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Results for “Clinical Trials”

Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

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At least 1,117 records · Page 62Linked to original sources

bioRxiv2019

RNA-seq transcriptome analysis reveals LTR-retrotransposons modulation in Human Peripheral Blood Mononuclear Cells (PBMCs) after in vivo Lipopolysaccharides (LPS) injection

Human Endogenous Retroviruses (HERVs) and Mammalian apparent LTR-retrotransposons (MaLRs) are retroviral sequences that integrated into the germline cells millions year ago. Transcripts of these LTR-retrotransposons are present in several tissues, and their expression is modulated in pathological conditions, although their function remains often far from being understood. In this work, we focused on the HERVs/MaLRs expression and modulation in a scenario of immune system activation. We used a public dataset of Human Peripheral Blood Mononuclear Cells (PBMCs) RNA-seq from 15 healthy participants to a clinical trial before and after the exposure to Lipopolysaccharide (LPS), for which we established an RNA-seq workflow for the identification of expressed and modulated cellular genes and LTR-retrotransposon elements. ImportanceWe described the HERV and MaLR transcriptome in PBMCs, finding that about 8.4 % of the LTR-retrotransposons loci were expressed, and identifying the betaretrovirus-like HERVs as those with the highest percentage of expressed loci. We found 4,607 HERVs and MaLRs loci that were modulated as a result of in vivo stimulation with LPS. The HERV-H group showed the highest number of differentially expressed most intact proviruses. We characterized the HERV and MaLR loci differentially expressed checking their genomic context of insertion and, interestingly, we found a general co-localization with genes that are involved and modulated in the immune response, as consequence of LPS stimulation. The analyses of HERVs and MaLRs expression and modulation show that this LTR-retrotransposons are expressed in PBMCs and regulated in inflammatory settings. The similar regulation of HERVs/MaLRs and genes after LPS stimulation suggests possible interactions of LTR-retrotransposons and the immune host response.

microbiology↗

bioRxiv2019

Transfer Learning for Predicting Conversion from Mild Cognitive Impairment to Dementia of Alzheimer Type based on 3D-Convolutional Neural Network

Dementia of Alzheimers Type (DAT) is associated with a devastating and irreversible cognitive decline. As a pharmacological intervention has not yet been developed to reverse disease progression, preventive medicine will play a crucial role for patient care and treatment planning. However, predicting which patients will progress to DAT is difficult as patients with Mild Cognitive Impairment (MCI) could either convert to DAT (MCI-C) or not (MCI-NC). In this paper, we develop a deep learning model to address the heterogeneous nature of DAT development. Structural magnetic resonance imaging was utilized as a single biomarker, and a three-dimensional convolutional neural network (3D-CNN) was developed. The 3D-CNN was trained using transfer learning from the classification of Normal Control and DAT scans at the source task. This was applied to the target task of classifying MCI-C and MCI-NC scans. The model results in 82.4% classification accuracy, which outperforms current models in the field. Furthermore, by implementing an occlusion map approach, we visualize key brain regions that significantly contribute to the prediction of MCI-C and MCI-NC. Results show the hippocampus, amygdala, cerebellum, and pons regions as significant to prediction, which are consistent with current understanding of disease. Finally, the models prediction value is significantly correlated with rates of change in clinical assessment scores, indicating the model is able to predict an individual patients future cognitive decline. This information, in conjunction with the identified anatomical features, will aid in building a personalized therapeutic strategy for individuals with MCI. This model could also be useful for selection of participants for clinical trials.

bioinformatics↗

bioRxiv2019

Characterization of the phototoxicity, chemigenetic profile, and mutational signatures of the chemotherapeutic CX-5461 in Caenorhabditis elegans

New anti-cancer therapeutics require extensive in vivo characterization to identify endogenous and exogenous factors affecting efficacy, to measure toxicity and mutagenicity, and to determine genotypes resulting in therapeutic sensitivity or resistance. We used Caenorhabditis elegans as a platform with which to characterize properties of anti-cancer therapeutic agents in vivo. We generated a map of chemigenetic interactions between DNA damage response mutants and common DNA damaging agents. We used this map to investigate the properties of the new anti-cancer therapeutic CX-5461. We phenocopied the photoreactivity observed in CX-5461 clinical trials and found that CX-5461 generates reactive oxygen species when exposed to UVA radiation. We demonstrated that CX-5461 is a mutator, resulting in both large copy number variations and a high frequency of single nucleotide variations (SNVs). CX-5461-induced SNVs exhibited a distinct mutational signature. Consistent with the wide range of CX-5461-induced mutation types, we found that multiple repair pathways were needed for CX-5461 tolerance. Together, the data from C. elegans demonstrate that CX-5461 is a multimodal DNA damaging agent with strong similarity to ellipticines, a class of antineoplastic agents, and to anthracycline-based chemotherapeutics.

genetics↗

bioRxiv2020

OvirusTdb: A Repository of Oncolytic Viruses used in Cancer Treatment

One of the emerging technologies to fight against cancer is oncolytic virus-based immunotherapy which directly lysis tumor cells. Recently, the FDA approved an oncolytic virus named T-vec for the treatment of melanoma; several hundred other viruses are in clinical trials. In order to facilitate the scientific community to fight against cancer, we build a repository of oncolytic viruses called OvirusTdb (https://webs.iiitd.edu.in/raghava/ovirustdb/). This is a manually curated repository where information is curated from research papers and patents. The current version of the repository maintains comprehensive information on therapeutically important oncolytic viruses with 5927 records where each record has 25 fields such as the virus species, cancer cell line, synergism with anti-cancer drugs, and many more. It stores information on 09 types of DNA and 15 types of RNA viruses; 300 recombinant and 09 wildtype viral strains; tested against 124 cancer types and 427 cancer cell lines. Approximately, 1047 records show improved anti-cancer response using combinatorial approach of chemotherapeutic agents with virus strains. Nearly, 3243 and 1506 records show cancer cell death via apoptosis induction and immune activation, respectively. In summary, a user-friendly web repository of oncolytic viruses for information retrieval and analysis have been developed to facilitate researchers in designing and discovering new oncolytic viruses for effective cancer treatment.

bioinformatics↗

bioRxiv2020

Serum cytokine levels are modulated by specific frequencies, amplitudes, and pulse widths of vagus nerve stimulation

Electrical stimulation of peripheral nerves is a widely used technique to treat a variety of conditions including chronic pain, motor impairment, headaches, and epilepsy. Nerve stimulation to achieve efficacious symptomatic relief depends on the proper selection of electrical stimulation parameters to recruit the appropriate fibers within a nerve. Recently, electrical stimulation of the vagus nerve has shown promise for controlling inflammation and clinical trials have demonstrated efficacy for the treatment of inflammatory disorders. This application of vagus nerve stimulation activates the inflammatory reflex, reducing levels of inflammatory cytokines during inflammation. Here, we wanted to test whether altering the parameters of electrical vagus nerve stimulation would change circulating cytokine levels of normal healthy animals in the absence of increased inflammation. To examine this, we systematically tested a set of electrical stimulation parameters and measured serum cytokine levels in healthy mice. Surprisingly, we found that specific combinations of pulse width, pulse amplitude, and frequency produced significant increases of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF), while other parameters selectively lowered serum TNF levels, as compared to sham-stimulated mice. In addition, serum levels of the anti-inflammatory cytokine interleukin-10 (IL-10) were significantly increased by select parameters of electrical stimulation but remained unchanged with others. These results indicate that electrical stimulation parameter selection is critically important for the modulation of cytokines via the cervical vagus nerve and that specific cytokines can be increased by electrical stimulation in the absence of inflammation. As the next generation of bioelectronic therapies and devices are developed to capitalize on the neural regulation of inflammation, the selection of nerve stimulation parameters will be a critically important variable for achieving cytokine-specific changes.

immunology↗

bioRxiv2020

Crowdsourcing digital health measures to predict Parkinson's disease severity: the Parkinson's Disease Digital Biomarker DREAM Challenge

Mobile health, the collection of data using wearables and sensors, is a rapidly growing field in health research with many applications. Deriving validated measures of disease and severity that can be used clinically or as outcome measures in clinical trials, referred to as digital biomarkers, has proven difficult. In part due to the complicated analytical approaches necessary to develop these metrics. Here we describe the use of crowdsourcing to specifically evaluate and benchmark features derived from accelerometer and gyroscope data in two different datasets to predict the presence of Parkinsons Disease (PD) and severity of three PD symptoms: tremor, dyskinesia and bradykinesia. Forty teams from around the world submitted features, and achieved drastically improved predictive performance for PD status (best AUROC=0.87), as well as tremor (best AUPR=0.75), dyskinesia (best AUPR=0.48) and bradykinesia (best AUPR=0.95) severity.

bioengineering↗

bioRxiv2020

Factor VIII exhibits chaperone-dependent and glucose-regulated reversible amyloid formation in the endoplasmic reticulum

Factor VIII (FVIII) is the coagulation factor deficient in hemophilia A, which is treated by protein replacement. Unfortunately, this regimen is costly due to the expense of producing recombinant FVIII as a consequence of its low level secretion. FVIII expression activates the endoplasmic reticulum (ER) stress response, causes oxidative stress and induces apoptosis. Importantly, little is known about the factors that cause protein misfolding and aggregation in metazoans. Here we identified intrinsic and extrinsic factors that cause FVIII to form aggregates in the ER. We show that FVIII forms amyloid-like fibrils within the ER upon increased FVIII synthesis or inhibition of glucose metabolism. Significantly, FVIII amyloids can be dissolved upon restoration of glucose metabolism to produce functional secreted FVIII. Two ER chaperones and their co-chaperones, BiP and CANX/CRT, promote FVIII solubility in the ER, where the former is also required for disaggregation. A short aggregation motif in the FVIII A1 domain (termed Aggron) is necessary and sufficient to seed {beta}-sheet polymerization and BiP binding to this Aggron prevents amyloidogenesis. Our findings provide novel insight into mechanisms that limit FVIII secretion and ER protein folding in general and have implication for ongoing hemophilia A gene therapy clinical trials. Key Points- FVIII forms amyloid aggregates in the ER that are dissolved in a chaperone- and glucose-dependent manner to produce secreted active FVIII. - A short amino acid sequence in the A1 domain causes {beta} sheet polymerization and ER chaperone BiP binding to this site prevents aggregation.

molecular biology↗

bioRxiv2020

Combined Treatment with Dopamine Receptor Antagonists and Radiation Creates a Metabolic Vulnerability in Mouse Models of Glioblastoma

BackgroundGlioblastoma is the deadliest brain tumor in adults and the standard-of-care consists of surgery followed by radiation and treatment with temozolomide. Overall survival times for patients suffering from glioblastoma are unacceptably low indicating an unmet need for novel treatment options. MethodsUsing patient-derived glioblastoma lines and mouse models of glioblastoma we test the effect of radiation and the dopamine receptor antagonist on glioblastoma self-renewal in vitro and survival in vivo. A possible resistance mechanism is investigated using RNA-Sequencing. ResultsTreatment of glioma cells with the dopamine receptor antagonist quetiapine reduced glioma cell self-renewal in vitro and combined treatment of mice with quetiapine and radiation prolonged the survival of glioma-bearing animals. The combined treatment induced the expression of genes involved in cholesterol biosynthesis. This rendered the tumors vulnerable to simultaneous treatment with atorvastatin and further significantly prolonged the survival of the animals. ConclusionsOur results indicate high efficacy of a triple combination of quetiapine, atorvastatin and radiation against glioblastoma without increasing the toxicity of radiation. With both drugs readily available for clinical use our study could be rapidly translated into a clinical trial.

neuroscience↗

bioRxiv2020

Non-invasive monitoring of drug action: a new live in vitro assay design for Chagas' disease drug discovery

New assay designs are needed to improve the predictive value of the Trypanosoma cruzi in vitro tests used as part of the Chagas disease drug development pipeline. Here, we employed a green fluorescent protein (eGFP)-expressing parasite line and live high-content imaging to monitor the growth of T. cruzi amastigotes in mouse embryonic fibroblasts. A novel assay design allowed us to follow parasite numbers over 6 days, in four-hour intervals, while occupying the microscope for only 24 hours per biological replicate. Dose-response curves were calculated for each time point after addition of test compounds, revealing how EC50 values first decreased over the time of drug exposure, and then leveled off. However, we observed that parasite numbers could vary, even in the untreated controls, and at different sites in the same well, which caused variability in the EC50 values. To overcome this, we established that fold change in parasite number per hour is a more robust and informative measure of drug activity. This was calculated based on an exponential growth model for every biological sample. The net fold change per hour is the result of parasite replication, differentiation, and death. The calculation of this fold change enabled us to determine the tipping point of drug action, i.e. the point immediately before the fold change becomes negative, independent of the drug concentration and exposure time. This time-to-kill over drug concentration revealed specific pharmacodynamic profiles of the benchmark drugs benznidazole and posaconazole. Author SummaryChagas disease, caused by Trypanosoma cruzi, is a chronic debilitating infection occurring mostly in Latin America. There is an urgent need for new, well tolerated drugs. However, the latest therapeutic candidates have yielded disappointing outcomes in clinical trials, despite promising preclinical results. This demands new and more predictive in vitro assays. To address this, we have developed an assay design that enables the growth of T. cruzi intracellular forms to be monitored in real time, under drug pressure, for 6 days post-infection. This allowed us to establish the tipping point of drug action, when the parasites stop multiplying and start to die. The resulting pharmacodynamics profiles can provide robust and informative details on anti-chagasic candidates, as demonstrated for the benchmark drugs benznidazole and posaconazole.

microbiology↗

bioRxiv2020

Ursodeoxycholic acid (UDCA) mitigates the host inflammatory response during Clostridioides difficile infection by altering gut bile acids which attenuates NF-κB signaling via bile acid activated receptors

Clostridioides difficile infection (CDI) is associated with increasing morbidity and mortality posing an urgent threat to public health. Recurrence of CDI after successful treatment with antibiotics is high, thus necessitating discovery of novel therapeutics against this enteric pathogen. Administration of the secondary bile acid ursodeoxycholic acid (UDCA, ursodiol) inhibits the life cycle of various strains of C. difficile in vitro, suggesting the FDA approved formulation of UDCA, known as ursodiol, may be able to restore colonization resistance against C. difficile in vivo. However, the mechanism(s) by which ursodiol is able to restore colonization resistance against C. difficile remains unknown. Here, we confirmed that ursodiol inhibits C. difficile R20291 spore germination and outgrowth, growth, and toxin activity in a dose dependent manner in vitro. In a murine model of CDI, exogenous administration of ursodiol resulted in significant alterations in the bile acid metabolome with little to no changes in gut microbial community structure. Ursodiol pretreatment resulted in attenuation of CDI pathogenesis early in the course of disease, which coincided with alterations in the cecal and colonic inflammatory transcriptome, bile acid activated receptors nuclear farnesoid X receptor (FXR), and transmembrane G protein-coupled membrane receptor 5 (TGR5), which are able to modulate the innate immune response through signaling pathways such as NF-{kappa}B. Although ursodiol pretreatment did not result in a consistent decrease in the C. difficile life cycle in vivo, it was able to attenuate an overly robust inflammatory response that is detrimental to the host during CDI. Ursodiol remains a viable non-antibiotic treatment and/or prevention strategy against CDI. Likewise, modulation of the host innate immune response via bile acid activated receptors, FXR and TGR5, represents a new potential treatment strategy for patients with CDI. ImportanceThe clinical utility of ursodiol for prevention of recurrent CDI is currently in Phase 4 clinical trials. However, the mechanism by which ursodiol exerts its impacts on C. difficile pathogenesis is poorly understood. Herein, we demonstrated that ursodiol pretreatment attenuates CDI pathogenesis early in the course of disease in mice, which coincides with alterations in the cecal and colonic inflammatory transcriptome, bile acid activated receptors nuclear farnesoid X receptor (FXR), and transmembrane G protein-coupled membrane receptor 5 (TGR5), which are able to modulate the innate immune response through signaling pathways such as NF-{kappa}B. Ursodiol attenuated an overly robust inflammatory response that is detrimental to the host during CDI, and thus remains a viable non-antibiotic treatment and/or prevention strategy against CDI. Likewise, modulation of the host innate immune response via bile acid activated receptors, FXR and TGR5, represents a new potential treatment strategy for patients with CDI. AbbreviationsMCA - -Muricholic acid; {beta}MCA -{beta}-Muricholic acid; {omega}MCA -{omega}-Muricholic acid; CA - Cholic acid; CDCA - Chenodeoxycholic acid; DCA - Deoxycholic acid; GCDCA - Glycochenodeoxycholic acid; GDCA - Glycodeoxycholic acid; GLCA - Glycolithocholic acid; GUDCA - Glycoursodeoxycholic acid; HCA - Hyodeoxycholic acid; iDCA - Isodeoxycholic acid; iLCA - Isolithocholic acid; LCA - Lithocholic acid; TCA - Taurocholic acid; TCDCA - Taurochenodeoxycholic acid; TDCA - Taurodeoxycholic acid; THCA - Taurohyodeoxycholic acid; TUDCA - Tauroursodeoxycholic acid; T{beta}MCA- Tauro-{beta}-muricholic acid; T{omega}MCA -Tauro {omega}-muricholic acid; UDCA Ursodeoxycholic acid.

microbiology↗

bioRxiv2020

Is cathodal prefrontal transcranial direct current stimulation capable of affecting inhibitory control and sustained attention? A single-blind, crossover,sham-controlled study

BackgroundAnodal transcranial direct current stimulation (a-tDCS) has been shown to promote performance improvement of normal individuals in tests of executive function, including tasks that demand sustained attention and inhibitory control. The presumed mechanism is facilitation of prefrontal cortex activation, since a-tDCS is thought to increase cortical excitability. Only a few studies, however, have investigated the effects of inhibitory, cathodal tDCS (c-tDCS) on cognitive tasks, and reported results are often inconsistent. Studies about the effects of c-tDCS upon accuracy and reaction times are particularly scant. Objective/HypothesisThis study assessed the effects of inhibitory c-tDCS over the left dorsolateral prefrontal cortex (l-DLPFC) on the performance of neurologically intact young adults in Stroop and reaction time tests. MethodsSeventeen healthy undergraduate students (ten women) performed Stroop and reaction time tasks after delivery of c-tDCS (1 mA, 20 min) over l-DLFPC or a sham session. All subjects underwent both real and sham sessions, which were separated by an interval of one week. We hypothesized that c-tDCS might lead to an impairment of inhibitory control and attention abilities. ResultsWe found an interference effect on the Stroop task and also a ceiling effect on the reaction Time task. There were no statistically significant performance differences in any of the neuropsychological tests as a function of stimulation condition and/or subject gender. ConclusionsC-tDCS over the l-DLPFC of neurologically intact young individuals did not affect performance in Stroop Test accuracy or in reaction times, irrespective of subject gender. These results raise the possibility that c-tDCS inhibitory effects, well documented for the primary motor area, do not necessarily apply to higher order associative areas. The assumption that c-tDCS has inhibitory effects upon any cortical area, common in clinical trials, should be made with caution.

neuroscience↗

bioRxiv2020

The logic of containing tumors

Challenging the paradigm of the maximum tolerated dose, recent studies have shown that a strategy aiming for containment, not elimination, can control tumor burden more effectively in vitro, in mouse models, and in the clinic. These outcomes are consistent with the hypothesis that emergence of resistance to cancer therapy may be prevented or delayed by exploiting competitive ecological interactions between drug-sensitive and resistant tumor cell subpopulations. However, although various mathematical and computational models have been proposed to explain the superiority of particular containment strategies, this evolutionary approach to cancer therapy lacks a rigorous theoretical foundation. Here we combine extensive mathematical analysis and numerical simulations to establish general conditions under which a containment strategy is expected to control tumor burden more effectively than applying the maximum tolerated dose. We show that when resistant cells are present, an idealized strategy of containing a tumor at a maximum tolerable size maximizes time to treatment failure (that is, the time at which tumor burden becomes intolerable). These results are very general and do not depend on any fitness cost of resistance. We further provide formulas for predicting the clinical benefits attributable to containment strategies in a wide range of scenarios, and we compare outcomes of theoretically optimal treatments with those of more practical protocols. Our results strengthen the rationale for clinical trials of evolutionarily-informed cancer therapy.

cancer biology↗

bioRxiv2020

Unacylated ghrelin and AZP531 suppress the 3D growth of breast cancers

Breast cancer is the most common type of cancer in women and notwithstanding important therapeutic advances, it remains the second leading cause of cancer-related death in the US. Despite extensive research relating to the hormone ghrelin, responsible for the stimulation of growth hormone release and appetite, little is known of the effects of its unacylated form, especially in cancer. One major area of research relates to its reported effects to increase insulin sensitivity in diabetics, this being the basis for the development of unacylated ghrelin analog, AZP531 or livoletide, now in clinical trials for the treatment of Prader-Willi Syndrome. The mechanism of action of unacylated ghrelin is largely uncharacterized, in any system, because it does not bind to or activate the cognate ghrelin receptor, GHSR1a. The present study aimed to characterize effects of unacylated ghrelin on breast cancer cells, define its mechanism of action, and explore the therapeutic potential of unacylated ghrelin or analog AZP531. We report potent effects of unacylated ghrelin, at picomolar doses, on the growth of breast cancer cells, dependent on 3D culture and activation of Gi. Suppression of MAPK signaling by unacylated ghrelin leads to cell cycle arrest and apoptosis. AZP531 also suppresses the growth of breast cancer cells in vitro and in xenografts, and may be a novel approach for the safe and effective treatment of breast cancer.

cancer biology↗

bioRxiv2020

PARP1 and MGMT interaction-based sensitivity to DNA damage in Ewing sarcoma

The Ewing family of sarcomas comprises the fourth most common highly aggressive bone tumor. Four of five Ewing sarcoma chemotherapeutics induce DNA damage, as does radiation therapy. At relapse, two additional DNA-damaging agents are routinely used to re-induce remission, indicating that Ewing sarcoma is intrinsically sensitive to DNA damage. However, current treatment regimens are relatively ineffective, specifically for relapsed or metastatic disease. Several preclinical studies, including our study in the Pediatric Preclinical Testing Program (PPTP), provide evidence for the synthetic lethal combination of PARP1 inhibitor talazoparib with a DNA-methylating agent, temozolomide, for Ewing sarcoma. Nevertheless, in both preclinical studies and clinical trials, doses of temozolomide were significantly reduced because of toxicity of the drug combination. Temozolomide-induced DNA lesions are repaired via poly(ADP) ribose polymerase I (PARP1)-dependent base excision repair and by O6-methylguanine-DNA methyltransferase (MGMT) in a single-step adduct removal. Here, we provide evidence that the two DNA repair pathways act in an epistatic manner in lesion removal. Further, we demonstrate that PARP1 and MGMT physically interact, and that this association is stimulated upon DNA damage. Protein co-immunoprecipitation and microscale thermophoresis analyses revealed that PARP1/MGMT complex formation is DNA and PARylation-independent. Collectively, our results show that: 1) DNA damage response pathways mediated by PARP1 and MGMT work epistatically to eliminate temozolomide-induced DNA adducts; 2) PARP1 and MGMT physically interact; and 3) PARP1/MGMT interaction is increased in response to DNA damage. We discuss how our findings may affect therapeutic advancement for Ewing sarcoma and potentially other cancer types.

biochemistry↗

bioRxiv2020

Pharmaceutical-grade Rigosertib is a Microtubule-destabilizing Agent

We recently used CRISPRi/a-based chemical-genetic screens and targeted cell biological, biochemical, and structural assays to determine that rigosertib, an anti-cancer agent in phase III clinical trials, kills cancer cells by destabilizing microtubules. In a recent manuscript, Reddy and co-workers suggest that this microtubule-destabilizing activity of rigosertib is mediated not by rigosertib itself but by a contaminating degradation product of rigosertib, ON01500, present in formulations obtained from commercial vendors (Baker et al., 2019). Here, we demonstrate that treatment of cells with pharmaceutical-grade rigosertib (>99.9% purity) results in qualitatively indistinguishable phenotypes as treatment with commercially obtained rigosertib across multiple assays. The two compounds have indistinguishable chemical-genetic interactions with genes involved in modulating the microtubule network (KIF2C and TACC3), both destabilize microtubules in cells and in vitro, and both show substantially reduced toxicity in cell lines expressing a rationally-designed mutant of tubulin (L240F TUBB mutant), in which the rigosertib binding site in tubulin is mutated. Importantly, the specificity of the L240F TUBB mutant for microtubule-destabilizing agents, which is disputed by Reddy and co-workers, was recently confirmed by an independent research group (Patterson et al., 2019). We conclude that rigosertib kills cancer cells by destabilizing microtubules, in agreement with our original findings.

cancer biology↗

bioRxiv2020

Long term AAV2/9-mediated silencing of PMP22 prevents CMT1A disease in rats and validates skin biomarkers as treatment outcome measure

Charcot-Marie-Tooth disease 1A (CMT1A) results from a duplication of the PMP22 gene leading to an excess of PMP22, a deficit of myelination and an instability of the myelin sheath in peripheral nerves. Patients present with reduced nerve conduction velocity, muscle waste, hand and foot deformations and foot drop walking problems. As gene silencing therapy has been shown to be effective in other monogenic neurological disorders, we evaluated the safety and efficacy of recombinant adeno-associated viral vector serotype 9 (AAV2/9)-based gene therapy for CMT1A. AAV2/9-mediated delivery of eGFP and shRNAs targeting PMP22 mRNA in the sciatic nerve allowed widespread gene expression in myelinating Schwann cells in mouse, rat and nonhuman primate. The treatment restored wild-type PMP22 level, increased myelination and prevented motor and sensory impairment over 12 months in a rat model of CMT1A. Intra-nerve injection limited off-target transduction and immune response to barely detectable levels. A combination of previously characterized human skin biomarkers successfully discriminated treated animals from their untreated littermate controls indicating their potential use as part of outcome measures in future clinical trials. Our results support intra nerve injection of AAV2/9 as an effective strategy for the treatment of CMT1A as well as other demyelinating CMT diseases.

neuroscience↗

bioRxiv2020

Telacebec for ultra-short treatment of Buruli ulcer in a mouse model

Telacebec (Q203) is a new anti-tubercular drug with extremely potent activity against Mycobacterium ulcerans. Here, we explored the treatment-shortening potential of Q203 alone or in combination with rifampin (RIF) in a mouse footpad infection model. The first study compared Q203 at 5 and 10 mg/kg doses alone and with rifampin. Q203 alone rendered most mouse footpads culture-negative in 2 weeks. Combining Q203 with rifampin resulted in relapse-free cure 24 weeks after completing 2 weeks of treatment, compared to a 25% relapse rate in mice receiving RIF+clarithromycin, the current standard of care, for 4 weeks. The second study explored the dose-ranging activity of Q203 alone and with RIF, including the extended activity of Q203 after treatment discontinuation. The bactericidal activity of Q203 persisted for [≥] 4 weeks beyond the last dose. All mice receiving just 1 week of Q203 at 2-10 mg/kg were culture-negative 4 weeks after stopping treatment. Mice receiving 2 weeks of Q203 at 0.5, 2 and 10 mg/kg were culture-negative 4 weeks after treatment. RIF did not increase the efficacy of Q203. A pharmacokinetics sub-study revealed that Q203 doses of 2-10 mg/kg in mice produce plasma concentrations similar to those produced by 100-300 mg doses in humans, with no adverse effect of RIF on Q203 concentrations. These results indicate the extraordinary potential of Q203 to reduce the duration of treatment necessary for cure to [≤] 1 week (or 5 doses of 2-10 mg/kg) in our mouse footpad infection model and warrant further evaluation of Q203 in clinical trials.

microbiology↗

bioRxiv2020

Integration of Brain and Behavior Measures for Identification of Data-Driven Groups Cutting Across Children with ASD, ADHD, or OCD

Autism spectrum disorder (ASD), obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD) are clinically and biologically heterogeneous neurodevelopmental disorders (NDDs). The objective of the present study was to integrate brain imaging and behavioral measures to identify new brain-behavior subgroups cutting across these disorders. A subset of the data from the Province of Ontario Neurodevelopmental Disorder (POND) Network including participants with different NDDs (aged 6-16 years) that underwent cross-sectional T1-weighted and diffusion-weighted magnetic resonance imaging (MRI) scanning on the same 3T scanner, and behavioral/cognitive assessments was used. Similarity Network Fusion was applied to integrate cortical thickness, subcortical volume, white matter fractional anisotropy (FA), and behavioral measures in 176 children with ASD, ADHD or OCD with complete data that passed quality control. Normalized mutual information (NMI) was used to determine top contributing model features. Bootstrapping, out-of-model outcome measures and supervised machine learning were each used to examine stability and evaluate the new groups. Cortical thickness in socio-emotional and attention/executive networks and inattention symptoms comprised the top ten features driving participant similarity and differences between four transdiagnostic groups. Subcortical volumes (pallidum, nucleus accumbens, thalamus) were also different among groups, although white matter FA showed limited differences. Features driving participant similarity remained stable across resampling, and the new groups showed significantly different scores on everyday adaptive functioning. Our findings open the possibility of studying new data-driven groups that represent children with NDDs more similar to each other than others within their own diagnostic group. Such new groups can be evaluated longitudinally for prognostic utility and could be stratified for clinical trials targeted toward each groups unique brain and behavioral profiles.

neuroscience↗