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Biology subjects

Sandoval, G.

Publications and source records attributed to Sandoval, G..

3 recordsLinked to original sources

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↗

Histone divergence in Trypanosoma brucei results in unique alterations to nucleosome structure

Eukaryotes have a multitude of diverse mechanisms for organising and using their genomes, but the histones that make up chromatin are highly conserved. Unusually, histones from kinetoplastids are highly divergent. The structural and functional consequences of this variation are unknown. Here, we have biochemically and structurally characterised nucleosome core particles (NCPs) from the kinetoplastid parasite Trypanosoma brucei. A structure of the T. brucei NCP reveals that global histone architecture is conserved, but specific sequence alterations lead to distinct DNA and protein interaction interfaces. The T. brucei NCP is unstable and has weakened overall DNA binding. However, dramatic changes at the H2A-H2B interface introduce local reinforcement of DNA contacts. The T. brucei acidic patch has altered topology and is refractory to known binders, indicating that the nature of chromatin interactions in T. brucei may be unique. Overall, our results provide a detailed molecular basis for understanding evolutionary divergence in chromatin structure.

biochemistry↗

A New Form of Decellularized Extracellular Matrix Hydrogel for Treating Ischemic Tissue via Intravascular Infusion

Biomaterials, such as extracellular matrix (ECM) hydrogels, have been widely used in preclinical studies as injectable tissue engineering therapies; however, injectable therapies are limited as they can cause localized trauma or organ perforation. We have developed a new ECM therapy, the low molecular weight fraction derived from decellularized, digested ECM, for intravascular infusion. This new form of ECM can be infused after injury, specifically localize to injured tissues by coating the leaky microvasculature, and promote cell survival and tissue repair. In this study, we show the feasibility and targeting of intravascular ECM infusions using models of acute myocardial infarction (MI), traumatic brain injury, and pulmonary arterial hypertension. Furthermore, safety and efficacy were demonstrated in small and large animal models of acute MI following intracoronary infusion, which included using a clinically-relevant catheter in the large animal model. Functional improvements, specifically reduced left ventricular volumes and improved wall motion scores were observed after ECM infusions post-MI. Genes related to tissue repair and inflammation were differential expressed in response to ECM infusions. This study shows proof-of-concept for a new paradigm of delivering pro-healing ECM biomaterials via intravascular infusion to heal tissue from the inside out.

bioengineering↗