Hepatic glucose uptake and disposition during short-term high-fat vs. high-fructose feeding

In dogs consuming a high-fat and -fructose diet (52 and 17% of total energy, respectively) for 4 wk, hepatic glucose uptake (HGU) in response to hyperinsulinemia, hyperglycemia, and portal glucose delivery is markedly blunted with reduction in glucokinase (GK) protein and glycogen synthase (GS) activity. The present study compared the impact of selective increases in dietary fat and fructose on liver glucose metabolism. Dogs consumed weight-maintaining chow (CTR) or hypercaloric high-fat (HFA) or high-fructose (HFR) diets diet for 4 wk before undergoing clamp studies with infusion of somatostatin and intraportal insulin (3–4 times basal) and glucagon (basal). The hepatic glucose load (HGL) was doubled during the clamp using peripheral vein (Pe) glucose infusion in the first 90 min (P1) and portal vein (4 mg·kg−1·min−1) plus Pe glucose infusion during the final 90 min (P2). During P2, HGU was 2.8 ± 0.2, 1.0 ± 0.2, and 0.8 ± 0.2 mg·kg−1·min−1 in CTR, HFA, and HFR, respectively (P < 0.05 for HFA and HFR vs. CTR). Compared with CTR, hepatic GK protein and catalytic activity were reduced (P < 0.05) 35 and 56%, respectively, in HFA, and 53 and 74%, respectively, in HFR. Liver glycogen concentrations were 20 and 38% lower in HFA and HFR than CTR (P < 0.05). Hepatic Akt phosphorylation was decreased (P < 0.05) in HFA (21%) but not HFR. Thus, HFR impaired hepatic GK and glycogen more than HFA, whereas HFA reduced insulin signaling more than HFR. HFA and HFR effects were not additive, suggesting that they act via the same mechanism or their effects converge at a saturable step

Increased Adiposity, Dysregulated Glucose Metabolism and Systemic Inflammation in Galectin-3 KO Mice

PMCID: PMC3579848This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Effects of elevated seawater pCO2 on gene expression patterns in the gills of the green crab, Carcinus maenas

Background: The green crab Carcinus maenas is known for its high acclimation potential to varying environmental abiotic conditions. A high ability for ion and acid-base regulation is mainly based on an efficient regulation apparatus located in gill epithelia. However, at present it is neither known which ion transport proteins play a key role in the acid-base compensation response nor how gill epithelia respond to elevated seawater pCO2 as predicted for the future. In order to promote our understanding of the responses of green crab acid-base regulatory epithelia to high pCO2, Baltic Sea green crabs were exposed to a pCO2 of 400 Pa. Gills were screened for differentially expressed gene transcripts using a 4,462-feature microarray and quantitative real-time PCR. Results: Crabs responded mainly through fine scale adjustment of gene expression to elevated pCO2. However, 2% of all investigated transcripts were significantly regulated 1.3 to 2.2-fold upon one-week exposure to CO2 stress. Most of the genes known to code for proteins involved in osmo- and acid-base regulation, as well as cellular stress response, were were not impacted by elevated pCO2. However, after one week of exposure, significant changes were detected in a calcium-activated chloride channel, a hyperpolarization activated nucleotide-gated potassium channel, a tetraspanin, and an integrin. Furthermore, a putative syntaxin-binding protein, a protein of the transmembrane 9 superfamily, and a Cl-/HCO3 - exchanger of the SLC 4 family were differentially regulated. These genes were also affected in a previously published hypoosmotic acclimation response study. Conclusions: The moderate, but specific response of C. maenas gill gene expression indicates that (1) seawater acidification does not act as a strong stressor on the cellular level in gill epithelia; (2) the response to hypercapnia is to some degree comparable to a hypoosmotic acclimation response; (3) the specialization of each of the posterior gill arches might go beyond what has been demonstrated up to date; and (4) a re-configuration of gill epithelia might occur in response to hypercapnia

In cold-hardy insects, seasonal, temperature, and reversible phosphorylation controls regulate sarco/endoplasmic reticulum Ca 2+-ATPase (SERCA)

Winter cold hardiness of insects typically involves one of two major strategies for survival below 0°C: freeze avoidance and freeze tolerance. The two strategies have some common features, including the accumulation of high concentrations of cryoprotectant polyols and the frequent occurrence of diapause. Entry into the hypometabolic state of diapause requires coordinated suppression of major ATP-consuming metabolic processes, and ion motive ATPases are important targets for regulation. This study documents the suppression of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) activity in the overwintering larvae of two cold-hardy species, the freeze-avoiding gall moth Epiblema scudderiana and the freeze-tolerant gall fly Eurosta solidaginis. Activity was reduced despite a lack of change in SERCA protein levels in E. solidaginis larvae over the winter and a six- to eightfold increase in SERCA protein in E. scudderiana. This implicated posttranslational modification as the mechanism of SERCA suppression, and in vitro incubations indicated that enzyme phosphorylation by protein kinases A, G, or C strongly reduced enzyme activity. A stable reduction in SERCA activity was also seen in cold-acclimated larvae of both species compared with 15°C controls, with significant changes in the kinetic parameters of the E. scudderiana enzyme (e.g., Km ATP was 3.2-fold higher in - 20°C-acclimated larvae) that were consistent with reduced enzyme function at low temperature. Epiblema scudderiana SERCA was also subject to regulation by differential temperature effects (Arrhenius activation energy increased by approximately threefold below 10°C) and by seasonal changes in the levels of a SERCA inhibitor protein, phospholamban

Racism, structural racism, and the American Association for Anatomy: Initial report from a task force

In 2021, the American Association for Anatomy (AAA) Board of Directors appointed a Task Force on Structural Racism to understand how the laws, rules, and practices in which the Association formed, developed and continues to exist affect membership and participation. This commentary is the first public report from the Task Force. We focus on African Americans with some comments on Jews and women, noting that all marginalized groups deserve study. Through much of its 130 year history, some members were an essential part of perpetuating racist ideas, the Association largely ignored racism and had some practices that prevented participation. The Task Force concluded that individual and structural racism within the AAA, combined with the broader social context in which the Association developed, contributed to the current underrepresentation of African Americans who constitute 4.1% of the membership even though 13.4% of the U.S. population is Black. Intentional efforts within the AAA to reckon with racism and other forms of bias have only begun in the last 10-20 years. These actions have led to more diverse leadership within the Association, and it is hoped that these changes will positively affect the recruitment and retention of marginalized people to science in general and anatomy in particular. The Task Force recommends that the AAA Board issue a statement of responsibility to acknowledge its history. Furthermore, the Task Force advocates that the Board commit to (a) sustaining ongoing projects to improve diversity, equity, and inclusion and (b) dedicating additional resources to facilitate novel initiatives

An analysis of anatomy education before and during Covid-19: August-December 2020

Coronavirus disease-2019 (Covid-19) disrupted the in-person teaching format of anatomy. To study changes in gross anatomy education that occurred during August-December, 2020 compared to before the pandemic, an online survey was distributed to anatomy educators. The 191 responses received were analyzed in total and by academic program, geographic region, and institution type. Cadaver use decreased overall (before: 74.1 ± 34.1%, during: 50.3 ± 43.0%, P \u3c 0.0001), as well as across allopathic and osteopathic medicine, therapy, undergraduate, and veterinary programs (P \u3c 0.05), but remained unchanged for other programs (P \u3e 0.05). Cadaver use decreased internationally and in the US (P \u3c 0.0001), at public and private (P \u3c 0.0001) institutions, and among allopathic medical programs in Northeastern, Central, and Southern (P \u3c 0.05), but not Western, US geographical regions. Laboratories during Covid-19 were delivered through synchronous (59%), asynchronous (4%), or mixed (37%) formats (P \u3c 0.0001) and utilized digital resources (47%), dissection (32%), and/or prosection (21%) (P \u3c 0.0001). The practical laboratory examination persisted during Covid-19 (P = 0.419); however, the setting and materials shifted to computer-based (P \u3c 0.0001) and image-based (P \u3c 0.0001), respectively. In-person lecture decreased during Covid-19 (before: 88%, during: 24%, P = 0.003). When anatomy digital resources were categorized, dissection media, interactive software, and open-access content increased (P ≤ 0.008), with specific increases in BlueLink, Acland\u27s Videos, and Complete Anatomy (P \u3c 0.05). This study provided evidence of how gross anatomy educators continued to adapt their courses past the early stages of the pandemic