Endocrine Disorder in Patients With Craniopharyngioma

Craniopharyngioma is an intracranial congenital epithelial tumor growing along the pathway of the embryonic craniopharyngeal tube. The main clinical symptoms of patients with craniopharyngioma include high intracranial pressure, visual field defect, endocrine dysfunction, and hypothalamic dysfunction. At present, the preferred treatment remains the surgical treatment, but the recovery of endocrine and hypothalamic function following surgery is limited. In addition, endocrine disorders often emerge following surgery, which seriously reduces the quality of life of patients after operation. So far, research on craniopharyngioma focuses on ways to ameliorate endocrine dysfunction. This article reviews the latest research progress on pathogenesis, manifestation, significance, and treatment of endocrine disorders in patients with craniopharyngioma.

A propensity-adjusted comparison of endoscopic endonasal surgery versus transcranial microsurgery for pediatric craniopharyngioma: a single-center study

OBJECTIVE When comparing endoscopic endonasal surgery (EES) and transcranial microsurgery (TCM) for adult and mixed-age population craniopharyngiomas, EES has become an alternative to TCM. To date, studies comparing EES and TCM for pediatric craniopharyngiomas are sparse. In this study, the authors aimed to compare postoperative complications and surgical outcomes between EES and TCM for pediatric craniopharyngiomas. METHODS The data of pediatric patients with craniopharyngiomas who underwent surgery between February 2009 and June 2021 at a single center were retrospectively reviewed. All included cases were divided into EES and TCM groups according to the treatment modality received. The baseline characteristics of patients were compared between the groups, as well as surgical results, perioperative complications, and long-term outcomes. To control for confounding factors, propensity-adjusted analysis was performed. RESULTS Overall, 51 pediatric craniopharyngioma surgeries were identified in 49 patients, among which 35 were treated with EES and 16 were treated with TCM. The proportion of gross-total resection (GTR) was similar between the groups (94.3% for EES vs 75% for TCM, p = 0.130). TCM was associated with a lower rate of hypogonadism (33.3% vs 64.7%, p = 0.042) and a higher rate of growth hormone deficiency (73.3% vs 26.5%, p = 0.002), permanent diabetes insipidus (DI) (60.0% vs 29.4%, p = 0.043), and panhypopituitarism (80.0% vs 47.1%, p = 0.032) at the last follow-up. CSF leakage only occurred in the EES group, with no significant difference observed between the groups (p > 0.99). TCM significantly increased the risk of worsened visual outcomes (25.0% vs 0.0%, p = 0.012). However, TCM was associated with a significantly longer median duration of follow-up (66.0 vs 40.5 months, p = 0.007) and a significantly lower rate of preoperative hypogonadism (18.8% vs 60.0%, p = 0.006). The propensity-adjusted analysis revealed no difference in the rate of recurrence, hypogonadism, or permanent DI. Additionally, EES was associated with a lower median gain in BMI (1.5 kg/m2 vs 7.5 kg/m2, p = 0.046) and better hypothalamic function (58.3% vs 8.3%, p = 0.027) at the last follow-up. CONCLUSIONS Compared with TCM, EES was associated with a superior visual outcome, better endocrinological and hypothalamic function, and less BMI gain, but comparable rates of GTR, recurrence, and perioperative complications. These findings have indicated that EES is a safe and effective surgical modality and can be a viable alternative to TCM for pediatric midline craniopharyngiomas.

Mechanisms Driving Palmitate-Mediated Neuronal Dysregulation in the Hypothalamus

The hypothalamus maintains whole-body homeostasis by integrating information from circulating hormones, nutrients and signaling molecules. Distinct neuronal subpopulations that express and secrete unique neuropeptides execute the individual functions of the hypothalamus, including, but not limited to, the regulation of energy homeostasis, reproduction and circadian rhythms. Alterations at the hypothalamic level can lead to a myriad of diseases, such as type 2 diabetes mellitus, obesity, and infertility. The excessive consumption of saturated fatty acids can induce neuroinflammation, endoplasmic reticulum stress, and resistance to peripheral signals, ultimately leading to hyperphagia, obesity, impaired reproductive function and disturbed circadian rhythms. This review focuses on the how the changes in the underlying molecular mechanisms caused by palmitate exposure, the most commonly consumed saturated fatty acid, and the potential involvement of microRNAs, a class of non-coding RNA molecules that regulate gene expression post-transcriptionally, can result in detrimental alterations in protein expression and content. Studying the involvement of microRNAs in hypothalamic function holds immense potential, as these molecular markers are quickly proving to be valuable tools in the diagnosis and treatment of metabolic disease.

Principles of Neuroendocrinology and Hypothalamic Function

The hypothalamus is the neural center of the endocrine system, the regulator of the autonomic nervous system, and the circadian and seasonal clock for behavioral and sleep-wake functions. The hypothalamus maintains homeostasis by integrating cortical, limbic, and spinal inputs and by affecting hormone release, temperature regulation, intake of food and water, sexual behavior and reproduction, emotional responses, and diurnal rhythms. As the link from the nervous system to the endocrine system, the hypothalamus synthesizes and secretes neurohormones that stimulate or inhibit the secretion of pituitary hormones.

Central Acting Hsp10 Regulates Mitochondrial Function, Fatty Acid Metabolism, and Insulin Sensitivity in the Hypothalamus

Mitochondria are critical for hypothalamic function and regulators of metabolism. Hypothalamic mitochondrial dysfunction with decreased mitochondrial chaperone expression is present in type 2 diabetes (T2D). Recently, we demonstrated that a dysregulated mitochondrial stress response (MSR) with reduced chaperone expression in the hypothalamus is an early event in obesity development due to insufficient insulin signaling. Although insulin activates this response and improves metabolism, the metabolic impact of one of its members, the mitochondrial chaperone heat shock protein 10 (Hsp10), is unknown. Thus, we hypothesized that a reduction of Hsp10 in hypothalamic neurons will impair mitochondrial function and impact brain insulin action. Therefore, we investigated the role of chaperone Hsp10 by introducing a lentiviral-mediated Hsp10 knockdown (KD) in the hypothalamic cell line CLU-183 and in the arcuate nucleus (ARC) of C57BL/6N male mice. We analyzed mitochondrial function and insulin signaling utilizing qPCR, Western blot, XF96 Analyzer, immunohistochemistry, and microscopy techniques. We show that Hsp10 expression is reduced in T2D mice brains and regulated by leptin in vitro. Hsp10 KD in hypothalamic cells induced mitochondrial dysfunction with altered fatty acid metabolism and increased mitochondria-specific oxidative stress resulting in neuronal insulin resistance. Consequently, the reduction of Hsp10 in the ARC of C57BL/6N mice caused hypothalamic insulin resistance with acute liver insulin resistance.

Hypothalamic Rax+ tanycytes contribute to tissue repair and tumorigenesis upon oncogene activation in mice

Hypothalamic tanycytes in median eminence (ME) are emerging as a crucial cell population that regulates endocrine output, energy balance and the diffusion of blood-born molecules. Tanycytes have recently been considered as potential somatic stem cells in the adult mammalian brain, but their regenerative and tumorigenic capacities are largely unknown. Here we found that Rax+ tanycytes in ME of mice are largely quiescent but quickly enter the cell cycle upon neural injury for self-renewal and regeneration. Mechanistically, Igf1r signaling in tanycytes is required for tissue repair under injury conditions. Furthermore, Braf oncogenic activation is sufficient to transform Rax+ tanycytes into actively dividing tumor cells that eventually develop into a papillary craniopharyngioma-like tumor. Together, these findings uncover the regenerative and tumorigenic potential of tanycytes. Our study offers insights into the properties of tanycytes, which may help to manipulate tanycyte biology for regulating hypothalamic function and investigate the pathogenesis of clinically relevant tumors.

Could there be a fine-tuning role for brain-derived adipokines in the regulation of bodyweight and prevention of obesity?

Obesity is one of the most prevalent medical conditions, often associated with several negative stereotypes. Although it is true that weight gain occurs when food intake exceeds energy expenditure, it is important to note that even a 1% mismatch between the two can lead to a substantial weight gain after only a few years. Further, the body appears to balance energy metabolism via an endogenous lipostatic loop in which adipose stores send hormonal signals (e.g. adipokines such as leptin) to the hypothalamus in order to reduce appetite and increase energy expenditure. However, the brain is also a novel site of expression of many of these adipokine genes. This led to the hypothesis that hypothalamic-derived adipokines might also be involved in bodyweight regulation by exerting some effect on the control of appetite or hypothalamic function. When RNA interference (RNAi) was used to specifically silence adipokine gene expression in various in vitro models, this led to increases in cell death, modification of the expression of key signaling genes (i.e. suppressor of cytokine signaling-3; SOCS-3), and modulation of the activation of cellular energy sensors (i.e. adenosine monophosphate-activated protein kinase; AMPK). Subsequently, when RNAi was used to inhibit the expression of brain-derived leptin in adult rats this resulted in minor increases in weight gain in addition to modifying the expression of other adipokine genes (eg. resistin). In summary, although adipokines secreted by adipose tissue appear to the main regulator of lipostatic loop, this review shows that the fine tuning that is required to maintain a stable bodyweight by this system might be accomplished by hypothalamic-derived adipokines. Perturbations in this central adipokine system could lead to alterations in normal hypothalamic function which leads to unintended weight gain.