scholarly journals AS1411 Nucleolin-Specific Binding Aptamers Reduce Pathological Angiogenesis through Inhibition of Nucleolin Phosphorylation

2021 ◽  
Vol 22 (23) ◽  
pp. 13150
Author(s):  
Emilio Iturriaga-Goyon ◽  
Oscar Vivanco-Rojas ◽  
Fátima Sofía Magaña-Guerrero ◽  
Beatriz Buentello-Volante ◽  
Ilse Castro-Salas ◽  
...  

Proliferative retinopathies produces an irreversible type of blindness affecting working age and pediatric population of industrialized countries. Despite the good results of anti-VEGF therapy, intraocular and systemic complications are often associated after its intravitreal use, hence novel therapeutic approaches are needed. The aim of the present study is to test the effect of the AS1411, an antiangiogenic nucleolin-binding aptamer, using in vivo, ex vivo and in vitro models of angiogenesis and propose a mechanistic insight. Our results showed that AS1411 significantly inhibited retinal neovascularization in the oxygen induced retinopathy (OIR) in vivo model, as well as inhibited branch formation in the rat aortic ex vivo assay, and, significantly reduced proliferation, cell migration and tube formation in the HUVEC in vitro model. Importantly, phosphorylated NCL protein was significantly abolished in HUVEC in the presence of AS1411 without affecting NFκB phosphorylation and -21 and 221-angiomiRs, suggesting that the antiangiogenic properties of this molecule are partially mediated by a down regulation in NCL phosphorylation. In sum, this new research further supports the NCL role in the molecular etiology of pathological angiogenesis and identifies AS1411 as a novel anti-angiogenic treatment.

2009 ◽  
Vol 53 (5) ◽  
pp. 1874-1883 ◽  
Author(s):  
Anne Sandberg ◽  
Jonas H. R. Hessler ◽  
Robert L. Skov ◽  
Jens Blom ◽  
Niels Frimodt-Møller

ABSTRACT Antibiotic treatment of Staphylococcus aureus infections is often problematic due to the slow response to therapy and the high frequency of infection recurrence. The intracellular persistence of staphylococci has been recognized and could offer a good explanation for these treatment difficulties. Knowledge of the interplay between intracellular antibiotic activity and the overall outcome of infection is therefore important. Several intracellular in vitro models have been developed, but few experimental animal models have been published. The mouse peritonitis/sepsis model was used as the basic in vivo model exploring a quantitative ex vivo extra- and intracellular differentiation assay. The intracellular presence of S. aureus was documented by electron microscopy. Five antibiotics, dicloxacillin, cefuroxime, gentamicin, azithromycin, and rifampin (rifampicin), were tested in the new in vivo model; and the model was able to distinguish between their extra- and intracellular effects. The intracellular effects of the five antibiotics could be ranked as follows as the mean change in the log10 number of CFU/ml (Δlog10 CFU/ml) between treated and untreated mice after 4 h of treatment: dicloxacillin (3.70 Δlog10 CFU/ml) > cefuroxime (3.56 Δlog10 CFU/ml) > rifampin (1.86 Δlog10 CFU/ml) > gentamicin (0.61 Δlog10 CFU/ml) > azithromycin (0.21 Δlog10 CFU/ml). We could also show that the important factors during testing of intracellular activity in vivo are the size, number, and frequency of doses; the time of exposure; and the timing between the start of infection and treatment. A poor correlation between the intracellular accumulation of the antibiotics and the actual intracellular effect was found. This stresses the importance of performing experimental studies, like those with the new in vivo model described here, to measure actual intracellular activity instead of making predictions based on cellular pharmacokinetic and MICs.


Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 56
Author(s):  
Dalila Mil-Homens ◽  
Maria Martins ◽  
José Barbosa ◽  
Gabriel Serafim ◽  
Maria J. Sarmento ◽  
...  

Klebsiella pneumoniae, one of the most common pathogens found in hospital-acquired infections, is often resistant to multiple antibiotics. In fact, multidrug-resistant (MDR) K. pneumoniae producing KPC or OXA-48-like carbapenemases are recognized as a serious global health threat. In this sense, we evaluated the virulence of K. pneumoniae KPC(+) or OXA-48(+) aiming at potential antimicrobial therapeutics. K. pneumoniae carbapenemase (KPC) and the expanded-spectrum oxacillinase OXA-48 isolates were obtained from patients treated in medical care units in Lisbon, Portugal. The virulence potential of the K. pneumonia clinical isolates was tested using the Galleria mellonella model. For that, G. mellonella larvae were inoculated using patients KPC(+) and OXA-48(+) isolates. Using this in vivo model, the KPC(+) K. pneumoniae isolates showed to be, on average, more virulent than OXA-48(+). Virulence was found attenuated when a low bacterial inoculum (one magnitude lower) was tested. In addition, we also report the use of a synthetic polycationic oligomer (L-OEI-h) as a potential antimicrobial agent to fight infectious diseases caused by MDR bacteria. L-OEI-h has a broad-spectrum antibacterial activity and exerts a significantly bactericidal activity within the first 5-30 min treatment, causing lysis of the cytoplasmic membrane. Importantly, the polycationic oligomer showed low toxicity against in vitro models and no visible cytotoxicity (measured by survival and health index) was noted on the in vivo model (G. mellonella), thus L-OEI-h is foreseen as a promising polymer therapeutic for the treatment of MDR K. pneumoniae infections.


Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 8 ◽  
Author(s):  
Mayra Antúnez-Mojica ◽  
Andrés Rojas-Sepúlveda ◽  
Mario Mendieta-Serrano ◽  
Leticia Gonzalez-Maya ◽  
Silvia Marquina ◽  
...  

By using a zebrafish embryo model to guide the chromatographic fractionation of antimitotic secondary metabolites, seven podophyllotoxin-type lignans were isolated from a hydroalcoholic extract obtained from the steam bark of Bursera fagaroides. The compounds were identified as podophyllotoxin (1), β-peltatin-A-methylether (2), 5′-desmethoxy-β-peltatin-A-methylether (3), desmethoxy-yatein (4), desoxypodophyllotoxin (5), burseranin (6), and acetyl podophyllotoxin (7). The biological effects on mitosis, cell migration, and microtubule cytoskeleton remodeling of lignans 1–7 were further evaluated in zebrafish embryos by whole-mount immunolocalization of the mitotic marker phospho-histone H3 and by a tubulin antibody. We found that lignans 1, 2, 4, and 7 induced mitotic arrest, delayed cell migration, and disrupted the microtubule cytoskeleton in zebrafish embryos. Furthermore, microtubule cytoskeleton destabilization was observed also in PC3 cells, except for 7. Therefore, these results demonstrate that the cytotoxic activity of 1, 2, and 4 is mediated by their microtubule-destabilizing activity. In general, the in vivo and in vitro models here used displayed equivalent mitotic effects, which allows us to conclude that the zebrafish model can be a fast and cheap in vivo model that can be used to identify antimitotic natural products through bioassay-guided fractionation.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Jinjiang Pi ◽  
Ting Tao ◽  
Tao Zhuang ◽  
Huimin Sun ◽  
Xiaoli Chen ◽  
...  

Angiogenic hypersprouting and leaky immature vessels of pathological angiogenesis are essential for tumor growth. MicroRNAs have unique therapeutic advantages by targeting multiple pathways of tumor-associated angiogenesis, but the function of individual miRNAs in angiogenesis and tumors has not yet been fully evaluated. Here, we show that miR302-367 elevation in endothelial cells reduces retina sprouting angiogenesis and promotes vascular stability in vivo, ex vivo and in vitro. Erk1/2 are identified as direct targets of miR302-367, and down-regulation of Erk1/2 upon miR302-367 elevation in endothelial cells increases the expression of Klf2 and in turn S1pr1 and its downstream target VE-cadherin, suppressing angiogenesis and improving vascular stability. Conversely, both pharmacological blockade and genetic deletion of S1pr1 in endothelial cells reverse the anti-angiogenic and vascular stabilizing effect of miR302-367 in mice. Pathological angiogenesis in tumors shares features of developmental angiogenesis, and endothelial specific elevation of miR302-367 reduces tumor growth by restricting sprout angiogenesis and decreasing vascular permeability via the same Erk1/2-Klf2-S1pr1 pathways. In conclusion, miR302-367 regulation of an Erk1/2-Klf2-S1pr1 pathway in the endothelium advances our understanding of angiogenesis, meanwhile also provides opportunities for therapeutic intervention of tumor growth.


Cephalalgia ◽  
2006 ◽  
Vol 26 (6) ◽  
pp. 642-659 ◽  
Author(s):  
U Arulmani ◽  
S Gupta ◽  
A Maassen VanDenBrink ◽  
D Centurión ◽  
CM Villalón ◽  
...  

Although the understanding of migraine pathophysiology is incomplete, it is now well accepted that this neurovascular syndrome is mainly due to a cranial vasodilation with activation of the trigeminal system. Several experimental migraine models, based on vascular and neuronal involvement, have been developed. Obviously, the migraine models do not entail all facets of this clinically heterogeneous disorder, but their contribution at several levels (molecular, in vitro, in vivo) has been crucial in the development of novel antimigraine drugs and in the understanding of migraine pathophysiology. One important vascular in vivo model, based on an assumption that migraine headache involves cranial vasodilation, determines porcine arteriovenous anastomotic blood flow. Other models utilize electrical stimulation of the trigeminal ganglion/nerve to study neurogenic dural inflammation, while the superior sagittal sinus stimulation model takes into account the transmission of trigeminal nociceptive input in the brainstem. More recently, the introduction of integrated models, namely electrical stimulation of the trigeminal ganglion or systemic administration of capsaicin, allows studying the activation of the trigeminal system and its effect on the cranial vasculature. Studies using in vitro models have contributed enormously during the preclinical stage to characterizing the receptors in cranial blood vessels and to studying the effects of several putative antimigraine agents. The aforementioned migraine models have advantages as well as some limitations. The present review is devoted to discussing various migraine models and their relevance to antimigraine therapy.


Author(s):  
Cristina Di Giorgio ◽  
Rosalinda Roselli ◽  
Michele Biagioli ◽  
Silvia Marchianò ◽  
Eleonora Distrutti ◽  
...  

Abstract: Advancements in stem cell research have enabled the establishment of three-dimensional (3D) primary cell cultures, known as organoids. These culture systems follow the organization of an in vivo organ, as they enclose the different epithelial cell lines of which it is normally composed. Generation of these 3D cultures has bridged the gap between in vitro models, made up by two-dimensional (2D) cancer cell lines cultures, and in vivo animal models, that have major differences with human diseases. Organoids are increasingly used as a model to study colonization of gastric mucosa by infectious agents and to better understand host-microbe interactions and the molecular events that lead to infection, pathogen-epithelial cells interactions and mechanisms of gastric mucosal injury. In this review we will focus on the role of organoids as a tool to investigate molecular interactions of Helicobacter (H.) pylori and Epstein Barr Virus (EBV) and gastric mucosa and how these infections, that affect ≈ 45% of the world population, might progress to gastric cancer, a highly prevalent cancer and the third leading cause of cancer death.


Author(s):  
Zheng-Hong Li ◽  
Rong Xu ◽  
Jun Shi ◽  
Man-Shu Yu ◽  
Yu Zhong ◽  
...  

Peritoneal fibrosis (PF) is a disease caused by prolonged exposure of the peritoneum to high levels of dialysis fluid. Astragalus total saponins (ATS) is a phytochemical naturally occurring in Radix Astragali that has anti-inflammatory and anti-oxidant properties. In this study, we constructed an in vivo model of PF using 4.25% glucose-containing administered intraperitoneally to rats and incubated peritoneal mesothelial cells (PMCs) with 4.25% glucose-containing peritoneal dialysis fluid to construct an in vitro model of PF. Furthermore, siRNA of PGC-1[Formula: see text] was used to inhibit the expression of PGC-1[Formula: see text] to further investigate the mechanism of the protective effect of ATS on PF. In both in vivo and in vitro models, ATS treatment showed a protective effect against PF, with ATS reducing the thickness of peritoneal tissues in PF rats, increasing the viability of PMCs, increasing the mitochondrial membrane potential and reducing apoptosis ratio. ATS treatment also reduced the expressions of peritoneal fibrosis markers (Smad2, p-Smad2 and [Formula: see text]-SMA) and apoptosis markers (Caspase3, cleaved-Caspase3 and Bax) and restored the expressions of mitochondrial synthesis proteins (PGC-1[Formula: see text], NRF1 and TFAM) in ATS-treated peritoneal tissues or PMCs. Furthermore, in the presence of PGC-1[Formula: see text] inhibition, the protective effect of ATS on PF was blocked. In conclusion, ATS treatment may be an effective therapeutic agent to inhibit high glucose-induced in peritoneal fibrosis through PGC-1[Formula: see text]-mediated apoptosis.


2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
A. F. Moleiro ◽  
G. Conceição ◽  
A. F. Leite-Moreira ◽  
A. Rocha-Sousa

Angiogenesis is a biological process with a central role in retinal diseases. The choice of the ideal method to study angiogenesis, particularly in the retina, remains a problem. Angiogenesis can be assessed throughin vitroandin vivostudies. In spite of inherent limitations,in vitrostudies are faster, easier to perform and quantify, and typically less expensive and allow the study of isolated angiogenesis steps. We performed a systematic review of PubMed searching for original articles that appliedin vitroor ex vivo angiogenic retinal assays until May 2017, presenting the available assays and discussing their applicability, advantages, and disadvantages. Most of the studies evaluated migration, proliferation, and tube formation of endothelial cells in response to inhibitory or stimulatory compounds. Other aspects of angiogenesis were studied by assessing cell permeability, adhesion, or apoptosis, as well as by implementing organotypic models of the retina. Emphasis is placed on how the methods are applied and how they can contribute to retinal angiogenesis comprehension. We also discuss how to choose the best cell culture to implement these methods. When applied together,in vitroand ex vivo studies constitute a powerful tool to improve retinal angiogenesis knowledge. This review provides support for researchers to better select the most suitable protocols in this field.


2014 ◽  
Vol 9 (4) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Seon-Il Park ◽  
Toshiro Ohta ◽  
Shigenori Kumazawa ◽  
Mira Jun ◽  
Mok-Ryeon Ahn

Propolis, a sticky material that honeybees collect from living plants, has been used for its pharmaceutical properties since ancient times. In this study, we examined the effects of ethanol extracts of Korean propolis (EEKP) from various geographic regions on the inhibition of angiogenesis, both in vitro and in vivo. The effects of EEKP were tested on in vitro models of angiogenesis, that is, tube formation and proliferation of human umbilical vein endothelial cells (HUVECs). All EEKP samples exhibited significant inhibitory effects on tube formation of HUVECs in a concentration-dependent manner (6.25-25 μg/mL). In addition, two EEKP samples, prepared from Uijeongbu and Pyoseon propolis, significantly suppressed the proliferation of HUVECs in a concentration-dependent manner (3.13-25 μg/mL). Furthermore, in an in vivo angiogenesis assay using the chick embryo chorioallantoic membrane (CAM) system, we found that the two EEKP samples significantly reduced the number of newly formed vessels. These results indicate that Korean propolis may have potential applications in the prevention and treatment of angiogenesis-related diseases such as cancer.


2009 ◽  
Vol 53 (8) ◽  
pp. 3337-3346 ◽  
Author(s):  
Kristy Dolan ◽  
Sara Montgomery ◽  
Bradley Buchheit ◽  
Louis DiDone ◽  
Melanie Wellington ◽  
...  

ABSTRACT Tamoxifen (TAM), an estrogen receptor antagonist used primarily to treat breast cancer, has well-recognized antifungal properties, but the activity of TAM has not been fully characterized using standardized (i.e., CLSI) in vitro susceptibility testing, nor has it been demonstrated in an in vivo model of fungal infection. In addition, its mechanism of action remains to be clearly defined at the molecular level. Here, we report that TAM displays in vitro activity (MIC, 8 to 64 μg/ml) against pathogenic yeasts (Candida albicans, other Candida spp., and Cryptococcus neoformans). In vivo, 200 mg/kg of body weight per day TAM reduced kidney fungal burden (−1.5 log10 CFU per g tissue; P = 0.008) in a murine model of disseminated candidiasis. TAM is a known inhibitor of mammalian calmodulin, and TAM-treated yeast show phenotypes consistent with decreased calmodulin function, including lysis, decreased new bud formation, disrupted actin polarization, and decreased germ tube formation. The overexpression of calmodulin suppresses TAM toxicity, hypofunctional calmodulin mutants are hypersensitive to TAM, and TAM interferes with the interaction between Myo2p and calmodulin, suggesting that TAM targets calmodulin as part of its mechanism of action. Taken together, these experiments indicate that the further study of compounds related to TAM as antifungal agents is warranted.


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