Biology subjects

Paramasivam, P.

Publications and source records attributed to Paramasivam, P..

6 recordsLinked to original sources

bioRxiv2025

Exercise Conditioning Enhances Insulin Sensitivity with Metabolic and Glycemic Control Driven by Hepatic Silencing of HMGB1 in Type 2 Diabetic Mice

Type 2 Diabetes (T2D) is characterized by chronic insulin resistance and inflammation. Exercise induces hyperglycemia control in T2D more than pharmacologic therapies alone. High Mobility Group Box 1 (HMGB1) is a ubiquitous nuclear factor for T2D progression. We hypothesize that hepatic silencing of HMGB1 in T2D and exercise will increase insulin sensitivity and shift metabolic routes, decrease liver damage and improve metabolic health in T2D mice. MethodsLiver HMGB1 KO (HMGB1{Delta}) was induced with AAV8-TBG in HMGB1 flox mice (AAV8-EGFP was used as wildtype controls). T2D mice were induced with a low-dose STZ and a high-fat diet. T2D mice ran for four weeks (1hr daily). Dual Energy X-Ray Absorptiometry (DEXA), A1C, glycemia, HMGB1, metabolomics and metabolic cage analysis were performed pre- and post-exercise. RT-PCR, immunoblotting and immunohistochemistry for glucose metabolism markers were performed in tissue samples. ResultsT2D HMGB1{Delta} mice show 20% less hyperglycemia compared to controls with a strong correlation between reduced HMGB1 levels and lower A1C following exercise. Additionally, fat percentage, liver damage, and glycogen storage were significantly reduced. These findings highlight the high potential effect of exercise potentiated has via HMGB1 governed mechanisms and highlights HMGB1 as a therapeutic target for managing hyperglycemia in T2D. ARTICLE HIGHLIGHTSHMGB1 hepatic silencing in Type 2 Diabetic mice is a promising therapeutic target for enhancing Insulin sensitivity. Combination of hepatic HMGB1 silencing and exercise potentiates the metabolic benefits and liver protection in Type 2 Diabetic mice. Shift in metabolic routes and carbohydrate metabolism due to regulation of hepatic HMGB1 expression makes HMGB1 an ideal target for pharmacologic intervention. However, our study also underscores the value of exercise as the primary focus of diabetic glucose control aided by enhanced therapeutic targeting of HMGB1 for chronic inflammation and hyperglycemia.

molecular biology↗

bioRxiv2025

Targeting CRM1-HMGB1 Nuclear Translocation in Type 2 Diabetes-Driven Metabolic Dysfunction Associated Steatotic Liver Disease

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) prevalent in Type-2 Diabetes (T2D) and contributes to progression of Non-Alcoholic Steatohepatitis (NASH). Acetyl-High Mobility Group Box 1 (HMGB1,) a proinflammatory isoform of HMGB1, is released as a DAMP in T2D associated hepatic inflammatory condition. Chromosomal Maintenance 1 (CRM1), a nuclear transporter protein, maintains the nuclear-cytoplasm translocation of hepatic HMGB1 in T2D. We hypothesize that inhibition of CRM1/HMGB1 nuclear shuttling is a therapeutic target for MASLD in T2D. Methods: We performed immunohistochemical analysis of acetyl-HMGB1 and CRM1 in human liver biopsies from control, T2D, and T2D-NASH (n:4 per group). H&E staining to evaluate inflammation and disease stratification. In vitro, studies involved targeted inhibition of CRM1 using Leptomycin-B and HMGB1 with Glycyrrhizin in T2D Huh7 human hepatocytes. Results: T2D subjects with NASH exhibit an increase in acetyl-HMGB1 nuclear and cytoplasmic translocation compared to DM and controls. Acetyl-HMGB1 increased 2-fold in the nucleus and 4-fold in the cytoplasm; CRM1 increased 6-fold in the nucleus and 8-fold in the cytoplasm of T2D/NASH subjects compared to controls. Targeted inhibition of CRM1 and HMGB1 prevented acetyl-HMGB1 hepatocyte release with the most prominent effect in T2D-NASH conditions. Conclusions: Hepatic CRM1/HMGB1 inhibition could be a potential therapeutic target for T2D-driven MASLD.

pathology↗

bioRxiv2024

High-Intensive Interval Training Decreases Circulating HMGB1 in Insulin Resistant Patients; Plasma Lipidomics Identifies Associated Cardiometabolic Benefits

Background: Exercise is a fundamental primary standard of care for cardiometabolic health. Body Weight (BW) High-Intensity Interval Training (HIIT) is an effective strategy for reducing cardiometabolic markers in individuals with insulin resistance and Type-2 diabetes (T2D). High-mobility group box 1 (HMGB1), a ubiquitous nuclear factor, plays an ample role beyond an alarmin in T2D development and progression. Our group has described this novel role previously, showing the beneficial effect of whole body HMGB1 silencing in decreasing hyperglycemia in diabetic mice. In the present study we tested the hypothesis that BW-HIIT as an effective exercise training modality will decrease cardiometabolic risk with a concomitant decrease in circulating HMGB1 more prominently in insulin resistant individuals compared to non-insulin resistant individuals contrasting to what we can evidence in a preclinical murine model of insulin resistance; Methods: Human and mouse pre- and post-exercise serum/plasma samples were analyzed for Lipidomics as well as Metabolic and Cytokine Multiplex assays. Standard of care, as well as cardiometabolic parameters, was also performed in human subjects; Results: insulin resistant individuals had the most positive effect, primarily with a decrease in the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). as an index of insulin resistance as well as decreased HMGB1 post-exercise. Lipidomic analysis illustrated the highly beneficial effect of exercise training using a modified HIIT program, showing an enhanced panel of circulating lipids post-exercise exclusively in insulin resistant individuals. Plasma multiplex revealed significant translational heterogeneity in our studies with distinct metabolic hormone responses to exercise conditioning with a decrease in inflammatory markers in insulin resistant individuals; Conclusions: The current study demonstrated that 6-week BW-HIIT training improves cardiometabolic, anti-inflammatory markers, metabolic hormones, and insulin sensitivity in humans, strongly associated with decreased circulating HMGB1. Overall, these experiments reinforce the potential of HMGB1 as a marker of changes in insulin resistance and the positive effect of exercise training on insulin resistance possibly preventing the development of T2D and associated complications.

molecular biology↗

bioRxiv2021

Quantitative intracellular retention of delivered RNAs through optimized cell fixation and immuno-staining

Detection of nucleic acids within sub-cellular compartments is key to understanding their function. Determining the intracellular distribution of nucleic acids requires quantitative retention and estimation of their association with different organelles by immunofluorescence microscopy. This is important also for the delivery of nucleic acid therapeutics which depends on endocytic uptake and endosomal escape. However, the current methods fail to preserve the majority of exogenously delivered nucleic acids in the cytoplasm. To solve this problem, by monitoring Cy5-labeled mRNA delivered to primary human adipocytes via lipid nanoparticles (LNP), we optimized cell fixation, permeabilization and immuno-staining of a number of organelle markers, achieving quantitative retention of mRNA and allowing visualization of levels which escape detection using conventional procedures. Additionally, we demonstrated the protocol to be effective on exogenously delivered siRNA, miRNA, as well as endogenous miRNA. Our protocol is compatible with RNA probes of single molecule fluorescence in-situ hybridization (smFISH) and molecular beacon, thus demonstrating that it is broadly applicable to study a variety of nucleic acids.

cell biology↗

bioRxiv2020

Endosomal escape of delivered mRNA from endosomal recycling tubules visualized at the nanoscale

Delivery of exogenous mRNA using lipid nanoparticles (LNP) is a promising strategy for therapeutics. However, a bottleneck remains the poor understanding of the parameters that correlate with endosomal escape vs. cytotoxicity. To address this problem, we compared the endosomal distribution of six LNP-mRNA formulations of diverse chemical composition and efficacy, similar to those employed in mRNA-based vaccines, in primary human adipocytes, fibroblasts and HeLa cells. Surprisingly, we found that total uptake is not a sufficient predictor of delivery and different LNP vary considerably in endosomal distributions. Prolonged uptake impaired endosomal acidification, a sign of cytotoxicity, and caused mRNA to accumulate in compartments defective in cargo transport and unproductive for delivery. In contrast, early endocytic/recycling compartments have the highest probability for mRNA escape. By super-resolution microscopy we could resolve single LNP-mRNA within sub-endosomal compartments and capture events of mRNA escape from endosomal recycling tubules. Our results change the view of the mechanisms of endosomal escape and define quantitative parameters to guide the development of mRNA formulations towards higher efficacy and lower cytotoxicity.

bioengineering↗

bioRxiv2020

Interplay of host regulatory network on SARS-CoV-2 binding and replication machinery

We dissect the mechanism of SARS-CoV-2 in human lung host from the initial phase of receptor binding to viral replication machinery. We constructed two independent lung protein interactome to reveal the signaling process on receptor activation and host protein hijacking machinery in the pathogenesis of virus. Further, we test the functional role of the hubs derived from both interactome. Most hubs proteins were differentially regulated on SARS-CoV-2 infection. Also, the proteins of viral replication hubs were related with cardiovascular disease, diabetes and hypertension confirming the vulnerability and severity of infection in the risk individual. Additionally, the hub proteins were closely linked with other viral infection, including MERS and HCoVs which suggest similar infection pattern in SARS-CoV-2. We identified five interconnecting cascades between hubs of both networks that show the preparation of optimal environment in the host for viral replication process upon receptor attachment. Interestingly, we propose that seven potential miRNAs, targeting the intermediate phase that connects receptor and viral replication process a better choice as a drug for SARS-CoV-2.

systems biology↗