Phosphoinositide 3-kinase(PI3K)catalyzes the conversion of phosphatidylinositol 4,5-bisphosphate(PIP_(2))to phosphatidylinositol 3,4,5-trisphosphate(PIP_(3)),a key second messenger that orchestrates downstream signali...Phosphoinositide 3-kinase(PI3K)catalyzes the conversion of phosphatidylinositol 4,5-bisphosphate(PIP_(2))to phosphatidylinositol 3,4,5-trisphosphate(PIP_(3)),a key second messenger that orchestrates downstream signaling by recruiting and activating effector proteins,such as protein kinase B(AKT).PI3Ks are categorized into four classes(IA,IB,II,and III)based on structural characteristics and substrate preferences1.Class IA PI3K enzymes are heterodimeric complexes composed of a catalytic subunit(p110α,p110β,or p110δ)and a regulatory subunit(p85α,p55α,p50α,p85β,or p55γ)2.Although the catalytic isoforms p110αand p110β,are ubiquitously expressed across tissues,p110δis predominantly found in leukocytes3.Notably,p85αfunctions as the primary regulatory subunit.展开更多
Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to ext...Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to external experiments.Traditional RTKs heterodimerization always occur in the same families and is lack of agonists to activate the heterodimeric RTKs signaling pathway.Herein,we developed the DNA agonist based on bivalent aptamers for the heterodimerized RTKs of different families,AF/AM-1,which could simultaneously activate FGFR1 and c-Met signaling.It is the first agonist that realizing the heterodimerization and activation of FGFR1 and c-Met,two different RTK families.The activation of FGFR1/c-Met heterodimer result in the down-stream signals transduction,such as the phosphorylation of Akt and Erk,inducing the cell migration and proliferation.The DNA agonist for RTK heterodimer of different families would have potential applications in the fields of biomedicine.展开更多
The occurrence of benign prostate hyperplasia(BPH)was related to disrupted sex steroid hormones,and metformin(Met)had a clinical response to sex steroid hormone-related gynaecological disease.However,whether Met exert...The occurrence of benign prostate hyperplasia(BPH)was related to disrupted sex steroid hormones,and metformin(Met)had a clinical response to sex steroid hormone-related gynaecological disease.However,whether Met exerts an antiproliferative effect on BPH via sex steroid hormones remains unclear.Here,our clinical study showed that along with prostatic epithelial cell(PEC)proliferation,sex steroid hormones were dysregulated in the serum and prostate of BPH patients.As the major contributor to dysregulated sex steroid hormones,elevated dihydrotestosterone(DHT)had a significant positive relationship with the clinical characteristics of BPH patients.Activation of adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)by Met restored dysregulated sex steroid hormone homeostasis and exerted antiproliferative effects against DHT-induced proliferation by inhibiting the formation of androgen receptor(AR)-mediated Yes-associated protein(YAP1)-TEA domain transcription factor(TEAD4)heterodimers.Met’s anti-proliferative effects were blocked by AMPK inhibitor or YAP1 overexpression in DHT-cultured BPH-1 cells.Our findings indicated that Met would be a promising clinical therapeutic approach for BPH by inhibiting dysregulated steroid hormone-induced PEC proliferation.展开更多
Four new norditerpenoid heterodimers with different dimerization patterns-namely,trigofragiloids A-C(denoted as compounds 1-3)and(+)-and(-)-trigofragiloid D(compound 4)-and three new phenanthrenone norditerpenoids-nam...Four new norditerpenoid heterodimers with different dimerization patterns-namely,trigofragiloids A-C(denoted as compounds 1-3)and(+)-and(-)-trigofragiloid D(compound 4)-and three new phenanthrenone norditerpenoids-namely,trigofragiloids E-G(compounds 5-7)-were isolated from Trigonostemon fragilis.Compounds 1 and 2 feature a novel heterodimeric carbon skeleton formed by the conjugation of a tetra-norditerpenoid and an ennea-norditerpenoid;they have been identified as class 2 atropisomers by means of quantum chemical calculations.Compound 3 is an unprecedented phenylpropanoid-norditerpenoid adduct with a new dimerization pattern.Compounds(+)-and(-)-4 are the first example of S-shaped 1,4-dioxane-fused norditerpenoid dimers.Inspired by the structure elucidation of compound 4,two co-occurring analogues,actephilol A and epiactephilol A,were structurally revised as a pair of geometrical isomers and were identified as two pairs of enantiomers,(+)-and(-)-8 and(+)-and(-)-9,respectively.Their structures were characterized using a combined method.Notably,compound 7 exhibits remarkable adenosine triphosphate-citrate lyase(ACLY)inhibition with a halfmaximal inhibition concentration(IC50)value of(0.46±0.11)lmol·L^(-1),as active as the positive control BMS-303141,and a molecular docking study offers deep insight into the interaction between compound 7 and ACLY.展开更多
Marine natural products offer a promising source in the development of new antibiotic drugs.Two previously undescribed compounds,including one sulfur-bearing alkaloid named quinosumycin(1)along with one chromone deriv...Marine natural products offer a promising source in the development of new antibiotic drugs.Two previously undescribed compounds,including one sulfur-bearing alkaloid named quinosumycin(1)along with one chromone derivative namely chromycone(2),were discovered from an ethyl acetate(EtOAc)extract of marine Streptomyces diastaticus NBU2966 through a bioactivity-guided isolation prioritized for antimicrobial potential.The analysis of nuclear magnetic resonance(NMR)spectroscopy,high resolution electrospray ionization mass spectroscopy(HRESIMS)data,and electronic circular dichroism(ECD)calculations enabled the elucidation of their structures and the determination of their absolute configurations.Quinosumycin(1)is the first heterodimer scaffold incorporating quinolinone and quinazolinone motifs coupled by a thioether bond.Interestingly,Compound 1 exhibited a relatively selective growth inhibition against methicillin-resistant Staphylococcus aureus(MRSA)with the minimal inhibitory concentration(MIC)value of 8μg/mL.展开更多
Optimal therapeutic and diagnostic efficacy is essential for healthcare's global mission of advancing oncologic drug development.Accurate diagnosis and detection are crucial prerequisites for effective risk strati...Optimal therapeutic and diagnostic efficacy is essential for healthcare's global mission of advancing oncologic drug development.Accurate diagnosis and detection are crucial prerequisites for effective risk stratification and person-alized patient care in clinical oncology.A paradigm shift is emerging with the promise of multi-receptor-targeting compounds.While existing detection and staging methods have demonstrated some success,the traditional approach of monotherapy is being reevaluated to enhance therapeutic effectiveness.Het-erodimeric site-specific agents are a versatile solution by targeting two distinct biomarkers with a single theranostic agent.This review describes the inno-vation of dual-targeting compounds,examining their design strategies,thera-peutic implications,and the promising path they present for addressing complex diseases.展开更多
The microtubule(MT)-associated proteins KIF3A and KIF3B are ubiquitously expressed in a wide range of taxa.This study investigated the functions of these proteins in spermiogenesis,which involves various MT-dependent ...The microtubule(MT)-associated proteins KIF3A and KIF3B are ubiquitously expressed in a wide range of taxa.This study investigated the functions of these proteins in spermiogenesis,which involves various MT-dependent processes,in Phasco-losoma esculenta.We cloned the complete cDNA of Pe-KIF3A/3B.Structural predictions showed that Pe-KIF3A/3B are composed of a highly conserved motor domain,a coiled-coil domain,and a tail domain.Real-time quantitative PCR showed that Pe-kif3a/3b are expressed in all tissues evaluated,with the highest levels in sperm masses.Fluorescence in situ hybridization and immunofluo-rescence were employed to analyze the dynamic expression patterns of KIF3A/3B during spermiogenesis.Pe-KIF3A/3B consistently co-localized with MTs at all stages of spermiogenesis,indicating their potential functions in cargo trafficking.Pe-KIF3A/3B co-localized with mitochondria,suggesting that they may mediate mitochondrial movement.In late-stage spermatids and mature sperm,co-localization was detected in the midpiece,suggesting that Pe-KIF3A/3B could facilitate midpiece formation.The co-localization of Pe-KIF3A and Pe-KIF3B at all stages of spermiogenesis suggests their function as the heterodimeric KIF3AB.Basing on the ob-served temporal and spatial expression patterns of Pe-KIF3A/3B,MTs,and mitochondria in our study,we suggest that heterodimer KIF3AB has a potential role in acrosome biogenesis,sperm head remodeling,enflagellation,and mitochondrial migration during spermiogenesis in P.esculenta.In addition,our study on the morphological characteristics of spermatogenic cells provided fundamental data on the reproductive biology of P.esculenta.展开更多
AIM: To understand the role of toll-like receptor 4 (TLR4) signaling in the regulation of iron-regulatory hormone, hepcidin by chronic alcohol consumption.
BACKGROUND Celiac Disease(CD)is an immune-mediated disorder,in which the HLA immunogenetic background(DQ2 and DQ8 heterodimers)and environmental trigger(gluten)are well established.Indeed,both factors are necessary–b...BACKGROUND Celiac Disease(CD)is an immune-mediated disorder,in which the HLA immunogenetic background(DQ2 and DQ8 heterodimers)and environmental trigger(gluten)are well established.Indeed,both factors are necessary–but not sufficient–to develop CD.However,it is very likely that CD is underdiagnosed in both developing and developed countries,due to several aspects,including the fact that a lot of patients present mild and/or atypical symptoms,without the presence of any recognized risk factors.Therefore,the possibility and feasibility of widened screening strategies to identify CD patients are debated.AIM To provide further evidence of the main epidemiological importance of HLADQB1*02 allele in the population of CD patients.METHODS We performed a systematic search in PubMed,EMBASE,Cochrane,Web of Science and Scopus databases,in order to produce a systematic review assessing the carrier frequency of HLA-DQB1*02 allele in the celiac population.Following the PRISMA guidelines,we retrieved all the original articles describing CD patients’HLA-DQB1 genotype in such a way that could allow to assess the HLADQB1*02 carrier frequency among CD patients,along with the evidence of the appropriate diagnostic work-up to achieve a correct and final diagnosis of CD.RESULTS The final output of this systematic search in the medical literature consisted of 38 studies providing the appropriate HLA-DQB1 genotype information of the respective CD population.According to this systematic review,including a pool of 4945 HLA-DQ genotyped CD patients,the HLA-DQB1*02 carrier frequency was 94.94%,meaning that only 5.06%of CD patients were completely lacking this allelic variant.Interestingly,if we consider only the studies whereby the prevalence of CD patients affected with type 1 diabetes mellitus was supposed or clearly established to be very low,the frequency of non-HLA-DQB1*02 carriers among CD patients dropped to 3.65%.CONCLUSION Such a high carrier frequency of the HLA-DQB1*02 allelic variant(which is>95%-96%in CD patients without risk factors,like type 1 diabetes mellitus comorbidity)might be exploited to consider a cost-effective and widened screening approach.If a sustainable strategy could be implemented through a low-cost targeted genetic test to detect the individual presence of HLA-DQB1*02 allele,an appropriate algorithm for serological screening in individuals resulting to be genetically predisposed to CD,might be considered.展开更多
AIM:To determine the expression of the catalytic subunit of DNA-dependent protein kinase(DNA-PKcs)and the Ku70/Ku80 heterodimer(Ku 70/80)in gastric carcinoma.METHODS:Gastric biopsies were obtained from 146gastric carc...AIM:To determine the expression of the catalytic subunit of DNA-dependent protein kinase(DNA-PKcs)and the Ku70/Ku80 heterodimer(Ku 70/80)in gastric carcinoma.METHODS:Gastric biopsies were obtained from 146gastric carcinoma patients[Helicobacter pylori(H.pylori)-negative:89 and H.pylori-positive:57]and 34from normal subjects(H.pylori-negative:16 and H.pylori-positive:18)via surgery and endoscopic detection from April 2011 to August 2012 at the First Affiliated Hospital of Nanchang University.Pathological diagnosis and classification were made according to the criteria of the World Health Organization and the updated Sydney system.An‘‘in-house’’rapid urease test and modified Giemsa staining were employed to detect H.pylori infection.The expression of DNA-PKcs and the Ku 70/80protein was detected by immunohistochemistry.RESULTS:Overall,the positive rates of both DNA-PKcs and Ku 70/80 were significantly increased in gastric cancer(χ2=133.04,P<0.001 for DNA-PKcs andχ2=13.06,P<0.01 for Ku)compared with normal gastric mucosa.There was hardly any detectable expression of DNA-PKcs in normal gastric mucosa,and the positive rate of DNA-PKcs protein expression in patients with a normal gastric mucosa was 0%(0/34),whereas the rate in gastric cancer(GC)was 93.8%(137/146).The difference between the two groups was statistically significant.Additionally,the positive rate of Ku 70/80 was79.4%(27/34)in normal gastric mucosa and 96.6%(141/146)in gastric cancer.The DNA-PKcs protein level was significantly increased in gastric cancer(MannWhitney U=39.00,P<0.001),compared with normal gastric mucosa.In addition,there was a significant difference in the expression of Ku 70/80(Mann-Whitney U=1117.00,P<0.001)between gastric cancer and normal gastric mucosa.There was also a significant difference in Ku70/80 protein expression between GC patients with and without H.pylori infection(P<0.05).Spearman analysis showed a negative correlation between tumor differentiation and DNA-PKcs expression(r=-0.447,P<0.05).Moreover,Ku70/80 expression was negatively correlated with both clinical stage(r=-0.189,P<0.05)and H.pylori colonization(r=-0.168,P<0.05).CONCLUSION:Overall,this research demonstrated that enhanced DNA-PKcs and Ku 70/80 expression may be closely associated with gastric carcinoma.展开更多
AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity w...AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS： A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa （P〈0.00）. However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses （P〈0.001）. Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION： Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.展开更多
Heterogeneous nuclear ribonucleoprotein （hnRNP） C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D （1,25（OH）2D） by functioning as a vitamin D ...Heterogeneous nuclear ribonucleoprotein （hnRNP） C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D （1,25（OH）2D） by functioning as a vitamin D response element-binding protein （VDRE-BP）. hnRNPC acts a tetramer of hnRNPC1 （huC1） and hnRNPC2 （huC2）, and organization of these subunits is critical to in vivo nucleic acid-binding. Overexpression of either huC1 or huC2 in human osteoblasts is sufficient to confer VDRE-BP suppression of 1,25（OH）2D-mediated transcription. However, huC1 or huC2 alone did not suppress 1,25（OH）2D-induced transcription in mouse osteoblastic cells. By contrast, overexpression of huC1 and huC2 in combination or transfection with a bone-specific polycistronic vector using a ＂self-cleaving＂ 2A peptide to co-express huC1/C2 suppressed 1,25D-mediated induction of osteoblast target gene expression. Structural diversity of hnRNPC between human/NWPs and mouse/rat/rabbit/dog was investigated by analysis of sequence variations within the hnRNP CLZ domain. The predicted loss of distal helical function in hnRNPC from lower species provides an explanation for the altered interaction between huC1/C2 and their mouse counterparts. These data provide new evidence of a role for hnRNPC1/C2 in 1,25（OH）2D-driven gene expression, and further suggest that species-specific tetramerization is a crucial determinant of its actions as a regulator of VDR-directed transactivation.展开更多
The infrared multiphoton dissociation(IRMPD)spectrum of the protonated heterodimer of Pro Phe H+,in the range of 2700-3700 cm^-1,has been obtained with a Fourier-transform ion cyclotron mass spectrometer combined with...The infrared multiphoton dissociation(IRMPD)spectrum of the protonated heterodimer of Pro Phe H+,in the range of 2700-3700 cm^-1,has been obtained with a Fourier-transform ion cyclotron mass spectrometer combined with an IR OPO laser.The experimental spectrum shows one peak at 3565 cm^-1 corresponding to the free carboxyl O-H stretching vibration,and two broad peaks centered at 2935 and 3195 cm^-1.Theoretical calculations were performed on the level of M062 X/6-311++G(d,p).Results show that the most stable isomer is characterized by a charge-solvated structure in which the proton is bound to the unit of proline.Its predicted spectrum is in good agreement with the experimental one,although the coexistence of salt-bridged structures cannot be entirely excluded.展开更多
Understanding the nature of cell surface markers on exfoliated colonic cells is a crucial step in establishing criteria for a normally functioning mucosa. We have found that colonic cells isolated from stool samples (...Understanding the nature of cell surface markers on exfoliated colonic cells is a crucial step in establishing criteria for a normally functioning mucosa. We have found that colonic cells isolated from stool samples (SCSR-010 Fecal Cell Isolation Kit, NonInvasive Technologies, Elkridge, MD), preserved at room temperature for up to one week, with viability of >85% and low levels of apoptosis (8% - 10%) exhibit two distinct cell size subpopulations, in the 2.5 μM - 5.0 μM and 5.0 μM - 8.0 μM range. In addition to IgA, about 60% of the cells expressed a novel heterodimeric IgA/IgG immunoglobulin that conferred a broad-spectrum cell mediated cytotoxicity against tumor cells. In a cohort of 58 subjects the exclusive absence of this immunoglobulin in two African-Americans was suggestive of a germline deletion. Serial cultures in stem cell medium retained the expression of this heterodimer. Since a majority of the cystic cells expressed the stem cell markers Lgr5 and Musashi-1 we termed these cells as gastrointestinal progenitor stem cells (GIP-C**). CXCR-4, the cytokine co-receptor for HIV was markedly expressed. These cells also expressed CD20, IgA, IgG, CD45, and COX-2. We assume that they originated from mature columnar epithelium by dedifferentiation. Our observations indicate that we have a robust noninvasive method to study mucosal pathophysiology and a direct method to create a database for applications in regenerative medicine.展开更多
A phytochemical investigation on Isodon flavidus led to the isolation of flavidanolide A(1),a rearranged diterpenoid featuring a six/seven/five-membered tricyclic skeleton,together with flavidanolide B(2),an uncommon ...A phytochemical investigation on Isodon flavidus led to the isolation of flavidanolide A(1),a rearranged diterpenoid featuring a six/seven/five-membered tricyclic skeleton,together with flavidanolide B(2),an uncommon heterodimeric diterpenoid consisting of a norabietane and a seco-isopimarane monomeric units.Their structures were elucidated by extensive spectroscopic data and single-crystal X-ray diffraction analyses.Their plausible biosynthetic routes were also proposed.In the bioassay,flavidanolide B was found to exhibit good inhibitory effect against lipopolysaccharide(LPS)-induced nitric oxide(NO)production in RAW264.7 cells comparable to positive control pyrrolidinedithiocarbamate ammonium(PDTC),which provided evidence for the medicinal value of I.flavidus as a folk medicine for treating inflammatory diseases.展开更多
The properties of nanocrystals are highly dependent on their morphology, composition and structure. To obtain full control over their properties, the behavior of nanocrystals under external stimuli, such as heat treat...The properties of nanocrystals are highly dependent on their morphology, composition and structure. To obtain full control over their properties, the behavior of nanocrystals under external stimuli, such as heat treatment, needs to be understood. Herein, to in situ observe their microstructure and morphology changes, Fe3O4–Ag heterodimers were selected as a model system. Their structural changes after heat treatment were investigated by in situ transmission electron microscopy. A combination of real-time imaging with elemental analysis enabled observation of the transformation of Fe3O4–Ag heterodimers having a loose interface configuration to those with a Janus structure at the atomic scale after heating from room temperature to 600 °C. After incubation at 600 °C for 32 min, two kinds of Janus structures could be seen, including a clear linear interface in the Fe3O4–Ag heterodimers and a semi-crescent-shaped interface between the Ag and Fe3O4 nanoparticles(NPs). These dynamic observations provide unique insights into NP growth mechanisms, which are essential for understanding and controlling the structure and morphology of nanoparticles.展开更多
Monodisperse Au-Fe3O4 heterodimeric nanoparticles （NPs） were prepared by injecting precursors into a hot reaction solution. The size of Au and Fe3O4 particles can be controlled by changing the injection temperature....Monodisperse Au-Fe3O4 heterodimeric nanoparticles （NPs） were prepared by injecting precursors into a hot reaction solution. The size of Au and Fe3O4 particles can be controlled by changing the injection temperature. UVis spectra show that the surface plasma resonance band of Au-Fe3O4 heterodimeric NPs was evidently red-shifted compared with the resonance band of Au NPs of similar size. The as-prepared heterodimeric Au-Fe3O4 NPs exhibited superparamagnetic properties at room temperature. The Ag-Fe3O4 heterodimeric NPs were also prepared by this synthetic method simply using AgNO3 as precursor instead of HAuCl4. It is indicated that the reported method can be readily extended to the synthesis of other noble metal conjugated heterodimeric NPs.展开更多
Combined theoretical and experimental studies have explained the mechanism of Pd-catalyzed δ-C(sp^(3))-H arylation of primary amines. Instead of the monomeric Pd mechanism, our research unveils that all steps includi...Combined theoretical and experimental studies have explained the mechanism of Pd-catalyzed δ-C(sp^(3))-H arylation of primary amines. Instead of the monomeric Pd mechanism, our research unveils that all steps including C–H activation, oxidative addition, and reductive elimination take place via the heterodimeric Pd–Ag intermediates and transition states. Experimentally, the active heterodimeric Pd–Ag species were detected by mass spectrometry, which further confirms the proposed heterodimeric mechanism. Insight gained through this study reveals the synergistic manner of palladium catalysis and silver(Ⅰ)additives in native NH;-directed C–H activation and C–C coupling reactions.展开更多
In a previous report we had reported on the discovery of a novel bispecific immunoglobulin expressed by colonic epithelial cells as they transform into immunomimetic cells during exfoliation (Albaugh <i>et al. &...In a previous report we had reported on the discovery of a novel bispecific immunoglobulin expressed by colonic epithelial cells as they transform into immunomimetic cells during exfoliation (Albaugh <i>et al. </i> (2020) <i>Open Journal of Preventive Medicine</i>, 10, 126-150). Colonic cells isolated from 0.5 gm aliquots of fresh stools (SCSR-10, Fecal Cell Isolation Kit, NonInvasive Technologies, Elkridge, MD) preserved at room temperature for up to one week, with viability of >85% were used to determine the number of cells expressing this novel bispecific immunoglobulin. Over the course of this period (18 years) we recognized that these cells opened the opportunity to investigate the expression of cell membrane biomarkers. As the applications grew, we introduced a new terminology, termed COPROCYTOBIOLOGY*. In this study, we surveyed a cohort of 58 free-living adults for the expression of the newly discovered bi-specific chimeric antibody. Almost all of the subjects showed a strong signal during flow-cytometric evaluation of their stool samples;averaging around 65%. However, two subjects exhibited a total loss of this signal and both these individuals were of African-American lineage (one male and one female). These cells upon culturing <i>in vitro</i> remained defective in contrast to the rest of the group where their progeny continued to generate the antibody. We propose that this signals the existence of a germ-line deletion of the gene for which a novel test (MEDISHIELD†) is suggested. This syndrome may be associated with a lack of response to prophylactic vaccines involving m-RNA.展开更多
The atypical PKC isoforms （ζ and t） play essential roles in regulating various cellular processes. Both the hetero-interaction between PKCζand p62 through their N-terminal PB 1 domains and the homo-oligomerization...The atypical PKC isoforms （ζ and t） play essential roles in regulating various cellular processes. Both the hetero-interaction between PKCζand p62 through their N-terminal PB 1 domains and the homo-oligomerization of p62 via its PB 1 domain are critical for the activation of NF-r.B signaling; however, the molecular mechanisms concerning the formation and regulation of these homotypic complexes remain unclear. Here we determined the crystal structure of PKCζ-PB 1 in complex with a mono- meric p62-PB 1 mutant, where the massive electrostatic interactions between the acidic OPCA motif of PKCζ-PB 1 and the basic surface of p62-PB 1, as well as additional hydrogen bonds, ensure the formation of a stable and specific complex. The PKCζ-p62 interaction is interfered with the modification of a specific Cys of PKCζ by the antiarthritis drug aurothiomalate, though all four cysteine residues in the PKCζ-PB 1 domain can be modified in in vitro assay. In addition, detailed structural and biochemical analyses demonstrate that the PB 1 domains of aPKCs belong to the type I group, which can depolymerize the high-molecular-weight p62 aggregates into homo-oligomers of lower order. These data together unravel the molecular mecha- nisms of the homo- or hetero-interactions between p62 and PKCζ and provide the basis for designing inhibitors of NF-r,.B sig- naling.展开更多
基金supported by grants from the Ministry of Science and Technology of China(Grant No.2020YFA0803301)the Natural Science Foundation of Shandong Province(Grant No.ZR2024QH181)The Postdoctoral Fellowship Program(Grade C)of the China Postdoctoral Science Foundation(Grant No.GZC20240770).
文摘Phosphoinositide 3-kinase(PI3K)catalyzes the conversion of phosphatidylinositol 4,5-bisphosphate(PIP_(2))to phosphatidylinositol 3,4,5-trisphosphate(PIP_(3)),a key second messenger that orchestrates downstream signaling by recruiting and activating effector proteins,such as protein kinase B(AKT).PI3Ks are categorized into four classes(IA,IB,II,and III)based on structural characteristics and substrate preferences1.Class IA PI3K enzymes are heterodimeric complexes composed of a catalytic subunit(p110α,p110β,or p110δ)and a regulatory subunit(p85α,p55α,p50α,p85β,or p55γ)2.Although the catalytic isoforms p110αand p110β,are ubiquitously expressed across tissues,p110δis predominantly found in leukocytes3.Notably,p85αfunctions as the primary regulatory subunit.
基金the National Natural Science Foundation of China(Nos.22104158,82174104,U1903211)the Natural Science Foundation of Hunan Province(No.2021JJ40041)+1 种基金Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011346)Shenzhen Science and Technology Program(No.SZBH202130)。
文摘Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to external experiments.Traditional RTKs heterodimerization always occur in the same families and is lack of agonists to activate the heterodimeric RTKs signaling pathway.Herein,we developed the DNA agonist based on bivalent aptamers for the heterodimerized RTKs of different families,AF/AM-1,which could simultaneously activate FGFR1 and c-Met signaling.It is the first agonist that realizing the heterodimerization and activation of FGFR1 and c-Met,two different RTK families.The activation of FGFR1/c-Met heterodimer result in the down-stream signals transduction,such as the phosphorylation of Akt and Erk,inducing the cell migration and proliferation.The DNA agonist for RTK heterodimer of different families would have potential applications in the fields of biomedicine.
基金supported by the National Natural Science Foundation of China(Grant Nos.:81973377,81903689,82073906 and 82273987)the Key Natural Science Foundation of Jiangsu Higher Education Institutions of China(Grant Nos.:19KJB350006 and 19KJA460008)+1 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),the initializing Fund of Xuzhou Medical University(Grant No.:D2018011)Postgraduate Research Practice Innovation Program of Jiangsu Province(Grant Nos.:KYCX21-2733 and KYCX22-2966).
文摘The occurrence of benign prostate hyperplasia(BPH)was related to disrupted sex steroid hormones,and metformin(Met)had a clinical response to sex steroid hormone-related gynaecological disease.However,whether Met exerts an antiproliferative effect on BPH via sex steroid hormones remains unclear.Here,our clinical study showed that along with prostatic epithelial cell(PEC)proliferation,sex steroid hormones were dysregulated in the serum and prostate of BPH patients.As the major contributor to dysregulated sex steroid hormones,elevated dihydrotestosterone(DHT)had a significant positive relationship with the clinical characteristics of BPH patients.Activation of adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)by Met restored dysregulated sex steroid hormone homeostasis and exerted antiproliferative effects against DHT-induced proliferation by inhibiting the formation of androgen receptor(AR)-mediated Yes-associated protein(YAP1)-TEA domain transcription factor(TEAD4)heterodimers.Met’s anti-proliferative effects were blocked by AMPK inhibitor or YAP1 overexpression in DHT-cultured BPH-1 cells.Our findings indicated that Met would be a promising clinical therapeutic approach for BPH by inhibiting dysregulated steroid hormone-induced PEC proliferation.
基金support from the National Natural Science Foundation of China(22237007 and 22177122)the Biological Resources Program of Chinese Academy of Sciences(CAS)(KFJ-BRP-008-001)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022282)is gratefully acknowledged.We thank Prof.Shi-Man Huang,Department of Biology,Hainan University,China,for the identification of the plant material.
文摘Four new norditerpenoid heterodimers with different dimerization patterns-namely,trigofragiloids A-C(denoted as compounds 1-3)and(+)-and(-)-trigofragiloid D(compound 4)-and three new phenanthrenone norditerpenoids-namely,trigofragiloids E-G(compounds 5-7)-were isolated from Trigonostemon fragilis.Compounds 1 and 2 feature a novel heterodimeric carbon skeleton formed by the conjugation of a tetra-norditerpenoid and an ennea-norditerpenoid;they have been identified as class 2 atropisomers by means of quantum chemical calculations.Compound 3 is an unprecedented phenylpropanoid-norditerpenoid adduct with a new dimerization pattern.Compounds(+)-and(-)-4 are the first example of S-shaped 1,4-dioxane-fused norditerpenoid dimers.Inspired by the structure elucidation of compound 4,two co-occurring analogues,actephilol A and epiactephilol A,were structurally revised as a pair of geometrical isomers and were identified as two pairs of enantiomers,(+)-and(-)-8 and(+)-and(-)-9,respectively.Their structures were characterized using a combined method.Notably,compound 7 exhibits remarkable adenosine triphosphate-citrate lyase(ACLY)inhibition with a halfmaximal inhibition concentration(IC50)value of(0.46±0.11)lmol·L^(-1),as active as the positive control BMS-303141,and a molecular docking study offers deep insight into the interaction between compound 7 and ACLY.
基金Supported by the National Natural Science Foundation of China(No.42176101)the Ningbo Youth Science and Technology Innovation Leading Project(No.2024QL063)+2 种基金the National 111 Project of China(No.D16013)the Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202250186)the Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Development Fund。
文摘Marine natural products offer a promising source in the development of new antibiotic drugs.Two previously undescribed compounds,including one sulfur-bearing alkaloid named quinosumycin(1)along with one chromone derivative namely chromycone(2),were discovered from an ethyl acetate(EtOAc)extract of marine Streptomyces diastaticus NBU2966 through a bioactivity-guided isolation prioritized for antimicrobial potential.The analysis of nuclear magnetic resonance(NMR)spectroscopy,high resolution electrospray ionization mass spectroscopy(HRESIMS)data,and electronic circular dichroism(ECD)calculations enabled the elucidation of their structures and the determination of their absolute configurations.Quinosumycin(1)is the first heterodimer scaffold incorporating quinolinone and quinazolinone motifs coupled by a thioether bond.Interestingly,Compound 1 exhibited a relatively selective growth inhibition against methicillin-resistant Staphylococcus aureus(MRSA)with the minimal inhibitory concentration(MIC)value of 8μg/mL.
基金NIH Research Evaluation and Commercilization Hub,Grant/Award Number:1U01HL152410USVA Medical Research Service,Grant/Award Number:I01 BX00096409National Institutes of Health,Grant/Award Numbers:R01CA269221,R01CA225837。
文摘Optimal therapeutic and diagnostic efficacy is essential for healthcare's global mission of advancing oncologic drug development.Accurate diagnosis and detection are crucial prerequisites for effective risk stratification and person-alized patient care in clinical oncology.A paradigm shift is emerging with the promise of multi-receptor-targeting compounds.While existing detection and staging methods have demonstrated some success,the traditional approach of monotherapy is being reevaluated to enhance therapeutic effectiveness.Het-erodimeric site-specific agents are a versatile solution by targeting two distinct biomarkers with a single theranostic agent.This review describes the inno-vation of dual-targeting compounds,examining their design strategies,thera-peutic implications,and the promising path they present for addressing complex diseases.
基金supported by the Ningbo Science and Technology Plan Projects (Nos. 2019B10016, 2016C 10004)the Major Science and Technology Projects in Zhejiang Province (No. 2011C12013)+2 种基金the Natural Science Foundation of Zhejiang Province (No. LY18C190007)the National Natural Science Foundation of China (No. 312 72642)the Collaborative Innovation Center for Marine High-efficiency and Healthy Aquaculture of Zhejiang Province, and K.C.Wong Magna Fund in Ningbo University
文摘The microtubule(MT)-associated proteins KIF3A and KIF3B are ubiquitously expressed in a wide range of taxa.This study investigated the functions of these proteins in spermiogenesis,which involves various MT-dependent processes,in Phasco-losoma esculenta.We cloned the complete cDNA of Pe-KIF3A/3B.Structural predictions showed that Pe-KIF3A/3B are composed of a highly conserved motor domain,a coiled-coil domain,and a tail domain.Real-time quantitative PCR showed that Pe-kif3a/3b are expressed in all tissues evaluated,with the highest levels in sperm masses.Fluorescence in situ hybridization and immunofluo-rescence were employed to analyze the dynamic expression patterns of KIF3A/3B during spermiogenesis.Pe-KIF3A/3B consistently co-localized with MTs at all stages of spermiogenesis,indicating their potential functions in cargo trafficking.Pe-KIF3A/3B co-localized with mitochondria,suggesting that they may mediate mitochondrial movement.In late-stage spermatids and mature sperm,co-localization was detected in the midpiece,suggesting that Pe-KIF3A/3B could facilitate midpiece formation.The co-localization of Pe-KIF3A and Pe-KIF3B at all stages of spermiogenesis suggests their function as the heterodimeric KIF3AB.Basing on the ob-served temporal and spatial expression patterns of Pe-KIF3A/3B,MTs,and mitochondria in our study,we suggest that heterodimer KIF3AB has a potential role in acrosome biogenesis,sperm head remodeling,enflagellation,and mitochondrial migration during spermiogenesis in P.esculenta.In addition,our study on the morphological characteristics of spermatogenic cells provided fundamental data on the reproductive biology of P.esculenta.
基金Supported by NIH grant No.R01AA017738(to Harrison Findik DD)University of Nebraska Medical Center Undergraduate Scholarship(to Lu S)
文摘AIM: To understand the role of toll-like receptor 4 (TLR4) signaling in the regulation of iron-regulatory hormone, hepcidin by chronic alcohol consumption.
基金the Nazarbayev University Faculty Development Competitive Research Grant 2020-2022,No.240919FD3912.
文摘BACKGROUND Celiac Disease(CD)is an immune-mediated disorder,in which the HLA immunogenetic background(DQ2 and DQ8 heterodimers)and environmental trigger(gluten)are well established.Indeed,both factors are necessary–but not sufficient–to develop CD.However,it is very likely that CD is underdiagnosed in both developing and developed countries,due to several aspects,including the fact that a lot of patients present mild and/or atypical symptoms,without the presence of any recognized risk factors.Therefore,the possibility and feasibility of widened screening strategies to identify CD patients are debated.AIM To provide further evidence of the main epidemiological importance of HLADQB1*02 allele in the population of CD patients.METHODS We performed a systematic search in PubMed,EMBASE,Cochrane,Web of Science and Scopus databases,in order to produce a systematic review assessing the carrier frequency of HLA-DQB1*02 allele in the celiac population.Following the PRISMA guidelines,we retrieved all the original articles describing CD patients’HLA-DQB1 genotype in such a way that could allow to assess the HLADQB1*02 carrier frequency among CD patients,along with the evidence of the appropriate diagnostic work-up to achieve a correct and final diagnosis of CD.RESULTS The final output of this systematic search in the medical literature consisted of 38 studies providing the appropriate HLA-DQB1 genotype information of the respective CD population.According to this systematic review,including a pool of 4945 HLA-DQ genotyped CD patients,the HLA-DQB1*02 carrier frequency was 94.94%,meaning that only 5.06%of CD patients were completely lacking this allelic variant.Interestingly,if we consider only the studies whereby the prevalence of CD patients affected with type 1 diabetes mellitus was supposed or clearly established to be very low,the frequency of non-HLA-DQB1*02 carriers among CD patients dropped to 3.65%.CONCLUSION Such a high carrier frequency of the HLA-DQB1*02 allelic variant(which is>95%-96%in CD patients without risk factors,like type 1 diabetes mellitus comorbidity)might be exploited to consider a cost-effective and widened screening approach.If a sustainable strategy could be implemented through a low-cost targeted genetic test to detect the individual presence of HLA-DQB1*02 allele,an appropriate algorithm for serological screening in individuals resulting to be genetically predisposed to CD,might be considered.
基金Supported by The National natural science foundation of China,No.81270479
文摘AIM:To determine the expression of the catalytic subunit of DNA-dependent protein kinase(DNA-PKcs)and the Ku70/Ku80 heterodimer(Ku 70/80)in gastric carcinoma.METHODS:Gastric biopsies were obtained from 146gastric carcinoma patients[Helicobacter pylori(H.pylori)-negative:89 and H.pylori-positive:57]and 34from normal subjects(H.pylori-negative:16 and H.pylori-positive:18)via surgery and endoscopic detection from April 2011 to August 2012 at the First Affiliated Hospital of Nanchang University.Pathological diagnosis and classification were made according to the criteria of the World Health Organization and the updated Sydney system.An‘‘in-house’’rapid urease test and modified Giemsa staining were employed to detect H.pylori infection.The expression of DNA-PKcs and the Ku 70/80protein was detected by immunohistochemistry.RESULTS:Overall,the positive rates of both DNA-PKcs and Ku 70/80 were significantly increased in gastric cancer(χ2=133.04,P<0.001 for DNA-PKcs andχ2=13.06,P<0.01 for Ku)compared with normal gastric mucosa.There was hardly any detectable expression of DNA-PKcs in normal gastric mucosa,and the positive rate of DNA-PKcs protein expression in patients with a normal gastric mucosa was 0%(0/34),whereas the rate in gastric cancer(GC)was 93.8%(137/146).The difference between the two groups was statistically significant.Additionally,the positive rate of Ku 70/80 was79.4%(27/34)in normal gastric mucosa and 96.6%(141/146)in gastric cancer.The DNA-PKcs protein level was significantly increased in gastric cancer(MannWhitney U=39.00,P<0.001),compared with normal gastric mucosa.In addition,there was a significant difference in the expression of Ku 70/80(Mann-Whitney U=1117.00,P<0.001)between gastric cancer and normal gastric mucosa.There was also a significant difference in Ku70/80 protein expression between GC patients with and without H.pylori infection(P<0.05).Spearman analysis showed a negative correlation between tumor differentiation and DNA-PKcs expression(r=-0.447,P<0.05).Moreover,Ku70/80 expression was negatively correlated with both clinical stage(r=-0.189,P<0.05)and H.pylori colonization(r=-0.168,P<0.05).CONCLUSION:Overall,this research demonstrated that enhanced DNA-PKcs and Ku 70/80 expression may be closely associated with gastric carcinoma.
基金Supported by Italian Ministero della Salute, IRCCS, RC0302TG13 by Ministero dell'Istruzíone, Università e Ricerca scientifica e tecnologica (MIUR), COFIN2002, to the Universita Campus Bio-Medico
文摘AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS： A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa （P〈0.00）. However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses （P〈0.001）. Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION： Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Number 5R01AR037399the UCLA Vector Core (Emmanuelle Faure and Kip Hermann) for vector and viral preparations supported by JCCC/P30 CA016042 and CURE/P30 DK41301
文摘Heterogeneous nuclear ribonucleoprotein （hnRNP） C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D （1,25（OH）2D） by functioning as a vitamin D response element-binding protein （VDRE-BP）. hnRNPC acts a tetramer of hnRNPC1 （huC1） and hnRNPC2 （huC2）, and organization of these subunits is critical to in vivo nucleic acid-binding. Overexpression of either huC1 or huC2 in human osteoblasts is sufficient to confer VDRE-BP suppression of 1,25（OH）2D-mediated transcription. However, huC1 or huC2 alone did not suppress 1,25（OH）2D-induced transcription in mouse osteoblastic cells. By contrast, overexpression of huC1 and huC2 in combination or transfection with a bone-specific polycistronic vector using a ＂self-cleaving＂ 2A peptide to co-express huC1/C2 suppressed 1,25D-mediated induction of osteoblast target gene expression. Structural diversity of hnRNPC between human/NWPs and mouse/rat/rabbit/dog was investigated by analysis of sequence variations within the hnRNP CLZ domain. The predicted loss of distal helical function in hnRNPC from lower species provides an explanation for the altered interaction between huC1/C2 and their mouse counterparts. These data provide new evidence of a role for hnRNPC1/C2 in 1,25（OH）2D-driven gene expression, and further suggest that species-specific tetramerization is a crucial determinant of its actions as a regulator of VDR-directed transactivation.
基金supported by the National Natural Science Foundation of China(No.21627810)the Fundamental Research Funds for the Central Universities,Nankai University(No.63191523)。
文摘The infrared multiphoton dissociation(IRMPD)spectrum of the protonated heterodimer of Pro Phe H+,in the range of 2700-3700 cm^-1,has been obtained with a Fourier-transform ion cyclotron mass spectrometer combined with an IR OPO laser.The experimental spectrum shows one peak at 3565 cm^-1 corresponding to the free carboxyl O-H stretching vibration,and two broad peaks centered at 2935 and 3195 cm^-1.Theoretical calculations were performed on the level of M062 X/6-311++G(d,p).Results show that the most stable isomer is characterized by a charge-solvated structure in which the proton is bound to the unit of proline.Its predicted spectrum is in good agreement with the experimental one,although the coexistence of salt-bridged structures cannot be entirely excluded.
文摘Understanding the nature of cell surface markers on exfoliated colonic cells is a crucial step in establishing criteria for a normally functioning mucosa. We have found that colonic cells isolated from stool samples (SCSR-010 Fecal Cell Isolation Kit, NonInvasive Technologies, Elkridge, MD), preserved at room temperature for up to one week, with viability of >85% and low levels of apoptosis (8% - 10%) exhibit two distinct cell size subpopulations, in the 2.5 μM - 5.0 μM and 5.0 μM - 8.0 μM range. In addition to IgA, about 60% of the cells expressed a novel heterodimeric IgA/IgG immunoglobulin that conferred a broad-spectrum cell mediated cytotoxicity against tumor cells. In a cohort of 58 subjects the exclusive absence of this immunoglobulin in two African-Americans was suggestive of a germline deletion. Serial cultures in stem cell medium retained the expression of this heterodimer. Since a majority of the cystic cells expressed the stem cell markers Lgr5 and Musashi-1 we termed these cells as gastrointestinal progenitor stem cells (GIP-C**). CXCR-4, the cytokine co-receptor for HIV was markedly expressed. These cells also expressed CD20, IgA, IgG, CD45, and COX-2. We assume that they originated from mature columnar epithelium by dedifferentiation. Our observations indicate that we have a robust noninvasive method to study mucosal pathophysiology and a direct method to create a database for applications in regenerative medicine.
基金supported by the National Natural Science Foundation of China(No.82204605)the National Natural Science Foundation of China(No.81560709)+3 种基金the Technology Fund of Guizhou Administration of Traditional Chinese Medicine(No.QZYY-2022019)Science and Technology Tip-top Talent Foundation of Universities in Guizhou Province(No.Qian jiao he KY(2021)034)the Research Grant Council of the Hong Kong Special Administrative Region,China(No.HKBU 12102219)the University Grants Committee of the Hong Kong Special Administrative Region,China(UGC Research Matching Grant Scheme,No.RMG2019_1_19)。
文摘A phytochemical investigation on Isodon flavidus led to the isolation of flavidanolide A(1),a rearranged diterpenoid featuring a six/seven/five-membered tricyclic skeleton,together with flavidanolide B(2),an uncommon heterodimeric diterpenoid consisting of a norabietane and a seco-isopimarane monomeric units.Their structures were elucidated by extensive spectroscopic data and single-crystal X-ray diffraction analyses.Their plausible biosynthetic routes were also proposed.In the bioassay,flavidanolide B was found to exhibit good inhibitory effect against lipopolysaccharide(LPS)-induced nitric oxide(NO)production in RAW264.7 cells comparable to positive control pyrrolidinedithiocarbamate ammonium(PDTC),which provided evidence for the medicinal value of I.flavidus as a folk medicine for treating inflammatory diseases.
基金the Zhejiang Provincial Natural Science Foundation of China(No.LD19E010001)the National Natural Science Foundation of China(Nos.51771219,51771095 and 51771220)。
文摘The properties of nanocrystals are highly dependent on their morphology, composition and structure. To obtain full control over their properties, the behavior of nanocrystals under external stimuli, such as heat treatment, needs to be understood. Herein, to in situ observe their microstructure and morphology changes, Fe3O4–Ag heterodimers were selected as a model system. Their structural changes after heat treatment were investigated by in situ transmission electron microscopy. A combination of real-time imaging with elemental analysis enabled observation of the transformation of Fe3O4–Ag heterodimers having a loose interface configuration to those with a Janus structure at the atomic scale after heating from room temperature to 600 °C. After incubation at 600 °C for 32 min, two kinds of Janus structures could be seen, including a clear linear interface in the Fe3O4–Ag heterodimers and a semi-crescent-shaped interface between the Ag and Fe3O4 nanoparticles(NPs). These dynamic observations provide unique insights into NP growth mechanisms, which are essential for understanding and controlling the structure and morphology of nanoparticles.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.60571045 and 50872147)the National High-Tech.Research and Development Program of China (Grant No.2007AA03Z035)
文摘Monodisperse Au-Fe3O4 heterodimeric nanoparticles （NPs） were prepared by injecting precursors into a hot reaction solution. The size of Au and Fe3O4 particles can be controlled by changing the injection temperature. UVis spectra show that the surface plasma resonance band of Au-Fe3O4 heterodimeric NPs was evidently red-shifted compared with the resonance band of Au NPs of similar size. The as-prepared heterodimeric Au-Fe3O4 NPs exhibited superparamagnetic properties at room temperature. The Ag-Fe3O4 heterodimeric NPs were also prepared by this synthetic method simply using AgNO3 as precursor instead of HAuCl4. It is indicated that the reported method can be readily extended to the synthesis of other noble metal conjugated heterodimeric NPs.
基金supported by the Tianjin University and the National Natural Science Foundation of China (Nos. 22073067 and 21673156)。
文摘Combined theoretical and experimental studies have explained the mechanism of Pd-catalyzed δ-C(sp^(3))-H arylation of primary amines. Instead of the monomeric Pd mechanism, our research unveils that all steps including C–H activation, oxidative addition, and reductive elimination take place via the heterodimeric Pd–Ag intermediates and transition states. Experimentally, the active heterodimeric Pd–Ag species were detected by mass spectrometry, which further confirms the proposed heterodimeric mechanism. Insight gained through this study reveals the synergistic manner of palladium catalysis and silver(Ⅰ)additives in native NH;-directed C–H activation and C–C coupling reactions.
文摘In a previous report we had reported on the discovery of a novel bispecific immunoglobulin expressed by colonic epithelial cells as they transform into immunomimetic cells during exfoliation (Albaugh <i>et al. </i> (2020) <i>Open Journal of Preventive Medicine</i>, 10, 126-150). Colonic cells isolated from 0.5 gm aliquots of fresh stools (SCSR-10, Fecal Cell Isolation Kit, NonInvasive Technologies, Elkridge, MD) preserved at room temperature for up to one week, with viability of >85% were used to determine the number of cells expressing this novel bispecific immunoglobulin. Over the course of this period (18 years) we recognized that these cells opened the opportunity to investigate the expression of cell membrane biomarkers. As the applications grew, we introduced a new terminology, termed COPROCYTOBIOLOGY*. In this study, we surveyed a cohort of 58 free-living adults for the expression of the newly discovered bi-specific chimeric antibody. Almost all of the subjects showed a strong signal during flow-cytometric evaluation of their stool samples;averaging around 65%. However, two subjects exhibited a total loss of this signal and both these individuals were of African-American lineage (one male and one female). These cells upon culturing <i>in vitro</i> remained defective in contrast to the rest of the group where their progeny continued to generate the antibody. We propose that this signals the existence of a germ-line deletion of the gene for which a novel test (MEDISHIELD†) is suggested. This syndrome may be associated with a lack of response to prophylactic vaccines involving m-RNA.
基金supported in part by the National Natural Science Foundation of China(31070643 and 31130062)Tsinghua University(20121080028)
文摘The atypical PKC isoforms （ζ and t） play essential roles in regulating various cellular processes. Both the hetero-interaction between PKCζand p62 through their N-terminal PB 1 domains and the homo-oligomerization of p62 via its PB 1 domain are critical for the activation of NF-r.B signaling; however, the molecular mechanisms concerning the formation and regulation of these homotypic complexes remain unclear. Here we determined the crystal structure of PKCζ-PB 1 in complex with a mono- meric p62-PB 1 mutant, where the massive electrostatic interactions between the acidic OPCA motif of PKCζ-PB 1 and the basic surface of p62-PB 1, as well as additional hydrogen bonds, ensure the formation of a stable and specific complex. The PKCζ-p62 interaction is interfered with the modification of a specific Cys of PKCζ by the antiarthritis drug aurothiomalate, though all four cysteine residues in the PKCζ-PB 1 domain can be modified in in vitro assay. In addition, detailed structural and biochemical analyses demonstrate that the PB 1 domains of aPKCs belong to the type I group, which can depolymerize the high-molecular-weight p62 aggregates into homo-oligomers of lower order. These data together unravel the molecular mecha- nisms of the homo- or hetero-interactions between p62 and PKCζ and provide the basis for designing inhibitors of NF-r,.B sig- naling.
