Filtering by
- All Subjects: Metabolism
- Creators: School of Molecular Sciences
- Creators: Sweazea, Karen
Over 40% of adults in the United States are considered obese. Obesity is known to cause abnormal metabolic effects and lead to other negative health consequences. Interestingly, differences in metabolism and contractile performance between obese and healthy weight individuals are associated with differences in skeletal muscle fiber type composition between these groups. Each fiber type is characterized by unique metabolic and contractile properties, which are largely determined by the myosin heavy chain isoform (MHC) or isoform combination that the fiber expresses. In previous studies, SDS-PAGE single fiber analysis has been utilized as a method to determine MHC isoform distribution and single fiber type distribution in skeletal muscle. Herein, a methodological approach to analyze MHC isoform and fiber type distribution in skeletal muscle was fine-tuned for use in human and rodent studies. In the future, this revised methodology will be implemented to evaluate the effects of obesity and exercise on the phenotypic fiber type composition of skeletal muscle.
Depression is a worldwide public health problem that affects millions of people every year. Due to recent reports that depressed individuals have an altered gut microbiome composition, there is speculation that treatments that influence microorganisms in the gut could potentially lead to alleviation of depressive symptoms. Apple cider vinegar has been studied extensively for its health-promoting properties and benefits. Apple cider vinegar’s main ingredient is the short chain fatty acid, acetic acid. Short chain fatty acids have been shown to improve mood state and depressive symptoms, as well as amplify the effect of prebiotics in restoring the gut microbiome. This experimental design study examined the effects of ingesting 2 tbsp. apple cider vinegar (1 g acetic acid) twice daily with a meal on the levels of urinary metabolites in 14 college students compared to a control group of 11 college students that took one vinegar supplement tablet (0.015 g of acetic acid) daily for 28 days. All participants were healthy, normal to underactive (< 300 minutes of moderate exercise a week), and free of chronic or acute illnesses. Urinary metabolite analysis revealed a significant production of enzymes involved in the hexosamine pathway in the liquid vinegar group compared to baseline levels. However, anticipation of an alteration in tryptophan metabolites, a possible consequence of altered metabolism of gut microflora, was not observed. These data suggest that apple cider vinegar might be a potential treatment for depression through the production of hexosamine pathway enzymes.
Our current understanding of the mitochondrial genome was revolutionized in 2015 with the discovery of short open reading frames (sORFs) that produced protein products called mitochondrial-derived peptides (MDPs). Interestingly, unlike other proteins produced by the organelle, these MDPs are not directly involved in the electron transport chain but rather serve the role of metabolic regulators. In particular, one of these peptides called MOTS-c has been shown to regulate glucose and fat metabolism in an AMPK-dependent manner. With its capacity to enter the mitochondria and impact gene expression, MOTS-c has also displayed the ability to increase aerobic exercise performance by triggering elevated synthesis of the HO-1 antioxidant. Overall these findings position MOTS-c as a promising treatment for metabolic diseases as well as a potential dietary supplement to boost ATP availability.
This pilot study aimed to ascertain the potential for keto acid supplementation in the attempt to supply adequate protein building blocks to healthy populations, with the caveats that said supplementation 1) would utilize non-synthetic methods, 2) offer an alternative to high-phosphate protein supplies such as ruminant animals, and 3) reverse the ill effects of ammonia load by reducing nitrogen intake and consuming ammonia as a fuel for the process of protein synthesis. This proposed solution turns to orange juice and certain varietals of potato juice for their familiarity to consumers, innate nutritional values, and potential for mass-production by many existing companies. The work contained here represents the first phase of experimentation: qualifying the presence of α-keto-analogues of amino acids in these types of produce which, with transamination, could yield the amino acids necessary for adequate protein intake.
Results suggest that these juices do not contain adequate α-keto-analogs of amino acids to supplement proteins in either healthy or ill individuals.
Disclaimer: The initial goal of this project was to present this information as a podcast episode as a part of a series aimed at teaching the general public about human physiological adaptations. Due to the circumstances with COVID-19 we were unable to meet to make a final recording of the podcast episode. A recording of a practice session recorded earlier in the year has been uploaded instead and is therefore only a rough draft.
within cells that result in changes in the metabolism of carbohydrates and immune functions.
Ingesting glucocorticoids has also been linked to insulin resistance, a main feature of Type 2
diabetes. Experiments including polymerase chain reaction, western blotting, and glycogen
synthase analysis were conducted to determine if exposure to higher doses of dexamethasone, a
glucocorticoid, induces insulin resistance in cultured rat skeletal muscle via interaction with
thioredoxin-interacting protein (TXNIP). Treatment with dexamethasone was shown to cause
mild increases in TXNIP while a definitive increase or decrease in insulin signaling was unable
to be determined.