Amygdala-liver signaling orchestrates rapid glycemic responses to stress and drives stress-induced metabolic dysfunction.

Behavioral adaptations to environmental threats are crucial for survival and necessitate rapid deployment of energy reserves. The amygdala coordinates behavioral adaptations to threats, but little is known about its involvement in underpinning metabolic adaptations. Here, we show that acute stress activates medial amygdala (MeA) neurons that innervate the ventromedial hypothalamus (MeAVMH neurons), which precipitates hyperglycemia and hypophagia. The glycemic actions of MeAVMH neurons occur independent of adrenal or pancreatic glucoregulatory hormones. Instead, using whole-body virus tracing, we identify a polysynaptic connection from MeA to the liver, which promotes the rapid synthesis of glucose by hepatic gluconeogenesis. Repeated stress exposure disrupts MeA control of blood glucose and appetite, resulting in diabetes-like dysregulation of glucose homeostasis and weight gain. Our findings reveal a novel amygdala-liver axis that regulates rapid glycemic adaptations to stress and links recurrent stress to metabolic dysfunction.

RANKL/RANK is required for cytokine-induced beta cell death; osteoprotegerin, a RANKL inhibitor, reverses rodent type 1 diabetes.

Treatment for type 1 diabetes (T1D) requires stimulation of functional ß cell regeneration and survival under stress. Previously, we showed that inhibition of the RANKL/RANK [receptor activator of nuclear factor kappa Β (NF-κB) ligand] pathway, by osteoprotegerin and the anti-osteoporotic drug denosumab, induces rodent and human ß cell proliferation. We demonstrate that the RANK pathway mediates cytokine-induced rodent and human ß cell death through RANK-TRAF6 interaction and induction of NF-κB activation. Osteoprotegerin and denosumab protected ß cells against this cytotoxicity. In human immune cells, osteoprotegerin and denosumab reduce proinflammatory cytokines in activated T-cells by inhibiting RANKL-induced activation of monocytes. In vivo, osteoprotegerin reversed recent-onset T1D in nonobese diabetic/Ltj mice, reduced insulitis, improved glucose homeostasis, and increased plasma insulin, ß cell proliferation, and mass in these mice. Serum from T1D subjects induced human ß cell death and dysfunction, but not α cell death. Osteoprotegerin and denosumab reduced T1D serum-induced ß cell cytotoxicity and dysfunction. Inhibiting RANKL/RANK could have therapeutic potential.

Magnetogenetic cell activation using endogenous ferritin.

The ability to precisely control the activity of defined cell populations enables studies of their physiological roles and may provide therapeutic applications. While prior studies have shown that magnetic activation of ferritin-tagged ion channels allows cell-specific modulation of cellular activity, the large size of the constructs made the use of adeno-associated virus, AAV, the vector of choice for gene therapy, impractical. In addition, simple means for generating magnetic fields of sufficient strength have been lacking. Toward these ends, we first generated a novel anti-ferritin nanobody that when fused to transient receptor potential cation channel subfamily V member 1, TRPV1, enables direct binding of the channel to endogenous ferritin in mouse and human cells. This smaller construct can be delivered in a single AAV and we validated that it robustly enables magnetically induced cell activation in vitro . In parallel, we developed a simple benchtop electromagnet capable of gating the nanobody-tagged channel in vivo . Finally, we showed that delivering these new constructs by AAV to pancreatic beta cells in combination with the benchtop magnetic field delivery stimulates glucose-stimulated insulin release to improve glucose tolerance in mice in vivo . Together, the novel anti-ferritin nanobody, nanobody-TRPV1 construct and new hardware advance the utility of magnetogenetics in animals and potentially humans.

Psychological Harms and Treatment of Sexual Assault and Sexual Harassment in Adults: Systematic and Scoping Reviews to Inform Improved Care for Military Populations.

Victims of sexual assault and sexual harassment often experience a variety of psychological outcomes and mental health symptoms related to posttraumatic stress disorder (PTSD), depression, anxiety, substance abuse, suicidal ideation, and self-harm. Sexual trauma also might affect careers. Despite a need to address these harms, some service members have reported that connecting to health care or mental health services following sexual assault or sexual harassment can be difficult-in part because of a lack of leadership support. Given these persistent challenges, the Psychological Health Center of Excellence identified an urgent need to better understand research that is pertinent to sexual assault and sexual harassment during military service so that the U.S. Department of Defense and the military services can improve the health care response for service members. RAND researchers investigated and synthesized relevant research in three topic areas: (1) the effectiveness of psychotherapy treatments designed for adult victims of sexual assault or sexual harassment in military settings; (2) barriers faced by U.S. military members to accessing and remaining in mental health care settings; and (3) associations between sexual assault or sexual harassment and mental health conditions.

Evaluation of Mental Health First Aid in New York City.

More than 155,000 New Yorkers were trained in Mental Health First Aid (MHFA) between 2016 and 2020. Free citywide trainings were made available to all New Yorkers and were disseminated through city agencies and community-based settings. RAND Corporation researchers conducted a mixed-methods study that included a web-based survey of past trainees and a series of focus groups with leaders of community-based organizations and city agency staff to assess the impact of the MHFA trainings and needs for future training. In this article, the authors describe the evaluation activities that took place; the methods behind them; and the results at the individual, agency, and community levels. They also offer recommendations for ways to improve future mental health education efforts. Respondents applied MHFA skills extensively and broadly across their social networks. Nine in ten respondents had contact with an individual with a mental health problem in the past six months. Among those who had contact, 84 percent indicated using their MHFA skills to help a friend or family member, and nearly half reported applying skills with a co-worker, neighbor, or acquaintance. Because MHFA was offered through city agency workplaces and community-based settings, tens of thousands of New Yorkers were given tools to come to the aid of individuals in their personal and professional lives. MHFA may be a promising approach to building supportive social networks, organizations, and communities that are primed to recognize and assist those experiencing mental health challenges.

Does removing menthol cigarettes in convenience stores reduce susceptibility to cigarette smoking? An experimental investigation in young people.

BACKGROUND: Evidence for the effectiveness of menthol cigarette bans comes mostly from studies of adults that smoke. This experiment evaluated whether the absence of menthol products from a convenience store influenced young people's susceptibility to cigarette smoking after they shopped in the store. METHODS: This experiment took place in the RAND StoreLab (RSL), a life-sized research convenience store. A three-group, between-subjects design was used. Study conditions differed in the mix of flavored tobacco products the RSL displayed: 1) All tobacco-, sweet-, and menthol-flavors displayed; 2) only tobacco- and menthol-flavors displayed; and 3) only tobacco-flavors displayed. Participants were randomly assigned to shop in the RSL under one of these conditions and after shopping, completed measures of their susceptibility to cigarette smoking, one measure for menthol cigarettes and one for unflavored cigarettes (scores on each susceptibility measure was dichotomized: 0 = not susceptible; 1 = susceptible). RESULTS: Multivariable logistic regression assessed the main effects of condition on susceptibility to smoking menthol and unflavored cigarettes. There was no condition effect on susceptibility to smoking unflavored cigarettes. However, removing menthol-flavored products significantly increased participants' susceptibility to smoking menthol cigarettes compared to when all flavored products were available (OR = 3.66, 95% CI [1.33, 10.03]). This significant effect was only found among young people with some pre-existing risk of cigarette smoking (OR = 5.92, 95% CI [1.81, 19.39]). CONCLUSION: Results suggest the need to consider that menthol bans could unintentionally increase the appeal of menthol cigarettes among youth already at risk of smoking.

An experimental evaluation of the effects of banning the sale of flavored tobacco products on adolescents' and young adults' future nicotine vaping intentions.

BACKGROUND: Some U.S. states and municipalities have banned the sale of flavored tobacco products to help curb youth vaping. However, evidence supporting such bans is limited. This experiment tested whether removing flavored tobacco products from a retail setting diminished adolescents' (ages 11-20) future intentions to use vaping products. METHODS: The study was implemented in the RAND StoreLab, a life-sized model convenience store. The display of flavored tobacco products in the store was manipulated with these conditions: 1) tobacco, sweet, and menthol/mint flavors displayed; 2) only tobacco and menthol/mint displayed; and 3) only tobacco flavors displayed. Participants were randomly assigned to shop in one of these conditions and completed measures of future vaping intentions post-shopping. Separate logistic regression models assessed effect of condition on future intentions to use different flavors (tobacco-, menthol/mint-, and sweet-flavored) and any flavor (composite score across flavor categories) of vaping products. RESULTS: Study condition was not associated with intentions to use menthol/mint-, sweet-flavored, or any flavor. Compared to the condition in which all flavored products were displayed, removing menthol/mint- and sweet-flavored products significantly increased future intentions to use tobacco-flavored vaping products (OR = 3.97, 95 % CI [1.01, 15.58], p < .05). This effect was only observed among adolescents with history of vaping (OR = 11.30, 95 % CI [1.42, 89.96], p = .02). CONCLUSIONS: Flavor bans may not affect adolescents' intentions to use menthol/mint, sweet, or "any" flavor of vaping products but may increase intentions to use tobacco-flavored products for teens who have already started vaping.

Diversity in U.S. Military Families: An Environmental Scan of the Peer-Reviewed Literature on Race and Ethnic Variation for Select Well-Being Outcomes.

Researchers explore the literature on race and ethnicity (R/E) in relation to U.S. military service member well-being in the areas of mental health, behavioral health, family violence, marital satisfaction, and financial stress to uncover whether past research has focused on R/E differences in outcomes as a driving research question; the variables used to capture R/E; and the quality of research in terms of design, data, and analysis. The Department of Defense (DoD) has expressed commitment to improving diversity and inclusion in the military. If leaders seek to do this based on existing evidence, they will find that information about how R/E intersects with the well-being of service members and their families is extremely limited. DoD should consider developing a deliberate, strategic, and comprehensive research agenda on R/E diversity in service member and family well-being outcomes. This will help DoD identify where differences exist and where policies and programs can address those gaps.

Availability and Accessibility of Mental Health Services in New York City.

Mental health services are critical components of public health infrastructure that provide essential supports to people living with psychiatric disorders. In a typical year, about 20 percent of people will have a psychiatric disorder, and about 5 percent will experience serious psychological distress, indicating a potentially serious mental illness. Nationally, the use of mental health services is low, and the use of care is not equitably distributed. In the United States as a whole and in New York City (NYC), non-Hispanic white individuals are more likely to use mental health services than non-Hispanic black individuals or Hispanic individuals. The challenges of ensuring the availability of mental health services for all groups in NYC are particularly acute, given the size of the population and its diversity in income, culture, ethnicity, and language. Adding to these underlying challenges, the coronavirus disease 2019 (COVID-19) pandemic has disrupted established patterns of care. To advance policy strategy for addressing gaps in the mental health services system, RAND researchers investigate the availability and accessibility of mental health services in NYC. The RAND team used two complementary approaches to address these issues. First, the team conducted interviews with a broad group of professionals and patients in the mental health system to identify barriers to care and potential strategies for improving access and availability. Second, the team investigated geographic variations in the availability of mental health services by compiling and mapping data on the locations and service characteristics of mental health treatment facilities in NYC.

Optical Clearing and 3D Analysis Optimized for Mouse and Human Pancreata.

The pancreas is a heavily innervated organ, but pancreatic innervation can be challenging to comprehensively assess using conventional histological methods. However, recent advances in whole-mount tissue clearing and 3D rendering techniques have allowed detailed reconstructions of pancreatic innervation. Optical clearing is used to enhance tissue transparency and reduce light scattering, thus eliminating the need to section the tissue. Here, we describe a modified version of the optical tissue clearing protocol iDISCO+ (immunolabeling-enabled three-dimensional imaging of solvent-cleared organs) optimized for pancreatic innervation and endocrine markers. The protocol takes 13-19 days, depending on tissue size. In addition, we include protocols for imaging using light sheet and confocal microscopes and for 3D segmentation of pancreatic innervation and endocrine cells using Imaris.

Repeated hypoglycemia remodels neural inputs and disrupts mitochondrial function to blunt glucose-inhibited GHRH neuron responsiveness.

Hypoglycemia is a frequent complication of diabetes, limiting therapy and increasing morbidity and mortality. With recurrent hypoglycemia, the counterregulatory response (CRR) to decreased blood glucose is blunted, resulting in hypoglycemia-associated autonomic failure (HAAF). The mechanisms leading to these blunted effects are only poorly understood. Here, we report, with ISH, IHC, and the tissue-clearing capability of iDISCO+, that growth hormone releasing hormone (GHRH) neurons represent a unique population of arcuate nucleus neurons activated by glucose deprivation in vivo. Repeated glucose deprivation reduces GHRH neuron activation and remodels excitatory and inhibitory inputs to GHRH neurons. We show that low glucose sensing is coupled to GHRH neuron depolarization, decreased ATP production, and mitochondrial fusion. Repeated hypoglycemia attenuates these responses during low glucose. By maintaining mitochondrial length with the small molecule mitochondrial division inhibitor-1, we preserved hypoglycemia sensitivity in vitro and in vivo. Our findings present possible mechanisms for the blunting of the CRR, significantly broaden our understanding of the structure of GHRH neurons, and reveal that mitochondrial dynamics play an important role in HAAF. We conclude that interventions targeting mitochondrial fission in GHRH neurons may offer a new pathway to prevent HAAF in patients with diabetes.

A 3D atlas of the dynamic and regional variation of pancreatic innervation in diabetes.

Understanding the detailed anatomy of the endocrine pancreas, its innervation, and the remodeling that occurs in diabetes can provide new insights into metabolic disease. Using tissue clearing and whole-organ imaging, we identified the 3D associations between islets and innervation. This technique provided detailed quantification of α and ß cell volumes and pancreatic nerve fibers, their distribution and heterogeneity in healthy tissue, canonical mouse models of diabetes, and samples from normal and diabetic human pancreata. Innervation was highly enriched in the mouse endocrine pancreas, with regional differences. Islet nerve density was increased in nonobese diabetic mice, in mice treated with streptozotocin, and in pancreata of human donors with type 2 diabetes. Nerve contacts with ß cells were preserved in diabetic mice and humans. In summary, our whole-organ assessment allows comprehensive examination of islet characteristics and their innervation and reveals dynamic regulation of islet innervation in diabetes.

Lactogens Reduce Endoplasmic Reticulum Stress-Induced Rodent and Human ß-Cell Death and Diabetes Incidence in Akita Mice.

Diabetes occurs due to a loss of functional ß-cells, resulting from ß-cell death and dysfunction. Lactogens protect rodent and human ß-cells in vitro and in vivo against triggers of ß-cell cytotoxicity relevant to diabetes, many of which converge onto a common pathway of endoplasmic reticulum (ER) stress. However, whether lactogens modulate the ER stress pathway is unknown. This study examines whether lactogens can protect ß-cells against ER stress and mitigate diabetes incidence in Akita (Ak) mice, a rodent model of ER stress-induced diabetes, akin to neonatal diabetes in humans. We show that lactogens protect INS-1 cells, primary rodent and human ß-cells in vitro against two distinct ER stressors, tunicamycin and thapsigargin, through activation of the JAK2/STAT5 pathway. Lactogens mitigate expression of proapoptotic molecules in the ER stress pathway that are induced by chronic ER stress in INS-1 cells and rodent islets. Transgenic expression of placental lactogen in ß-cells of Ak mice drastically reduces the severe hyperglycemia, diabetes incidence, hypoinsulinemia, ß-cell death, and loss of ß-cell mass observed in Ak littermates. These are the first studies in any cell type demonstrating that lactogens modulate the ER stress pathway, causing enhanced ß-cell survival and reduced diabetes incidence in the face of chronic ER stress.

CDK4/6 Inhibition on Glucose and Pancreatic Beta Cell Homeostasis in Young and Aged Rats.

Genetic deletion of cyclin-dependent kinase 4 (Cdk4) is associated with pancreatic beta cell loss and glucose dysregulation in rodents. Palbociclib, one of the first selective CDK4/6 inhibitors approved for the treatment of advanced breast cancer, is currently being investigated as an adjuvant treatment in patients with early-stage breast cancer and in a variety of cancers covering a wide-range of patient populations. Hence, longer chronic toxicity studies were necessary to further examine its safety profile. The effects of different doses and duration of palbociclib administration on glucose and beta cell homeostasis in young (two months) versus aged (12 months) rats was compared. Glucose dysregulation, due to pancreatic beta cell degeneration, was observed in young rats administered the highest dose of palbociclib for 6 months. Abnormal pancreatic islet histology and activation of the endoplasmic reticulum stress response in beta cells were detected after shorter administration with high-dose palbociclib in young rats. To test the hypothesis that palbociclib-associated inhibition of beta cell proliferation will more profoundly affect younger animals that have not achieved replicative quiescence, we administered high-dose palbociclib to aged rats for 6 months. In contrast to the young rats, despite equivalent exposures to palbociclib, no evidence of impaired glucose tolerance, hypoinsulinemia, beta cell vacuolization, or beta cell loss was seen in aged rats. Palbociclib administration induces beta cell failure in young but not aged rats.Implications: Although adult humans receiving palbociclib have not displayed detectable adverse effects on glucose metabolism, the risk of beta cell failure in children remains unexplored. Mol Cancer Res; 15(11); 1531-41. ©2017 AACR.

Parathyroid Hormone-Related Peptide (1-36) Enhances Beta Cell Regeneration and Increases Beta Cell Mass in a Mouse Model of Partial Pancreatectomy.

AIMS/HYPOTHESIS: Finding ways to stimulate the regeneration of endogenous pancreatic beta cells is an important goal in the treatment of diabetes. Parathyroid hormone-related protein (PTHrP), the full-length (1-139) and amino-terminal (1-36) peptides, enhance beta cell function, proliferation, and survival. Therefore, we hypothesize that PTHrP(1-36) has the potential to regenerate endogenous beta cells. METHODS: The partial pancreatectomy (PPx) mouse model of beta cell injury was used to test this hypothesis. Male Balb/c mice underwent either sham-operation or PPx, and were subsequently injected with PTHrP(1-36) (160µg/kg) or vehicle (veh), for 7, 30, or 90 days. The four groups of mice, sham-veh, sham-PTHrP, PPx-veh, and PPx-PTHrP were assessed for PTHrP and receptor expression, and glucose and beta cell homeostasis. RESULTS: PTHrP-receptor, but not the ligand, was significantly up-regulated in islets from mice that underwent PPx compared to sham-operated mice. This suggests that exogenous PTHrP could further enhance beta cell regeneration after PPx. PTHrP did not significantly affect body weight, blood glucose, plasma insulin, or insulin sensitivity, in either sham or PPx mice. Glucose tolerance improved in the PPx-PTHrP versus PPx-veh mice only in the early stages of treatment. As hypothesized, there was a significant increase in beta cell proliferation in PPx-PTHrP mice at days 7 and 30; however, this was normalized by day 90, compared to PPx-veh mice. Enhanced beta cell proliferation translated to a marked increase in beta cell mass at day 90, in PPx-PTHrP versus PPx-veh mice. CONCLUSIONS: PTHrP(1-36) significantly enhances beta cell regeneration through increased beta cell proliferation and beta cell mass after PPx. Future studies will determine the potential of PTHrP to enhance functional beta cell mass in the setting of diabetes.