Biology subjects

Saxena, U.

Publications and source records attributed to Saxena, U..

11 recordsLinked to original sources

bioRxiv2022

Suppression of insulin stimulated muscle glucose uptake by non-caloric sweetener sucralose and its reversal by an antidiabetic nutraceutical supplement

Non caloric sweeteners (NCS) have been used for decades now as sugar substitutes in foods and beverages. The market for such products has grown immensely over time. There are human studies which report their negative effects on glucose metabolism with various results of disturbances in glucose metabolism, weight gain etc. No studies to the best of our knowledge have directly addressed the impact of the NCS on muscle glucose uptake. Muscle tissue can account for over 70 percent of whole-body glucose uptake. Therefore, we examined directly the effect of NCS on muscle cell glucose uptake. We find that aspartame moderately increased insulin stimulated glucose uptake by muscle cells in vitro. But sucralose, saccharin and stevia suppressed insulin stimulated glucose uptake. Sucralose is one of the most often used sweetener in foods and beverages globally it is important to understand its effects on glucose metabolism. Therefore, we explored the mechanism of its inhibition of glucose uptake by using an anti-diabetic nutraceutical which is known to target insulin mediated glucose uptake and metabolism pathways. We show here that the nutraceutical is able to relieve the suppression by sucrose in muscle uptake by a novel mechanism of action. We propose that such nutraceuticals may be useful to combine with sucralose containing products to offset negative effects of the NCS on glucose metabolism.

pharmacology and toxicology↗

bioRxiv2022

Pharmacogenetic allele variant frequencies: An analysis of the VAs Million Veteran Program (MVP) as a representation of the diversity in US population.

We present allele frequencies of pharmacogenomics relevant variants across multiple ancestry in a sample representative of the US population. We analyzed 658,582 individuals with genotype data and extracted pharmacogenomics relevant single nucleotide variant (SNV) alleles, human leukocyte antigens (HLA) 4-digit alleles and an important copy number variant (CNV), the full deletion/duplication of CYP2D6. We compiled distinct allele frequency tables for European, African American, Hispanic, and Asian ancestry individuals. In addition, we compiled allele frequencies based on local ancestry reconstruction in the African-American (2-way deconvolution) and Hispanic (3-way deconvolution) cohorts.

genomics↗

bioRxiv2022

Nutraceutical supplement targeting multiple molecular steps synergistically enhances muscle glucose uptake and improves in vivo oral glucose disposal

Pre diabetes and type 2 diabetes are increasingly becoming rampant world wide. While there are medications to control blood glucose in type 2 diabetics, currently there are no interventions prescribed for pre diabetes. Alternate strategies to control blood glucose are needed either to act alone in pre diabetes or as supplement to the existing drugs for type 2 diabetes. We report here the targeting of critical molecular steps in muscle glucose uptake and metabolism to result in glucose lowering using a combination of safe vitamins. Our in vitro and in vivo data support the potential for using such vitamin combination for glucose control in pre diabetes and as a supplement in type 2 diabetics.

pharmacology and toxicology↗

bioRxiv2022

An Integrated 3D bioprinted disease in a dish lung cancer model to simultaneously study drug efficacy, toxicity and metabolism

Discovery and development of new drugs is a long, expensive and high risk proposition. Millions of dollars spent and decade plus years of time taken to discover a new drug have haunted pharma industry for many years. In part, the reliance on animal models to make go or no go decisions for selecting drugs for human trials has been a problem because animal biology does not capture human disease in entirety. In recognition of this, the last decade has seen the emergence of more human like tools being developed in the hope of better prediction of human outcomes. Towards that end we have developed a 3D bioprinted disease in a dish lung cancer model which uses human cells and includes ability to measure drug efficacy, toxicity and metabolism simultaneously. For drug profiling studies in our disease in a dish model we 3D bioprinted intestinal cells, layered below which were liver cells and finally underneath were target lung cancer cells. The idea was to simulate the path taken by an oral drug which encounters the gut, followed by liver and target organs. We demonstrate here that a 3D bioprinted disease model composed of human derived cells is able to concurrently measure in vitro drug efficacy, toxicity and metabolism. Such humanized models will help make early go or no go decisions on the potential of a drug to enter human trials.

pharmacology and toxicology↗

bioRxiv2022

A 3-Dimensional bioprinted human gut-liver axis model for studying Alcoholic Liver Disease

Gut-liver axis is the interaction between the gut, its microbiome and the liver. The crosstalk and interaction between these organs plays an important role in their individual health and disease. Alcoholic liver disease (ALD) is a case in point where dysfunction of intestine actively promotes liver damage by alcohol. A flashpoint in ALD is the breach of intestinal integrity caused by gut bacteria Enterococcus faecalis (E.Faecalis). More specifically, Cytolysin, a toxin secreted by this bacteria may have a central role in the genesis of ALD. 3-D bioprinted human simulations of the gut-liver axis may help better understand the genesis of ALD. Here we developed a 3 dimensional bioprinted in vitro model composed of human origin intestinal and liver cells to explore the role of Cytolysin and ethanol in intestinal and liver damage. We find that neither Cytolysin or ethanol are sufficient for cell damage but a combination of the two act in concert to cause maximum breach in intestinal integrity. Secondly we find that enhanced transport of macromolecules thru the intestinal layer is not caused by overt cell toxicity but occurs through potentially paracellular/transcellular pathways. Our model will be used to test repurposed and new drugs/ biologics for treatment of ALD as well as other intestinal inflammatory diseases.

pharmacology and toxicology↗

bioRxiv2022

Differential Activity of Repurposed Drugs as Receptor Binding Domain Antagonists for Omicron and Native Strains of SarsCov2

Omicron strain is the latest variant of concern of SarsCov2 virus. The mutations in this strain in the S protein Receptor Binding domain (RBD) enable it to be more transmissible as well as escape neutralizing activity by antibodies in response to vaccine. Thus, Omicron specific strategies are need to counter infection by this strain. We investigated a collection of approved drugs shown to antagonize the binding of native strain RBD to human ACE2, for their ability to antagonize binding to Omicron strain RBD. While most of the drugs the drugs that antagonize binding to native RBD are also active for Omicron RBD but some were inactive, namely drugs that contain iodine are completely inactive against Omicron RBD. Our data strongly indicate that presence of a single iodine molecule in the drug renders it inactive against Omicron strain. Thus, there is molecular specificity of drugs for antagonizing Omicron strain RBD versus native strain RBD of this virus. Such information will pave way for specific drugs for Omicron. A pragmatic message from our data is that the often-used iodine containing mouth wash and rises may be ineffective in antagonizing receptor binding of Omicron strain.

pharmacology and toxicology↗

bioRxiv2022

Edible formulations of chicken egg derived IgY antibodies neutralize SarsCoV2 Omicron RBD binding to human ACE2

SarsCoV2 virus driven pandemic continues to surge propelled by new mutations such as seen in Omicron strain. Omicron is now rapidly becoming the dominant strain globally with more than 30 mutations in the spike protein. The mutations have resulted in Omicron strain escaping most of the neutralizing antibodies generated by the current set of approved vaccines and diluting the protection offered by the vaccines and therapeutic monoclonal antibodies. This has necessitated the need for newer strategies to prevent this strain from spreading. Towards this unmet need we have developed chicken egg derived anti-RBD IgY antibodies that neutralize the binding of Omicron RBD to human ACE2. Furthermore, we have formulated the edible IgY as flavored beverages to allow for use as oral rinse and prevent the entry of Omicron in the oropharyngeal passage, a major access and accumulation point for this strain in humans.

immunology↗

bioRxiv2021

Preparation of ingestible antibodies to neutralize the binding of SarsCoV2 RBD (receptor binding domain) to human ACE2 Receptor

COVID19 continues to be a serious threat to human health and mortality. There is dire need for new solutions to combat this pandemic especially for those individuals who are not vaccinated or unable to be vaccinated and continue to be exposed to the SARSCoV2. In addition, the emergence of new more transmissible variants such as delta pose additional threat from this virus. To explore another solution for prevention and treatment of COVID 19, we have produced chicken egg derived IgY antibodies against the Receptor binding domain (RBD) of SARSCoV2 spike protein which is involved in binding to human cell ACE2 receptors. The - RBD IgY effectively neutralize the binding of RBD to ACE2 and prevent pseudovirus entry in a PRNT assay. Importantly our anti-RBD IgY also neutralize the binding of Sars CoV2 delta variant RBD to ACE2. Given that chicken egg derived IgY are safe and permissible for human consumption, we plan to develop these ingestible antibodies for prevention of viral entry in the oropharyngeal and digestive tract in humans as passive immunotherapy.

immunology↗

bioRxiv2021

Identification of SGLT2 inhibitor Ertugliflozin as a treatment for COVID-19 using computational and experimental paradigm

Drug repurposing can expedite the process of drug development by identifying known drugs which are effective against SARS-CoV-2. The RBD domain of SARS-CoV-2 Spike protein is a promising drug target due to its pivotal role in viral-host attachment. These specific structural domains can be targeted with small molecules or drug to disrupt the viral attachment to the host proteins. In this study, FDA approved Drugbank database were screened using a virtual screening approach and computational chemistry methods. Five drugs were short listed for further profiling based on docking score and binding energies. Further these selected drugs were tested for their in vitro biological activity. There was significant correlation between the prediction from computational studies and the actual RBD-ACE2 binding inhibition by the drugs. Then, we performed a series of studies that mimic some of the biological events seen in COVID-19 patients such as secretion of IL1{beta}, presentation of a more thrombogenic endothelium by production of thrombomodulin and accumulation of inflammatory cells such as monocytes in the lungs. Of all the drugs, most promising drug was Ertugliflozin which is used for type-2 diabetes. This drug possesses several desired properties and may be a good candidate for immediate repurposing for treatment of COVID-19.

pharmacology and toxicology↗

bioRxiv2021

Tyrosine Kinase Inhibitor Family of Drugs as Prospective Targeted Therapy for COVID-19 Based on In Silico And 3D-Human Vascular Lung Model Studies

COVID-19 pandemic has ravaged the world and vaccines have been rapidly developed as preventive measures. But there is no target-based therapy which can be used if infection sets in. Remdesiver and dexamethasone were not designed to combat COVID-19 but are used clinically till better targeted therapies are available. Given this situation target based therapies that intervene in the disease pathway are urgently needed. Since COVID-19 genesis is driven by uncontrolled inflammation/thrombosis and protein kinases are critical in mounting this response, we explored if available tyrosine kinase inhibitors (TKIs) can be used as intervention. We profiled four TKIs namely; Lapatinib, Dasatinib, Pazopanib and Sitravatinib which inhibit tyrosine kinases but are completely distinct in their chemical structures. We demonstrate using in silico and an in vitro 3D-human vascular lung model which profiles anti-inflammatory and anti-thrombogenic properties that all four TKIs are active in varying degrees. Our findings that chemically different TKIs which share kinase inhibition as the common mechanism of action are active, strongly indicates that its a tyrosine kinase target-based activity and not off-target arbitrary effect. We propose that TKIs, approved for human use and widely available, can be rapidly deployed as specific target-based therapy for COVID-19.

pharmacology and toxicology↗

bioRxiv2021

In silico and in vitro Demonstration of Homoharrintonine Antagonism of RBD-ACE2 Binding and its Anti-inflammatory and anti-thrombogenic Properties in a 3D human vascular lung model

Since 2019 the world has seen severe onslaught of SARS-CoV-2 viral pandemic. There is an urgent need for drugs that can be used to either prevent or treat the potentially fatal disease COVD-19. To this end, we screened FDA approved antiviral drugs which could be repurposed for COVID-19 through molecular docking approach in the various active sites of receptor binding domain (RBD). The RBD domain of SARS-CoV-2 spike protein is a promising drug target due to its pivotal role in viral-host attachment. Specifically, we focussed on identifying antiviral drugs which could a) block the entry of virus into host cells, b) demonstrate anti-inflammatory and/or anti-thrombogenic properties. Drugs which poses both properties could be useful for prevention and treatment of the disease. While we prioritized a few antiviral drugs based on molecular docking, corroboration with in vitro studies including a new 3D human vascular lung model strongly supported the potential of Homoharringtonine, a drug approved for chronic myeloid leukaemia to be repurposed for COVID-19. This natural product drug not only antagonized the biding of SARS-CoV-2 spike protein RBD binding to human angiotensin receptor 2 (ACE-2) protein but also demonstrated for the first time anti-thrombogenic and anti-leukocyte adhesive properties in a human cell model system. Overall, this work provides an important lead for development of rapid treatment of COVID-19 and also establishes a screening paradigm using molecular modelling and 3D human vascular lung model of disease to identify drugs with multiple desirable properties for prevention and treatment of COVID-19.

pharmacology and toxicology↗