RESUMO
Epstein-Barr virus (EBV) contributes to ~1% of all human cancers including several B-cell neoplasms. A characteristic feature of EBV life cycle is its ability to transform metabolically quiescent B-lymphocytes into hyperproliferating B-cell blasts with the establishment of viral latency, while intermittent lytic cycle induction is necessary for the production of progeny virus. Our RNA-Seq analyses of both latently infected naïve B-lymphocytes and transformed B-lymphocytes upon lytic cycle replication indicate a contrasting expression pattern of a membrane-associated carbonic anhydrase isoform CA9, an essential component for maintaining cell acid-base homeostasis. We show that while CA9 expression is transcriptionally activated during latent infection model, lytic cycle replication restrains its expression. Pharmacological inhibition of CA-activity using specific inhibitors retards EBV induced B-cell transformation, inhibits B-cells outgrowth and colony formation ability of transformed B-lymphocytes through lowering the intracellular pH, induction of cell apoptosis and facilitating degradation of CA9 transcripts. Reanalyses of ChIP-Seq data along with utilization of EBNA2 knockout virus, ectopic expression of EBNA2 and sh-RNA mediated knockdown of CA9 expression we further demonstrate that EBNA2 mediated CA9 transcriptional activation is essential for EBV latently infected B-cell survival. In contrast, during lytic cycle reactivation CA9 expression is transcriptionally suppressed by the key EBV lytic cycle transactivator, BZLF1 through its transactivation domain. Overall, our study highlights the dynamic alterations of CA9 expression and its activity in regulating pH homeostasis act as one of the major drivers for EBV induced B-cell transformation and subsequent B-cell lymphomagenesis.
Assuntos
Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Humanos , Herpesvirus Humano 4/fisiologia , Infecções por Vírus Epstein-Barr/genética , Linfócitos B , Latência Viral , Transativadores/genética , Ativação Viral , Regulação Viral da Expressão GênicaRESUMO
To swim through a viscous fluid, a flagellated bacterium must overcome the fluid drag on its body by rotating a flagellum or a bundle of multiple flagella. Because the drag increases with the size of bacteria, it is expected theoretically that the swimming speed of a bacterium inversely correlates with its body length. Nevertheless, despite extensive research, the fundamental size-speed relation of flagellated bacteria remains unclear with different experiments reporting conflicting results. Here, by critically reviewing the existing evidence and synergizing our own experiments of large sample sizes, hydrodynamic modeling, and simulations, we demonstrate that the average swimming speed of Escherichia coli, a premier model of peritrichous bacteria, is independent of their body length. Our quantitative analysis shows that such a counterintuitive relation is the consequence of the collective flagellar dynamics dictated by the linear correlation between the body length and the number of flagella of bacteria. Notably, our study reveals how bacteria utilize the increasing number of flagella to regulate the flagellar motor load. The collective load sharing among multiple flagella results in a lower load on each flagellar motor and therefore faster flagellar rotation, which compensates for the higher fluid drag on the longer bodies of bacteria. Without this balancing mechanism, the swimming speed of monotrichous bacteria generically decreases with increasing body length, a feature limiting the size variation of the bacteria. Altogether, our study resolves a long-standing controversy over the size-speed relation of flagellated bacteria and provides insights into the functional benefit of multiflagellarity in bacteria.
Assuntos
Movimento , Natação , Movimento/fisiologia , Flagelos/fisiologia , Rotação , Escherichia coli/fisiologiaRESUMO
The therapeutic application of CRISPR-Cas9 is limited due to its off-target activity. To have a better understanding of this off-target effect, we focused on its mismatch-prone PAM distal end. The off-target activity of SpCas9 depends directly on the nature of mismatches, which in turn results in deviation of the active site of SpCas9 due to structural instability in the RNA-DNA duplex strand. In order to test the hypothesis, we designed an array of mismatched target sites at the PAM distal end and performed in vitro and cell line-based experiments, which showed a strong correlation for Cas9 activity. We found that target sites having multiple mismatches in the 18th to 15th position upstream of the PAM showed no to little activity. For further mechanistic validation, Molecular Dynamics simulations were performed, which revealed that certain mismatches showed elevated root mean square deviation values that can be attributed to conformational instability within the RNA-DNA duplex. Therefore, for successful prediction of the off-target effect of SpCas9, along with complementation-derived energy, the RNA-DNA duplex stability should be taken into account.
Assuntos
Pareamento Incorreto de Bases , Proteína 9 Associada à CRISPR , Sistemas CRISPR-Cas , Humanos , Proteína 9 Associada à CRISPR/metabolismo , Proteína 9 Associada à CRISPR/genética , Proteína 9 Associada à CRISPR/química , DNA/química , DNA/metabolismo , Simulação de Dinâmica Molecular , RNA/química , RNA/metabolismo , RNA Guia de Sistemas CRISPR-Cas/metabolismo , RNA Guia de Sistemas CRISPR-Cas/química , Células HEK293 , Edição de GenesRESUMO
Lapatinib (LTP) commercially available as lapatinib ditosylate (LTP-DTS) salt is the only drug approved for the treatment of HER-positive metastatic breast cancer. A low and pH-dependent solubility results in poor and variable oral bioavailability, thus driving significant interest in molecular modification and formulation strategies of the drug. Furthermore, due to very high crystallinity, LTP and LTP-DTS have low solubility in lipid excipients, making it difficult to be delivered by lipid-based carrier systems. Thus, the present work reports a new salt form of LTP with a docusate counterion to enhance the pharmaceutical properties of the drug (LTP-DOC). NMR spectra showed a downfield shift of the methylene singlet proton from 3.83 and 4.41 ppm, indicating a lowering of electron density on the adjacent nitrogen atom and confirming the formation of amine-sulfonyl salt through the specified basic nitrogen center located adjacent to the furan ring. PXRD diffractograms of LTP-DOC indicated a reduced crystallinity of the prepared salt. The dissolution, equilibrium solubility, lipid excipient solubility, partitioning coefficient, distribution coefficient, tabletability, and in vitro cytotoxicity of the lipophilic salt of LTP were investigated. The equilibrium solubility data showed that LTP-DOC possesses a pH-independent solubility profile in the pH range of 3.5 to 7.4 with a 3.14 times higher permeability coefficient than commercial ditosylate salt. Furthermore, the prepared LTP-DOC salts showed twice higher log P than the free base and 8 times higher than LTP-DTS. The prepared LTP-DOC was found to have 4- to 9-fold higher solubility in lipid excipients like Capmul MCM C8 and Maisine CC compared to the ditosylate salt. The LTP-DOC salt was tabletable and showed approximately 1.2 times lower dissolution than commercial ditosylate salt, indicating extended-release behavior. A cytotoxicity study of LTP-DOC salt showed an approximately 2.5 times lower IC50 value than the LTP-free base and 1.7 times lower than commercial ditosylate salt with an approximately 3 times higher selectivity index. The investigations strongly indicate a high translational potential of the prepared salt form in maintaining solubility-lipophilicity interplay, enhancing the drug's bioavailability, and developing lipidic formulations.
Assuntos
Excipientes , Lapatinib , Solubilidade , Lapatinib/química , Humanos , Excipientes/química , Lipídeos/química , Sais/química , Disponibilidade Biológica , Concentração de Íons de Hidrogênio , Química Farmacêutica/métodos , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/administração & dosagem , Liberação Controlada de FármacosRESUMO
The anti-oxidant and anti-inflammatory effect of beta-glucogallin (BGG), a plant-derived natural product, was evaluated in both in vitro and in vivo studies. For the in vitro study, the ability of BGG pre-treatment to quench LPS-induced effects compared to LPS alone in macrophages was investigated. It was found that BGG pre-treatment showed a significant decrease in ROS, NO, superoxide, and pro-inflammatory cytokines (TNF-alpha, IL-4, IL-17, IL-1ß, and IL-6) and increased reduced glutathione coupled with the restoration of mitochondrial membrane potential. Gene profiling and further validation by qPCR showed that BGG pre-treatment downregulated the LPS-induced expression of c-Fos, Fas, MMP-9, iNOS, COX-2, MyD88, TRIF, TRAF6, TRAM, c-JUN, and NF-κB. We observed that BGG pre-treatment reduced nuclear translocation of LPS-activated NF-κB and thus reduced the subsequent expressions of NLRP3 and IL-1ß, indicating the ability of BGG to inhibit inflammasome formation. Molecular docking studies showed that BGG could bind at the active site of TLR4. Finally, in the LPS-driven sepsis mouse model, we showed that pre-treatment with BGG sustained toxic shock, as evident from their 100% survival. Our study clearly showed the therapeutic potential of BGG in toxic shock syndrome.
Assuntos
Produtos Biológicos , Sepse , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Anti-Inflamatórios/efeitos adversos , Antioxidantes/farmacologia , Produtos Biológicos/farmacologia , Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Glutationa/metabolismo , Taninos Hidrolisáveis , Inflamassomos/metabolismo , Interleucina-17/metabolismo , Interleucina-4/metabolismo , Interleucina-6/metabolismo , Lipopolissacarídeos/efeitos adversos , Macrófagos/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sepse/metabolismo , Superóxidos/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Chronic arsenic (As) poisoning is mostly due to subsoil water contaminated with As and its salts. Exposure to As has been found to cause an elevation in reactive oxygen species (ROS), leading to the damage of DNA and proteins, and it also causes immunotoxicity. Treatment regimens are primarily based on chelation therapy and amino acid and vitamin supplementations. Recent studies have established that natural products display effective and progressive relief from arsenicosis without any side effects. ß-glucogallin (BGG), a gallo-tannin natural product, is reported to possess anti-oxidant and anti-inflammatory properties. In the present study, we aim to observe the protective role of BGG against As-induced cytotoxicity, apoptosis, mitochondrial dysfunction, and the underlying mechanisms in RAW 264.7 macrophage cells. We found that BGG alleviates As-induced ROS, apoptosis, and mitochondrial dysfunction in RAW 264.7 macrophage cells. Thus, BGG can be used therapeutically to prevent As-induced toxicity.
Assuntos
Intoxicação por Arsênico , Arsênio , Animais , Apoptose , Arsênio/toxicidade , Intoxicação por Arsênico/metabolismo , Intoxicação por Arsênico/prevenção & controle , Trióxido de Arsênio/farmacologia , Taninos Hidrolisáveis/farmacologia , Camundongos , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Estresse Oxidativo , Óxidos/toxicidade , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismoRESUMO
The emergence of SARS-CoV-2 has brought the world to a standstill, and till date, effective treatments and diagnostics against this idiosyncratic pathogen are lacking. As compared to the standard WHO/CDC qPCR detection method, which consumes several hours for detection, CRISPR-based SHERLOCK, DETECTR, and FELUDA have emerged as rapid diagnostic tools for the detection of the RNA genome of SARS-CoV-2 within an hour with 100% accuracy, specificity, and sensitivity. These attributes of CRISPR-based detection technologies have taken themselves one step ahead of available detection systems and are emerging as an inevitable tool for quick detection of the virus. Further, the discovery of Cas13s nucleases and their orthologs has opened a new corridor for exploitation of Cas13s as an antiviral therapy against SARS-CoV-2 and other viral diseases. One such approach is Prophylactic Antiviral CRISPR in huMAN cells (PACMAN), which needs a long haul to bring into therapy. The approval of SHERLOCK as the first CRISPR-based SARS-CoV-2 test kit by the FDA, for emergency diagnosis of COVID-19 patients, has given positive hope to scientists that sooner human trials of CRISPR-based therapy will be ratified. In this review, we have extensively reviewed the present CRISPR-based approaches, challenges, and future prospects in the light of diagnostics and therapeutics against SARS-CoV-2. KEY POINTS: ⢠The discovery of Cas12 and Cas13 siblings allowed scientists to detect the viral genes. ⢠Cas13d's identification aided scientists in precisely cleaving the SARS-CoV-2 ssRNA. ⢠CRISPR-Cas system acts as "molecular detector and antiviral proctor."
Assuntos
COVID-19 , SARS-CoV-2 , Antivirais , Sistemas CRISPR-Cas , Humanos , RNA Viral , Reação em Cadeia da Polimerase em Tempo RealRESUMO
The current pandemic, caused by SARS-CoV-2 virus, is a severe challenge for human health and the world economy. There is an urgent need for development of drugs that can manage this pandemic, as it has already infected 19 million people and led to the death of around 711,277 people worldwide. At this time, in-silico studies are providing lots of preliminary data about potential drugs, which can be a great help in further in-vitro and in-vivo studies. Here, we have selected three polyphenolic compounds, mangiferin, glucogallin, and phlorizin. These compounds are isolated from different natural sources but share structural similarities and have been reported for their antiviral activity. The objective of this study is to analyze and predict the anti-protease activity of these compounds on SARS-CoV-2main protease (Mpro) and TMPRSS2 protein. Both the viral protein and the host protein play an important role in the viral life cycle, such as post-translational modification and viral spike protein priming. This study has been performed by molecular docking of the compounds using PyRx with AutoDock Vina on the two aforementioned targets chosen for this study, i.e., SARS-CoV-2 Mpro and TMPRSS2. The compounds showed good binding affinity and are further analyzed by (Molecular dynamic) MD and Molecular Mechanics Poisson-Boltzmann Surface Area MM-PBSA study. The MD-simulation study has predicted that these natural compounds will have a great impact on the stabilization of the binding cavity of the Mpro of SARS-CoV-2. The predicted pharmacokinetic parameters also show that these compounds are expected to have good solubility and absorption properties. Further predictions for these compounds also showed no involvement in drug-drug interaction and no toxicity.
Assuntos
Betacoronavirus/isolamento & purificação , Produtos Biológicos/farmacologia , Infecções por Coronavirus/tratamento farmacológico , Cisteína Endopeptidases/química , Pneumonia Viral/tratamento farmacológico , Polifenóis/farmacologia , Inibidores de Proteases/farmacologia , Serina Endopeptidases/química , Proteínas não Estruturais Virais/química , Antivirais/farmacologia , COVID-19 , Simulação por Computador , Proteases 3C de Coronavírus , Infecções por Coronavirus/virologia , Cisteína Endopeptidases/metabolismo , Humanos , Simulação de Acoplamento Molecular , Pandemias , Pneumonia Viral/virologia , SARS-CoV-2 , Serina Endopeptidases/metabolismo , Proteínas não Estruturais Virais/metabolismoRESUMO
Induction of apoptosis is the target of choice for modern chemotherapeutic treatment of cancer, where lack of potent "target-specific" drugs has led to extensive research on anticancer compounds from natural sources. In our study, we have used astrakurkurone, a triterpene isolated from wild edible mushroom, Astraeus hygrometricus. We have discussed the structure and stability of astrakurkurone employing single-crystal X-ray crystallography and studied its potential apoptogenicity in hepatocellular carcinoma (HCC) cells. Our experiments reveal that it is cytotoxic against the HCC cell lines (Hep 3B and Hep G2) at significantly low doses. Further investigations indicated that astrakurkurone acts by inducing apoptosis in the cells, disrupting mitochondrial membrane potential and inducing the expression of Bcl-2 family proteins, for example, Bax, and the downstream effector caspases 3 and 9. A molecular docking study also predicted direct interactions of the drug with antiapoptotic proteins Bcl-2 and Bcl-xL. Thus, astrakurkurone could become a valuable addition to the conventional repertoire of future anticancer drugs. © 2019 IUBMB Life, 1-11, 2019.
Assuntos
Agaricales/química , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Hepáticas/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sesquiterpenos/farmacologia , Antineoplásicos/química , Apoptose , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Ciclo Celular , Proliferação de Células , Cristalografia por Raios X , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Modelos Moleculares , Simulação de Acoplamento Molecular , Proteínas Proto-Oncogênicas c-bcl-2/genética , Sesquiterpenos/química , Células Tumorais CultivadasRESUMO
We used clustered regularly interspaced short palindromic repeats/Cas9-mediated genomic modification to investigate B-cell receptor (BCR) signaling in cell lines of diffuse large B-cell lymphoma (DLBCL). Three manipulations that altered BCR genes without affecting surface BCR levels showed that BCR signaling differs between the germinal center B-cell (GCB) subtype, which is insensitive to Bruton tyrosine kinase inhibition by ibrutinib, and the activated B-cell (ABC) subtype. Replacing antigen-binding BCR regions had no effect on BCR signaling in GCB-DLBCL lines, reflecting this subtype's exclusive use of tonic BCR signaling. Conversely, Y188F mutation in the immunoreceptor tyrosine-based activation motif of CD79A inhibited tonic BCR signaling in GCB-DLBCL lines but did not affect their calcium flux after BCR cross-linking or the proliferation of otherwise-unmodified ABC-DLBCL lines. CD79A-GFP fusion showed BCR clustering or diffuse distribution, respectively, in lines of ABC and GCB subtypes. Tonic BCR signaling acts principally to activate AKT, and forced activation of AKT rescued GCB-DLBCL lines from knockout (KO) of the BCR or 2 mediators of tonic BCR signaling, SYK and CD19. The magnitude and importance of tonic BCR signaling to proliferation and size of GCB-DLBCL lines, shown by the effect of BCR KO, was highly variable; in contrast, pan-AKT KO was uniformly toxic. This discrepancy was explained by finding that BCR KO-induced changes in AKT activity (measured by gene expression, CXCR4 level, and a fluorescent reporter) correlated with changes in proliferation and with baseline BCR surface density. PTEN protein expression and BCR surface density may influence clinical response to therapeutic inhibition of tonic BCR signaling in DLBCL.
Assuntos
Linfoma Difuso de Grandes Células B/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais , Antígenos/metabolismo , Sistemas CRISPR-Cas/genética , Linhagem Celular Tumoral , Proliferação de Células , Análise por Conglomerados , Técnicas de Inativação de Genes , Centro Germinativo/patologia , Humanos , Linfoma Difuso de Grandes Células B/patologia , Mutação/genética , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
Directed assembly of dielectric and paramagnetic nanoparticles can be used to synthesize diverse functional materials that polarize in response to an externally applied electric or magnetic field. However, theories capable of predicting the self-assembled states are lacking. In the proposed work, we develop a complete thermodynamic description of such assemblies for spherical nanoparticles. We show how an important physical feature of these types of particles, mutual polarization, sculpts the free energy landscape and has a remarkably strong influence on the nature of the self-assembled states. Modeling the mutual polarization among nanoparticles requires solving a many-bodied problem for the particle dipole moments. Typically, this computationally expensive task is avoided by neglecting mutual polarization and assuming that each particle in a concentrated dispersion acquires the same dipole moment as a single, isolated particle. Although valid in the limit of small dielectric or permeability contrasts between particles and solvent, this constant dipole assumption leads to qualitatively incorrect predictions for coexisting phases in equilibrium at large dielectric or permeability contrasts. Correctly accounting for mutual polarization enables a thermodynamic theory that describes the equilibrium phase diagram of polarizable dispersions in terms of experimentally controllable variables. Our theoretical predictions agree with the phase behavior we observe in dynamic simulations of these dispersions as well as that in experiments of field-directed structural transitions. In contrast to predictions of a constant dipole model, we find that dispersions of particles with different dielectric constants or magnetic permeabilities exhibit qualitatively different phase behavior. This new model also predicts the existence of a eutectic point at which two crystalline phases and a disordered phase of nanoparticles all simultaneously coexist.
RESUMO
Accessory cholera enterotoxin (Ace) of Vibrio cholerae has been shown to contribute to diarrhea. However, the signaling mechanism and specific type of Cl- channel activated by Ace are still unknown. We have shown here that the recombinant Ace protein induced ICl of apical plasma membrane, which was inhibited by classical CaCC blockers. Surprisingly, an Ace-elicited rise of current was neither affected by ANO1 (TMEM16A)-specific inhibitor T16A(inh)-AO1(TAO1) nor by the cystic fibrosis transmembrane conductance regulator (CFTR) blocker, CFTR inh-172. Ace stimulated whole-cell current in Caco-2 cells. However, the apical ICl was attenuated by knockdown of ANO6 (TMEM16F). This impaired phenotype was restored by re-expression of ANO6 in Caco-2 cells. Whole-cell patch clamp recordings of ANO currents in HEK293 cells transiently expressing mouse ANO1-mCherry or ANO6-GFP confirmed that Ace induced Cl- secretion. Application of Ace produced ANO6 but not the ANO1 currents. Ace was not able to induce a [Ca2+]i rise in Caco-2 cells, but cellular abundance of phosphatidylinositol 4,5-bisphosphate (PIP2) increased. Identification of the PIP2-binding motif at the N-terminal sequence among human and mouse ANO6 variants along with binding of PIP2 directly to ANO6 in HEK293 cells indicate likely PIP2 regulation of ANO6. The biophysical and pharmacological properties of Ace stimulated Cl- current along with intestinal fluid accumulation, and binding of PIP2 to the proximal KR motif of channel proteins, whose mutagenesis correlates with altered binding of PIP2, is comparable with ANO6 stimulation. We conclude that ANO6 is predominantly expressed in intestinal epithelia, where it contributes secretory diarrhea by Ace stimulation in a calcium-independent mechanism of RhoA-ROCK-PIP2 signaling.
Assuntos
Cloretos/metabolismo , Toxina da Cólera/toxicidade , Cólera/metabolismo , Proteínas de Transferência de Fosfolipídeos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Sequência de Aminoácidos , Animais , Anoctaminas , Sequência de Bases , Sistemas CRISPR-Cas , Células CACO-2 , Cálcio/metabolismo , Cólera/induzido quimicamente , Regulador de Condutância Transmembrana em Fibrose Cística/antagonistas & inibidores , Células HEK293 , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/virologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Patch-Clamp , Proteínas de Transferência de Fosfolipídeos/antagonistas & inibidores , Proteínas de Transferência de Fosfolipídeos/genética , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Homologia de Sequência de Aminoácidos , Transdução de Sinais/efeitos dos fármacos , Vibrio cholerae/patogenicidade , Proteína rhoA de Ligação ao GTP/antagonistas & inibidores , Proteína rhoA de Ligação ao GTP/genéticaRESUMO
B cell acute lymphoblastic leukaemia (B-ALL) cells express high levels of CXCR4 chemokine receptors for homing and retention within the marrow microenvironment. Bone marrow stromal cells (BMSC) secrete CXCL12, the ligand for CXCR4, and protect B-ALL cells from cytotoxic drugs. Therefore, the therapeutic use of CXCR4 antagonists has been proposed to disrupt cross talk between B-ALL cells and the protective stroma. Because CXCR4 antagonists can have activating agonistic function, we compared the genetic and pharmacological deletion of CXCR4 in B-ALL cells, using CRISPR-Cas9 gene editing and CXCR4 antagonists that are in clinical use (plerixafor, BKT140). Both genetic and pharmacological CXCR4 inhibition significantly reduced B-ALL cell migration to CXCL12 gradients and beneath BMSC, and restored drug sensitivity to dexamethasone, vincristine and cyclophosphamide. NOD/SCID/IL-2rγnull mice injected with CXCR4 gene-deleted B-ALL cells had significant delay in disease progression and superior survival when compared to control mice injected with CXCR4 wild-type B-ALL cells. These findings indicate that anti-leukaemia activity of CXCR4 antagonists is primarily due to CXCR4 inhibition, rather than agonistic activity, and corroborate that CXCR4 is an important target to overcome stroma-mediated drug resistance in B-ALL.
Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Receptores CXCR4/antagonistas & inibidores , Animais , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Quimiocina CXCL12/metabolismo , Resistência a Medicamentos/efeitos dos fármacos , Edição de Genes , Humanos , Leucemia de Células B/metabolismo , Leucemia de Células B/patologia , Camundongos , Camundongos Endogâmicos , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Receptor Cross-Talk/efeitos dos fármacos , Receptores CXCR4/genética , Células Estromais/metabolismo , Células Tumorais CultivadasRESUMO
Chandipura Virus is an emerging tropical pathogen with a high mortality rate among children. No mode of treatment or antivirals exists against CHPV infection, due to little information regarding its host interaction. Studying viral pathogen interaction with its host can not only provide valuable information regarding its propagation strategy, but also on which host proteins interact with the virus. Identifying these proteins and understanding their role in the infection process can provide more stable anti-viral targets. In this study, we focused on identifying host factors that interact with CHPV and may play a critical role in CHPV infection. We are the first to report the successful identification of Alpha-2-Macroglobulin (A2M), a secretory protein of the host that interacts with CHPV. We also established that LRP1 (Low-density lipoprotein receptor-related protein 1) and GRP78 (Glucose regulated protein 78), receptors of A2M, also interact with CHPV. Furthermore, we could also demonstrate that knocking out A2M has a severe effect on viral infection. We conclusively show the interaction of these host proteins with CHPV. Our findings also indicate that these host proteins could play a role in viral entry into the host cell.
Assuntos
Fatores de Transcrição , Vesiculovirus , Criança , Humanos , Macroglobulinas , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa DensidadeRESUMO
COVID-19 pandemic is the biggest global crisis. The frequent mutations in coronavirus to generate new mutants are of major concern. The pathophysiology of SARS-CoV-2 infection has been well studied to find suitable molecular targets and candidate drugs for effective treatment. FDArecommended etiotropic therapies are currently followed along with mass vaccination. The drug delivery system and the route of administration have a great role in enhancing the efficacy of therapeutic agents and vaccines. Since COVID-19 primarily infects the lungs in the affected individuals, pulmonary administration may be the best possible route for the treatment of COVID-19. Liposomes, solid lipid nanoparticles, polymeric nanoparticles, porous microsphere, dendrimers, and nanoparticles encapsulated microparticles are the most suitable drug delivery systems for targeted drug delivery. The solubility, permeability, chemical stability, and biodegradability of drug molecules are the key factors for the right selection of suitable nanocarriers. The application of nanotechnology has been instrumental in the successful development of mRNA, DNA and subunit vaccines, as well as the delivery of COVID-19 therapeutic agents.
Assuntos
COVID-19 , Humanos , Pandemias/prevenção & controle , SARS-CoV-2 , Sistemas de Liberação de Medicamentos , Vacinas contra COVID-19RESUMO
During the last two decades, yeast has been used as a biological tool to produce various small molecules, biofuels, etc., using an inexpensive bioprocess. The application of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-associated protein (Cas) techniques in yeast genetic and metabolic engineering has made a paradigm shift, particularly with a significant improvement in targeted chromosomal integration using synthetic donor constructs, which was previously a challenge. This study reports the CRISPR-Cas9-based highly efficient strategy for targeted chromosomal integration and in-frame expression of a foreign gene in the genome of Saccharomyces cerevisiae (S. cerevisiae) by homology-dependent recombination (HDR); our optimized methods show that CRISPR-Cas9-based chromosomal targeted integration of small constructs at multiple target sites of the yeast genome can be achieved with an efficiency of 74%. Our study also suggests that 15 bp microhomology flanked arms are sufficient for 50% targeted knock-in at minimal knock-in construct concentration. Whole-genome sequencing confirmed that there is no off-target effect. This study provides a comprehensive and streamlined protocol that will support the targeted integration of essential genes into the yeast genome for synthetic biology and other industrial purposes.Highlights⢠CRISPR-Cas9 based in-frame expression of foreign protein in Saccharomyces cerevisiae using Homology arm without a promoter.⢠As low as 15 base pairs of microhomology (HDR) are sufficient for targeted integration in Saccharomyces cerevisiae.⢠The methodology is highly efficient and very specific as no off-targeted effects were shown by the whole-genome sequence.
Assuntos
Sistemas CRISPR-Cas , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sistemas CRISPR-Cas/genética , Genoma , Engenharia Metabólica/métodos , Recombinação Homóloga , Edição de Genes/métodosRESUMO
The discovery of Clustered Regularly Interspaced Palindromic Repeats (CRISPR) and its associated Cas endonucleases in bacterial and archaeal species allowed scientists to modify, utilized, and revolutionize this tool for genetic alterations in any species. Especially the type II CRISPR-Cas9 system has been extensively studied and utilized for precise and efficient DNA manipulation in plant and mammalian systems over the past few decades. Further, the discovery of the type V CRISPR-Cas12 (Cpf1) system provides more flexibility and precision in DNA manipulation in prokaryotes, plants, and animals. However, much effort has been made to employ and utilize the above CRISPR tools for RNA manipulation but the ability of Cas9 and Cas12 to cut DNA involves the nuisance of off-target effects on genes and thus may not be employed in all RNA-targeting applications. Therefore, the search for new and diverse Cas effectors which can precisely detect and manipulate the targeted RNA begins and this led to the discovery of a novel RNA targeting class 2, type VI CRISPR-Cas13 system. The CRISPR-Cas13 system consists of single RNA-guided Cas13 effector nucleases that solely target single-stranded RNA (ssRNA) in a programmable way without altering the DNA. The Cas13 effectors family comprises four subtypes (a-d) and each subtype has distinctive primary sequence divergence except the two consensuses Higher eukaryotes and prokaryotes nucleotide-binding domain (HEPN) that includes RNase motifs i.e. R-X4-6-H. These two HEPN domains are solely responsible for executing targetable RNA cleavage activity with high efficiency. Further, recent studies have shown that Cas13d exhibits higher efficiency and specificity in cleaving targeted RNA in the mammalian system compared to other Cas13 endonucleases of the Cas13 enzyme family. In addition to that, Cas13d has shown additional advantages over other Cas13 variants, structurally as well as functionally which makes it a prominent and superlative tool for RNA engineering and editing. Therefore considering the advantages of Cas13d over previously characterized Cas13 subtypes, in this review, we encompass the structural and mechanistic properties of type VI CRISPR-Cas13d systems, an overview of the current reported various applications of Cas13d, and the prospects to improve Cas13d based tools for diagnostic and therapeutic purposes.
RESUMO
Plant derived natural products have multifaceted beneficial roles in human pathophysiology. Plant secondary metabolites have been used as an adjunct medicine for a long time and ß- Glucogallin is one such pharmaceutically important plant derived natural product. Β-glucogallin (1-O-galloyl-ß-d-glucopyranose), a plant-derived polyphenolic ester, is regarded as the primary metabolite in the biosynthesis of hydrolyzable tannins. It is majorly found in amla, pomegranate, strawberry etc. Owing to its free radical scavenging properties, ß-glucogallin (BG) is believed to protect against several diseases like diabetes and related complications like retinopathy, glaucoma, inflammation, hepatic damage, skin damage from UV, etc. Several semisynthetic derivatives of ß-Glucogallin are being developed, which have better pharmacokinetic and pharmacodynamic parameters than ß-glucogallin. Studies have shown the prophylactic role of ß-Glucogallin in developing defence mechanisms against the advent and progression of certain diseases. ß- glucogallin formulations have shown a positive effect as a neutraceutical. In this manuscript, we have discussed ß-glucogallin, its natural sources, biosynthetic pathways, its semi-synthetic derivatives, and the plethora of its pharmacological activities like antioxidant-antiinflammatory, antidiabetic, cataract-preventing, anti glaucoma, and UV protectant. We have also highlighted various biological pathways, which are modulated by ß-glucogallin. The manuscript will convey the importance of ß-glucogallin as a compound of natural origin, having multifaceted health benefits.
Assuntos
Produtos Biológicos , Taninos Hidrolisáveis , Humanos , Taninos Hidrolisáveis/farmacologia , Taninos Hidrolisáveis/metabolismo , Antioxidantes/farmacologia , Hipoglicemiantes/farmacologia , Ésteres , Radicais LivresRESUMO
Recent studies have shed light on the role of epigenetic marks in certain diseases like cancer, type II diabetes mellitus (T2DM), obesity, and cardiovascular dysfunction, to name a few. Epigenetic marks like DNA methylation and histone acetylation are randomly altered in the disease state. It has been seen that methylation of DNA and histones can result in down-regulation of gene expression, whereas histone acetylation, ubiquitination, and phosphorylation are linked to enhanced expression of genes. How can we precisely target such epigenetic aberrations to prevent the advent of diseases? The answer lies in the amalgamation of the efficient genome editing technique, CRISPR, with certain effector molecules that can alter the status of epigenetic marks as well as employ certain transcriptional activators or repressors. In this review, we have discussed the rationale of epigenetic editing as a therapeutic strategy and how CRISPR-Cas9 technology coupled with epigenetic effector tags can efficiently edit epigenetic targets. In the later part, we have discussed how certain epigenetic effectors are tagged with dCas9 to elicit epigenetic changes in cancer. Increased interest in exploring the epigenetic background of cancer and non-communicable diseases like type II diabetes mellitus and obesity accompanied with technological breakthroughs has made it possible to perform large-scale epigenome studies.
Assuntos
Diabetes Mellitus Tipo 2 , Neoplasias , Sistemas CRISPR-Cas , Metilação de DNA , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/terapia , Epigênese Genética , Epigenoma , Histonas/metabolismo , Humanos , Neoplasias/genética , Neoplasias/terapia , Obesidade , Fatores de Transcrição/metabolismoRESUMO
Recently published clinical data from COVID-19 patients indicated that statin therapy is associated with a better clinical outcome and a significant reduction in the risk of mortality. In this study by computational analysis, we have aimed to predict the possible mechanism of the statin group of drugs by which they can inhibit SARS-CoV-2 pathogenesis. Blind docking of the critical structural and functional proteins of SARS-CoV-2 like RNA-dependent RNA polymerase, M-protease of 3-CL-Pro, Helicase, and the Spike proteins ( wild type and mutants from different VOCs) were performed using the Schrodinger docking tool. We observed that fluvastatin and pitavastatin showed fair, binding affinities to RNA polymerase and 3-CL-Pro, whereas fluvastatin showed the strongest binding affinity to the helicase. Fluvastatin also showed the highest affinity for the SpikeDelta and a fair docking score for other spike variants. Additionally, molecular dynamics simulation confirmed the formation of a stable drug-protein complex between Fluvastatin and target proteins. Thus our study shows that of all the statins, fluvastatin can bind to multiple target proteins of SARS-CoV-2, including the spike-mutant proteins. This property might contribute to the potent antiviral efficacy of this drug.