Female Mice with Selenocysteine tRNA Deletion in Agrp Neurons Maintain Leptin Sensitivity and Resist Weight Gain While on a High-Fat Diet.

The role of the essential trace element selenium in hypothalamic physiology has begun to come to light over recent years. Selenium is used to synthesize a family of proteins participating in redox reactions called selenoproteins, which contain a selenocysteine residue in place of a cysteine. Past studies have shown that disrupted selenoprotein expression in the hypothalamus can adversely impact energy homeostasis. There is also evidence that selenium supports leptin signaling in the hypothalamus by maintaining proper redox balance. In this study, we generated mice with conditional knockout of the selenocysteine tRNA[Ser]Sec gene (Trsp) in an orexigenic cell population called agouti-related peptide (Agrp)-positive neurons. We found that female TrspAgrpKO mice gain less weight while on a high-fat diet, which occurs due to changes in adipose tissue activity. Female TrspAgrpKO mice also retained hypothalamic sensitivity to leptin administration. Male mice were unaffected, however, highlighting the sexually dimorphic influence of selenium on neurobiology and energy homeostasis. These findings provide novel insight into the role of selenoproteins within a small yet heavily influential population of hypothalamic neurons.

Exploring Native Hawaiian and Pacific Islander Youths' E-Cigarette Resistance Strategies: Implications for Tobacco Product Use Prevention.

This study examined the e-cigarette and vaping resistance strategies used by Native Hawaiian and Pacific Islander (NHPI) youths in rural Hawai'i. Focus groups (N = 17) were conducted in eight geographically dispersed elementary, middle/intermediate, and multilevel schools in low-income communities on Hawai'i Island. Sixty-nine youths (67% NHPI, Mage = 12.5 years) participated in this study. The resistance strategies discussed across the greatest number of groups were "refuse" (saying no), "explain" (providing reasons for vaping refusal), "avoid" (avoiding people or places where e-cigarettes were used), and "leave" (walking away from a situation where e-cigarettes were being used). Participants described the challenges in using these strategies within contexts characterized by widespread peer and family vaping and strong social demands to use e-cigarettes. The findings suggest the need for multi-level interventions based on youths' resistance strategies to meaningfully reduce youth vaping use in rural and/or NHPI communities.

A Systematic Literature Review of Asian American, Native Hawaiian, and Pacific Islander Youth Electronic Nicotine Delivery Systems (ENDS) Use.

Rates of electronic nicotine delivery systems (ENDS) use are exponentially increasing in youth and young adults within the United States, including Asian American, Native Hawaiian, and Pacific Islander (AANHPI) youth in Hawai'i. Disproportionately high ENDS use rates for AANHPI youth point to the need to understand the empirical literature in this area. A systematic literature review is a prerequisite for programs effectively curbing AANHPI youths' elevated use of ENDS. This systematic literature review examines empirical studies published between 2010-2020 on ENDS and their use as it applies to AANHPI youth. A total of 11 articles were identified using specific inclusionary and exclusionary criteria in a literature search. Studies described individual and interpersonal correlates to ENDS use. Notably, there were no published ENDS intervention studies detailed to AANHPI youth. Implications of these studies for prevention and social welfare interventions are discussed.

Selenium Protects Mouse Hypothalamic Cells from Glucocorticoid-Induced Endoplasmic Reticulum Stress Vulnerability and Insulin Signaling Impairment.

The use of glucocorticoid medications is known to cause metabolic side effects such as overeating, excess weight gain, and insulin resistance. The hypothalamus, a central regulator of feeding behavior and energy expenditure, is highly responsive to glucocorticoids, and it has been proposed that it plays a role in glucocorticoid-induced metabolic defects. Glucocorticoids can alter the expression and activity of antioxidant enzymes and promote the accumulation of reactive oxygen species. Recent evidence indicates that selenium can counter the effects of glucocorticoids, and selenium is critical for proper hypothalamic function. This study sought to determine whether selenium is capable of protecting hypothalamic cells from dysfunction caused by glucocorticoid exposure. We treated mHypoE-44 mouse hypothalamic cells with corticosterone to study the effects on cellular physiology and the involvement of selenium. We found that corticosterone administration rendered cells more vulnerable to endoplasmic reticulum stress and the subsequent impairment of insulin signaling. Supplementing the cell culture media with additional selenium alleviated endoplasmic reticulum stress and promoted insulin signaling. These findings implicate a protective role of selenium against chronic glucocorticoid-induced hypothalamic dysfunction.