrobial and hemolytic abilities,components of secondary structure,hydrophobicity,amphipathicity,net charge,and sequence length were investigated.The current work provided suggestions for structural and functional modification of linear,α-helical antimicrobial peptides containing no disulfided bridges.
基金the National Key Research and Development Program of China(2022YFF1301601)the Ministry of Science and Technology of China(2018YFA0801403 and 2022YFC2105003)+6 种基金the National Science Foundation of China(31930015,32100907,U2002219,and 32371162)the Chinese Academy of Sciences(KFJ-BRP-008 and SAJC202103)Yunnan Province(202003AD150008,202202AA100002 and 202301AS070074)the Kunming Science and Technology Bureau(2022SCP007)the New Cornerstone Investigator Program from Shenzhen New Cornerstone Science Foundation,Excellent Young Scientists Foundation of Shandong Province(ZR2023YQ025)the Frontiers Medical Center,Tianfu Jincheng Laboratory Foundation(TFJC2023010007)the PI Project of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML2021GD0807).
文摘Cross-talks (e.g., host-driven iron withdrawal and microbial iron uptake between host gastrointestinal tract and commensal microbes) regulate immunotolerance and intestinal homeostasis. However, underlying mechanisms that regulate the cross-talks remain poorly understood. Here, we show that bacterial products up-regulate iron-transporter transferrin and transferrin acts as an immunosuppressor by interacting with cluster of differentiation 14 (CD14) to inhibit pattern recognition receptor (PRR) signaling and induce host immunotolerance. Decreased intestinal transferrin is found in germ-free mice and human patients with ulcerative colitis, which are characterized by impaired intestinal immunotolerance. Intestinal transferrin and host immunotolerance are returned to normal when germ-free mice get normal microbial commensalism, suggesting an association between microbial commensalism, transferrin, and host immunotolerance. Mouse colitis models show that transferrin shortage impairs host’s tolerogenic responses, while its supplementation promotes immunotolerance. Designed peptide blocking transferrin–CD14 interaction inhibits immunosuppressive effects of transferrin. In monkeys with idiopathic chronic diarrhea, transferrin shows comparable or even better therapeutic effects than hydrocortisone. Our findings reveal that by up-regulating host transferrin to silence PRR signaling, commensal bacteria counteract immune activation induced by themselves to shape host immunity and contribute for intestinal tolerance.
基金supported by the National Natural Science Foundation of China(21761142002 and 81770464)Ministry of Science and Technology of the People’s Republic of China(2018ZX09301043-003)+2 种基金Chinese Academy of Science(QYZDJSSW-SMC012,SAJC201606the West Light Foundation and Youth Innovation Promotion Association(2017432))Yunnan Provincial Science and Technology Department(2017FB038,2015BC005)
文摘Bacterial DNA(bacDNA) is frequently found in serum of patient with ulcerative colitis(UC) and Crohn's disease, even blood bacterial culture is negative. How bacDNA evades immune elimination and is translocated into blood remain unclear. Here, we showed that bacDNA avoids elimination and disables bacteriakilling function of antimicrobial peptide LL-37(Cramp in mice) by forming complex with LL-37, which is inducible after culture with bacteria or bacterial products. Elevated LL-37-bacDNA complex was found in plasma and lesions of patients with UC. LL-37-bacDNA promoted inflammation by inducing Th1, Th2 and Th17 differentiation and activating toll-like receptor-9(TLR9). The complex also increased paracellular permeability, which possibly combines its inflammatory effects to promote local damage and bacDNA translocation into blood. Cramp-bacDNA aggravated mouse colitis severity while interference with the complex ameliorated the disease. The study identifies that inflammatogenic bacDNA utilizes LL-37 as a vehicle for blood translocation and to evade immune elimination. Additionally, bacteria may make a milieu by releasing bacDNA to utilize and resist host antimicrobial peptides as a ‘trojan horse'.
文摘Dear Editor,The Ras superfamily of GTPases are conserved in eukary?otes from yeast to humans,and play essential roles in the regulation of a variety of key cellular processes,including cell differentiation and proliferation,membrane trafficking,nuclear import and export,cytoskeletal remodeling and mitogenic signaling(Karnoub and Weinberg,2008).Notably,numerous studies have shown that many members of the Ras-related small GTPases are involved in diverse aspects of tumorigenesis and tumor progress!on(Chen et al.,2014;Liu et al.,2017).
基金the National Natural Science Foundation of China(81903666 and 31930015)the Chinese Academy of Sciences(XDB31000000,KFJ-STS-SCYD-304,and K.C.Wong Education Foundation,China)+4 种基金the Science and Technology Department of Yunnan Province (202101AT070301,2019ZF003,202002AA100007,202003AD150008,and 2019FB103China)Project of Innovative Research Team of Yunnan Province(2019HC005China)the Department of Industry and Information Technology of Yunnan Province (2019-YT-053,China)。
文摘Unlike healthy, non-transformed cells, the proteostasis network of cancer cells is taxed to produce proteins involved in tumor development. Cancer cells have a higher dependency on molecular chaperones to maintain proteostasis. The chaperonin T-complex protein ring complex(TRiC) contains eight paralogous subunits(CCT1-8), and assists the folding of as many as 10% of cytosolic proteome.TRiC is essential for the progression of some cancers, but the roles of TRiC subunits in osteosarcoma remain to be explored. Here, we show that CCT4/TRiC is significantly correlated in human osteosarcoma,and plays a critical role in osteosarcoma cell survival. We identify a compound anticarin-β that can specifically bind to and inhibit CCT4. Anticarin-β shows higher selectivity in cancer cells than in normal cells. Mechanistically, anticarin-β potently impedes CCT4-mediated STAT3 maturation. Anticarin-β displays remarkable antitumor efficacy in orthotopic and patient-derived xenograft models of osteosarcoma.Collectively, our data uncover a key role of CCT4 in osteosarcoma, and propose a promising treatment strategy for osteosarcoma by disrupting CCT4 and proteostasis.
基金supported by grants from the Emergency Project of West China Hospital(number HX-2019-nCoV-025)the Program from Chongqing Education Commission(number KYYJ202010).
文摘Dear editor,To date,a number of clinically approved drugs have been evaluated for potential to treat coronavirus disease 2019(COVID-19),such as lopinavir/ritonavir,hydroxychloroquine,cobicistat,and darunavir.Some of these drugs have been proven to be effective in vitro;however,clinical trials showed that none of these compounds led to a significant improvement in symptoms or length of hospitalization.Thus,it is essential and more reliable to start from a defined target to ide ntify can didate drugs.
