Rudy M Ortiz

University of California, Merced | UCM · Department of Molecular Cell Biology

The onset of type II diabetes increases the heart’s susceptibility to oxidative damage because of the associated inflammation and diminished antioxidant response. Transcription factor NF-κB initiates inflammation while Nrf2 controls antioxidant defense. Current evidence suggests crosstalk between these transcription factors that may become dysregul...

Perilipins (PLINs) isoforms are proteins associated to surface of intracelular lipid droplets (LDs) that participate in the regulation of lipid metabolism and storage during hypertrophic cardiomyopathies. PLINs can associate to the PPAR coactivators peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and Sirtuin 1 (SIRT1)...

Very little is known about the effects of CBD on age-associated cardiovascular and metabolic dysfunction. The prevalence of metabolic syndrome (MetS) is 54.9% among people ≥60 years of age, which increases the risk of the development of associated pathologies like cardiovascular disease and type II diabetes. Additionally, synthetic CBD alternatives...

Almond consumption can improve cardiometabolic (CM) health. However, the mechanisms underlying those benefits are not well characterized. This study explored the effects of consuming a snack of almonds vs. crackers for 8 weeks on changes in metabolomic profiles in young adults (clinicaltrials.gov ID: NCT03084003). Participants (n = 73, age: 18-19...

Purpose Angiotensin receptor blockers (ARBs) can ameliorate metabolic syndrome (MetS)-associated dyslipidemia, hepatic steatosis, and glucose intolerance, suggesting that angiotensin receptor (AT1) over-activation contributes to impaired lipid and glucose metabolism, which is characteristic of MetS. The aim of this study was to evaluate changes in...

Caloric restriction (CR) is one of the most important behavioral interventions to reduce excessive abdominal adiposity, which is a risk factor for the development of insulin resistance. Previous metabolomics studies have characterized substrate metabolism during healthy conditions; however, the effects of CR and subsequent mass recovery on shifts i...

Inappropriate activation of the renin-angiotensin system decreases glucose uptake in peripheral tissues. Chronic angiotensin receptor type 1 (AT 1 ) blockade increases glucose uptake in skeletal muscle, decreases the abundance of large adipocytes, and macrophage infiltration in adipose. However, the contributions of each tissue to the improvement i...

Caloric restriction (CR) is the first line intervention to reduce adiposity and total body mass (BM) to improve insulin resistance and ameliorate metabolic derangements. However, the lost adipose mass is difficult to maintain reduced in the long term due to several factors including compensatory changes in orexigenic hormones, adipokine release, pr...

Mitochondria are dynamic, interactive organelles that connect cellular signaling and whole-cell homeostasis. This "mitochatting" allows the cell to receive information about the mitochondria's condition before accommodating energy demands. Mitofusin 2 (Mfn2), an outer mitochondrial membrane fusion protein specializes in mediating mitochondrial home...

The prolonged, post-weaning fast of northern elephant seal (Mirounga angustirostris) pups is characterized by a reliance on lipid metabolism and reversible, fasting-induced insulin resistance providing a unique model to examine the effects of insulin on lipid metabolism. We have previously shown that acute insulin infusion induced a shift in fatty...

In order for the heart to maintain its continuous mechanical work and provide the systolic movement to uphold coronary blood flow, substantial synthesis of adenosine triphosphate (ATP) is required. Under normal conditions cardiac tissue utilizes roughly 70% fatty acids (FA), and 30% glucose for the production of ATP; however, during impaired metabo...

Objectives This study explored the effects of diet-induced (almonds vs. crackers) changes on blood transcriptome profiles of young adults. Methods Young adults (age: 18–22 years) were randomly assigned to consume either almonds (2 oz./d, n = 13) or an isocaloric control snack of graham crackers (325 kcal/d, n = 10) daily for 4 weeks. Blood samples...

Caloric restriction (CR) is one of the most important behavioral interventions to reduce excessive abdominal adiposity, which is a risk factor for the development of insulin resistance. Previous metabolomics studies have characterized substrate metabolism during healthy conditions; however, the effects of CR and subsequent mass recovery on shifts i...

Almond consumption can improve cardiometabolic (CM) health. However, the mechanisms underlying those benefits are not well characterized. This study explored the effects of consuming a snack of almonds vs. crackers for 8 weeks on changes in metabolomic profiles in young adults (clinicaltrials.gov ID: NCT03084003). Participants (n=73, age: 18-19 yea...

The post-weaning fast of northern elephant seal pups is characterized by a lipid-dependent metabolism and associated with a decrease in plasma glucagon-like peptide-1 (GLP-1), insulin, and glucose and increased gluconeogenesis (GNG) and ketogenesis. We have also demonstrated that exogenous GLP-1 infusion increased plasma insulin despite simultaneou...

Caloric restriction, among other behavioral interventions, has demonstrated benefits on improving glycemic control in obesity-associated diabetic subjects. However, an acute and severe intervention without proper maintenance could reverse the initial benefits, with additional metabolic derangements. To assess the effects of an acute caloric restric...

Objectives Almond consumption can improve cardiometabolic health. However, the mechanisms underlying those physiological changes are not well characterized. This study explored the effects of consuming a snack of almonds for 8 weeks on changes in omics profiles in young adults. Methods Newly enrolled, college students (n = 73, age: 18–19 years, BM...

The metabolic syndrome (MetS) affects 20% of the US population. MetS comprises several disorders that raise the risk of atherosclerosis, insulin resistance, and diabetes. Angiotensin receptor blockers (ARBs) are used to ameliorate hypertension associated with metabolic disorders. Nonetheless, the potential benefits of ARBs on the metabolic state ar...

Insulin resistance increases renal oxidant production by up‐regulating NADPH oxidase 4 (Nox4) expression contributing to oxidative damage and ultimately albuminuria. Inhibition of the renin‐angiotensin system (RAS) and activation of glucagon‐like peptide‐1 (GLP‐1) receptor signaling may reverse this effect. However, whether angiotensin receptor typ...

A 5-10% reduction of body mass by caloric restriction (CR) has been effective in normalizing SBP in hypertensive patients. Moreover, SGLT2 inhibitors lowered SBP in spontaneous hypertensive rats and are considered a therapeutic alternative to patients with T2DM concomitant with hypertension. However, these potential benefits have not been fully add...

Background Changes in gut microbiota are associated with cardiometabolic disorders and are influenced by diet. Almonds are a rich source of fiber, unsaturated fats, and polyphenols, all nutrients that can that can favorably alter the gut microbiome. Objective The study aimed to examine the effects of 8 weeks of almond snacking on the gut (fecal) m...

Background Recent reports indicate widespread food insecurity among college students. More than 50% of students attending a university campus, located in the California's Central Valley, reported having experienced food insecurity. Underrepresented minority students and their intersections are disproportionally affected. Resources to increase acces...

Objectives: Almond consumption can improve the cardiometabolic phenotype in young college students that routinely skip breakfast. However, the mechanisms underlying the above physiological changes are not well characterized. The study aimed to explore the effects of consuming a morning snack of almonds (high-fat) vs. crackers (high-carbohydrate) f...

Understanding the molecular and cellular mechanisms that are affected by activation of the renin-angiotensin system (RAS) are important for development of novel therapeutic strategies to more specifically treat hypertension and reduce cardiovascular risk. RAS regulates blood pressure (BP) in part via its effector molecule, angiotensin II (AngII), a...

First-year college students are at particular risk of dietary maladaptation during their transition to adulthood. A college environment that facilitates consistent access to nutritious food is critical to ensuring dietary adequacy among students. The objective of the study was to examine perceptions of the campus food environment and its influence...

Diabetic hearts are susceptible to damage from inappropriate activation of the renin angiotensin system (RAS) and hyperglycemic events both of which contribute to increased oxidant production. Prolonged elevation of oxidants impairs mitochondrial enzyme function, further contributing to metabolic derangement. Nuclear factor erythriod-2-related fact...

The transition to nutritional independence makes new college students vulnerable to alterations in eating patterns, which can increase the risk of cardiometabolic disorders. The aim of the study was to examine the potential benefits of almond vs. cracker snacking in improving glucoregulatory and cardiometabolic profiles in new college students. A r...

Pathological activation of the renin-angiotensin system and inflammation are associated with hypertension and the development of metabolic syndrome (MetS). The contributions of angiotensin receptor type 1 (AT1) activation, independent of blood pressure, and inflammation on glucose intolerance and renal damage are not well defined. Using a rat model...

Obesity is associated with an inappropriately activated renin–angiotensin–aldosterone system, suppressed glucagon-like peptide-1 (GLP-1), increased renal Na+ reabsorption, and hypertension. To assess the link between GLP-1 and angiotensin receptor type 1 (AT1) signaling on obesity-associated impairment of urinary Na+ excretion (UNaV) and elevated a...

Hypoxia inducible factor-1 (HIF-1) is a transcriptional factor that induces genes involved in glucose metabolism. HIF-1 is formed by a regulatory α-subunit (HIF-1α) and a constitutive β-subunit (HIF-1β). The white spot syndrome virus (WSSV) induces a shift in glucose metabolism and oxidative stress. HIF-1α is associated with the induction of metabo...

Obesity is associated with the inappropriate activation of the renin-angiotensin-system (RAS), which increases arterial pressure, impairs insulin secretion, and decreases peripheral tissue insulin sensitivity. RAS blockade reverses these detriments; however, it is not clear whether the disease state of the organism and treatment duration determine...

Lactate dehydrogenase (LDH) is key for anaerobic glycolysis. LDH is induced by the hypoxia inducible factor -1 (HIF-1). HIF-1 induces genes involved in glucose metabolism and regulates cellular oxygen homeostasis. HIF-1 is formed by a regulatory α-subunit (HIF-1α) and a constitutive β-subunit (HIF-1β). The white spot syndrome virus (WSSV) induces a...

Diabetic hearts may be very susceptible to mitochondrial damage during hyperglycemic conditions. These hyperglycemic events are often acute, dietary-derived, and increase oxidant production from a variety of pathways primarily from cellular substrate metabolism. Furthermore, the renin angiotensin system is inappropriately elevated during metabolic...

Hyperglycemia increases the risk of oxidant overproduction in the heart through activation of a multitude of pathways. Oxidation of mitochondrial enzymes may impair their function resulting in accumulation of intermediates and reverse electron transfer, contributing to mitochondrial dysfunction. Furthermore, the renin-angiotensin system (RAS) becom...

Activation of the Renin-Angiotensin-Aldosterone-System (RAAS) is proposed to play a role in the development of insulin resistance and type II diabetes. Angiotensin II (AngII) is a principal effector molecule that binds AT1 receptors (AT1R) in various tissues. Recent data shows that activated endothelial cells secrete protein disulfide isomerase (PD...

IntroductionProlonged fasting in northern elephant seals (NES) is characterized by a reliance on lipid metabolism, conservation of protein, and reduced plasma insulin. During early fasting, glucose infusion previously reduced plasma free fatty acids (FFA); however, during late-fasting, it induced an atypical elevation in FFA despite comparable incr...

The contribution of thyroidal status in insulin signaling and glucose homeostasis has been implicated as a potential pathophysiological factor in humans, but the specific mechanisms remain largely elusive. Fasting induces changes in both thyroid hormone secretion and insulin signaling. Here, we explore how mammals that undergo natural, prolonged bo...

Fasting typically suppresses thyroid hormone (TH)-mediated cellular events and increases sirtuin 1 (SIRT1) activity. THs may regulate metabolism through nongenomic pathways and directly through activation of adenosine monophosphate-activated protein kinase (AMPK). Adult male elephant seals (Mirounga angustirostris) are active, hypermetabolic, and n...

Both hypothyroidism and hyperthyroidism are associated with glucose intolerance, calling into question the contribution of thyroid hormones (TH) on glucose regulation. TH analogues and derivatives may be effective treatment options for glucose intolerance and insulin resistance (IR), but their potential gluco-regulatory effects during conditions of...

Thyroid hormones (TH) regulate metabolism, but are typically suppressed during times of stressful physiological conditions, including fasting. Interestingly, prolonged fasting in northern elephant seal pups is associated with reliance on a lipid-based metabolism and increased levels of circulating thyroid hormones that are partially attributed to a...

Diabetic hearts are in great risk of increased oxidant production from sustained elevations of glucose through activation of several pathways. One of the major sources of oxidant production within the cell are mitochondria through substrate metabolism. Oxidation of mitochondrial enzymes may impair their function resulting in accumulation of interme...

Pregnancy-induced physiologic cardiac hypertrophy with important changes in the energetic metabolism to support its contractile demands and maintain viability. HIF-1α and PPARγ activates glycolytic and glycerol-lipid biosynthesis genes in response to pathologic hypertrophy, respectively. Therefore, these changes increase the rate of glycolysis and...

Prolonged food deprivation in mammals typically reduces glucose, insulin and thyroid hormone (TH) concentrations, as well as tissue deiodinase (DI) content and activity, which, collectively, suppress metabolism. However, in elephant seal pups, prolonged fasting does not suppress TH levels, and is associated with up-regulation of adipose TH-mediated...

Constancy of the milieu interieur is critically important for Metazoan organisms because the cells can only live within a narrow range of physicochemical conditions necessary for proper cellular functions. Water and salt are fundamental for life and the main determinants of the osmolality of the extracellular fluid. In most vertebrates, water and s...

The northern elephant seal, Mirounga angustirostris, is a valuable animal model of fasting adaptation and hypoxic stress tolerance. However, no reference sequence is currently available for this and many other marine mammal study systems, hindering molecular understanding of marine adaptations and unique physiology. We sequenced a transcriptome of...

Angiotensin II (Ang II) and aldosterone contribute to hypertension, oxidative stress and cardiovascular damage, but the contributions of aldosterone during Ang II-dependent hypertension are not well defined because of the difficulty to assess each independently. To test the hypothesis that during Ang II infusion, oxidative and nitrosative damage is...

Northern elephant seals show a remarkable plasticity of their metabolic network. They are able to switch between extreme stages of weight gain and prolonged fasting without adverse effects on energy balance. The prolonged fasting of the Northern elephant seal is characterized by reliance on lipid metabolism and conservation of protein. Insulin secr...

While much of our understanding of stress physiology is derived from biomedical studies, little is known about the downstream molecular consequences of adaptive stress responses in free-living animals. We examined molecular effectors of the stress hormones cortisol and aldosterone in the northern elephant seal, a free-ranging study system in which...

1.The trade-off between current reproductive effort and survival is a key concept of life history theory. A variety of studies support the existence of this trade-off but the underlying physiological mechanisms are not well-understood. Oxidative stress has been proposed as a potential mechanism underlying the observed inverse relationship between r...