MRI Radiomics Features of Adenohypophysis Determine the Activation of Hypothalamic-Pituitary-Gonadal Axis in Peri-Puberty Children

BACKGROUND

The status of the hypothalamic-pituitary-gonadal (HPG) axis is important for assessing the onset of physiological or pathological puberty. The reference standard gonadotropin-releasing hormone (GnRH) stimulation test requires hospital admission and repeated blood samples. A simple noninvasive method would be beneficial.

OBJECTIVES

To explore a noninvasive method for evaluating HPG axis activation in children using an MRI radiomics model.

STUDY TYPE

Retrospective.

POPULATION

Two hundred thirty-nine children (83 male; 3.6-14.6 years) with hypophysial MRI and GnRH stimulation tests, randomly divided a training set (168 children) and a test set (71 children).

FIELD STRENGTH/SEQUENCE

3.0 T, 3D isotropic fast spin echo (CUBE) T1-weighted imaging (T1WI) sequences.

ASSESSMENT

Radiomics features were extracted from sagittal 3D CUBE T1WI, and imaging signatures were generated using the least absolute shrinkage and selection operator (LASSO) with 10-fold cross-validation. Diagnostic performance for differential diagnosis of HPG status was compared between a radiomics model and MRI features (adenohypophyseal height [aPH] and volume [aPV]).

STATISTICAL TESTS

Receiver operating characteristic (ROC) and decision curve analysis (DCA). A P value <0.05 was considered statistically significant.

RESULTS

Eight hundred fifty-one radiomics features were extracted and reduced to 10 by the LASSO method in the training cohort. The radiomics model based on CUBE T1WI showed good performance in assessment of HPG axis activation with an area under the ROC curve (AUC) of 0.81 (95% CI: 0.71, 0.91) in the test set. The AUC of the radiomics model was significantly higher than that of aPH (0.81 vs. 0.65) but there was no significant difference compared to aPV (0.81 vs. 0.78, P = 0.58). In DCA analysis, the radiomics signature showed higher net benefit over the aPV and aPH models.

DATA CONCLUSIONS

The MRI radiomics model has potential to assess HPG axis activation status noninvasively, potentially providing valuable information in the diagnosis of patients with pathological puberty onset.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 2.

Integrated untargeted and targeted testicular metabolomics to reveal the regulated mechanism of Gushudan on the hypothalamic-pituitary-gonadal axis of kidney-yang-deficiency-syndrome rats

Modern studies have shown that neuroendocrine disorders caused by the dysfunction of the hypothalamic-pituitary-gonadal (HPG) axis are one of the important pathogenetic mechanisms of kidney-yang-deficiency-syndrome (KYDS). The preventive effect of Gushudan on KYDS has been reported, but its regulatory mechanisms on the HPG axis have not been elucidated. In this study, we developed an integrated untargeted and targeted metabolomics analysis strategy to investigate the regulatory mechanism of Gushudan on the HPG axis in rats with KYDS. In untargeted metabolomics, we screened 14 potential biomarkers such as glycine, lysine, and glycerol that were significantly associated with the HPG axis. To explore the effect of changes in the levels of potential biomarkers on KYDS, all of them were quantified in targeted metabolomics. With the quantitative results, correlations between potential biomarkers and testosterone, a functional indicator of the HPG axis, were explored. The results showed that oxidative stress, inflammatory response, and energy depletion, induced by metabolic disorders in rats, were responsible for the decrease in testosterone levels. Gushudan improves metabolic disorders and restores testosterone levels, thus restoring HPG axis dysfunction. This finding elucidates the special metabolic characteristics of KYDS and the therapeutic mechanism of Gushudan from a new perspective.

Effect of relaxin-3 on Kiss-1, gonadotropin-releasing hormone, and gonadotropin subunit gene expression

PURPOSE

Relaxin-3 is a hypothalamic neuropeptide that belongs to the insulin superfamily. We examined whether relaxin-3 could affect hypothalamic Kiss-1, gonadotropin-releasing hormone (GnRH), and pituitary gonadotropin subunit gene expression.

METHODS

Mouse hypothalamic cell models, mHypoA-50 (originated from the hypothalamic anteroventral periventricular region), mHypoA-55 (originated from arcuate nucleus), and GT1-7, and the mouse pituitary gonadotroph LβT2 were used. Expression of Kiss-1, GnRH, and luteinizing hormone (LH)/follicle-stimulating hormone (FSH) β-subunits was determined after stimulation with relaxin-3.

RESULTS

RXFP3, a principle relaxin-3 receptor, was expressed in these cell models. In mHypoA-50 cells, relaxin-3 did not exert a significant effect on Kiss-1 expression. In contrast, the Kiss-1 gene in mHypoA-55 was significantly increased by 1 nmol/L relaxin-3. These cells also express GnRH mRNA, and its expression was significantly stimulated by relaxin-3. In GT1-7 cells, relaxin-3 significantly upregulated Kiss-1 expression; however, GnRH mRNA expression in GT1-7 cells was not altered. In primary cultures of fetal rat neuronal cells, 100 nmol/L relaxin-3 significantly increased GnRH expression. In pituitary gonadotroph LβT2, both LHβ- and FSHβ-subunit were significantly increased by 1 nmol/L relaxin-3.

CONCLUSIONS

Our findings suggest that relaxin-3 exerts its effect by modulating the expression of Kiss-1, GnRH, and gonadotropin subunits, all of which are part of the hypothalamic-pituitary-gonadal axis.

Animal models of polycystic ovary syndrome: A review of hormone-induced rodent models focused on hypothalamus-pituitary-ovary axis and neuropeptides

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disorder among women of reproductive age and a major cause of infertility; however, the pathophysiology of this syndrome is not fully understood. This can be addressed using appropriate animal models of PCOS. In this review, we describe rodent models of hormone-induced PCOS that focus on the perturbation of the hypothalamic-pituitary-ovary (HPO) axis and abnormalities in neuropeptide levels.

METHODS

Comparison of rodent models of hormone-induced PCOS.

MAIN FINDINGS

The main method used to generate rodent models of PCOS was subcutaneous injection or implantation of androgens, estrogens, antiprogestin, or aromatase inhibitor. Androgens were administered to animals pre- or postnatally. Alterations in the levels of kisspeptin and related molecules have been reported in these models.

CONCLUSION

The most appropriate model for the research objective and hypothesis should be established. Dysregulation of the HPO axis followed by elevated serum luteinizing hormone levels, hyperandrogenism, and metabolic disturbance contribute to the complex etiology of PCOS. These phenotypes of the human disease are recapitulated in hormone-induced PCOS models. Thus, evidence from animal models can help to clarify the pathophysiology of PCOS.