P2X7 Receptor as a Key Player in Oxidative Stress-Driven Cell Fate in Nonalcoholic Steatohepatitis

Incidences of nonalcoholic fatty liver disease parallels increase in the global obesity epidemic. NAFLD has been shown to be associated with risks of cardiometabolic disorders and kidney disturbances. It is accompanied by insulin and leptin resistance that complicate the diagnosis and treatment of this public health menace. Though significant research is underway for understanding the molecular mechanisms of NAFLD and its subsequent inflammatory and fibrotic manifestations like nonalcoholic steatohepatitis, the role of purinergic receptors has been unclear. It is increasingly being recognized that damage associated molecular patterns like NAD and ATP that are released from injured cells via hepatocellular injury either by oxidative stress or lipotoxicity from steatosis activate the purinergic receptor. Based on evidence from inflammatory responses in the airways and vasculature and autoimmune complications in humans and rodents, it is beyond doubt that hepatocellular inflammation such as that seen in NASH can result from the activation of purinergic receptors. This event can result in the formation of inflammasomes and can be an important pathway for the progression of NASH. The present review evaluates the current knowledge of the role of oxidative stress and its signaling via P2X7 receptors in hepatocellular injury that might contribute to the NASH pathophysiology

Molecular Cues Of Pattern-Recognition-Receptor Pathways In Redox-Toxicity-Driven Environmental NAFLD

With the pandemic proportions of obesity and a correlative increase in fatty liver disease, there was a dire need to explore the missing link between the changed environment and progression of NAFLD in obesity. My research implies that environmental toxin bromodichloromethane induces early liver lesions in obesity, and is mediated by the synchronous insult of oxidative stress and increased levels of the adipokine leptin. In a two-pronged approach to investigate the molecular cues, I looked at the role of Purinergic receptor X7 and Toll 4 receptor. Both rodent models and cell-based systems were used. Also, in order to validate my findings in humans, I used diseased liver samples and corresponding age-matched controls. All diseased samples, and toxin-primed cell systems tested positive for oxidative stress markers. My first set of findings strongly suggest that P2X7r is a key regulator of autophagy-induced metabolic oxidative stress and early liver inflammation. In the second part of my investigation, I observed that toll 4 receptor recruitment to raft-zones of the liver cell membranes is crucial for its induction and inflammation in NAFLD. Most importantly, instead of the well-established stimulator of toll-receptor 4, LPS, I show that peroxynitrite which is elevated in the system as a result of the free radical chemistry, post environmental toxin exposure, is a potent inducer of TLR4-mediated inflammation in the disease. High-end confocal microscopy and immunofluorescence imaging techniques were utilized in addition to quantifying gene expressions, and immunoblotting proteins. Also, in a first-ever report in any model of NAFLD I used a peroxynitite-scavenging molecule FBA, showing positive remediation of NAFLD symptoms. This could be a very promising treatment regimen for redox-toxicity driven NAFLD. In conclusion, this novel disease model of NAFLD, helps us better understand the environmental link to the disease in presence of obesity, and exemplifies the molecular cues as potential therapeutic targets for alleviation of this silent-killer

Loop-mediated isothermal amplification (Lamp): A rapid, sensitive, specific, and cost-effective point-of-care test for coronaviruses in the context of covid-19 pandemic

The rampant spread of COVID-19 and the worldwide prevalence of infected cases demand a rapid, simple, and cost-effective Point of Care Test (PoCT) for the accurate diagnosis of this pandemic. The most common molecular tests approved by regulatory bodies across the world for COVID-19 diagnosis are based on Polymerase Chain Reaction (PCR). While PCR-based tests are highly sensitive, specific, and remarkably reliable, they have many limitations ranging from the requirement of sophisticated laboratories, need of skilled personnel, use of complex protocol, long wait times for results, and an overall high cost per test. These limitations have inspired researchers to search for alternative diagnostic methods that are fast, economical, and executable in low-resource laboratory settings. The discovery of Loop-mediated isothermal Amplification (LAMP) has provided a reliable substitute platform for the accurate detection of low copy number nucleic acids in the diagnosis of several viral diseases, including epidemics like Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). At present, a cocktail of LAMP assay reagents along with reverse transcriptase enzyme (Reverse Transcription LAMP, RT-LAMP) can be a robust solution for the rapid and cost-effective diagnosis for COVID-19, particularly in developing, and low-income countries. In summary, the development of RT-LAMP based diagnostic tools in a paper/strip format or the integration of this method into a microfluidic platform such as a Lab-on-a-chip may revolutionize the concept of PoCT for COVID-19 diagnosis. This review discusses the principle, technology and past research underpinning the success for using this method for diagnosing MERS and SARS, in addition to ongoing research, and the prominent prospect of RT-LAMP in the context of COVID-19 diagnosis

Upregulation of MIR21 and Repression of GRHL3 by Leptin Mediates Sinusoidal Endothelial Injury in Experimental Nonalcoholic Steatohepatitis

Sinusoidal endothelial dysfunction (SED) has been found to be an early event in nonalcoholic steatohepatitis (NASH) progression but the molecular mechanisms underlying its causation remains elusive. We hypothesized that adipokine leptin worsens sinusoidal injury by decreasing functionally active nitric oxide synthase 3 (NOS)3 via miR21. Using rodent models of NASH, and transgenic mice lacking leptin and leptin receptor, results showed that hyperleptinemia caused a 4-5 fold upregulation of hepatic miR21 as assessed by qRTPCR. The upregulation of miR21 led to a time-dependent repression of its target protein Grhl3 levels as shown by western blot analyses. NOS3-p/NOS3 ratio which is controlled by Grhl3 was significantly decreased in NASH models. SED markers ICAM-1, VEGFR-2, and E-selectin as assessed by immunofluorescence microscopy were significantly up regulated in the progressive phases of NASH. Lack of leptin or its receptor in vivo, reversed the upregulation of miR21 and restored the levels of Grhl3 and NOS3-p/NOS3 ratio coupled with decreased SED dysfunction markers. Interestingly, leptin supplementation in mice lacking leptin, significantly enhanced miR21 levels, decreased Grhl3 repression and NOS3 phosphorylation. Leptin supplementation in isolated primary endothelial cells, Kupffer cells and stellate cells showed increased mir21 expression in stellate cells while sinusoidal injury was significantly higher in all cell types. Finally miR21 KO mice showed increased NOS3-p/NOS3 ratio and reversed SED markers in the rodent models of NASH. The experimental results described here show a close association of leptin-induced miR21 in aiding sinusoidal injury in NASH

Rapid Antibody-Based COVID-19 Mass Surveillance: Relevance, Challenges, and Prospects in a Pandemic and Post-Pandemic World.

The aggressive outbreak of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) as COVID-19 (coronavirus disease-2019) pandemic demands rapid and simplified testing tools for its effective management. Increased mass testing and surveillance are crucial for controlling the disease spread, obtaining better pandemic statistics, and developing realistic epidemiological models. Despite the advantages of nucleic acid- and antigen-based tests such as accuracy, specificity, and non-invasive approaches of sample collection, they can only detect active infections. Antibodies (immunoglobulins) are produced by the host immune system within a few days after infection and persist in the blood for at least several weeks after infection resolution. Antibody-based tests have provided a substitute and effective method of ultra-rapid detection for multiple contagious disease outbreaks in the past, including viral diseases such as SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome). Thus, although not highly suitable for early diagnosis, antibody-based methods can be utilized to detect past infections hidden in the population, including asymptomatic ones. In an active community spread scenario of a disease that can provide a bigger window for mass detections and a practical approach for continuous surveillance. These factors encouraged researchers to investigate means of improving antibody-based rapid tests and employ them as reliable, reproducible, sensitive, specific, and economic tools for COVID-19 mass testing and surveillance. The development and integration of such immunoglobulin-based tests can transform the pandemic diagnosis by moving the same out of the clinics and laboratories into community testing sites and homes. This review discusses the principle, technology, and strategies being used in antibody-based testing at present. It also underlines the immense prospect of immunoglobulin-based testing and the efficacy of repeated planned deployment in pandemic management and post-pandemic sustainable screenings globally

Mempelajari Sifat Fisika Sol Karet Cetak Dengan Filler Cangkang Telur Ayam

Tujuan penelitian adalah untuk menpelajari sifat fisika sol karet cetak dengan filler cangkang telur ayam. Sifat fisika yang dipelajari meliputi kekerasan, tegangan putus, ketahanan sobek dan ketahanan kikis. Penelitian dilakukan dengan 4 tahap yaitu pembuatan filler cangkang telur ayam, pembuatan sol karet cetak, pengujian sifat fisika dan penilaian secara visual. Perlakuan terdiri dari penggunaan cangkang telur ayam menggantikan filer karbon hitam meliputi perlakuan tanpa penggunaan cangkang telur ayam (A1), penggunaan filler cangkang telur ayam 15 Phr (B1), penggunaan filer cangkang telur ayam 30 Phr (C1) dan penggunaan filler cangkang telur ayam 45 Phr (D1). Hasil penelitian menunjukkan bahwa cangkang telur ayam dapat digunakan sebagai filler pada pembuatan sol karet cetak. Penggunaan filler cangkang telur ayam yang semakin meningkat menghasilkan sol karet cetak dengan kekerasan yang cenderung semakin menurun, tegangan putus yang semakin menurun, ketahanan sobek yang semakin menurun dan ketahanan kikis yang semakin meningkat. Secara fisual sol karet cetak yang dihasilkan dari filler cangkang telur ayam menghasilkan sol karet cetak yang baik (tidak cacat berupa sobek, lubang, lepuh, retak dan goresan)

Altered Gut Microbiome in a Mouse Model of Gulf War Illness Causes Neuroinflammation and Intestinal Injury via Leaky Gut and TLR4 Activation

Many of the symptoms of Gulf War Illness (GWI) that include neurological abnormalities, neuroinflammation, chronic fatigue and gastrointestinal disturbances have been traced to Gulf War chemical exposure. Though the association and subsequent evidences are strong, the mechanisms that connect exposure to intestinal and neurological abnormalities remain unclear. Using an established rodent model of Gulf War Illness, we show that chemical exposure caused significant dysbiosis in the gut that included increased abundance of phylum Firmicutes and Tenericutes, and decreased abundance of Bacteroidetes. Several gram negative bacterial genera were enriched in the GWI-model that included Allobaculum sp. Altered microbiome caused significant decrease in tight junction protein Occludin with a concomitant increase in Claudin-2, a signature of a leaky gut. Resultant leaching of gut caused portal endotoxemia that led to upregulation of toll like receptor 4 (TLR4) activation in the small intestine and the brain. TLR4 knock out mice and mice that had gut decontamination showed significant decrease in tyrosine nitration and inflammatory mediators IL1β and MCP-1 in both the small intestine and frontal cortex. These events signified that gut dysbiosis with simultaneous leaky gut and systemic endotoxemia-induced TLR4 activation contributes to GW chemical-induced neuroinflammation and gastrointestinal disturbances