Neuronal ablation of GHSR mitigates diet-induced depression and memory impairment via AMPK-autophagy signaling-mediated inflammation.

Obesity is associated with chronic inflammation in the central nervous system (CNS), and neuroinflammation has been shown to have detrimental effects on mood and cognition. The growth hormone secretagogue receptor (GHSR), the biologically relevant receptor of the orexigenic hormone ghrelin, is primarily expressed in the brain. Our previous study showed that neuronal GHSR deletion prevents high-fat diet-induced obesity (DIO). Here, we investigated the effect of neuronal GHSR deletion on emotional and cognitive functions in DIO. The neuron-specific GHSR-deficient mice exhibited reduced depression and improved spatial memory compared to littermate controls under DIO. We further examined the cortex and hippocampus, the major regions regulating cognitive and emotional behaviors, and found that the neuronal deletion of GHSR reduced DIO-induced neuroinflammation by suppressing proinflammatory chemokines/cytokines and decreasing microglial activation. Furthermore, our data showed that neuronal GHSR deletion suppresses neuroinflammation by downregulating AMPK-autophagy signaling in neurons. In conclusion, our data reveal that neuronal GHSR inhibition protects against DIO-induced depressive-like behavior and spatial cognitive dysfunction, at least in part, through AMPK-autophagy signaling-mediated neuroinflammation.

The effect of a bone-preserving board game program on the knowledge, attitudes and preventive behaviors of osteoporosis in older adults.

Osteoporosis predisposes to fractures, which affect the quality of life and can be life-threatening. However, the knowledge, attitudes and preventive behaviors of osteoporosis in older adults are insufficient. The aim of this paper was to develop and test the effect of a bone-preserving board game program among older adults. A convenience sample of 85 older adults recruited from two community activity centers in southern Taiwan were assigned to either an experimental group or a control group. The experimental group played a bone-preserving board game for 4 weeks, and the control group participated in routine community center activities. The generalized estimating equation showed significantly larger improvements in knowledge, attitudes, and preventive behaviors in the experimental group than in the control group. Board games designed for older adults can support public health education and help prevent osteoporosis. Our results provide a reference for educators, clinical practitioners and researchers.

Nutrient-sensing growth hormone secretagogue receptor in macrophage programming and meta-inflammation.

OBJECTIVE: Obesity-associated chronic inflammation, aka meta-inflammation, is a key pathogenic driver for obesity-associated comorbidity. Growth hormone secretagogue receptor (GHSR) is known to mediate the effects of nutrient-sensing hormone ghrelin in food intake and fat deposition. We previously reported that global Ghsr ablation protects against diet-induced inflammation and insulin resistance, but the site(s) of action and mechanism are unknown. Macrophages are key drivers of meta-inflammation. To unravel the role of GHSR in macrophages, we generated myeloid-specific Ghsr knockout mice (LysM-Cre;Ghsrf/f). METHODS: LysM-Cre;Ghsrf/f and control Ghsrf/f mice were subjected to 5 months of high-fat diet (HFD) feeding to induce obesity. In vivo, metabolic profiling of food intake, physical activity, and energy expenditure, as well as glucose and insulin tolerance tests (GTT and ITT) were performed. At termination, peritoneal macrophages (PMs), epididymal white adipose tissue (eWAT), and liver were analyzed by flow cytometry and histology. For ex vivo studies, bone marrow-derived macrophages (BMDMs) were generated from the mice and treated with palmitic acid (PA) or lipopolysaccharide (LPS). For in vitro studies, macrophage RAW264.7 cells with Ghsr overexpression or Insulin receptor substrate 2 (Irs2) knockdown were studied. RESULTS: We found that Ghsr expression in PMs was increased under HFD feeding. In vivo, HFD-fed LysM-Cre;Ghsrf/f mice exhibited significantly attenuated systemic inflammation and insulin resistance without affecting food intake or body weight. Tissue analysis showed that HFD-fed LysM-Cre;Ghsrf/f mice have significantly decreased monocyte/macrophage infiltration, pro-inflammatory activation, and lipid accumulation, showing elevated lipid-associated macrophages (LAMs) in eWAT and liver. Ex vivo, Ghsr-deficient macrophages protected against PA- or LPS-induced pro-inflammatory polarization, showing reduced glycolysis, increased fatty acid oxidation, and decreased NF-κB nuclear translocation. At molecular level, GHSR metabolically programs macrophage polarization through PKA-CREB-IRS2-AKT2 signaling pathway. CONCLUSIONS: These novel results demonstrate that macrophage GHSR plays a key role in the pathogenesis of meta-inflammation, and macrophage GHSR promotes macrophage infiltration and induces pro-inflammatory polarization. These exciting findings suggest that GHSR may serve as a novel immunotherapeutic target for the treatment of obesity and its associated comorbidity.

Comparing the effectiveness of board game-based and drill-based education programs in improving Taiwanese nurses' fire safety knowledge, attitudes, and behavior: A quasi-experimental study.

BACKGROUND: Fire education is currently dominated by drill-based programs, however only a limited number of participants may take part in fire drills. This gap could be addressed by the development of innovative board game-based educational programs. OBJECTIVE: This study sought to compare the effectiveness of board game-based and drill-based fire safety education programs in improving nurses' fire safety knowledge, attitudes, and behavior. METHODS: In this quasi-experimental study, 122 nurses were purposively sampled from a hospital in southern Taiwan. The participants were divided into two groups based on their willingness. Sixty-two nurses in the game-based group took part in an hour-long educational board game for fire safety; and 60 in the drill-based group took part in an hour-long fire drill organized by the hospital. The participants' pre- (T0) and post-intervention (T1) questionnaire scores on fire safety knowledge, attitudes, and behavior were recorded. The statistical methods included descriptive statistics and t-tests. RESULTS: After the interventions, both groups had improved safety knowledge, attitudes, and behavior. However, from T0 to T1, only fire safety knowledge was significantly higher in the game-based group than in the drill-based group, and there were no significant differences in fire safety attitudes and behavior between the two groups. CONCLUSIONS: A board game-based fire education program is similar to a tabletop exercise, and drill-based programs more accurately reflect actual circumstances. Both methods can be applied based on the educational objectives and actual educational settings. The results of this study may function as a reference for designing clinical, educational, and academic interventions for fire safety in healthcare settings.

Effectiveness of a nursing board games in psychiatric nursing course for undergraduate nursing students: An experimental design.

AIM: To examine the effectiveness of a psychiatric nursing board game in an undergraduate psychiatric nursing course. BACKGROUND: Didactic teaching fails to assist students in deepening their understanding of abstract concepts in psychiatric nursing. The game-based learning of professional courses can address the demands of digital-age students, which may improve their learning outcomes. DESIGN: A parallel two-arm experimental design was adopted in a nursing college in southern Taiwan. METHODS: The participants were fourth-year students enroled in a college nursing programme in southern Taiwan. Simple random sampling was used to divide the class into intervention and control groups. The former participated in an eight-week game-based intervention course, while the latter continued to receive traditional instruction. In addition to collecting the students' demographic data, three structural questionnaires were developed to examine the variation in students' nursing knowledge and attitudes toward psychiatric nursing, as well as their learning satisfaction before and after the intervention. RESULTS: There were a total of 106 participants, with 53 in each group. After the intervention, the two groups were significantly different in terms of their psychiatric nursing knowledge, attitudes and self-reported learning satisfaction. The intervention group's scores were significantly higher than those of the control group across all three dimensions. This suggests the positive effects of the board game intervention on students' learning outcomes. CONCLUSION: The research outcome can be applied in formative and undergraduate nursing education in teaching psychiatric nursing globally. The game-based learning materials developed can be used to train psychiatric nursing teachers. Future studies should recruit a larger sample and increase the follow-up time for assessing students' learning outcomes, as well as examine the similarities and differences in the learning outcomes of students from different educational systems.

The efficacy of a mindfulness-based exercise program in older residents of a long-term care facility in Taiwan.

Older people living in long-term care facilities remain largely inactive, and therefore promoting exercise in this population is necessary. This study evaluated the efficacy of a mindfulness-based exercise program in older residents of a long-term care facility in Taiwan. A convenience sample of 72 older residents of a long-term care facility were recruited and assigned to either an experimental group or a control group. The experimental group (n = 36) participated in an 8-week mindfulness-based exercise program, and the control group (n = 36) received routine care. The generalized estimating equation showed significantly larger improvements in a fear of falling, exercise self-efficacy, dynamic balance, and muscle strength in the experimental group than in the control group from baseline to the end of the intervention and 3 months after the end of the intervention. This study provides a reference for how to improve exercise practice in older people living in long-term care facilities.

Prior episode of colitis impairs contextual fear memory.

Accumulating evidence has shown that intestinal inflammations in inflammatory bowel disease (IBD) also drive pathological responses in organs outside the intestine, including the brain. Previous studies using the dextran sodium sulfate (DSS)-induced colitis model have shown that colonic inflammation contributes to the development of anxiety- and depression-related behaviors; however, little is known about whether memory function is affected. Here, we subjected male and female C57BL/6J mice to DSS-induced colitis for 6 days, followed by Pavlovian conditioned fear (CF) tests 15 days after the start of inflammation, when local colonic inflammation has receded. The contextual and cued CF tests were used to assess associative fear memory. We found that DSS-induced colitis led to significant impairment in contextual fear memory in both male and female mice; on the other hand, auditory cued fear memories were comparable between control and DSS-treated mice. There were marked signs of astrogliosis in the hippocampal regions 17 days (D17) after colitis induction. Furthermore, molecular characterization of hippocampi showed marked but transient increases in the expression of inflammatory genes Nfkb, Trem2 (microglial marker), GFAP (astrocyte marker), Il1b, and S100a8 in DSS-treated mice. While the expression of Nfkb, Trem2, and GFAP showed a peak on day 10, the S100a8 expression was high on days 10 and 17 and subsided on day 42. Interestingly, expression of Bdnf remained elevated in the times assessed (D10, 17, 42). Together, these results demonstrated that DSS-induced colitis could induce prolonged neuroinflammation and impaired contextual fear memory.

Deletion of ghrelin alters tryptophan metabolism and exacerbates experimental ulcerative colitis in aged mice.

A major component of aging is chronic, low-grade inflammation, attributable in part by impaired gut barrier function. We previously reported that deletion of ghrelin, a peptidergic hormone released mainly from the gut, exacerbates experimental muscle atrophy in aged mice. In addition, ghrelin has been shown to ameliorate colitis in experimental models of inflammatory bowel disease (IBD), although the role of endogenous ghrelin in host-microbe interactions is less clear. Here, we showed that 22-month-old global ghrelin knockout (Ghrl-/-) mice exhibited significantly increased depressive-like behaviors, while anxiety levels and working memory were similar to littermate wild-type (WT) mice. Furthermore, old Ghrl-/- mice showed significantly increased intestinal permeability to fluorescein isothiocyanate (FITC)-dextran, significantly higher colonic interleukin (IL-1ß) levels, and trends for higher colonic IL-6 and tumor necrosis factor-α (TNF-α) compared to WT mice. Interestingly, young Ghrl-/- and WT mice showed comparable depressive-like behavior and gut permeability, suggesting age-dependent exacerbation in gut barrier dysfunction in Ghrl-/- mice. While fecal short-chain fatty acids levels were comparable between old Ghrl-/- and WT mice, serum metabolome revealed alterations in metabolic cascades including tryptophan metabolism. Specifically, tryptophan and its microbial derivatives indole-3-acetic acid and indole-3-lactic acid were significantly reduced in old Ghrl-/-mice. Furthermore, in an experimental model of dextran sulfate sodium (DSS)-induced colitis, Ghrl-/- mice showed exacerbated disease symptoms, and higher levels of chemoattractant and pro-inflammatory cytokines in the colon. Overall, these data demonstrated that ghrelin deficiency is associated with gut barrier dysfunction, alterations in microbially derived tryptophan metabolites, and increased susceptibility to colitis. These data suggested that endogenous ghrelin contributes to maintaining a healthy host-microbe environment, ultimately impacting on brain function.

Effectiveness of a Problem-Based Geropsychiatric Nursing Clinical Internship Program.

Clinical internships that effectively incorporate the care of older adults with mental health disorders are sparse in many countries, including Taiwan. This study investigated the effectiveness of a problem-based geropsychiatric clinical internship program for nursing students in Taiwan. We conducted a quasi-experimental study among 126 nursing students. Experimental and control groups received problem-based geropsychiatric and general psychiatric practice sessions, respectively. Knowledge, attitude, skills, and self-reflection were evaluated before (T1) and after (T2) measurements. There were no significant differences between the groups in knowledge, attitude, skills, and self-reflection at T1. At T2, knowledge was significantly higher in the experimental group (t = 2.39, p = 0.02). Attitude, skills, and self-reflection ability did not differ between the groups at T2. Our results showed that clinical problem-based approaches can be applied in geropsychiatric mental health nursing internship programs. The problem-based approach was helpful in improving nursing students' knowledge about psychiatric symptoms and the health problems of older adults with mental illness. However, it did not significantly enhance or change the attitudes, skills, or the ability to self-reflect among students.

Differential effects of the soluble fiber inulin in reducing adiposity and altering gut microbiome in aging mice.

Inulin, a soluble dietary fiber, is thought to exert multiple beneficiary effects through promoting growth of bacteria that metabolize the fiber to short-chain fatty acids (SCFAs); however, the effect and efficacy of inulin in aging subjects is unknown. This study aims to systematically evaluate the capacity of SCFAs production and host response in mice of different ages. Male C57BL/6J mice across young (5 months), middle (11 months) and old (26 months) age were subjected to a control diet for 2 weeks, followed by 6 weeks of inulin-containing diet. Inulin-induced increase in fecal butyric acid levels was most prominent in middle-age group compared to other age groups. In addition, inulin-induced increase in fecal propionic acids showed age-dependent decline. Interestingly, the SCFA-producing Roseburia was most abundantly and persistently increased in the middle-age group. Furthermore, inulin intake significantly reduced Firmicutes to Bacteroidetes ratio, and several dysbiotic bacteria associated with pro-inflammatory state. Concomitantly, circulating levels of CXCL1, a chemoattractant for neutrophils, was reduced by inulin intake. Inulin decreased fat mass in all age groups, with middle-aged mice being most responsive to fat-reducing effects of inulin. Moreover, inulin significantly increased energy expenditure and voluntary wheel running in middle-aged mice, but not in old mice. Overall, our data suggest that the efficacy of inulin in altering the microbiome and SCFA production, and the subsequent metabolic response was diminished in old mice, and highlight the importance of including age as a variable in studies determining host-microbe response to diets.

Mechanistic Investigation of GHS-R Mediated Glucose-Stimulated Insulin Secretion in Pancreatic Islets.

Ghrelin receptor, a growth hormone secretagogue receptor (GHS-R), is expressed in the pancreas. Emerging evidence indicates that GHS-R is involved in the regulation of glucose-stimulated insulin secretion (GSIS), but the mechanism by which GHS-R regulates GSIS in the pancreas is unclear. In this study, we investigated the role of GHS-R on GSIS in detail using global Ghsr-/- mice (in vivo) and Ghsr-ablated pancreatic islets (ex vivo). GSIS was attenuated in both Ghsr-/- mice and Ghsr-ablated islets, while the islet morphology was similar between WT and Ghsr-/- mice. To elucidate the mechanism underpinning Ghsr-mediated GSIS, we investigated the key steps of the GSIS signaling cascade. The gene expression of glucose transporter 2 (Glut2) and the glucose-metabolic intermediate-glucose-6-phosphate (G6P) were reduced in Ghsr-ablated islets, supporting decreased glucose uptake. There was no difference in mitochondrial DNA content in the islets of WT and Ghsr-/- mice, but the ATP/ADP ratio in Ghsr-/- islets was significantly lower than that of WT islets. Moreover, the expression of pancreatic and duodenal homeobox 1 (Pdx1), as well as insulin signaling genes of insulin receptor (IR) and insulin receptor substrates 1 and 2 (IRS1/IRS2), was downregulated in Ghsr-/- islets. Akt is the key mediator of the insulin signaling cascade. Concurrently, Akt phosphorylation was reduced in the pancreas of Ghsr-/- mice under both insulin-stimulated and homeostatic conditions. These findings demonstrate that GHS-R ablation affects key components of the insulin signaling pathway in the pancreas, suggesting the existence of a cross-talk between GHS-R and the insulin signaling pathway in pancreatic islets, and GHS-R likely regulates GSIS via the Akt-Pdx1-GLUT2 pathway.

Novel Role of Ghrelin Receptor in Gut Dysbiosis and Experimental Colitis in Aging.

Chronic low-grade inflammation is a hallmark of aging, which is now coined as inflamm-aging. Inflamm-aging contributes to many age-associated diseases such as obesity, type 2 diabetes, cardiovascular disease, and inflammatory bowel disease (IBD). We have shown that gut hormone ghrelin, via its receptor growth hormone secretagogue receptor (GHS-R), regulates energy metabolism and inflammation in aging. Emerging evidence suggests that gut microbiome has a critical role in intestinal immunity of the host. To determine whether microbiome is an integral driving force of GHS-R mediated immune-metabolic homeostasis in aging, we assessed the gut microbiome profiles of young and old GHS-R global knockout (KO) mice. While young GHS-R KO mice showed marginal changes in Bacteroidetes and Firmicutes, aged GHS-R KO mice exhibited reduced Bacteroidetes and increased Firmicutes, featuring a disease-susceptible microbiome profile. To further study the role of GHS-R in intestinal inflammation in aging, we induced acute colitis in young and aged GHS-R KO mice using dextran sulfate sodium (DSS). The GHS-R KO mice showed more severe disease activity scores, higher proinflammatory cytokine expression, and decreased expression of tight junction markers. These results suggest that GHS-R plays an important role in microbiome homeostasis and gut inflammation during aging; GHS-R suppression exacerbates intestinal inflammation in aging and increases vulnerability to colitis. Collectively, our finding reveals for the first time that GHS-R is an important regulator of intestinal health in aging; targeting GHS-R may present a novel therapeutic strategy for prevention/treatment of aging leaky gut and inflammatory bowel disease.

Ghrelin Alleviates Experimental Ulcerative Colitis in Old Mice and Modulates Colonocyte Metabolism via PPARγ Pathway.

There is a growing prevalence of inflammatory bowel disease (IBD), a chronic inflammatory condition of the gastrointestinal tract, among the aging population. Ghrelin is a gut hormone that, in addition to controlling feeding and energy metabolism, has been shown to exert anti-inflammatory effects; however, the effect of ghrelin in protecting against colitis in old mice has not been assessed. Here, we subjected old female C57BL/6J mice to dextran sulfate sodium (DSS) in drinking water for six days, then switched back to normal drinking water, administered acyl-ghrelin or vehicle control from day 3 to 13, and monitored disease activities throughout the disease course. Our results showed that treatment of old mice with acyl-ghrelin attenuated DSS-induced colitis. Compared to the DSS group, ghrelin treatment decreased levels of the inflammation marker S100A9 in the colons collected on day 14 but not on day 8, suggesting that the anti-inflammatory effect was more prominent in the recovery phase. Ghrelin treatment also significantly reduced F4/80 and interleukin-17A on day 14. Moreover, acyl-ghrelin increased mitochondrial respiration and activated transcriptional activity of the peroxisome proliferator-activated receptor gamma (PPARγ) in Caco-2 cells. Together, our data show that ghrelin alleviated DSS-induced colitis, suggesting that ghrelin may promote tissue repair in part through regulating epithelial metabolism via PPARγ mediated signaling.

Enterovirus board game for elementary school children: A pilot study.

OBJECTIVE: To evaluate the effect of an enterovirus board game on improving knowledge of enterovirus for elementary school children in Taiwan. DESIGN: A pilot study with a one-group pretest-posttest design. SAMPLE: Using convenience sampling, 27 children were recruited from a single elementary school in Taiwan in June 2020. MEASUREMENTS: Demographic data were collected and the children completed an enterovirus knowledge questionnaire. Statistical analyses included descriptive statistics, McNemar test, and Wilcoxon test. INTERVENTION: Each experimental group of four to five children participated in a 40-min enterovirus board game. RESULTS: After using the board game, the children had significantly higher mean scores for enterovirus knowledge. Specifically, the children had a higher proportion of correct answers for seven questions related to enterovirus after playing the game compared to before. CONCLUSIONS: Board games designed for elementary school-aged children can support public health education and help prevent outbreaks of infectious diseases such as enterovirus.

Metabolic and inflammatory functions of cannabinoid receptor type 1 are differentially modulated by adiponectin.

BACKGROUND: Antagonists of cannabinoid type 1 receptor (CB1) have been shown to promote body weight loss and improve insulin sensitivity. Cannabinoids decrease adiponectin, and CB1 blocker increase adiponectin. However, the mediators of CB1 actions are not well defined. AIM: To investigate whether the beneficial effects of CB1 inhibition are, at least in part, mediated by adiponectin. METHODS: We compared metabolic and inflammatory phenotypes of wild-type (WT) mice, CB1-null (CB1 -/-) and CB1/adiponectin double-knockout (DKO) mice. We assessed the insulin sensitivity using insulin tolerance test and glucose tolerance test, and inflammation using flow cytometry analysis of macrophages. RESULTS: CB1 -/- mice exhibited significantly reduced body weight and fat mass when compared to WT mice. While no significance was found in total daily food intake and locomotor activity, CB1 -/- mice showed increased energy expenditure, enhanced thermogenesis in brown adipose tissue (BAT), and improved insulin sensitivity compared to WT mice. DKO showed no difference in body weight, adiposity, nor insulin sensitivity; only showed a modestly elevated thermogenesis in BAT compared to CB1 -/- mice. The metabolic phenotype of DKO is largely similar to CB1 -/- mice, suggesting that adiponectin is not a key mediator of the metabolic effects of CB1. Interestingly, CB1 -/- mice showed reduced pro-inflammatory macrophage polarization in both peritoneal macrophages and adipose tissue macrophages compared to WT mice; in contrast, DKO mice exhibited increased pro-inflammatory macrophage polarization in these macrophages compared to CB1 -/- mice, suggesting that adiponectin is an important mediator of the inflammatory effect of CB1. CONCLUSION: Our findings reveal that CB1 functions through both adiponectin-dependent and adiponectin-independent mechanisms: CB1 regulates energy metabolism in an adiponectin-independent manner, and inflammation in an adiponectin-dependent manner. The differential effects of adiponectin on CB1-mediated metabolic and inflammatory functions should be taken into consideration in CB1 antagonist utilization.

Factors associated with perceived stress of clinical practice among associate degree nursing students in Taiwan.

BACKGROUND: Clinical placements play an important role in helping nursing students to achieve clinical competence, but these placements can be highly challenging and stressful. It has been shown that stress can be either a trigger or aggravating factor for ill-health in general, but studies have seldom differentiated the impact of general health status on perceived stress. This study examined factors associated with perceived stress of clinical practice among nursing students with a particular focus on the effect of general health status on stress. METHODS: This was a cross-sectional quantitative study conducted among 724 associate nursing degree students in Southern Taiwan. RESULTS: Health status scores varied from 28 to 139, with an average of 68.40 (SD = 25.75). Health status was reported to be 'good' (scores 28-55) in 35.5% of participants, moderate (scores 56-83) in 24.6%, and poor (Scores ≧ 84) in 39.9% of participants. Perceived stress scores ranged from 0 to 95 points with an average score of 36.65 (SD ± 15.95). The classification and regression tree (CART) analysis showed health status as the most important factor linked to perceived stress with a Normalized Importance value of 100%. Those who reported general health status (measured through General Health Questionnaire (GHQ)-28) score of ≤34.5 perceived mild stress and those with a score of > 34.5-< 84.5 perceived moderate stress. A score of 84.5 was found to be the point of transition to perceptions of severe stress. When health status score was greater than 84.5, perceived stress was at a severe or extremely severe level. CONCLUSIONS: Our findings indicated health status as a potential measure to identify students who were most vulnerable to perceived stress. Given the cross-sectional design of this study and the bidirectional relationship between health and stress, more studies are needed to fully establish the predictive link between general health status and vulnerability to stress.

ß Cell GHS-R Regulates Insulin Secretion and Sensitivity.

Growth hormone secretagogue receptor (GHS-R) is widely known to regulate food intake and adiposity, but its role in glucose homeostasis is unclear. In this study, we investigated the expression of GHS-R in mouse pancreatic islets and its role in glycemic regulation. We used Ghsr-IRES-tauGFP mice, with Green Fluorescent Protein (GFP) as a surrogate for GHS-R, to demonstrate the GFP co-localization with insulin and glucagon expression in pancreatic islets, confirming GHS-R expression in ß and α cells. We then generated ß-cell-specific GHSR-deleted mice with MIP-Cre/ERT and validated that GHS-R suppression was restricted to the pancreatic islets. MIP-Cre/ERT;Ghsrf/f mice showed normal energy homeostasis with similar body weight, body composition, and indirect calorimetry profile. Interestingly, MIP-Cre/ERT;Ghsrf/f mice exhibited an impressive phenotype in glucose homeostasis. Compared to controls, MIP-Cre/ERT;Ghsrf/f mice showed lower fasting blood glucose and insulin; reduced first-phase insulin secretion during a glucose tolerance test (GTT) and glucose-stimulated insulin secretion (GSIS) test in vivo. The isolated pancreatic islets of MIP-Cre/ERT;Ghsrf/f mice also showed reduced insulin secretion during GSIS ex vivo. Further, MIP-Cre/ERT;Ghsrf/f mice exhibited improved insulin sensitivity during insulin tolerance tests (ITT). Overall, our results confirmed GHS-R expression in pancreatic ß and α cells; GHS-R cell-autonomously regulated GSIS and modulated systemic insulin sensitivity. In conclusion, ß cell GHS-R was an important regulator of glucose homeostasis, and GHS-R antagonists may have therapeutic potential for Type 2 Diabetes.

GHS-R suppression in adipose tissues protects against obesity and insulin resistance by regulating adipose angiogenesis and fibrosis.

BACKGROUND/OBJECTIVES: Ghrelin is an orexigenic hormone that increases food intake, adiposity, and insulin resistance through its receptor Growth Hormone Secretagogue Receptor (GHS-R). We previously showed that ghrelin/GHS-R signaling has important roles in regulation of energy homeostasis, and global deletion of GHS-R reduces obesity and improves insulin sensitivity by increasing thermogenesis. However, it is unknown whether GHS-R regulates thermogenic activation in adipose tissues directly. METHODS: We generated a novel adipose tissue-specific GHS-R deletion mouse model and characterized the mice under regular diet (RD) and high-fat diet (HFD) feeding. Body composition was measured by Echo MRI. Metabolic profiling was determined by indirect calorimetry. Response to environmental stress was assessed using a TH-8 temperature monitoring system. Insulin sensitivity was evaluated by glucose and insulin tolerance tests. Tissue histology was analyzed by hematoxylin/eosin and immunofluorescent staining. Expression of genes involved in thermogenesis, angiogenesis and fibrosis in adipose tissues were analyzed by real-time PCR. RESULTS: Under RD feeding, adipose tissue-specific GHS-R deletion had little or no impact on metabolic parameters. However, under HFD feeding, adipose tissue-specific GHS-R deletion attenuated diet-induced obesity and insulin resistance, showing elevated physical activity and heat production. In addition, adipose tissue-specific GHS-R deletion increased expression of master adipose transcription regulator of peroxisome proliferator-activated receptor (PPAR) γ1 and adipokines of adiponectin and fibroblast growth factor (FGF) 21; and differentially modulated angiogenesis and fibrosis evident in both gene expression and histological analysis. CONCLUSIONS: These results show that GHS-R has cell-autonomous effects in adipocytes, and suppression of GHS-R in adipose tissues protects against diet-induced obesity and insulin resistance by modulating adipose angiogenesis and fibrosis. These findings suggest adipose GHS-R may constitute a novel therapeutic target for treatment of obesity and metabolic syndrome.

Age-dependent remodeling of gut microbiome and host serum metabolome in mice.

The interplay between microbiota and host metabolism plays an important role in health. Here, we examined the relationship between age, gut microbiome and host serum metabolites in male C57BL/6J mice. Fecal microbiome analysis of 3, 6, 18, and 28 months (M) old mice showed that the Firmicutes/Bacteroidetes ratio was highest in the 6M group; the decrease of Firmicutes in the older age groups suggests a reduced capacity of gut microflora to harvest energy from food. We found age-dependent increase in Proteobacteria, which may lead to altered mucus structure more susceptible to bacteria penetration and ultimately increased intestinal inflammation. Metabolomic profiling of polar serum metabolites at fed state in 3, 12, 18 and 28M mice revealed age-associated changes in metabolic cascades involved in tryptophan, purine, amino acids, and nicotinamide metabolism. Correlation analyses showed that nicotinamide decreased with age, while allantoin and guanosine, metabolites in purine metabolism, increased with age. Notably, tryptophan and its microbially derived compounds indole and indole-3-lactic acid significantly decreased with age, while kynurenine increased with age. Together, these results suggest a significant interplay between bacterial and host metabolism, and gut dysbiosis and altered microbial metabolism contribute to aging.

Developing an assessment tool for geropsychiatric mental healthcare knowledge and attitude evaluations in clinical practice for nursing students.

AIM: To develop an instrument to investigate geropsychiatric psychological symptoms, health problem nursing knowledge (GPN-K), geropsychiatric psychological symptoms and health problem nursing attitude scale (GPN-A) in clinical practice for nursing students. DESIGN: Instrument development and cross-sectional study for psychometric testing. METHODS: Construct validity was evaluated using confirmatory factor analysis (CFA) and exploratory factor analysis (EFA), and internal consistency was calculated using Cronbach's α. RESULTS: A total of 300 students have completed the questionnaires (85.71% response rate). The CFA of GPN-K showed good fitness and validity. The Kuder-Richardson 20 (KR-20) value of the internal consistency reliability is 0.64. The GPN-A overall content validity index is 0.95. A three-factor structure was shown by exploratory factor analysis. The three factors are communication and care, helping others improve and problem evaluation tendency. The total variance explained is 59.01%. Cronbach's alpha of GPN-A equals 0.84, which represents good internal consistency.