17β-Estradiol attenuates p38MAPK activity but not PKCα induced by angiotensin II in the brain

Inhibition of salty taste and sodium appetite by estrogens in spontaneously hypertensive rats

Estrogen has a well-known effect of reducing salt intake in rats. This mini review focuses on recent findings regarding the interaction of estradiol with brain angiotensin II to control increased sodium palatability that occurs as a result of sodium appetite in spontaneously hypertensive rats.

Naoxintong Capsule Activates the Nrf2/HO-1 Signaling Pathway and Suppresses the p38α Signaling Pathway Via Estrogen Receptors to Ameliorate Heart Remodeling in Female Mice With Postmenopausal Hypertension

ABSTRACT

Limited treatments are available for alleviating heart remodeling in postmenopausal hypertension. The cardioprotective effect of naoxintong (NXT) has been widely accepted. This study aimed to explore the effects of NXT on pathological heart remodeling in a postmenopausal hypertension mouse model in vivo and H9c2 cardiomyocytes in vitro. In vivo, ovariectomy combined with chronic angiotensin II infusion was used to establish the postmenopausal hypertension animal model. NXT significantly ameliorated cardiac remodeling as indicated by a reduced ratio of heart weight/body weight and left ventricle weight/body weight, left ventricular wall thickness, diameter of cardiomyocytes, and collagen deposition in the heart. NXT also significantly increased the expression of estrogen receptors (ERs) and downregulated the expression of nicotinamide adenine dinucleotide phosphate oxidase 2 (Nox2). In vitro, NXT treatment greatly suppressed angiotensin II-induced cardiac hypertrophy, cardiac fibrosis, and excessive oxidative stress as proven by reducing the diameter of H9c2 cardiomyocytes, expression of hypertrophy and fibrosis markers, intracellular reactive oxygen species, and oxidative enzymes. Mechanistically, NXT significantly upregulated the expression of ERs, which activated the Nrf2/HO-1 signaling pathway and inhibited the phosphorylation of the p38α pathway. Collectively, the results indicated that NXT administration might attenuate cardiac remodeling through upregulating the expression of ERs, which activated the Nrf2/HO-1 signaling pathway, inhibited the phosphorylation of the p38α signaling pathway, and reduced oxidative stress.

Screening and Validation of p38 MAPK Involved in Ovarian Development of Brachymystax lenok

Brachymystax lenok (lenok) is a rare cold-water fish native to China that is of high meat quality. Its wild population has declined sharply in recent years, and therefore, exploring the molecular mechanisms underlying the development and reproduction of lenoks for the purposes of artificial breeding and genetic improvement is necessary. The lenok comparative transcriptome was analyzed by combining single molecule, real-time, and next generation sequencing (NGS) technology. Differentially expressed genes (DEGs) were identified in five tissues (head kidney, spleen, liver, muscle, and gonad) between immature [300 days post-hatching (dph)] and mature [three years post-hatching (ph)] lenoks. In total, 234,124 and 229,008 full-length non-chimeric reads were obtained from the immature and mature sequencing data, respectively. After NGS correction, 61,405 and 59,372 non-redundant transcripts were obtained for the expression level and pathway enrichment analyses, respectively. Compared with the mature group, 719 genes with significantly increased expression and 1,727 genes with significantly decreased expression in all five tissues were found in the immature group. Furthermore, DEGs and pathways involved in the endocrine system and gonadal development were identified, and p38 mitogen-activated protein kinases (MAPKs) were identified as potentially regulating gonadal development in lenok. Inhibiting the activity of p38 MAPKs resulted in abnormal levels of gonadotropin-releasing hormone, follicle-stimulating hormone, and estradiol, and affected follicular development. The full-length transcriptome data obtained in this study may provide a valuable reference for the study of gene function, gene expression, and evolutionary relationships in B. lenok and may illustrate the basic regulatory mechanism of ovarian development in teleosts.

Effects of gonadotropin inducible ovarian transcription factor 1 in the paraventricular nucleus on fluid intake after dehydration of ovariectomized female rats

NEW FINDINGS

What is the central question of this study? Giot1, the gene for gonadotropin inducible ovarian transcription factor 1 (GIOT1), is upregulated in osmotically challenged rats: does Giot1 gene expression in the paraventricular nucleus have a role in controlling fluid intake following dehydration and what is the role of ovarian hormones in the modulation of GIOT1 actions? What is the main finding and its importance? GIOT1 acts to regulate water and salt intake as well as hormone secretion after dehydration. The identification of genes that participate in the hormone and behavioural responses involved with hydromineral homeostasis is essential for future exploration of novel drug targets for the treatment of metabolic disease.

ABSTRACT

In order to maintain body fluid balance after dehydration, hypothalamic neurons of the paraventricular nucleus (PVN) are activated to promote secretion of vasopressin (AVP) and oxytocin (OXT) from the neurohypophysis, and to modulate the behavioural allostatic responses of thirst and salt appetite. Gonadotropin inducible transcription factor (GIOT1) is a Krüppel-type zinc finger protein induced by gonadotropins and oestradiol (E2). This transcription factor is expressed in the hypothalamus, specifically in the PVN where expression of Giot1 mRNA increases following hydromineral challenges such as water deprivation or salt loading, although its physiological role is not clear. We hypothesize that GIOT1 has a central role in the integrated homeostatic and allostatic responses to disturbances in hydromineral balance, especially in the presence of female gonadal hormones. Female rats with intact ovaries or ovariectomized rats were subjected to specific microinjection of a lentiviral vector mediating Giot1 knockdown in the PVN. Three weeks after injection, rats were subjected to 48 h water deprivation, and thereafter water and salt intake were evaluated. Giot1 knockdown in PVN reduced water and saline intake as well as AVP and OXT secretion. Furthermore, Giot1 knockdown had profound effects on gene expression in the PVN, reducing the abundance of transcripts encoded by the Avp, Oxt, Nr4a1 and Crh genes. In conclusion, the present study shows for the first time that GIOT1 in the PVN regulates both transcription and fluid intake, although any connection to ovarian hormones remains to be established.

Level of sex hormones and their association with acetylsalicylic acid intolerance and nasal polyposis

BACKGROUND

Chronic rhinosinusitis may be associated with nasal polyposis. Recurrence of disease is often observed and may be due to an intolerance of acetylsalicylic acid. Sex hormones are known to modulate allergic reactions and inflammation. Whether they may be involved in the development and progression of nasal polyposis has not been investigated yet.

AIM

Examine the relationship between levels of sex hormones and nasal polyposis.

METHODS

Hormonal levels (estradiol, testosterone and progesterone) in patients with nasal polyposis (n = 26) with or without acetylsalicylic acid-intolerance were determined and compared to hormonal levels in patients with septal deviation (n = 35). Cone-beam computed tomography scans were analysed by using scores as defined by Lund and Mackay and by Kennedy.

RESULTS

Our results show a 5 times greater odds (p = 0.01) for developing nasal polyposis in the presence of lowered estradiol plasma levels than in the presence of normal / elevated levels. When analyzing females and males separately, a 6 times greater odds for females to develop nasal polyposis in the presence of lowered estradiol plasma levels was calculated (p = 0.02). Thus, females are more likely to develop nasal polyposis when they have lowered estradiol levels than males. In addition, female patients showed an increased risk for developing ASA intolerance (p = 0.01).

CONCLUSION

Variation of sex hormones may be involved in nasal polyposis. Further studies including more patients to validate the presented results are required.

SIGNIFICANCE

Retrospective clinical investigation suggesting a correlation between varying sex hormones and nasal polyposis.