Insulin receptor substrate signaling controls cardiac energy metabolism and heart failure
The heart is an insulin-dependent and energy-consuming organ in which insulin and nutritional signaling integrates to the regulation of cardiac metabolism, growth and survival. Heart failure is highly associated with insulin resistance, and heart failure patients suffer from the cardiac energy deficiency and structural and functional dysfunction. Chronic pathological conditions, such as obesity and type 2 diabetes mellitus, involve various mechanisms in promoting heart failure by remodeling metabolic pathways, modulating cardiac energetics and impairing cardiac contractility. Recent studies demonstrated that insulin recept...
Source: Journal of Endocrinology - May 15, 2017 Category: Endocrinology Authors: Guo, C. A., Guo, S. Tags: Review Source Type: research
Exposure to endocrine disruptors during adulthood: consequences for female fertility
Endocrine disrupting chemicals are ubiquitous chemicals that exhibit endocrine disrupting properties in both humans and animals. Female reproduction is an important process, which is regulated by hormones and is susceptible to the effects of exposure to endocrine disrupting chemicals. Disruptions in female reproductive functions by endocrine disrupting chemicals may result in subfertility, infertility, improper hormone production, estrous and menstrual cycle abnormalities, anovulation, and early reproductive senescence. This review summarizes the effects of a variety of synthetic endocrine disrupting chemicals on fertility...
Source: Journal of Endocrinology - May 15, 2017 Category: Endocrinology Authors: Rattan, S., Zhou, C., Chiang, C., Mahalingam, S., Brehm, E., Flaws, J. A. Tags: Review Source Type: research
Decrease in Ins+Glut2LO {beta}-cells with advancing age in mouse and human pancreas
The presence and location of resident pancreatic β-cell progenitors is controversial. A subpopulation of insulin-expressing but glucose transporter-2-low (Ins+Glut2LO) cells may represent multipotent pancreatic progenitors in adult mouse and in human islets, and they are enriched in small, extra-islet β-cell clusters (<5 β cells) in mice. Here, we sought to identify and compare the ontogeny of these cells in mouse and human pancreata throughout life. Mouse pancreata were collected at postnatal days 7, 14, 21, 28, and at 3, 6, 12, and 18 months of age, and in the first 28 days after β-cell mass deplet...
Source: Journal of Endocrinology - April 28, 2017 Category: Endocrinology Authors: Beamish, C. A., Mehta, S., Strutt, B. J., Chakrabarti, S., Hara, M., Hill, D. J. Tags: Research Source Type: research
Increased vimentin in human {alpha}- and {beta}-cells in type 2 diabetes
In conclusion, islet cell expression of vimentin indicates a degree of plasticity and dedifferentiation with potential loss of cellular identity in diabetes. This could contribute to α- and β-cell dysfunction in T2DM. (Source: Journal of Endocrinology)
Source: Journal of Endocrinology - April 28, 2017 Category: Endocrinology Authors: Roefs, M. M., Carlotti, F., Jones, K., Wills, H., Hamilton, A., Verschoor, M., Durkin, J. M. W., Garcia-Perez, L., Brereton, M. F., McCulloch, L., Engelse, M. A., Johnson, P. R. V., Hansen, B. C., Docherty, K., de Koning, E. J. P., Clark, A. Tags: Research Source Type: research
Hypophysectomy abolishes rhythms in rat thyroid hormones but not in the thyroid clock
The endocrine body rhythms including the hypothalamic–pituitary–thyroid axis seem to be regulated by the circadian timing system, and daily rhythmicity of circulating thyroid-stimulating hormone (TSH) is well established. The circadian rhythms are generated by endogenous clocks in the central brain oscillator located in the hypothalamic suprachiasmatic nucleus (SCN) as well as multiple peripheral clocks, but information on the existence and function of a thyroid clock is limited. The molecular machinery in all clock cells is composed of a number of clock genes and their gene products are connected by autoregula...
Source: Journal of Endocrinology - April 28, 2017 Category: Endocrinology Authors: Fahrenkrug, J., Georg, B., Hannibal, J., Jorgensen, H. L. Tags: Research Source Type: research
High-density lipoprotein (HDL) metabolism and bone mass
It is well appreciated that high-density lipoprotein (HDL) and bone physiology and pathology are tightly linked. Studies, primarily in mouse models, have shown that dysfunctional and/or disturbed HDL can affect bone mass through many different ways. Specifically, reduced HDL levels have been associated with the development of an inflammatory microenvironment that affects the differentiation and function of osteoblasts. In addition, perturbation in metabolic pathways of HDL favors adipoblastic differentiation and restrains osteoblastic differentiation through, among others, the modification of specific bone-related chemokin...
Source: Journal of Endocrinology - April 13, 2017 Category: Endocrinology Authors: Papachristou, N. I., Blair, H. C., Kypreos, K. E., Papachristou, D. J. Tags: Review Source Type: research
Dynamics of progesterone and estrogen receptor alpha in the ventromedial hypothalamus
Cyclic fluctuations of estradiol and progesterone in females influence neuronal activity in the ventrolateral division of the ventromedial hypothalamic nucleus (VMNvl), through the activation of progesterone receptors (PRs) and estrogen receptors (ERs). The expression of ER and PR in the VMNvl is influenced by their cognate ligands and is a central upstream trigger in the pathway of VMNvl-dependent modulation of endocrine responses. By studying the role played by estradiol and progesterone in PR and ERa expression in the VMNvl along the estrous cycle and how the two receptors interact in the same neuron, we aim to evaluate...
Source: Journal of Endocrinology - April 11, 2017 Category: Endocrinology Authors: Sa, S. I., Fonseca, B. M. Tags: Research Source Type: research
Mode of GH administration and gene expression in the female rat brain
In conclusion, the results indicate that there is a small but significant difference in response to mode of GH administration in the hippocampus as compared to the cortex. For both modes of GH administration, there was a robust effect on Hbb and Alas2. (Source: Journal of Endocrinology)
Source: Journal of Endocrinology - April 11, 2017 Category: Endocrinology Authors: Walser, M., Schioler, L., Oscarsson, J., Aberg, M. A. I., Wickelgren, R., Svensson, J., Isgaard, J., Aberg, N. D. Tags: Research Source Type: research
Attenuation of epidermal growth factor (EGF) signaling by growth hormone (GH)
Transgenic mice overexpressing growth hormone (GH) show increased hepatic protein content of the epidermal growth factor receptor (EGFR), which is broadly associated with cell proliferation and oncogenesis. However, chronically elevated levels of GH result in desensitization of STAT-mediated EGF signal and similar response of ERK1/2 and AKT signaling to EGF compared to normal mice. To ascertain the mechanisms involved in GH attenuation of EGF signaling and the consequences on cell cycle promotion, phosphorylation of signaling mediators was studied at different time points after EGF stimulation, and induction of proteins in...
Source: Journal of Endocrinology - March 31, 2017 Category: Endocrinology Authors: Gonzalez, L., Miquet, J. G., Irene, P. E., Diaz, M. E., Rossi, S. P., Sotelo, A. I., Frungieri, M. B., Hill, C. M., Bartke, A., Turyn, D. Tags: Research Source Type: research
Neurokinin B regulates reproduction via inhibition of kisspeptin in a teleost, the striped bass
Kisspeptin and neurokinin B (NKB) are neuropeptides co-expressed in the mammalian hypothalamus and coordinately control GnRH signaling. We have found that Nkb and kisspeptin neurons are distinct in the teleost, striped bass (STB) and capitalized on this phenomenon to study the mode of action of Nkb and its related neuropeptide-F (Nkf), both of which are encoded by the tac3 gene. In vitro brain slices and in vivo administration studies revealed that Nkb/f consistently downregulated kiss2, whereas antagonist (AntD) administration restored this effect. Overall, a minor effect was noted on gnrh1 expression, whereas Gnrh1 conte...
Source: Journal of Endocrinology - March 27, 2017 Category: Endocrinology Authors: Zmora, N., Wong, T.-T., Stubblefield, J., Levavi-Sivan, B., Zohar, Y. Tags: Research Source Type: research
Gja1 acts downstream of Acvr1 to regulate uterine decidualization via Hand2 in mice
Although Gja1 has been proved to play an important role in uterine decidualization, its regulatory mechanism remains largely unknown. Here, we showed that Gja1 was highly expressed in the decidual cells and promoted the proliferation of uterine stromal cells and expression of Prl8a2 and Prl3c1, which were two well-known differentiation markers for decidualization. Further analysis revealed that Gja1 might act downstream of Acvr1 and cAMP to regulate the differentiation of uterine stromal cells. Administration of cAMP analog 8-Br-cAMP to Acvr1 siRNA-transfected stromal cells resulted in an obvious increase of Gja1 expressio...
Source: Journal of Endocrinology - March 20, 2017 Category: Endocrinology Authors: Yu, H.-F., Yue, Z.-P., Wang, K., Yang, Z.-Q., Zhang, H.-L., Geng, S., Guo, B. Tags: Research Source Type: research
Akt signaling as a mediator of cardiac adaptation to low birth weight
Intrauterine insults, such as poor nutrition and placental insufficiency, can alter cardiomyocyte development, and this can have significant long-term implications for heart health. Consequently, epidemiological studies have shown that low-birth-weight babies have an increased risk of death from cardiovascular disease in adult life. In addition, intrauterine growth restriction can result in increased left ventricular hypertrophy, which is the strongest predictor for poor health outcomes in cardiac patients. The mechanisms responsible for these associations are not clear, but a suboptimal intrauterine environment can progra...
Source: Journal of Endocrinology - March 20, 2017 Category: Endocrinology Authors: Wang, K. C. W., Botting, K. J., Zhang, S., McMillen, I. C., Brooks, D. A., Morrison, J. L. Tags: Review Source Type: research
FoxO integration of insulin signaling with glucose and lipid metabolism
The forkhead box O family consists of FoxO1, FoxO3, FoxO4 and FoxO6 proteins in mammals. Expressed ubiquitously in the body, the four FoxO isoforms share in common the amino DNA-binding domain, known as ‘forkhead box’ domain. They mediate the inhibitory action of insulin or insulin-like growth factor on key functions involved in cell metabolism, growth, differentiation, oxidative stress, senescence, autophagy and aging. Genetic mutations in FoxO genes or abnormal expression of FoxO proteins are associated with metabolic disease, cancer or altered lifespan in humans and animals. Of the FoxO family, FoxO6 is the ...
Source: Journal of Endocrinology - March 20, 2017 Category: Endocrinology Authors: Lee, S., Dong, H. H. Tags: Review Source Type: research
Continuous model of conceptus implantation to the maternal endometrium
As placental morphology as well as trophoblast characteristics exhibit wide diversity across mammalian species, underling molecules were also thought to vary greatly. In the majority of cases, however, regardless of the mode of implantation, physiological and biochemical processes in conceptus implantation to the maternal endometrium including the kinds of gene expression and their products are now considered to share many similarities. In fact, recent progress has identified that in addition to the hormones, cytokines, proteases and cell adhesion molecules classically characterized, molecules related to lymphocyte homing ...
Source: Journal of Endocrinology - March 15, 2017 Category: Endocrinology Authors: Imakawa, K., Bai, R., Fujiwara, H., Ideta, A., Aoyagi, Y., Kusama, K. Tags: Review Source Type: research
Metformin and thyroid disease
An intriguing area of research in thyroidology is the recently discovered association of insulin resistance with thyroid functional and morphological abnormalities. Individuals with hyperinsulinemia have larger thyroid gland and a higher prevalence of thyroid nodules and cancer. Accordingly, patients treated with metformin have a smaller thyroid volume and a lower risk of incident goiter, thyroid nodule and cancer. Multiple studies in vitro and in vivo have demonstrated that metformin can inhibit the growth of thyroid cells and different types of thyroid cancer cells by affecting the insulin/IGF1 and mTOR pathways. Besides...
Source: Journal of Endocrinology - March 15, 2017 Category: Endocrinology Authors: Meng, X., Xu, S., Chen, G., Derwahl, M., Liu, C. Tags: Review Source Type: research
