IGFBP-4 regulates adult skeletal growth in a sex-specific manner
In this study, we hypothesized that IGFBP-4 might potentiate the actions of IGF-1 on the skeleton. To test this, we comprehensively studied 8- and 16-week-old Igfbp4–/– mice. Both male and female adult Igfbp4–/– mice had marked growth retardation with reductions in body weight, body and femur lengths, fat proportion and lean mass at 8 and 16 weeks. Marked reductions in aBMD and aBMC were observed in 16-week-old Igfbp4–/– females, but not in males. Femoral trabecular BV/TV and thickness, cortical fraction and thickness in 16-week-old Igfbp4–/– females were significantly reduce...
Source: Journal of Endocrinology - March 12, 2017 Category: Endocrinology Authors: Maridas, D. E., DeMambro, V. E., Le, P. T., Nagano, K., Baron, R., Mohan, S., Rosen, C. J. Tags: Research Source Type: research
Gain-of-function {beta}-catenin in the uterine mesenchyme leads to impaired implantation and decidualization
Embryo implantation and endometrial decidualization are critical events that occur during early pregnancy in humans and mice, and perturbation in either can result in infertility. WNT signaling through the canonical β-catenin pathway plays a pivotal role in embryonic Müllerian duct development, postnatal uterine maturation and establishment of pregnancy. Loss of β-catenin in the Müllerian duct mesenchyme (MDM)-derived stroma and myometrium results in impaired decidualization and infertility, whereas gain-of-function (GOF) results in the formation of mesenchymal tumors and sub-fertility attributed to mal...
Source: Journal of Endocrinology - March 8, 2017 Category: Endocrinology Authors: Patterson, A. L., Pirochta, J., Tufano, S. Y., Teixeira, J. M. Tags: Research Source Type: research
ANGPTL6 expression is coupled with mitochondrial OXPHOS function to regulate adipose FGF21
In conclusion, mitochondrial OXPHOS function governs the expression of ANGPTL6, which is an essential factor for FGF21 production in adipose tissue and cultured adipocytes. (Source: Journal of Endocrinology)
Source: Journal of Endocrinology - March 5, 2017 Category: Endocrinology Authors: Kang, S. G., Yi, H.-S., Choi, M. J., Ryu, M. J., Jung, S., Chung, H. K., Chang, J. Y., Kim, Y. K., Lee, S. E., Kim, H.-W., Choi, H., Kim, D. S., Lee, J. H., Kim, K. S., Kim, H. J., Lee, C.-H., Oike, Y., Shong, M. Tags: Research Source Type: research
The effects of liraglutide in mice with diet-induced obesity studied by metabolomics
Liraglutide is the glucagon-like peptide-1 receptor agonist widely used for the treatment of type 2 diabetes mellitus. Recently, it has been demonstrated to decrease cardiovascular morbidity and mortality in patients with type 2 diabetes and high cardiovascular risk. Although the major modes of liraglutide action are well-known, its detailed action at the metabolic level has not been studied. To this end, we explored the effect of 2-week liraglutide treatment in C57BL/6 male mice with obesity and diabetes induced by 13 weeks of high-fat diet using NMR spectroscopy to capture the changes in urine metabolic profile induced b...
Source: Journal of Endocrinology - March 1, 2017 Category: Endocrinology Authors: Bugaňova, M., Pelantova, H., Holubova, M., Šediva, B., Maletinska, L., Železna, B., Kuneš, J., Kačer, P., Kuzma, M., Haluzik, M. Tags: Research Source Type: research
Sub-erythemal ultraviolet radiation reduces metabolic dysfunction in already overweight mice
Exposure to sunlight may limit cardiometabolic risk. In our previous studies, regular exposure to sub-erythemal (non-burning) ultraviolet radiation (UVR) reduced signs of adiposity and cardiometabolic dysfunction in mice fed a high-fat diet. Some of the observed effects were dependent on skin release of nitric oxide after UVR exposure. Here, we examine the effects of sub-erythemal UVR on signs of adiposity and metabolic dysfunction in already overweight mice, comparing the effects of two sunlamps with distinct emitted light spectra. Mice were fed a high-fat diet from 8 weeks of age, with UVR administered twice a week from ...
Source: Journal of Endocrinology - March 1, 2017 Category: Endocrinology Authors: Fleury, N., Feelisch, M., Hart, P. H., Weller, R. B., Smoothy, J., Matthews, V. B., Gorman, S. Tags: Research Source Type: research
Blockage of androgen and administration of estrogen induce transdifferentiation of testis into ovary
Induction of sex reversal of XY fish has been restricted to the sex undifferentiated period. In the present study, differentiated XY tilapia were treated with trilostane (TR), metopirone (MN) and glycyrrhetinic acid (GA) (inhibitor of 3β-HSD, Cyp11b2 and 11β-HSD, respectively) alone or in combination with 17β-estradiol (E2) from 30 to 90 dah (days after hatching). At 180 dah, E2 alone resulted in 8.3%, and TR, MN and GA alone resulted in no secondary sex reversal (SSR), whereas TR + E2, MN + E2 and GA + E2 resulted in 88.3, 60.0 and 46.7% of SSR, respectively. This sex reversal could be rescued by simultaneo...
Source: Journal of Endocrinology - March 1, 2017 Category: Endocrinology Authors: Shi, H., Gao, T., Liu, Z., Sun, L., Jiang, X., Chen, L., Wang, D. Tags: Research Source Type: research
Expression of concern
(Source: Journal of Endocrinology)
Source: Journal of Endocrinology - March 1, 2017 Category: Endocrinology Tags: Expression of concern Source Type: research
High fat feeding unmasks variable insulin responses in male C57BL/6 mouse substrains
Mouse models are widely used for elucidating mechanisms underlying type 2 diabetes. Genetic background profoundly affects metabolic phenotype; therefore, selecting the appropriate model is critical. Although variability in metabolic responses between mouse strains is now well recognized, it also occurs within C57BL/6 mice, of which several substrains exist. This within-strain variability is poorly understood and could emanate from genetic and/or environmental differences. To better define the within-strain variability, we performed the first comprehensive comparison of insulin secretion from C57BL/6 substrains 6J, 6JWehi, ...
Source: Journal of Endocrinology - February 22, 2017 Category: Endocrinology Authors: Hull, R. L., Willard, J. R., Struck, M. D., Barrow, B. M., Brar, G. S., Andrikopoulos, S., Zraika, S. Tags: Research Source Type: research
Mechanisms for PACAP-induced prolactin gene expression in grass carp pituitary cells
In mammals, pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic hormone with diverse functions but its role in prolactin (PRL) regulation is highly controversial. To shed light on Prl regulation by PACAP in fish model, grass carp pituitary cells was used as a model to examine the receptor specificity and signal transduction for PACAP modulation of prl gene expression in the carp pituitary. Using RT-PCR, PACAP-selective PAC1 receptor was detected in carp lactotrophs. In carp pituitary cells, nanomolar doses of PACAP, but not VIP, could elevate Prl secretion and protein production with concurrent rise...
Source: Journal of Endocrinology - February 22, 2017 Category: Endocrinology Authors: Lin, C., Jiang, X., He, M., Zhao, L., Huang, T., Bian, Z., Wong, A. O. L. Tags: Research Source Type: research
Tissue thyroid hormone metabolism is differentially regulated during illness in mice
Illness induces major modifications in central and peripheral thyroid hormone (TH) metabolism, so-called nonthyroidal illness syndrome (NTIS). As a result, organ-specific changes in local TH availability occur depending on the type and severity of illness. Local TH availability is of importance for the regulation of the tissue-specific TH target genes and determined by the interplay between deiodinating enzymes, TH transport and TH receptor (TR) expression. In the present study, we evaluated changes in TH transport, deiodination and TR expression, the resulting tissue TH concentrations and the expression of TH target genes...
Source: Journal of Endocrinology - February 22, 2017 Category: Endocrinology Authors: Boelen, A., van der Spek, A. H., Bloise, F., de Vries, E. M., Surovtseva, O. V., van Beeren, M., Ackermans, M. T., Kwakkel, J., Fliers, E. Tags: Research Source Type: research
Skeletal muscle insulin resistance: role of mitochondria and other ROS sources
At present, obesity is one of the most important public health problems in the world because it causes several diseases and reduces life expectancy. Although it is well known that insulin resistance plays a pivotal role in the development of type 2 diabetes mellitus (the more frequent disease in obese people) the link between obesity and insulin resistance is yet a matter of debate. One of the most deleterious effects of obesity is the deposition of lipids in non-adipose tissues when the capacity of adipose tissue is overwhelmed. During the last decade, reduced mitochondrial function has been considered as an important con...
Source: Journal of Endocrinology - February 22, 2017 Category: Endocrinology Authors: Di Meo, S., Iossa, S., Venditti, P. Tags: Review Source Type: research
Reduced metabolism in the hypothalamus of the anorectic anx/anx mouse
The anorectic anx/anx mouse exhibits a mitochondrial complex I dysfunction that is related to aberrant expression of hypothalamic neuropeptides and transmitters regulating food intake. Hypothalamic activity, i.e. neuronal firing and transmitter release, is dependent on glucose utilization and energy metabolism. To better understand the role of hypothalamic activity in anorexia, we assessed carbohydrate and high-energy phosphate metabolism, in vivo and in vitro, in the anx/anx hypothalamus. In the fasted state, hypothalamic glucose uptake in the anx/anx mouse was reduced by ~50% of that seen in wild-type (wt) mice (P < 0...
Source: Journal of Endocrinology - February 22, 2017 Category: Endocrinology Authors: Bergstrom, U., Lindfors, C., Svedberg, M., Johansen, J. E., Haggkvist, J., Schalling, M., Wibom, R., Katz, A., Nilsson, I. A. K. Tags: Research Source Type: research
A putative role for anti-Mullerian hormone (AMH) in optimising ovarian reserve expenditure
The mammalian ovary has a finite supply of oocytes, which are contained within primordial follicles where they are arrested in a dormant state. The number of primordial follicles in the ovary at puberty is highly variable between females of the same species. Females that enter puberty with a small ovarian reserve are at risk of a shorter reproductive lifespan, as their ovarian reserve is expected to be depleted faster. One of the roles of anti-Müllerian hormone (AMH) is to inhibit primordial follicle activation, which slows the rate at which the ovarian reserve is depleted. A simple interpretation is that the function...
Source: Journal of Endocrinology - February 22, 2017 Category: Endocrinology Authors: Pankhurst, M. W. Tags: Review Source Type: research
Hormone deprivation alters mitochondrial function and lipid profile in the hippocampus
In conclusion, chronic ovarian hormone deprivation induces mitochondrial dysfunction and changes in the mitochondrial membrane lipid profile comparable to an aging phenotype. Our study provides insights into ovarian hormone loss-induced early lipidomic changes with bioenergetic deficits in the hippocampus that may contribute to the increased risk of Alzheimer’s disease and other age-associated disorders observed in postmenopause. (Source: Journal of Endocrinology)
Source: Journal of Endocrinology - February 22, 2017 Category: Endocrinology Authors: Zarate, S., Astiz, M., Magnani, N., Imsen, M., Merino, F., Alvarez, S., Reines, A., Seilicovich, A. Tags: Research Source Type: research
Precocious glucocorticoid exposure reduces skeletal muscle satellite cells in the fetal rat
Perinatal skeletal muscle growth rates are a function of protein and myonuclear accretion. Precocious exposure of the fetus to glucocorticoids (GLC) in utero impairs muscle growth. Reduced muscle protein synthesis rates contribute to this response, but the consequences for myonuclear hyperplasia are unknown. To test the hypothesis that blunting of Pax7+ muscle progenitor cell proliferative activity by GLC in vivo also contributes to reduced fetal muscle growth, pregnant rats were administered dexamethasone (DEX: 1 mg/L drinking water) from embryonic day (ED) 13 to ED21. Their responses were compared to pair-fed (PF) and ad...
Source: Journal of Endocrinology - February 14, 2017 Category: Endocrinology Authors: Gokulakrishnan, G., Chang, X., Fleischmann, R., Fiorotto, M. L. Tags: Research Source Type: research
