Τρίτη 12 Νοεμβρίου 2019

Multifactorial control of reproductive and growth axis in male goldfish: Influences of GnRH, GnIH and thyroid hormone
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Y. Ma, C. Ladisa, J.P. Chang, H.R. Habibi
Abstract
Reproduction and growth are under multifactorial control of neurohormones and peripheral hormones. This study investigated seasonally related effects of GnIH, GnRH, and T3 on the reproductive and growth axis in male goldfish at three stages of gonadal recrudescence. The effects of injection treatments with GnRH, GnIH and/or T3 were examined by measuring serum LH and GH levels, as well as peripheral transcript levels, using a factorial design. As expected, GnRH elevated serum LH and GH levels in a seasonally dependant manner, with maximal elevations of LH in late stages of gonadal recrudescence (Spring) and maximal increases in GH in the regressed gonadal stage (Summer). GnIH injection increased serum LH and GH levels only in fish at the regressed stage but exerted both stimulatory and inhibitory effects on GnRH-induced LH responses depending on season. T3 treatment mainly had stimulatory effects on circulating LH levels and inhibitory effects on serum GH concentrations. In the liver and testes, we observed seasonal differences in thyroid receptors, estrogen receptors, vitellogenin, follicle-stimulating hormone receptor, aromatase and IGF-I transcript levels that were tissue- and sex-specific. Generally, there were no clear correlation between circulating LH and GH levels and peripheral transcript levels, presumably due to time-related response and possible direct interaction of GnRH and GnIH at the level of liver and testis. The results support the hypothesis that GnRH and GnIH are important components of multifactorial mechanisms that work in concert with T3 to regulate reciprocal control of reproduction and growth in goldfish.

Disposing of misfolded ER proteins: A troubled substrate's way out of the ER
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Christina Oikonomou, Linda M. Hendershot
Abstract
Secreted, plasma membrane, and resident proteins of the secretory pathway are synthesized in the endoplasmic reticulum (ER) where they undergo post-translational modifications, oxidative folding, and subunit assembly in tightly monitored processes. An ER quality control (ERQC) system oversees protein maturation and ensures that only those reaching their native state will continue trafficking into the secretory pathway to reach their final destinations. Those that fail must be recognized and eliminated to maintain ER homeostasis. Two cellular mechanisms have been identified to rid the ER of terminally unfolded, misfolded, and aggregated proteins. ER-associated degradation (ERAD) was discovered nearly 30 years ago and entails the identification of improperly matured secretory pathway proteins and their retrotranslocation to the cytosol for degradation by the ubiquitin-proteasome system. ER-phagy has been more recently described and caters to larger, more complex proteins and protein aggregates that are not readily handled by ERAD. This pathway has unique upstream components and relies on the same downstream effectors of autophagy used in other cellular processes to deliver clients to lysosomes for degradation. In this review, we describe the main elements of ERQC, ERAD, and ER-phagy and focus on recent advances in these fields.

Testosterone induces up-regulation of mitochondrial gene expression in murine C2C12 skeletal muscle cells accompanied by an increase of nuclear respiratory factor-1 and its downstream effectors
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Lucía Pronsato, Lorena Milanesi, Andrea Vasconsuelo
Abstract
The reduction in muscle mass and strength with age, sarcopenia, is a prevalent condition among the elderly, linked to skeletal muscle dysfunction and cell apoptosis. We demonstrated that testosterone protects against H2O2-induced apoptosis in C2C12 muscle cells. Here, we analyzed the effect of testosterone on mitochondrial gene expression in C2C12 skeletal muscle cells. We found that testosterone increases mRNA expression of genes encoded by mitochondrial DNA, such as NADPH dehydrogenase subunit 1 (ND1), subunit 4 (ND4), cytochrome b (CytB), cytochrome c oxidase subunit 1 (Cox1) and subunit 2 (Cox2) in C2C12. Additionally, the hormone induced the expression of the nuclear respiratory factors 1 and 2 (Nrf-1 and Nrf-2), the mitochondrial transcription factors A (Tfam) and B2 (TFB2M), and the optic atrophy 1 (OPA1). The simultaneous treatment with testosterone and the androgen receptor antagonist, Flutamide, reduced these effects. H2O2-oxidative stress induced treatment, significantly decreased mitochondrial gene expression. Computational analysis revealed that mitochondrial DNA contains specific sequences, which the androgen receptor could recognize and bind, probably taking place a direct regulation of mitochondrial transcription by the receptor. These findings indicate that androgen plays an important role in the regulation of mitochondrial transcription and biogenesis in skeletal muscle.

Curcumin-activated autophagy plays a negative role in its anti-osteoclastogenic effect
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Dianshan Ke, Yu Wang, Yunlong Yu, Yongxuan Wang, Wang Zheng, Xiaomin Fu, Junyong Han, Guoyou Zhang, Jie Xu
Abstract
Background/purpose
It remains unclear what role curcumin plays in the autophagy of osteoclast precursors (OCPs) during osteoclastogenesis, since some researchers found that curcumin has the ability to inhibit osteoclastogenesis. While others have considered it as an autophagy activator. This study aimed to determine the effect of curcumin-regulated autophagy on osteoclastogenesis.
Results
The results revealed that direct administration of curcumin enhanced the OCP autophagy response in bone marrow-derived macrophages (BMMs). Curcumin could also abate RANKL's stimulatory effect on OCP autophagy and osteoclastogenesis. Autophagic suppression related to pharmacological inhibitors or gene silencing could further enhance the inhibitory effect of curcumin on osteoclastogenesis. As expected, curcumin ameliorated ovariectomy (OVX)-induced bone loss and its effect could be promoted by an autophagy inhibitor (chloroquine).
Conclusions
In conclusion, curcumin can directly enhance the autophagic activity of OCPs, which inhibits its anti-osteoclastogeneic effects. Autophagy inhibition-based drugs are expected to enhance curcumin's efficacy in treating osteoporosis.

The impact of progesterone and RU-486 on classic pro-labour proteins & contractility in human myometrial tissues during 24-hour exposure to tension & Interleukin-1β
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Pei F. Lai, Ektoras X. Georgiou, Rachel M. Tribe, Mark R. Johnson
Abstract
Increased expression of pro-labour genes that encode cyclooxygenase-2 (COX-2), oxytocin receptor (OTR) and connexin-43 (Cx43) at parturition is often attributed to P4 functional withdrawal, based on findings from animal models and human primary myometrial cells. However, the cause of reduced myometrial P4 responsiveness that promotes contractions at labour is not fully determined. Uterine stretch occurs with advancing gestation but most in vitro experimental models do not take this into consideration. We aimed to examine whether tissue-level myometrial stretch influences the ability of P4 to regulate pro-labour protein abundance by using myometrial biopsies from term gestation pregnant women to assess the impact of 24 h exposure to combinations of (i) stretch-mediated tension, (ii) P4 (100 nM) and (iii) an anti-progestin, RU-486 (1 μM). Firstly, we observed baseline COX-2 and Cx43 protein levels increased, whereas P4 content along with calponin-1 and progesterone receptor (PR) protein abundance decreased, in vehicle-treated tissues. P4 supplementation subtly reduced COX-2 levels in un-stretched tissues. Spontaneous and oxytocin-augmented contractility were unchanged by tissue culture exposure to P4 and/or RU-486. Interleukin-1β (IL-1β; 1 ng/ml) enhanced COX-2 protein and PGE2 content in un-stretched tissues. Overall, tissue stretch may, in part, regulate P4-sensitive pro-labour protein levels, but this is likely to be reliant on interaction with other in utero factors that were absent in our tissue cultures. More complex culture conditions should be evaluated in future to aid further development of a physiologically relevant model to improve our understanding of in utero myometrial P4 responsiveness.

Inhibition of LncRNA FOXD3-AS1 suppresses the aggressive biological behaviors of thyroid cancer via elevating miR-296-5p and inactivating TGF-β1/Smads signaling pathway
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Yonghui Chen, Hongbo Gao, Yaomei Li
Abstract
Background
Thyroid cancer is the most common malignant tumor with relatively high incidence and mortality in endocrine system. Research about thyroid cancer-related targets is the basis for the diagnosis of thyroid cancer and the development of new drugs. However, the predictive value of long non-coding RNA (lncRNA) for the diagnosis and prognosis of thyroid cancer is still in the preliminary stage of exploration. Thus, we for the first time investigated the effects and associated regulatory mechanism of lncRNA Forkhead box D3 antisense RNA 1 (FOXD3-AS1) in thyroid cancer in vitro and in vivo.
Methods
Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression of lncRNA FOXD3-AS1 and miR-296-5p. Cell proliferation was detected through colony formation assay. Cell cycle was analyzed through flow cytometry. Cell mobility was valued through transwell invasion assay and wound healing assay. Western blotting was used to examine the expression of proteins related to cell proliferation and cell migration and TGF-β1/Smads signaling pathway. Luciferase reporter assay was used to verify the targeting relationship between FOXD3-AS1 and miR-296-5p. Tumor xenograft model was established and immunohistochemistry (IHC) was used to examine the expression of Ki67 and VEGF.
Results
We found that the expression of lncRNA FOXD3-AS1was upregulated and it had negative correlation with the level of miR-296-5p in thyroid cancer tissues and cells. LncRNA FOXD3-AS1 knockdown effectively suppressed cell proliferation and cell invasion in vitro. Further study revealed that miR-296-5p was a target of lncRNA FOXD3-AS1 and FOXD3-AS1 exerted anti-tumor effect through up-regulating miR-296-5p. Moreover, we found that FOXD3-AS1 knockdown suppressed the aggressive biological behaviors of thyroid cancer through inactivating the TGF-β1/Smads signaling pathway. Subsequently, the in vivo experiments further verified that the FOXD3-AS1/miR-296-5p axis exerted obvious anti-tumor effect through inhibiting tumor growth and metastasis and the TGF-β1/Smads signaling pathway was also inactivated in vivo by the inhibition of FOXD3-AS1.
Conclusion
Inhibition of LncRNA FOXD3-AS1 suppresses the aggressive biological behaviors of thyroid cancer via elevating miR-296-5p and inactivating TGF-β1/Smads signaling pathway.

Metformin alleviates oxidative stress and enhances autophagy in diabetic kidney disease via AMPK/SIRT1-FoxO1 pathway
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Huiwen Ren, Ying Shao, Can Wu, Xiaoyu Ma, Chuan Lv, Qiuyue Wang
Abstract
Metformin, as the basic pharmacological therapy and the first preventive drug in type 2 diabetes mellitus (T2DM), is proved to have potential protection in diabetic kidney disease (DKD). Here, we established a diabetic rat model induced by high-fat diet and low dose streptozotocin, and high glucose cultured rat mesangial cells (RMCs) pre-treated with metformin or transfected with AMPK, SIRT1 and FoxO1 small interfering RNA, and detected oxidative stress and autophagy related factors to explore the molecular mechanisms of metformin on DKD via adenosine monophosphate-activated protein kinase (AMPK)/silent mating type information regulation 2 homolog-1 (sirtuin-1, SIRT1)-Forkhead box protein O1 (FoxO1) pathway. We found that metformin effectively alleviated the disorders of glycolipid metabolism, renal function injury in diabetic rats, and relieved oxidative stress, enhanced autophagy and slowed down abnormal cell proliferation in high glucose cultured RMCs through AMPK/SIRT1-FoxO1 pathway, indicating the protective role of metformin against the pathological process of DKD.

Type 1 diabetes affects zona pellucida and genome methylation in oocytes and granulosa cells
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Li Li, Ying Jing, Ming-Zhe Dong, Li-Hua Fan, Qian-Nan Li, Zhen-Bo Wang, Yi Hou, Heide Schatten, Cui-Lian Zhang, Qing-Yuan Sun
Abstract
Diabetes affects oocyte nuclear and cytoplasmic quality. In this study, we generated a type 1 diabetes (T1D) mouse model by STZ injection to study the effects of T1D on zona pellucida and genomic DNA methylation of oocytes and granulosa cells. T1D mice showed fewer ovulated oocytes, reduced ovarian reserve, disrupted estrus cycle, and significantly ruptured zona pellucida in 2-cell in vivo embryos compared to controls. Notably, diabetic oocytes displayed thinner zona pellucida and treatment of oocytes with high concentration glucose reduced the zona pellucida thickness. Differential methylation genes in oocytes and granulosa cells were analyzed by methylation sequencing. These genes were significantly enriched in GO terms by GO analysis, and these GO terms were involved in multiple aspects of growth and development. Most notably, the abnormal methylation genes in oocytes may be related to oocyte zona pellucida changes in diabetic mice. These findings provide novel basic data for further understanding and elucidating dysgenesis and epigenetic changes in type 1 diabetes mellitus.

Genome-wide methylation profiling in granulosa lutein cells of women with polycystic ovary syndrome (PCOS)
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): E. Makrinou, A.W. Drong, G. Christopoulos, A. Lerner, I. Chapa-Chorda, T. Karaderi, S. Lavery, K. Hardy, C.M. Lindgren, S. Franks
Abstract
Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder amongst women of reproductive age, whose aetiology remains unclear. To improve our understanding of the molecular mechanisms underlying the disease, we conducted a genome-wide DNA methylation profiling in granulosa lutein cells collected from 16 women suffering from PCOS, in comparison to 16 healthy controls. Samples were collected by follicular aspiration during routine egg collection for IVF treatment. Study groups were matched for age and BMI, did not suffer from other disease and were not taking confounding medication.
Comparing women with polycystic versus normal ovarian morphology, after correcting for multiple comparisons, we identified 106 differentially methylated CpG sites with p-values <5.8 × 10−8 that were associated with 88 genes, several of which are known to relate either to PCOS or to ovarian function. Replication and validation of the experiment was done using pyrosequencing to analyse six of the identified differentially methylated sites. Pathway analysis indicated potential disruption in canonical pathways and gene networks that are, amongst other, associated with cancer, cardiogenesis, Hedgehog signalling and immune response. In conclusion, these novel findings indicate that women with PCOS display epigenetic changes in ovarian granulosa cells that may be associated with the heterogeneity of the disorder.

Neuroendocrine, autocrine, and paracrine control of follicle-stimulating hormone secretion
Publication date: 15 January 2020
Source: Molecular and Cellular Endocrinology, Volume 500
Author(s): Vasantha Padmanabhan, Rodolfo C. Cardoso
Abstract
Follicle-stimulating hormone (FSH) is a glycoprotein hormone produced by gonadotropes in the anterior pituitary that plays a central role in controlling ovarian folliculogenesis and steroidogenesis in females. Moreover, recent studies strongly suggest that FSH exerts extragonadal actions, particularly regulating bone mass and adiposity. Despite its crucial role, the mechanisms regulating FSH secretion are not completely understood. It is evident that hypothalamic, ovarian, and pituitary factors are involved in the neuroendocrine, paracrine, and autocrine regulation of FSH production. Large animal models, such as the female sheep, represent valuable research models to investigate specific aspects of FSH secretory processes. This review: (i) summarizes the role of FSH controlling reproduction and other biological processes; (ii) discusses the hypothalamic, gonadal, and pituitary regulation of FSH secretion; (iii) considers the biological relevance of the different FSH isoforms; and (iv) summarizes the distinct patterns of FSH secretion under different physiological conditions.

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