A Novel Peptide Aldehyde with Activity against Human Cytomegalovirus in Two Different in Vivo Models

2000 ◽  
Vol 11 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Olaf Weber ◽  
Jürgen Reefschläger ◽  
Helga Rübsamen-Waigmann ◽  
Siegfried Raddatz ◽  
Matthias Hesseling ◽  
...  

Novel peptide aldehydes (PAs) were identified as potent inhibitors of human cytomegalovirus (HCMV) in vitro. Although these compounds were highly effective against HCMV, they did not exhibit any activity against murine cytomegalovirus (MCMV). The purpose of this study was to test the antiviral activity of PA 8 as a representative of this novel class of inhibitors against HCMV in vivo. Because of the strict species specificity of HCMV we had to use two artificial animal models. In the first model, HCMV-infected human cells were entrapped into agarose plugs and transplanted into mice. In the second model, SCID mice were transplanted with human tissues that were subsequently infected with a clinical isolate of HCMV. In these two models the antiviral activity of PA 8 was clearly demonstrated, ganciclovir only being slightly superior in its in vivo antiviral activity.

Author(s):  
Zachary Fralish ◽  
Ethan M. Lotz ◽  
Taylor Chavez ◽  
Alastair Khodabukus ◽  
Nenad Bursac

The neuromuscular junction (NMJ) is a specialized cholinergic synaptic interface between a motor neuron and a skeletal muscle fiber that translates presynaptic electrical impulses into motor function. NMJ formation and maintenance require tightly regulated signaling and cellular communication among motor neurons, myogenic cells, and Schwann cells. Neuromuscular diseases (NMDs) can result in loss of NMJ function and motor input leading to paralysis or even death. Although small animal models have been instrumental in advancing our understanding of the NMJ structure and function, the complexities of studying this multi-tissue system in vivo and poor clinical outcomes of candidate therapies developed in small animal models has driven the need for in vitro models of functional human NMJ to complement animal studies. In this review, we discuss prevailing models of NMDs and highlight the current progress and ongoing challenges in developing human iPSC-derived (hiPSC) 3D cell culture models of functional NMJs. We first review in vivo development of motor neurons, skeletal muscle, Schwann cells, and the NMJ alongside current methods for directing the differentiation of relevant cell types from hiPSCs. We further compare the efficacy of modeling NMDs in animals and human cell culture systems in the context of five NMDs: amyotrophic lateral sclerosis, myasthenia gravis, Duchenne muscular dystrophy, myotonic dystrophy, and Pompe disease. Finally, we discuss further work necessary for hiPSC-derived NMJ models to function as effective personalized NMD platforms.


2020 ◽  
Vol 21 (14) ◽  
pp. 4993 ◽  
Author(s):  
Raphael Mohr ◽  
Burcin Özdirik ◽  
Jana Knorr ◽  
Alexander Wree ◽  
Münevver Demir ◽  
...  

Cholangiocarcinoma (CCA) comprises a heterogeneous group of primary liver tumors. They emerge from different hepatic (progenitor) cell populations, typically via sporadic mutations. Chronic biliary inflammation, as seen in primary sclerosing cholangitis (PSC), may trigger CCA development. Although several efforts were made in the last decade to better understand the complex processes of biliary carcinogenesis, it was only recently that new therapeutic advances have been achieved. Animal models are a crucial bridge between in vitro findings on molecular or genetic alterations, pathophysiological understanding, and new therapeutic strategies for the clinic. Nevertheless, it is inherently difficult to recapitulate simultaneously the stromal microenvironment (e.g., immune-competent cells, cholestasis, inflammation, PSC-like changes, fibrosis) and the tumor biology (e.g., mutational burden, local growth, and metastatic spread) in an animal model, so that it would reflect the full clinical reality of CCA. In this review, we highlight available data on animal models for CCA. We discuss if and how these models reflect human disease and whether they can serve as a tool for understanding the pathogenesis, or for predicting a treatment response in patients. In addition, open issues for future developments will be discussed.


Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 426 ◽  
Author(s):  
Sabari Nath Neerukonda ◽  
Upendra Katneni

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of CoV disease 2019 (COVID-19) is a highly pathogenic and transmissible CoV that is presently plaguing the global human population and economy. No proven effective antiviral therapy or vaccine currently exists, and supportive care remains to be the cornerstone treatment. Through previous lessons learned from SARS-CoV-1 and MERS-CoV studies, scientific groups worldwide have rapidly expanded the knowledge pertaining to SARS-CoV-2 virology that includes in vitro and in vivo models for testing of antiviral therapies and randomized clinical trials. In the present narrative, we review SARS-CoV-2 virology, clinical features, pathophysiology, and animal models with a specific focus on the antiviral and adjunctive therapies currently being tested or that require testing in animal models and randomized clinical trials.


2009 ◽  
Vol 53 (7) ◽  
pp. 2865-2870 ◽  
Author(s):  
John D. Morrey ◽  
Brent E. Korba ◽  
James R. Beadle ◽  
David L. Wyles ◽  
Karl Y. Hostetler

ABSTRACT Alkoxyalkyl esters of acyclic nucleoside phosphonates have previously been shown to have increased antiviral activity when they are administered orally in animal models of viral diseases, including lethal infections with vaccinia virus, cowpox virus, ectromelia virus, murine cytomegalovirus, and adenovirus. 9-(S)-(3-Hydroxy-2-phosphonomethoxypropyl)adenine [(S)-HPMPA] was previously shown to have activity against hepatitis B virus (HBV) in vitro. To assess the effect of alkoxyalkyl esterification of (S)-HPMPA, we prepared the hexadecyloxypropyl (HDP), 15-methyl-hexadecyloxypropyl (15M-HDP), and octadecyloxyethyl (ODE) esters and compared their activities with the activity of adefovir dipivoxil in vitro and in vivo. Alkoxyalkyl esters of (S)-HPMPA were 6 to 20 times more active than unmodified (S)-HPMPA on the basis of their 50% effective concentrations in 2.2.15 cells. The increased antiviral activity appeared to be due in part to the increased uptake and conversion of HDP-(S)-HPMPA to HPMPA diphosphate observed in HepG2 cells in vitro. HDP-(S)-HPMPA retained full activity against HBV mutants resistant to lamivudine (L180M, M204V), but cross-resistance to a mutant resistant to adefovir (N236T) was detected. HDP-(S)-HPMPA is orally bioavailable and provides excellent liver exposure to the drug. Oral treatment of HBV transgenic mice with HDP-(S)-HPMPA, 15M-HDP-(S)-HPMPA, and ODE-(S)-HPMPA for 14 days reduced liver HBV DNA levels by roughly 1.5 log units, a response equivalent to that of adefovir dipivoxil.


Author(s):  
Yoko Ambrosini ◽  
Dana Borcherding ◽  
Anumantha Kanthasamy ◽  
Hyun Jung Kim ◽  
Albert Jergens ◽  
...  

Identifying appropriate animal models is critical in developing translatable in vitro and in vivo systems for therapeutic development and investigating disease pathophysiology. These animal models should have direct biological and translational relevance to the underlying disease they are supposed to mimic. Aging dogs naturally develop a cognitive decline in many aspects including learning and memory, but also exhibit human-like individual variability in the aging process. Neurodegenerative processes that can be observed in both human and canine brains include the progressive accumulation of β-amyloid (Aβ) found as diffuse plaques in the prefrontal cortex, including the gyrus proreus, the hippocampus, and in the cerebral vasculature. A growing body of epidemiological data shows that human patients with neurodegenerative diseases have concurrent intestinal lesions, and histopathological changes in the gastrointestinal (GI) tract occurs decades that evolve before neurodegenerative changes. Gut microbiome alterations also have been observed in many neurodegenerative diseases including Alzheimer’s and Parkinson’s diseases, and inflammatory CNS diseases. Interestingly, only recently has the dog gut microbiome been recognized to more closely resemble in composition and in functional overlap with the human gut microbiome as compared to rodent models. This article aims to review the physiology of the gut-brain axis (GBA), and its involvement with neurodegenerative diseases in dogs and humans. Additionally, we outline the advantages and disadvantages of traditional in vitro and in vivo models and discuss future research directions investigating major human neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases using dogs.


2021 ◽  
Vol 27 ◽  
Author(s):  
Alexandra Ainatzoglou ◽  
Eleni Stamoula ◽  
Ioannis Dardalas ◽  
Spyridon Siafis ◽  
Georgios Papazisis

Background: Multiple sclerosis (MS) is a chronic inflammatory and immune-mediated disease, whose current therapeutic means are mostly effective in the relapsing-remitting form of MS, where inflammation is still prominent, but fall short of preventing long term impairment. However, apart from inflammation-mediated demyelination, autoimmune mechanisms play a major role in MS pathophysiology, constituting a promising pharmacological target. Phosphodiesterase (PDE) inhibitors have been approved for clinical use in psoriasis and have undergone trials suggesting their neuroprotective effects, rendering them eligible as an option for accessory MS therapy. Objective: In this review, we discuss the potential role of PDE inhibitors as a complementary MS therapy. Methods: We conducted a literature search through which we screened and comparatively assessed papers on the effects of PDE inhibitor use, both in vitro and in animal models of MS, taking into account a number of inclusion and exclusion criteria. Results: In vitro studies indicated that PDE inhibitors promote remyelination and axonal sustenance, while curbing inflammatory cell infiltration, hindering oligodendrocyte and neuronal loss and suppressing cytokine production. In vivo studies underlined that these agents alleviate symptoms and reduce disease scores in MS animal models. Conclusion: PDE inhibitors proved to be effective in addressing various aspects of MS pathogenesis both in vitro and in vivo models. Given the latest clinical trials proving that the PDE4 inhibitor Ibudilast exerts neuroprotective effects in patients with progressive MS, research on this field should be intensified and selective PDE4 inhibitors with enhanced safety features should be seriously considered as prospective complementary MS therapy.


Author(s):  
Zahra Zahedi-Tabar ◽  
Shadab Bagheri-Khoulenjani ◽  
Saeid Amanpour ◽  
Hamid Mirzadeh

Hyperthermia is a novel method for cancer therapy. To have the best control when heating tissues in hyperthermia, the use of magnetic nanoparticles is suggested. The local control of heat is very important in this technique, to prevent the damage of healthy tissues around the tumor, and therefore it is necessary to measure changes in temperature to determine the optimum conditions in which hyperthermia can create the desired results. The type and concentration of nanoparticles and nanoparticle distribution within the cancerous tissue are key factors affecting temperature distribution throughout the hyperthermia process. One of the main factors influencing nanoparticle distribution is the characteristics of the diffusion media, such as chemical composition, morphological and mechanical features, all of which affect the diffusion of nanoparticles at the cancer site. In this review, the most common in vitro and in vivo media and their influence on the results of hyperthermia are discussed. We also mention in silico as a computational model. Buffer solutions, cell cultures, microfluids, dead tissues and animal models are some of the in vitro media that are discussed in this review paper. In addition, some of the animal models used for hyperthermia will be mentioned.


2020 ◽  
Vol 88 (3) ◽  
pp. 32
Author(s):  
Eduardo Costa ◽  
Tânia Ferreira-Gonçalves ◽  
Gonçalo Chasqueira ◽  
António S. Cabrita ◽  
Isabel V. Figueiredo ◽  
...  

Breast cancer is one of the most common cancers worldwide, which makes it a very impactful malignancy in the society. Breast cancers can be classified through different systems based on the main tumor features and gene, protein, and cell receptors expression, which will determine the most advisable therapeutic course and expected outcomes. Multiple therapeutic options have already been proposed and implemented for breast cancer treatment. Nonetheless, their use and efficacy still greatly depend on the tumor classification, and treatments are commonly associated with invasiveness, pain, discomfort, severe side effects, and poor specificity. This has demanded an investment in the research of the mechanisms behind the disease progression, evolution, and associated risk factors, and on novel diagnostic and therapeutic techniques. However, advances in the understanding and assessment of breast cancer are dependent on the ability to mimic the properties and microenvironment of tumors in vivo, which can be achieved through experimentation on animal models. This review covers an overview of the main animal models used in breast cancer research, namely in vitro models, in vivo models, in silico models, and other models. For each model, the main characteristics, advantages, and challenges associated to their use are highlighted.


2005 ◽  
Vol 86 (8) ◽  
pp. 2141-2151 ◽  
Author(s):  
G. M. Scott ◽  
H.-L. Ng ◽  
C. J. Morton ◽  
M. W. Parker ◽  
W. D. Rawlinson

Human cytomegalovirus (HCMV) resistance to antivirals is a significant clinical problem. Murine cytomegalovirus (MCMV) infection of mice is a well-described animal model for in vivo studies of CMV pathogenesis, although the mechanisms of MCMV antiviral susceptibility need elucidation. Mutants resistant to nucleoside analogues aciclovir, adefovir, cidofovir, ganciclovir, penciclovir and valaciclovir, and the pyrophosphate analogue foscarnet were generated by in vitro passage of MCMV (Smith) in increasing concentrations of antiviral. All MCMV antiviral resistant mutants contained DNA polymerase mutations identical or similar to HCMV DNA polymerase mutations known to confer antiviral resistance. Mapping of the mutations onto an MCMV DNA polymerase three-dimensional model generated using the Thermococcus gorgonarius Tgo polymerase crystal structure showed that the DNA polymerase mutations potentially confer resistance through changes in regions surrounding a catalytic aspartate triad. The ganciclovir-, penciclovir- and valaciclovir-resistant isolates also contained mutations within MCMV M97 identical or similar to recognized GCV-resistant mutations of HCMV UL97 protein kinase, and demonstrated cross-resistance to antivirals of the same class. This strongly suggests that MCMV M97 has a similar role to HCMV UL97 in the phosphorylation of nucleoside analogue antivirals. All MCMV mutants demonstrated replication-impaired phenotypes, with the lowest titre and plaque size observed for isolates containing mutations in both DNA polymerase and M97. These findings indicate DNA polymerase and protein kinase regions of potential importance for antiviral susceptibility and replication. The similarities between MCMV and HCMV mutations that arise under antiviral selective pressure increase the utility of MCMV as a model for in vivo studies of CMV antiviral resistance.


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