RESUMEN
Skeletal muscle atrophy is commonly associated with aging, immobilization, muscle unloading, and congenital myopathies. Generation of mature muscle cells from skeletal muscle satellite cells (SCs) is pivotal in repairing muscle tissue. Exercise therapy promotes muscle hypertrophy and strength. Primary cilium is implicated as the mechanical sensor in some mammalian cells, but its role in skeletal muscle cells remains vague. To determine mechanical sensors for exercise-induced muscle hypertrophy, we established three SC-specific cilium dysfunctional mouse models-Myogenic factor 5 (Myf5)-Arf-like Protein 3 (Arl3)-/-, Paired box protein Pax-7 (Pax7)-Intraflagellar transport protein 88 homolog (Ift88)-/-, and Pax7-Arl3-/--by specifically deleting a ciliary protein ARL3 in MYF5-expressing SCs, or IFT88 in PAX7-expressing SCs, or ARL3 in PAX7-expressing SCs, respectively. We show that the Myf5-Arl3-/- mice develop grossly the same as WT mice. Intriguingly, mechanical stimulation-induced muscle hypertrophy or myoblast differentiation is abrogated in Myf5-Arl3-/- and Pax7-Arl3-/- mice or primary isolated Myf5-Arl3-/- and Pax7-Ift88-/- myoblasts, likely due to defective cilia-mediated Hedgehog (Hh) signaling. Collectively, we demonstrate SC cilia serve as mechanical sensors and promote exercise-induced muscle hypertrophy via Hh signaling pathway.
Asunto(s)
Cilios , Fuerza Muscular , Condicionamiento Físico Animal , Células Satélite del Músculo Esquelético , Animales , Diferenciación Celular , Cilios/fisiología , Terapia por Ejercicio , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Ratones , Fibras Musculares Esqueléticas/citología , Fibras Musculares Esqueléticas/fisiología , Factor de Transcripción PAX7/genética , Factor de Transcripción PAX7/metabolismo , Células Satélite del Músculo Esquelético/citología , Células Satélite del Músculo Esquelético/fisiologíaRESUMEN
Precise manipulation of liquid metal (LM) droplets possesses the potential to enable a wide range of applications in reconfigurable electronics, robotics, and microelectromechanical systems. Although a variety of methods have been explored to actuate LM droplets on a 2D plane, versatile 3D manipulation remains a challenge due to the difficulty in overcoming their heavy weight. Here, foam-core liquid metal (FCLM) droplets that can maintain the surface properties of LM while significantly reducing the density are developed, enabling 3D manipulation in an electrolyte. The FCLM droplet is fabricated by coating LM on the surface of a copper-grafted foam sphere. The actuation of the FCLM droplet is realized by electrically inducing Marangoni flow on the LM surface. Two motion modes of the FCLM droplet are observed and studied and the actuation performance is characterized. Multiple FCLM droplets can be readily controlled to form 3D structures, demonstrating their potential to be further developed to form collaborative robots for enabling wider applications.
RESUMEN
Glioblastoma multiforme (GBM) has been characterized by the high incidence, therapy tolerance and relapse. The molecular events controlling GBM resistant to chemotherapy temozolomide (TMZ) remain to be elusive. Here, we identified WNT signaling was amplified by TMZ and mediated drug response in GBM. We found O6-methylguanine DNA methyltransferase (MGMT) was redundant to WNT-mediated chemoresistance, which was highly associated with p53 mutation status. In GBM with p53 mutation, loss of function of p53 downregulated miR-34a expression, which represses transcription of WNT ligand 6 (WNT6) by directly binding to 3' UTR of WNT6 mRNA, leading to activation of WNT signaling, and the eventual WNT-mediated chemoresistance to TMZ. Combined treatment of TMZ with WNT inhibitor or miR34a mimic induced drug sensitivity of p53-mutant GBM cells and extended survival in xenograft mice in vivo. Our findings provide insight into understanding the molecular mechanism of GBM chemoresistance to TMZ and facilitating to develop novel treatment strategy to combat p53-mutant GBM by targeting miR-34a/WNT6 axis.
Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Animales , Antineoplásicos Alquilantes/farmacología , Antineoplásicos Alquilantes/uso terapéutico , Apoptosis , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Resistencia a Antineoplásicos/genética , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Humanos , Ratones , Recurrencia Local de Neoplasia/tratamiento farmacológico , Temozolomida/farmacología , Temozolomida/uso terapéutico , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Vía de Señalización WntRESUMEN
The purpose of this study was to explore the function of the MarR family regulator slnO. Additionally, a high-yield strain of salinomycin was constructed using combined regulation strategies. First, the slnO gene overexpression strain (GO) was constructed in Streptomyces albus. Compared to the wild-type (WT) strain, salinomycin production in the GO strain increased by approximately 28%. Electrophoretic mobility gel shift assays (EMSAs) confirmed that the SlnO protein can bind specifically to the intergenic regions of slnN-slnO, slnQ-slnA1, and slnF-slnT. qRT-PCR experiments also showed that slnA1, slnF, and slnT1 were significantly upregulated, whereas the expression level of the slnN gene was downregulated in the GO strain. Second, the slnN gene deletion strain (slnNDM) was used as the starting strain, and the pathway-specific gene slnR in the salinomycin gene cluster was overexpressed in slnNDM. This new strain was named ZJUS01. The yield of salinomycin in the ZJUS01 strain was 25% and 56% higher than those in the slnNDM and WT strains, respectively. The above results indicate that the slnO gene has a positive regulatory effect on the biosynthesis of salinomycin. Meanwhile, the yield of salinomycin can be greatly increased by manipulating multiple transcriptional regulations.
Asunto(s)
Streptomyces , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Familia de Multigenes , Piranos/metabolismo , Streptomyces/genéticaRESUMEN
MAP30 (Momordica antiviral protein 30kD) is a single-chain â -type ribosome inactivating protein with a variety of biological activities, including anti-tumor ability. It was reported that MAP30 would serve as a novel and relatively safe agent for prophylaxis and treatment of liver cancer. To determine whether adding two tumor targeting peptides could improve the antitumor activities of MAP30, we genetically modified MAP30 with an RGD motif and a EGFRi motif, which is a ligand with high affinity for αvß3 integrins and with high affinity for EGFR. The recombinant protein ELRL-MAP30 (rELRL-MAP30) containing a GST-tag was expressed in E. coli. The rELRL-MAP30 was highly expressed in the soluble fraction after induction with 0.15 mM IPTG for 20 h at 16 °C. The purified rELRL-MAP30 appeared as a band on SDS-PAGE. It was identified by western blotting. Cytotoxicity of recombinant protein to HepG2, MDA-MB-231, HUVEC and MCF-7 cells was detected by MTT analysis. Half maximal inhibitory concentration (IC50) values were 54.64 µg/mL, 70.13 µg/mL, 146 µg/mL, 466.4 µg/mL, respectively. Proliferation inhibition assays indicated that rELRL-MAP30 could inhibit the growth of Human liver cancer cell HepG2 effectively. We found that rELRL-MAP30 significantly induced apoptosis in liver cancer cells, as evidenced by nuclear staining of DAPI. In addition, rELRL-MAP30 induced apoptosis in human liver cancer HepG2 cells by up-regulation of Bax as well as down-regulation of Bcl-2. Migration of cell line were markedly inhibited by rELRL-MAP30 in a dose-dependent manner compared to the recombinant MAP30 (rMAP30). In summary, the fusion protein displaying extremely potent cytotoxicity might be highly effective for tumor therapy.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Momordica charantia/química , Péptidos/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Inactivadoras de Ribosomas Tipo 2/genética , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/metabolismo , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Clonación Molecular , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Vectores Genéticos/química , Vectores Genéticos/metabolismo , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Células Hep G2 , Células Endoteliales de la Vena Umbilical Humana , Humanos , Integrina alfa5/genética , Integrina alfa5/metabolismo , Integrina beta3/genética , Integrina beta3/metabolismo , Células MCF-7 , Péptidos/metabolismo , Unión Proteica , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes de Fusión/farmacología , Proteínas Inactivadoras de Ribosomas Tipo 2/metabolismo , Proteínas Inactivadoras de Ribosomas Tipo 2/farmacología , Proteína X Asociada a bcl-2/agonistas , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Osteonecrosis of the femoral head (ONFH) is a progressive, obstinate and disabling disease. At present, the treatment of ONFH is still a global medical problem. We aim to explore the role of bone mesenchymal stem cells (BMSCs)-derived and siRNAs-encapsulated exosomes (siRNAs-encapsulated BMSCexos) in ONFH. We first isolated BMSCexos and screened siRNAs of 6 ONFH-related genes for siRNAs-encapsulated BMSCexo. The expression of these 6 ONFH-related genes in dexamethasone (DXM)-treated MC3T3-E1 cell, cell model of ONFH, was detected by RT-qPCR and Western blot analysis. And then, we performed CCK-8 assay, angiogenesis assay and HE staining analysis to test the promotion role of the siRNAs-encapsulated BMSCexo for angiogenesis during ONFH repair. The results suggest that the obtained particles were BMSCexos. The screened effective siRNAs could effectively knock down their expression in VECs. Moreover, siRNAs-encapsulated BMSCexo could effectively knock down the expression of these genes in VECs. In addition, siRNAs-encapsulated BMSCexo promote angiogenesis during ONFH repair. In conclusion, we found siRNAs-encapsulated BMSCexos could promote ONFH repair by angiogenesis, and indicated exosome as the new siRNA carrier is of great significance to improve the efficiency of RNAi.
Asunto(s)
Exosomas/genética , Necrosis de la Cabeza Femoral/genética , Cabeza Femoral/patología , Células Madre Mesenquimatosas/patología , ARN Interferente Pequeño/genética , Células 3T3 , Animales , Línea Celular , Proliferación Celular/genética , Exosomas/patología , Necrosis de la Cabeza Femoral/patología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Ratones , Ratones Endogámicos C57BL , Neovascularización Fisiológica/genética , Osteogénesis/genéticaRESUMEN
The human transforming growth factor ß (TGF-ß)/bone morphogenic protein (BMP) signaling has been recognized as an attractive target to suppress fibroblast activation in osteonecrosis of the femoral head (ONFH). Here, we reported successful derivation of a self-inhibitory peptide from the crystal complex interface of TGF-ß with its cognate receptor TßRI using rational molecular design and in vitro binding assay. Computational modeling suggested that the peptide possesses a large flexibility and would incur considerable entropy penalty. To minimize the entropy effect, the peptide was extended and cyclized to obtain a modified version of cyclic peptide. Molecular dynamics (MD) simulations revealed that the cyclic peptide exhibits larger rigidity and lower thermal motion in unbound state as compared to its linear counterpart, thus causing less entropy penalty upon binding to TGF-ß. The computational findings were then substantiated by fluorescence polarization (FP) assays, that is, no binding affinity was detected for linear peptide (K d = n.d.), while cyclic version was determined to have a moderate affinity (K d = 76 ± 18 µM). Structural and energetic analysis identified two anchor residues Phe60 and Ser65 in cyclic peptide that can form a π-π stacking and a hydrogen bonding with the residues Trp30 and His68 of TGF-ß, respectively, conferring high stability and specificity to the complex system.
Asunto(s)
Necrosis de la Cabeza Femoral/tratamiento farmacológico , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Factor de Crecimiento Transformador beta/metabolismo , Proteínas Morfogenéticas Óseas/metabolismo , Ciclización , Diseño de Fármacos , Entropía , Necrosis de la Cabeza Femoral/metabolismo , Polarización de Fluorescencia , Humanos , Enlace de Hidrógeno , Simulación de Dinámica Molecular , Terapia Molecular Dirigida , Conformación Proteica , Receptores de Factores de Crecimiento Transformadores beta/química , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta/químicaRESUMEN
Salinomycin, a polyether antibiotic produced by Streptomyces albus, is widely used in animal husbandry as an anticoccidial drug and growth promoter. Situated within the salinomycin biosynthetic gene cluster, slnR encodes a LAL-family transcriptional regulator. The role of slnR in salinomycin production in S. albus was investigated by gene deletion, complementation, and overexpression. Gene replacement of slnR from S. albus chromosome results in almost loss of salinomycin production. Complementation of slnR restored salinomycin production, suggesting that SlnR is a positive regulator of salinomycin biosynthesis. Overexpression of slnR in S. albus led to about 25 % increase in salinomycin production compared to wild type. Quantitative RT-PCR analysis revealed that the expression of most sal structural genes was downregulated in the ΔslnR mutant but upregulated in the slnR overexpression strain. Electrophoretic mobility gel shift assays (EMSAs) also revealed that SlnRDBD binds directly to the three intergenic regions of slnQ-slnA1, slnF-slnT1, and slnC-slnB3. The SlnR binding sites within the three intergenic regions were determined by footprinting analysis and identified a consensus-directed repeat sequence 5'-ACCCCT-3'. These results indicated that SlnR modulated salinomycin biosynthesis as an enhancer via interaction with the promoters of slnA1, slnQ, slnF, slnT1, slnC, and slnB3 and activates the transcription of most of the genes belonging to the salinomycin gene cluster but not its own transcription.
Asunto(s)
Piranos/metabolismo , Streptomyces/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica/genética , Regulación Bacteriana de la Expresión Génica/fisiologíaRESUMEN
Simultaneous bilateral fractures of the femoral neck are rare injuries, which are reportedly induced by low-speed energy with predisposing factors including systemic diseases, medications and eclamptic seizures. Those caused by high energy are even rarer. High energy-induced bilateral fractures of the femoral neck conceive of high incidence of mortality and present great challenges in the early management. We report one case of a 52-year-old man with simultaneous bilateral fractures of the femoral neck which resulted from a motor pedestrian accident. One-stage closed reduction and internal fixation was done following the emergent resuscitation and neurosurgical management for concomitant brain injuries. The fractures united. There was no pain in the hips, and they had a normal range of motion. The treatment protocol, mechanism of the injury and possible postoperative complications were discussed to expand a comprehensive understanding about these infrequent types of fractures.
Asunto(s)
Fracturas del Cuello Femoral/etiología , Fracturas del Cuello Femoral/diagnóstico por imagen , Fracturas del Cuello Femoral/cirugía , Fijación Interna de Fracturas/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Tomografía Computarizada por Rayos XRESUMEN
Detailed mechanisms of WhiB-like (Wbl) proteins involved in antibiotic biosynthesis and morphological differentiation are poorly understood. Here, we characterize the role of WblAch, a Streptomyces chattanoogensis L10 protein belonging to this superfamily. Based on DNA microarray data and verified by real-time quantitative PCR (qRT-PCR), the expression of wblAch was shown to be positively regulated by AdpAch. Gel retardation assays and DNase I footprinting experiments showed that AdpAch has specific DNA-binding activity for the promoter region of wblAch. Gene disruption and genetic complementation revealed that WblAch acts in a positive manner to regulate natamycin production. When wblAch was overexpressed in the wild-type strain, the natamycin yield was increased by â¼30%. This provides a strategy to generate improved strains for natamycin production. Moreover, transcriptional analysis showed that the expression levels of whi genes (including whiA, whiB, whiH, and whiI) were severely depressed in the ΔwblAch mutant, suggesting that WblAch plays a part in morphological differentiation by influencing the expression of the whi genes.
Asunto(s)
Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Natamicina/biosíntesis , Streptomyces/enzimología , Streptomyces/crecimiento & desarrollo , Transactivadores/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Datos de Secuencia Molecular , Streptomyces/genética , Transactivadores/genéticaRESUMEN
The aim of this study was to investigate whether N-acetylcysteine (NAC), a known antioxidant, can protect kidney against ischemic injury through regulating Nrf2 signaling pathway. The expression of Nrf2, HO-1 and cleaved caspase 3 were analyzed by Western blot analysis. Apoptosis of renal tubular epithelial cells was assessed by the TUNEL method. Malondialdehyde (MDA) levels were measured by the thiobarbituric acid reaction. Blood serum creatinine and blood urea nitrogen levels were measured with an Olympus automatic multi-analyzer. We found that NAC significantly increased Nrf2 and downstream HO-1 expression. Furthermore, NAC significantly decreased cleaved caspase 3, p53 and renal epithelial tubular cell apoptosis. In addition, NAC reduced the MDA level. These findings suggest that the protective action of NAC on ischemia renal injury is associated closely with Nrf2 signaling pathway.
Asunto(s)
Acetilcisteína/administración & dosificación , Lesión Renal Aguda/prevención & control , Lesión Renal Aguda/fisiopatología , Factor 2 Relacionado con NF-E2/metabolismo , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/fisiopatología , Transducción de Señal/efectos de los fármacos , Animales , Depuradores de Radicales Libres/administración & dosificación , Masculino , Factor 2 Relacionado con NF-E2/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Resultado del TratamientoRESUMEN
Sediment cores are optimal mediums for investigating the historical presence of offshore microplastics (MPs). In this study, two sediment cores were collected at varying water depths, i.e., XS2 (10 m) and XS3 (20 m), from the Xiangshan offshore (XSO) in Ningbo. We focused on the spatiotemporal distribution characteristics of MPs within two sediment cores and explored the response differences of MPs abundance to natural factors and human activities. The results showed that the MPs abundance in sediments has gradually increased since the late 1960s, but with interannual fluctuations. MPs abundance in XS2 and XS3 were 1133-8700 and 633-11433 items/kg dry weight, respectively. The predominant polymers were PA, PU, PET and ACR, with fragmented particles being the most prevalent shape of MPs. The MPs abundance in XS2 and XS3 had a similar response to natural factors, mainly including (i) MPs abundance significantly correlated with the sediment load of the Qiantang River (p < 0.01), indicating that sediment load might be an important factor affecting the MPs abundance and that MPs transported by rivers had characteristics of near-source sedimentation; (ii) typhoons had the effect of weakening the MPs abundance; and (iii) geological activities might be potential contributing factors to variations in MPs' abundance in deep sediments. Correlation analyses demonstrated that MPs in XSO was the result of multiple sources, stemming from plastic production, sewage discharge, marine fisheries and shipping activities. Notably, XS3 exhibited higher sensitivity to human activities compared to XS2, owing to differences in sampling locations. This study underscores the significance of employing two sediment cores, rather than a single core, as it provides a more comprehensive insight into the overarching trends and disparities in the historical pollution of MPs. Our findings contribute to a deeper understanding of the history of offshore MPs pollution, shedding new light on this critical environmental issue.
Asunto(s)
Líquidos Corporales , Contaminantes Químicos del Agua , Humanos , Microplásticos , Plásticos , China , Transporte Biológico , Monitoreo del Ambiente , Sedimentos GeológicosRESUMEN
This study aims to analyze the epidemiological and pathogenic characteristics of an outbreak primarily caused by respiratory syncytial virus (RSV), human rhinovirus (HRV), and human metapneumovirus (HMPV) in a kindergarten and primary school. The outbreak was investigated by field epidemiological investigation, and the common respiratory pathogens were screened by RT-PCR detection technology. The attack rate of this outbreak was 63.95% (110/172). Main symptoms included cough (85.45%), sore throat (60.91%), and sneezing (60.00%). Multifactorial logistic regression analysis revealed that continuous handwashing and mouth and nose covering when sneezing were protective factors. All 15 collected throat swab specimens tested positive for viruses, with HMPV as the predominant pathogen (80.00%), followed by HRV (53.33%), and two cases of positive respiratory syncytial virus (13.33%). Among them, six samples showed coinfections of HMPV and HRV, and one had coinfections of HMPV and RSV, resulting in a coinfection rate of 46.67%. Genetic sequencing indicated that the HMPV genotype in this outbreak was A2c, and the HRV genotype was type A, resulting in a coinfection outbreak of HMPV, HRV, and RSV in schools and kindergartens, suggesting that multi-pathogen surveillance of respiratory tract infections should be strengthened.
Asunto(s)
Coinfección , Brotes de Enfermedades , Metapneumovirus , Epidemiología Molecular , Infecciones por Virus Sincitial Respiratorio , Infecciones del Sistema Respiratorio , Humanos , China/epidemiología , Coinfección/epidemiología , Coinfección/virología , Masculino , Preescolar , Femenino , Niño , Infecciones del Sistema Respiratorio/virología , Infecciones del Sistema Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/virología , Metapneumovirus/genética , Metapneumovirus/aislamiento & purificación , Genotipo , Rhinovirus/genética , Rhinovirus/aislamiento & purificación , Rhinovirus/clasificación , Filogenia , Infecciones por Paramyxoviridae/epidemiología , Infecciones por Paramyxoviridae/virología , Virus Sincitial Respiratorio Humano/genética , Virus Sincitial Respiratorio Humano/aislamiento & purificación , Instituciones AcadémicasRESUMEN
BACKGROUND: Oral antiviral drugs with improved antiviral potency and safety are needed to address current challenges in clinical practice for treatment of COVID-19, including the risks of rebound, drug-drug interactions, and emerging resistance. METHODS: Olgotrelvir (STI-1558) is designed as a next-generation antiviral targeting the SARS-CoV-2 main protease (Mpro), an essential enzyme for SARS-CoV-2 replication, and human cathepsin L (CTSL), a key enzyme for SARS-CoV-2 entry into host cells. FINDINGS: Olgotrelvir is a highly bioavailable oral prodrug that is converted in plasma to its active form, AC1115. The dual mechanism of action of olgotrelvir and AC1115 was confirmed by enzyme activity inhibition assays and co-crystal structures of AC1115 with SARS-CoV-2 Mpro and human CTSL. AC1115 displayed antiviral activity by inhibiting replication of all tested SARS-CoV-2 variants in cell culture systems. Olgotrelvir also inhibited viral entry into cells using SARS-CoV-2 Spike-mediated pseudotypes by inhibition of host CTSL. In the K18-hACE2 transgenic mouse model of SARS-CoV-2-mediated disease, olgotrelvir significantly reduced the virus load in the lungs, prevented body weight loss, and reduced cytokine release and lung pathologies. Olgotrelvir demonstrated potent activity against the nirmatrelvir-resistant Mpro E166 mutants. Olgotrelvir showed enhanced oral bioavailability in animal models and in humans with significant plasma exposure without ritonavir. In phase I studies (ClinicalTrials.gov: NCT05364840 and NCT05523739), olgotrelvir demonstrated a favorable safety profile and antiviral activity. CONCLUSIONS: Olgotrelvir is an oral inhibitor targeting Mpro and CTSL with high antiviral activity and plasma exposure and is a standalone treatment candidate for COVID-19. FUNDING: Funded by Sorrento Therapeutics.
Asunto(s)
Tratamiento Farmacológico de COVID-19 , COVID-19 , Inhibidores de Proteasa de Coronavirus , SARS-CoV-2 , Animales , Humanos , Ratones , Antivirales/farmacología , Antivirales/uso terapéutico , Catepsina L/antagonistas & inhibidores , COVID-19/prevención & control , Modelos Animales de Enfermedad , Ratones Transgénicos , Inhibidores de Proteasa de Coronavirus/química , Inhibidores de Proteasa de Coronavirus/farmacología , Proteasas 3C de Coronavirus/antagonistas & inhibidores , Tratamiento Farmacológico de COVID-19/métodosRESUMEN
The Kruppel-associated box (KRAB)-associated co-repressor KAP1 is an essential nuclear co-repressor for the KRAB zinc finger protein superfamily of transcriptional factors. Ataxia telangiectasia mutated (ATM)-Chk2 and ATM- and Rad3-related (ATR)-Chk1 are two primary kinase signaling cascades activated in response to DNA damage. A growing body of evidence suggests that ATM and ATR phosphorylate KAP1 at Ser-824 in response to DNA damage and regulate KAP1-dependent chromatin condensation, DNA repair, and gene expression. Here, we show that, depending on the type of DNA damage that occurs, KAP1 Ser-473 can be phosphorylated by ATM-Chk2 or ATR-Chk1 kinases. Phosphorylation of KAP1 at Ser-473 attenuated its binding to the heterochromatin protein 1 family proteins and inhibited its transcriptional repression of KRAB-zinc finger protein (KRAB-ZFP) target genes. Moreover, KAP1 Ser-473 phosphorylation induced by DNA damage stimulated KAP1-E2F1 binding. Overexpression of heterochromatin protein 1 significantly inhibited E2F1-KAP1 binding. Elimination of KAP1 Ser-473 phosphorylation increased E2F1-targeted proapoptotic gene expression and E2F1-induced apoptosis in response to DNA damage. Furthermore, loss of phosphorylation of KAP1 Ser-473 led to less BRCA1 focus formation and slower kinetics of loss of γH2AX foci after DNA damage. KAP1 Ser-473 phosphorylation was required for efficient DNA repair and cell survival in response to DNA damage. Our studies reveal novel functions of KAP1 Ser-473 phosphorylation under stress.
Asunto(s)
Apoptosis/fisiología , Ensamble y Desensamble de Cromatina , Daño del ADN , Proteínas Represoras/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Quinasa de Punto de Control 2 , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Factor de Transcripción E2F1/genética , Factor de Transcripción E2F1/metabolismo , Células HEK293 , Células HeLa , Humanos , Fosforilación/genética , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Represoras/genética , Serina/genética , Serina/metabolismo , Proteína 28 que Contiene Motivos Tripartito , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismoRESUMEN
The development of an indirect competitive immunomagnetic-proximity ligation assay (ICIPLA), which is a novel method for detecting small molecules, is described in this report. Free small molecules in samples can be detected using a proximity ligation assay (PLA); the detection is based on the proximity effect caused by a high concentration of small molecule-BSA conjugates bound to streptavidin magnetic beads. As an indirect format competitive immunoassay, the ICIPLA method has the advantage in that the quantity of monoclonal antibody (mAb) used for small-molecule detection is 8-fold lower than that required for the competitive immunomagnetic-proximity ligation assay (CIPLA) described in our previous work. Small molecules can be detected using a single monoclonal antibody, and the PLA method can be used to amplify high-performance signals. In this work, the small molecular compound ractopamine (RAC) was selected as a target for ICIPLA. The limit of detection (LOD) was 0.01 ng ml(-1), and the method exhibited a broad dynamic range of up to six orders of magnitude. We also employed the ICIPLA method to detect RAC in serum, urine, and muscle extracts; the results indicated that the LOD and dynamic range were not altered. The cross-reactivity studies showed that the cross-reactivity values for all RAC analogs were below 0.01%. These results suggest that ICIPLA is a sensitive, specific and practical method for small-molecule detection. This is the first report of the improved PLA technology for small-molecule detection by indirect competitive formats in the biological samples.
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Anticuerpos Monoclonales/inmunología , Inmunoensayo , Separación Inmunomagnética , Fenetilaminas/sangre , Fenetilaminas/orina , Anticuerpos Monoclonales/metabolismo , Técnicas Biosensibles , Límite de Detección , Músculos/química , Estreptavidina/químicaRESUMEN
OBJECTIVE: To explore the antimicrobial resistance of nosocomial Gram-negative bacilli across China. METHODS: A total of 1247 consecutive and non-repetitive Gram-negative bacilli were isolated from 13 Chinese teaching hospitals from March to August 2012. All isolates were sent to a central laboratory for reidentification and susceptibility testing. The minimal inhibitory concentration (MICs) of meropenem and other antibacterial agents were determined by agar dilution method. And the data were analyzed with WHONET-5.6 software. RESULTS: The activity of antimicrobial agents against Enterobacteriaceae was in the following descending order of susceptibility rate: meropenem (97.5%, 849/871) , amikacin (94.5%, 823/871) , imipenem (93.6%, 815/871) , ertapenem (92.9%, 809/871) , piperacillin/tazobactam (89.9%, 783/871) , cefoperazone/sulbactam (83.5%, 727/871) , cefepime (78.1%, 680/871) , polymyxin B (77.0%, 670/871) , cefiazidime (69.6%, 606/871) , levofloxacin (69.2%, 603/871) , ciprofloxacin (63.6%, 554/871) , minocyline (63.1%, 550/871) , ceftriaxone (55.7%, 485/871) , cefotaxime (54.2%, 472/871) and cefoxitin (51.4%, 448/871) . The prevalence of extended-spectrum beta-lactamase (ESBL) was 64.3% (117/182) in Escherichia coli (E. coli) and 32.1% (60/187) in Klebsiella pneumonia (K. pneumoniae) . The sensitivities of E. coli to meropenem and imipenem were 100%. And over 90% of E. coli was sensitive to ertapenem, amikacin, piperacillin/tazobactam and polymyxin B. However, over 60% of E. coli was resistant to ciprofloxacin, levofloxacin, ceftriaxone and cefotaxime. The susceptibility of K. pneumoniae to meropenem, imipenem, amikacin and polymyxin B maintained at over 90%. The activities of antimicrobial agents against E. cloacae, E. aerogenes and Citrobacter freundii were in the following descending order of susceptibility rate: meropenem (96.0%-100%) , imipenem (96.0%-100%) , polymyxin B (95.8%-100%) , amikacin (92.2%-100%) , ertapenem (85.6%-93.3%) , cefepime (77.8%-93.3%) , cefoperazone/sulbactam (78.4%-90.0%) and piperacillin/tazobactam (65.0%-89.8%) . The most susceptible agent against Acinetobacter baumannii (A. baumannii) was polymyxin B (100%) . The susceptibilities of A.baumannii to imipenem, meropenem and minocyline were 37.8% (65/172) , 36.0% (62/172) and 62.8% (108/172) respectively. The most active agents against Pseudomonas aeruginosa (P. aeruginosa) were polymyxin B (97.2%, 173/178) , followed by amikacin (89.3%, 159/178) and cefiazidime (83.7%, 149/178) . Clinical and Laboratory Standards Institute revised P.aeruginosa susceptibility standard in 2012. The sensitivity of piperacillin/tazobactam changed from 83.7% (149/178) to 77.5% (138/178) . The sensitivity of meropenem decreased from 78.1% ( 139/178 ) to 71.3% ( 127/178 ) while that of imipenem declined from 69.7% (124/178) to 59.6% (106/178) . The prevalence of multi-drug resistant A. baumannii and P. aeruginosa were 65.7% (113/172) and 9.0% (16/178) respectively. CONCLUSIONS: Carbapenems remain highly active against Enterobacteriaceae. Increasing resistance of A. baumannii to all antimicrobial agents is noted. New breakpoint to P.aeruginosa has obvious effects on antimicrobial sensitivity.
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Antiinfecciosos/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , China , Bacterias Gramnegativas/aislamiento & purificación , Hospitales de Enseñanza , Humanos , Pruebas de Sensibilidad MicrobianaRESUMEN
BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a common and severe complication following femoral neck fractures in young adults. Despite significant advances in surgical techniques, radiological evaluation and comprehensive treatment for the prevention of ONFH, the incidence of traumatic ONFH has remained unchanged at approximately 20% in recent decades. The injury-to-surgery interval is considered as a principal factor affecting the occurrence of ONFH, and traditionally, femoral neck fractures are treated emergently. However, the relationship between the injury-to-surgery interval and ONFH occurrence is poorly understood, and previous reviews have not provided a precise explanation due to the lack of strict selection criteria for studies. METHODS: We reviewed previously published articles and included in current systematic review those studies with accurate multivariate analyses that included age, fracture type, operation method, follow-up, ONFH occurrence and injury-to-surgery interval. RESULTS: Six case studies were included and reevaluated. The studies included 263 hips for final analysis, with an overall incidence of postfracture ONFH of 17.5%. Patients were categorized into groups of less/more than 8 h, less/more than 24 h, less/more than 48 h and less/more than 3 weeks based on the individual injury-to-surgery interval. The postfracture ONFH incidence ranged from 13.3% (<8 weeks) to 21.7% (>3 weeks). Operations performed within 3 weeks of injury resulted in a lower ONFH incidence compared with operations performed after 3 weeks; however, this difference was not statistically significant. The ONFH incidence remained relatively stable when the operations were performed within 3 weeks of injury. CONCLUSIONS: The injury-to-surgery interval did not significantly affect the incidence of postoperative ONFH.
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Fracturas del Fémur/complicaciones , Necrosis de la Cabeza Femoral/epidemiología , Adolescente , Adulto , Factores de Edad , Fracturas del Fémur/cirugía , Necrosis de la Cabeza Femoral/etiología , Fijación de Fractura , Humanos , Persona de Mediana Edad , Factores de Tiempo , Adulto JovenRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Danhong injection (DHI) is a renowned traditional Chinese medicine often used clinically to treat cardiovascular and cerebrovascular diseases. Studies have shown that DHI can significantly alter microRNA (miRNA) expression in the brain tissue. Therefore, exploring specific miRNAs' regulatory mechanisms during treatment with DHI is essential. AIM OF THE STUDY: To investigate DHI's regulatory mechanism on cerebral autophagy in rats with cerebral ischemia-reperfusion injury (CIRI). MATERIAL AND METHODS: Rats were randomly divided into the sham, middle cerebral artery occlusion (MCAO) model, and DHI-treatment groups. The extent of brain damage was evaluated using triphenyl tetrazolium chloride and hematoxylin-eosin staining. Hippocampal cell autophagy was observed using transmission electron microscopy. Autophagy-related proteins were analyzed using western blotting. Differentially expressed miRNAs were screened using high-throughput and real-time quantitative reverse transcription PCR. The relationship between miR-132-3p and ATG12 was confirmed using a dual-luciferase assay. The miR-132-3p mimics and inhibitors were transfected into PC12 cells subjected to oxygen-glucose deprivation (OGD) in vitro and MCAO model rats in vivo. RESULTS: DHI significantly altered the miRNA expression profile in rat brain tissues. The pathological changes in the brain tissues were improved, and the autophagic hippocampal cell vehicles were significantly reduced after DHI treatment. miRNA-132-3p, one of the miRNAs with a significantly different expression, was screened. Kyoto Encyclopedia of Genes and Genomes signal pathway analysis showed that its target genes were closely related to autophagy. Western blotting revealed that the p-PI3K, p-AKT, and mTOR expression increased significantly; AMPK, ULK1, ATG12, ATG16L1, and LC3II/I were downregulated in the DHI group. Dual-luciferase reporter gene experiments showed that miRNA-132-3p could target the ATG12 3'-UTR region directly. In vitro, miRNA-132-3p had a protective effect on OGD/R-induced oxidative stress injury in PC12 cells, improving cell viability, and affecting the expression of autophagy pathway-related proteins. In vivo transfection experiments showed that miR-132-3p could regulate ATG12 expression in CIRI rats' lateral brain tissue, affecting the autophagy signaling pathway. miR-132-3p overexpression reduces CIRI-induced autophagy and protects neurons. CONCLUSION: This study showed that DHI inhibits neuronal autophagy after cerebral ischemia-reperfusion. This may have resulted from miR-132-3p targeting ATG12 and regulating the autophagy signaling pathway protein expression.
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Isquemia Encefálica , MicroARNs , Daño por Reperfusión , Proteínas Quinasas Activadas por AMP , Animales , Apoptosis , Autofagia , Proteína 12 Relacionada con la Autofagia/metabolismo , Proteínas Relacionadas con la Autofagia/genética , Isquemia Encefálica/metabolismo , Cloruros , Medicamentos Herbarios Chinos , Eosina Amarillenta-(YS)/farmacología , Eosina Amarillenta-(YS)/uso terapéutico , Glucosa/farmacología , Hematoxilina/farmacología , Hematoxilina/uso terapéutico , Infarto de la Arteria Cerebral Media/patología , MicroARNs/metabolismo , Oxígeno/farmacología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Ratas , Daño por Reperfusión/metabolismo , Serina-Treonina Quinasas TORRESUMEN
Ribosome-inactivating proteins (RIPs) are a class of cytotoxic rRNA N-glycosylase, which widely exist in higher plants in different taxonomy, including many traditional Chinese medicinal materials and vegetables and fruits. In this paper, the traditional Chinese medicinal plants containing RIPs protein were sorted out, and their pharmacological effects and clinical applications were analyzed. Since many RIPs in traditional Chinese medicine plants exhibit antiviral and antitumor activities and show great clinical application potential, people's interest in these proteins is on the rise. This paper summarizes the possible mechanism of RIPs's anti-virus and anti-tumor effects, and discusses its potential problems and risks, laying a foundation for subsequent research on how to exert its anti-virus and anti-tumor effects.