Role of estrogen receptor signaling in skeletal response to leptin in female ob/ob mice
Leptin, critical in regulation of energy metabolism, is also important for normal bone growth, maturation and turnover. Compared to wild type (WT) mice, bone mass is lower in leptin-deficient ob/ob mice. Osteopenia in growing ob/ob mice is due to decreased bone accrual, and is associated with reduced longitudinal bone growth, impaired cancellous bone maturation and increased marrow adipose tissue (MAT). However, leptin deficiency also results in gonadal dysfunction, disrupting production of gonadal hormones which regulate bone growth and turnover. The present study evaluated the role of increased estrogen in mediating the ...
Source: Journal of Endocrinology - May 31, 2017 Category: Endocrinology Authors: Turner, R. T., Philbrick, K. A., Kuah, A. F., Branscum, A. J., Iwaniec, U. T. Tags: Research Source Type: research
PHLPP: a putative cellular target during insulin resistance and type 2 diabetes
Progressive research in the past decade converges to the impact of PHLPP in regulating the cellular metabolism through PI3K/AKT inhibition. Aberrations in PKB/AKT signaling coordinates with impaired insulin secretion and insulin resistance, identified during T2D, obesity and cardiovascular disorders which brings in the relevance of PHLPPs in the metabolic paradigm. In this review, we discuss the impact of PHLPP isoforms in insulin signaling and its associated cellular events including mitochondrial dysfunction, DNA damage, autophagy and cell death. The article highlights the plausible molecular targets that share the role ...
Source: Journal of Endocrinology - May 31, 2017 Category: Endocrinology Authors: Mathur, A., Pandey, V. K., Kakkar, P. Tags: Review Source Type: research
Nuclear factor-{kappa}B and advanced glycation end-products expression in lacrimal glands of aging rats
(Source: Journal of Endocrinology)
Source: Journal of Endocrinology - May 31, 2017 Category: Endocrinology Authors: Alves, M., Cunha, D. A., Calegari, V. C., Saad, M. J. A., Boschero, A. C., Velloso, L. A., Rocha, E. M. Tags: Erratum Source Type: research
On gonads and gadflies: the estrus angle
The first sex steroid to be crystallized was the vertebrate ovarian hormone, estrone – a less potent metabolite of 17β-estradiol, which in mammals stimulates the female urge to mate (estrus). The gadfly (Greek oistros) lent its name to the process of estrus, as an insect that bites and torments in classical Greek mythology. With the purification and crystallization of a moult-inducing steroid (ecdysone) from insects, an interesting parallel emerged between mating and moulting in lower mammals and arthropods. Ecdysterone (potent ecdysone metabolite) has anabolic effects in mammalian muscle cells that can be block...
Source: Journal of Endocrinology - May 31, 2017 Category: Endocrinology Authors: Hillier, S. G. Tags: Commentary Source Type: research
Activation of the P2Y2 receptor regulates bone cell function by enhancing ATP release
Bone cells constitutively release ATP into the extracellular environment where it acts locally via P2 receptors to regulate bone cell function. Whilst P2Y2 receptor stimulation regulates bone mineralisation, the functional effects of this receptor in osteoclasts remain unknown. This investigation used the P2Y2 receptor knockout (P2Y2R–/–) mouse model to investigate the role of this receptor in bone. MicroCT analysis of P2Y2R–/– mice demonstrated age-related increases in trabecular bone volume (≤48%), number (≤30%) and thickness (≤17%). In vitro P2Y2R–/– osteoblasts displayed a 3...
Source: Journal of Endocrinology - May 18, 2017 Category: Endocrinology Authors: Orriss, I. R., Guneri, D., Hajjawi, M. O. R., Shaw, K., Patel, J. J., Arnett, T. R. Tags: Research Source Type: research
Effect of metformin on bioactive lipid metabolism in insulin-resistant muscle
Intramuscular accumulation of bioactive lipids leads to insulin resistance and type 2 diabetes (T2D). There is lack of consensus concerning which of the lipid mediators has the greatest impact on muscle insulin action in vivo. Our aim was to elucidate the effects of high-fat diet (HFD) and metformin (Met) on skeletal muscle bioactive lipid accumulation and insulin resistance (IR) in rats. We employed a [U-13C]palmitate isotope tracer and mass spectrometry to measure the content and fractional synthesis rate (FSR) of intramuscular long-chain acyl-CoA (LCACoA), diacylglycerols (DAG) and ceramide (Cer). Eight weeks of HFD-ind...
Source: Journal of Endocrinology - May 18, 2017 Category: Endocrinology Authors: Zabielski, P., Chacinska, M., Charkiewicz, K., Baranowski, M., Gorski, J., Blachnio-Zabielska, A. U. Tags: Research Source Type: research
11{beta}-HSD1 suppresses cardiac fibroblast CXCL2, CXCL5 and neutrophil recruitment to the heart post MI
We have previously demonstrated that neutrophil recruitment to the heart following myocardial infarction (MI) is enhanced in mice lacking 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) that regenerates active glucocorticoid within cells from intrinsically inert metabolites. The present study aimed to identify the mechanism of regulation. In a mouse model of MI, neutrophil mobilization to blood and recruitment to the heart were higher in 11β-HSD1-deficient (Hsd11b1–/–) relative to wild-type (WT) mice, despite similar initial injury and circulating glucocorticoid. In bone marrow chimeric mice, ...
Source: Journal of Endocrinology - May 18, 2017 Category: Endocrinology Authors: Mylonas, K. J., Turner, N. A., Bageghni, S. A., Kenyon, C. J., White, C. I., McGregor, K., Kimmitt, R. A., Sulston, R., Kelly, V., Walker, B. R., Porter, K. E., Chapman, K. E., Gray, G. A. Tags: Research Source Type: research
Fabp4-Cre-mediated Sirt6 deletion impairs adipose tissue function and metabolic homeostasis in mice
In conclusion, our data suggest that the function of SIRT6 in the Fabp4-Cre-expressing cells in addition to mature adipocytes plays a critical role in body weight maintenance and metabolic homeostasis. (Source: Journal of Endocrinology)
Source: Journal of Endocrinology - May 18, 2017 Category: Endocrinology Authors: Xiong, X., Zhang, C., Zhang, Y., Fan, R., Qian, X., Dong, X. C. Tags: Research Source Type: research
Adipose tissue supports normalization of macrophage and liver lipid handling in obesity reversal
Adipose tissue inflammation and dysfunction are considered central in the pathogenesis of obesity-related dysmetabolism, but their role in the rapid metabolic recovery upon obesity reversal is less well defined. We hypothesized that changes in adipose tissue endocrine and paracrine mechanisms may support the rapid improvement of obesity-induced impairment in cellular lipid handling. C57Bl-6J mice were fed ad libitum either normal chow (NC) or high-fat diet (HFF) for 10 weeks. A dietary obesity reversal group was fed HFF for 8 weeks and then switched to NC for 2 weeks (HFF->NC). Whole-body glucose homeostasis rapidly nea...
Source: Journal of Endocrinology - May 18, 2017 Category: Endocrinology Authors: Vatarescu, M., Bechor, S., Haim, Y., Pecht, T., Tarnovscki, T., Slutsky, N., Nov, O., Shapiro, H., Shemesh, A., Porgador, A., Bashan, N., Rudich, A. Tags: Research Source Type: research
Role of the fatty acid-binding protein 4 in heart failure and cardiovascular disease
Obesity and ectopic fat accumulation in non-adipose tissues are major contributors to heart failure (HF) and cardiovascular disease (CVD). Adipocytes act as endocrine organs by releasing a large number of bioactive molecules into the bloodstream, which participate in a communication network between white adipose tissue and other organs, including the heart. Among these molecules, fatty acid-binding protein 4 (FABP4) has recently been shown to increase cardiometabolic risk. Both clinical and experimental evidence have identified FABP4 as a relevant player in atherosclerosis and coronary artery disease, and it has been direc...
Source: Journal of Endocrinology - May 18, 2017 Category: Endocrinology Authors: Rodriguez-Calvo, R., Girona, J., Alegret, J. M., Bosquet, A., Ibarretxe, D., Masana, L. Tags: Review Source Type: research
Nutritional approaches for managing obesity-associated metabolic diseases
Obesity is an ongoing pandemic and serves as a causal factor of a wide spectrum of metabolic diseases including diabetes, fatty liver disease, and cardiovascular disease. Much evidence has demonstrated that nutrient overload/overnutrition initiates or exacerbates inflammatory responses in tissues/organs involved in the regulation of systemic metabolic homeostasis. This obesity-associated inflammation is usually at a low-grade and viewed as metabolic inflammation. When it exists continuously, inflammation inappropriately alters metabolic pathways and impairs insulin signaling cascades in peripheral tissues/organs such as ad...
Source: Journal of Endocrinology - May 18, 2017 Category: Endocrinology Authors: Botchlett, R., Woo, S.-L., Liu, M., Pei, Y., Guo, X., Li, H., Wu, C. Tags: Review Source Type: research
Effect of androgen on Kiss1 expression and luteinizing hormone release in female rats
Hyperandrogenic women have various grades of ovulatory dysfunction, which lead to infertility. The purpose of this study was to determine whether chronic exposure to androgen affects the expression of kisspeptin (ovulation and follicle development regulator) or release of luteinizing hormone (LH) in female rats. Weaned females were subcutaneously implanted with 90-day continuous-release pellets of 5α-dihydrotestosterone (DHT) and studied after 10 weeks of age. Number of Kiss1-expressing cells in both the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) was significantly decreased in ovary-intact...
Source: Journal of Endocrinology - May 15, 2017 Category: Endocrinology Authors: Iwata, K., Kunimura, Y., Matsumoto, K., Ozawa, H. Tags: Research Source Type: research
Resolution of glucose intolerance in long-term high-fat, high-sucrose-fed mice
In conclusion, we have made the paradoxical observation that long-term HFSD feeding results in the resolution of glucose intolerance in the C57Bl/6 mouse. Mechanistically, we propose that the gross expansion of subcutaneous adipose tissue increases the glucose disposal capacity of the HFSD-fed mouse, which overcomes the prevailing insulin resistance to improve glucose tolerance. (Source: Journal of Endocrinology)
Source: Journal of Endocrinology - May 15, 2017 Category: Endocrinology Authors: Kowalski, G. M., Kraakman, M. J., Mason, S. A., Murphy, A. J., Bruce, C. R. Tags: Research Source Type: research
Phospho-ERK and sex steroids in the mPOA: involvement in male mouse sexual behaviour
This paper aimed to investigate the mechanisms triggering ERK phosphorylation and its functional role in male sexual behaviour. ERK1/2-phosphorylated form was detected in the medial preoptic area of the hypothalamus (mPOA) during the sexual stimulation of naive and sexually experienced males who were killed 5 min after the first intromission. This mating-induced ERK phosphorylation was increased in sexually experienced males compared to that in naive mice. The functional role of the ERK1/2 pathway activation during sexual behaviour was explored with the administration of a MEK inhibitor, SL-327 (30 mg/kg, i.p.), 45 min bef...
Source: Journal of Endocrinology - May 15, 2017 Category: Endocrinology Authors: Jean, A., Trouillet, A.-C., Andrianarivelo, N. A., Mhaouty-Kodja, S., Hardin-Pouzet, H. Tags: Research Source Type: research
Role of osteocytes in mediating bone mineralization during hyperhomocysteinemia
Hyperhomocysteinemia (HHCY) is a risk factor for osteoporosis but whether HHCY affects bone mineralization or not is still ambiguous. Herein we evaluated whether homocysteine affects tissue mineral density (TMD) of cortical bone and if so the role of osteocytes. CD1 mice administered with homocysteine (5 mg/100 g body weight, i.p.) for 7, 15 and 30 days showed temporal changes in TMD and osteocyte lacunar density in femoral cortices. Short-term administration of homocysteine (day 7) increased osteocyte lacunar density and reduced TMD evidenced by microCT50 while prolonged administration of homocysteine (day 30) reinstated ...
Source: Journal of Endocrinology - May 15, 2017 Category: Endocrinology Authors: Vijayan, V., Gupta, S. Tags: Research Source Type: research
