Prohormone Research Articles

Proteolytic activation of anti-Müllerian hormone is suppressed in adolescent girls.

The ratio of the anti-Müllerian hormone (AMH) precursor (proAMH) to active AMH (AMHN,C) is higher in childhood than in adulthood but has never been quantified during adolescence. The ratio of proAMH to total AMH (AMH prohormone index, API) was examined during the puberty in healthy girls. The API was also compared between girls with and without polycystic ovary syndrome (PCOS) to determine if there were differences that could assist in PCOS diagnosis during adolescence. Total AMH and proAMH were measured by immunoassay in a single-centre, cross-sectional observational study; 61 controls and 29 girls with PCOS were included in the study (age range 8-21 years). The API was calculated as proAMH as a percentage of total AMH. Differences in API between control and PCOS subjects and across age-groups were examined by Welch's ANOVA. The relationship between API and a range of metabolic parameters was examined by Pearson correlation. The API in healthy females increased between the ages of 10~15 years and declined from 15~20 years (p < 0.001). The API was negatively correlated with body mass index in the control (p = 0.04) and PCOS groups (p = 0.007). The API was associated with factors related to adiposity and lipid metabolism. The API was not significantly different in control girls and girls with PCOS. Higher API during adolescence suggests that proteolytic activation of proAMH is suppressed during this life stage. API was not different between control girls and girls with PCOS indicating that it is not useful in diagnosis of PCOS during adolescence.

Cholesterol metabolism and its implication in glioblastoma therapy.

Glioblastoma (GBM) is the most lethal malignant tumor in the central nervous system, with a median survival of only 14 months. Cholesterol, which is the main component of cell membrane and the precursor of many hormones, is one of the most important lipid components in human body. Since reprogramming of the cholesterol metabolic profile has been discovered in many cancers including GBM, cholesterol metabolism becomes a promising potential target for therapy. Since GBM cells rely on external cholesterol to survive and accumulate lipid droplets to meet their rapid growth needs, targeting the metabolism of cholesterol by different strategies including inhibition of cholesterol uptake and promotion of cholesterol efflux by activating LXRs and disruption of cellular cholesterol trafficking, inhibition of SREBP signaling, inhibition of cholesterol esterification, could potentially oppose the growth of glial tumors. In this review, we discussed the above findings and describe cholesterol synthesis and homeostatic feedback pathways in normal brain tissues and brain tumors, statin use in GBM and the role of lipid rafts and cholesterol precursors and oxysterols in the treatment and pathogenesis of GBM are also summarized.

Enzymatic isomerization of ζ-carotene mediated by the heme-containing isomerase Z-ISO.

Carotenoids are a large and diverse class of isoprenoid compounds synthesized by plants, algae, some bacteria, arthropods, and fungi. These pigments contribute to plant growth and survival by protecting plants from photooxidative stress and serving as precursors of plant hormones and other signaling compounds. In humans, carotenoids are essential components of the diet and contribute anti-oxidant and provitamin A activities. Carotenoids are synthesized in the membranes of plant plastids where phytoene is converted into all trans lycopene by a biosynthetic pathway that was only recently completed by the discovery of the new enzyme, 15-cis-ζ-carotene isomerase (Z-ISO), which controls carotenoid pathway flux to products necessary for plant development and function. Z-ISO catalysis of the cis to trans isomerization of the 15-cis double bond in 15-cis-ζ-carotene is mediated by a unique mechanism dependent on the redox-state of a heme b cofactor. This chapter describe methods for the functional analysis of Z-ISO, including complementation of Z-ISO in engineered E. coli, separation of Z-ISO enzyme substrate and products, ζ-carotene isomers, by high pressure liquid chromatography (HPLC), expression and purification of Z-ISO and in vitro enzymatic reactions.

The Utilization of Dehydroepiandrosterone as a Sexual Hormone Precursor in Premenopausal and Postmenopausal Women: An Overview.

Dehydroepiandrosterone (DHEA), and its metabolite, dehydroepiandrosterone sulfate ester (DHEAS), are the most abundant circulating steroid hormones, and are synthesized in the zona reticularis of the adrenal cortex, in the gonads, and in the brain. The precise physiological role of DHEA and DHEAS is not yet fully understood, but these steroid hormones can act as androgens, estrogens, and neurosteroids, and perform many roles in the human body. Since both levels decline with age, use of DHEA supplements have gained more attention due to being advertised as an antidote to aging in postmenopausal women, who may have concerns on age-related diseases and overall well-being. However, current research has not reached an overall consensus on the effects of DHEA on postmenopausal women. This overview is a summary of the current literature, addressing the metabolic pathway for DHEA synthesis and utilization, as well as the effects of DHEA on premenopausal and postmenopausal women with disease states and other factors. As for the therapeutic effects on menopausal syndrome and other age-related diseases, several studies have found that DHEA supplementations can alleviate vasomotor symptoms, preserve the integrity of the immune system, reduce bone loss, and increase muscle mass. Intravaginal DHEA has shown significant beneficial effects in menopausal women with severe vulvovaginal symptoms. On the other hand, DHEA supplements have not shown definitive effects in cardiovascular disease, adrenal insufficiency, insulin sensitivity, and cognition. Due to inadequate sample sizes and treatment durations of current studies, it is difficult to assess the safety and efficacy of DHEA and draw reliable conclusions for the physiological role, the optimal dosage, and the effects on premenopausal and postmenopausal women; therefore, the study of DHEA warrants future investigation. Further research into the roles of these steroid hormones may bring us closer to a therapeutic option in the future.

Abstract P139: An estrogen receptor beta agonist liquiritigenin potentiates inhibition of hormone-dependent breast-cancer growth by cholesterol biosynthesis inhibitor RO 48-8071

Abstract Hormone-dependent breast cancer represents approximately 70% of all diagnosed breast cancers. Estrogens and progestins stimulate breast cancer cell proliferation, angiogenesis and metastasis. Estrogen receptor (ER)-alpha positive breast cancers are treated with anti-estrogens and aromatase inhibitors, but resistance to these agents invariably develops during the course of therapy. Our goal was to identify novel treatment strategies to suppress breast cancer growth and avoid drug resistance. Cholesterol biosynthesis plays a vital role in tumor cell growth. Cholesterol is an integral part of membrane structure and is also a precursor of steroid hormones that are synthesized by tumor cells and cause cellular proliferation by interacting with specific receptors. Cancer cells have elevated levels of cholesterol, which could be responsible for anti-hormone resistance. During studies to determine the effects of the cholesterol biosynthesis inhibitor RO 48-8071 ([4’-[6-(Allylmethylamino)hexyloxy]-4-bromo-2’-fluorobenzophenone fumarate] (RO), which inhibits oxidosqualene cyclase (OSC), an enzyme that acts downstream of HMG-CoA reductase to convert 2, 3-monoepoxysqualene to lanosterol (a key step in the biosynthesis of cholesterol), it was serendipitously discovered that RO degraded ER-alpha (ERa), and elevated levels of ER-beta (ERb), a known tumor suppressor. We tested RO alone and in combination with liquiritigenin (LQ), a selective agonist for ERb, to ascertain their inhibitory effects against tumor cell progression. RO or LQ alone reduced significantly the in vitro viability of MCF-7 and BT-474 breast-cancer cells. BT-474 cells were more sensitive than MCF-7 cells to LQ (IC50 0.15 uM vs 0.25 mM, respectively). RO (5-10 uM) + LQ (0.1-0.3 mM) treatment reduced cell viability in an additive manner in MCF-7 cells and in a synergistic manner in BT-474 cells. Combination treatment was significantly more effective than treatment with a single agent. Administration of RO (10 mg/kg/iv) or LQ (20 mg/kg/ip) significantly inhibited growth of tamoxifen-resistant BT-474 tumor xenografts in vivo; combination treatment was even more effective. Both agents appeared to be non-toxic in vivo. Mechanistically, RO, LQ, or RO + LQ reduced ERa but induced ERb expression in tumor xenografts. Both compounds significantly reduced expression of markers of angiogenesis and increased apoptosis in tumor xenografts; use of RO + LQ significantly enhanced the effects observed with a single agent. The anti-tumor properties of RO may in part be due to an off-target effect that reduces ERa and increases ERb, the latter then interacting with LQ to more effectively promote its anti-proliferative effects. The potent anti-tumor properties of RO and LQ, particularly when used together, suggest that this combination has substantial potential as a means by which to clinically manage breast-cancer growth, including in disease types that are tamoxifen resistant. Citation Format: Yayun Liang, Salman Hyder. An estrogen receptor beta agonist liquiritigenin potentiates inhibition of hormone-dependent breast-cancer growth by cholesterol biosynthesis inhibitor RO 48-8071 [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P139.

Evaluation of vitamin D status and depression in thyroid patients referred to Yazd Diabetes Center clinic in 2020

Introduction: Vitamin D is a hormonal precursor that in addition to known roles, may have an important effect on mental disorders such as depression. Therefore, this study was performed to determine the extent of vitamin D deficiency and depression and their relationship in thyroid patients referred to The clinic of Yazd Diabetes Center has been performed. Methods: The present study is a cross-sectional-analytical study that was performed on 150 thyroid patients referred to the Yazd Diabetes Center Clinic. Results: In this study, 150 thyroid patients including 55 men and 11. women with a mean age of 41.40± 7.61years participated. The mean score of Beck depression among these patients was 28.71± 8.34 .The mean level of vitamin D in these patients was 20.58 ± 7.21 ng / ml so that a total of 85% of thyroid patients were in the group of insufficient levels of vitamin D. A significant negative correlation was observed between depression score and serum vitamin D levels (r = -0.79 and p &lt;0.001). Conclusion: The results of this study indicate a high prevalence of depression and vitamin D deficiency in thyroid patients. Another finding of this study was the relationship between vitamin D deficiency and depression, so that the less vitamin D in the body, the lower the rate of depression in The person becomes more. The use of vitamin D supplements in the treatment of thyroid patients with depression, as a clinical trial, can be a good solution in the treatment of patients.

COVID-19 pandemic leading to unidentified, silent-pandemic of vitamin D deficiency in young children: a case report

Vitamin D is a pro hormone needed for the homeostasis of calcium and phosphorus in the body. This state is crucial for maintaining metabolism, nerve conduction and general cellular functions in the body. Coronavirus disease 2019 (COVID-19) pandemic has led to long-term lockdowns. Schools are closed, people are confined to their homes and outdoor activities are at a halt. This has led to rise in cases of vitamin D deficiency (particularly in infants and toddlers) which is going un-noticed and can further lead us to another pandemic of non-communicable disease - vitamin D deficiency. We have presented a case report of healing rickets in a 19-month-old toddler. We aim to highlight this under-diagnosed and ignored vitamin deficiency that can affect the overall health of our younger generation in this COVID-19 era.

A retrospective analysis of the impact of a hospital pharmacist-led procalcitonin protocol.

Procalcitonin is a precursor hormone to calcitonin that increases in response to systemic inflammation, especially of bacterial origin, and is otherwise undetectable in healthy states. Studies have shown that following effective antimicrobial treatment, procalcitonin levels steadily decline. To be utilized however, procalcitonin levels determinations must be ordered at specific times during a patient's antimicrobial treatment. A retrospective medication-use evaluation of patients was performed at Medical Center Hospital and showed that in 70% of patients, initial procalcitonin levels were ordered inappropriately and procalcitonin levels were trended inconsistently during antibiotic treatment. A pharmacist-led procalcitonin protocol was developed and presented to medical staff committees for approval. Data was collected from patients presenting with suspected or confirmed sepsis or lower respiratory tract infections for whom procalcitonin levels were utilized. Patient outcomes before and after protocol implementation were compared. A total of 400 patients were included in the study. The primary outcome of appropriate ordering of initial procalcitonin levels was improved in the postprotocol group relative to the preprotocol group (28% of patients [n = 56] vs 72% of patients [n = 144]; P < 0.001). Patients in the postprotocol group had a procalcitonin level checked at discontinuation more frequently (8% [n = 16] vs 37% [n = 74], P < 0.001) and had a higher rate of appropriate discontinuation of antibiotics (12% [n = 21] vs 46% [n = 77]; P < 0.001). The postprotocol group also had fewer mean days of antibiotic therapy (9.17 vs 6.01; P < 0.001). Studies have shown the usefulness of procalcitonin levels for antimicrobial stewardship, but for procalcitonin testing to be properly utilized it must be ordered at the correct times during the patient's therapy. The implementation of a hospital-wide pharmacist-led protocol resulted in an increase in appropriate ordering of baseline procalcitonin levels.

Changes of lipoprotein(a) levels with endogenous steroid hormones.

BackgroundLipoprotein(a) [Lp(a)] is an LDL‐like molecule that is likely causal for cardiovascular events and Lp(a) variability has been shown to be mostly of genetic origin. Exogenous hormones (hormone replacement therapy) seem to influence Lp(a) levels, but the impact of endogenous hormone levels on Lp(a) is still unknown. The aim of the study was to assess the effect of endogenous steroid hormone metabolites on Lp(a).MethodsLipoprotein(a) levels were measured in 1,021 participants from the Swiss Kidney Project on Genes in Hypertension, a family‐based, multicentre, population‐based prospective cohort study. Endogenous levels of 28 steroid hormone precursors were measured in 24‐h urine collections from 883 individuals. Of the participants with Lp(a) data, 1,011 participants had also genotypes available.ResultsThe participants had an average age of 51 years and 53% were female. Median Lp(a) levels were 62 mg/L, and the 90th percentile was 616 mg/L. The prevalence of a Lp(a) elevation ≥700 mg/L was 3.2%. Forty‐three per cent of Lp(a) variability was explained respectively by: age (2%, p < .001), LDL‐C (1%, p = .001), and two SNPs (39%, p value<2⋅10−16). Of the 28 endogenous steroid hormones assessed, androstenetriol, androsterone, 16α‐OH‐DHEA and estriol were nominatively associated with serum Lp(a) levels in univariable analyses and explained 0.4%–1% of Lp(a) variability, but none of them reached significance in multivariable models.ConclusionsIn this contemporary population‐based study, the prevalence of a Lp(a) elevation ≥700 mg/L was 3.2%. The effect of endogenous steroid hormone levels of Lp(a) variability was small at best, suggesting a negligible impact on the wide range of Lp(a) variability.

Diagnostic algorithm of the subclinical forms of adrenal neoplasms

The possibility of modifying the existing diagnostic algorithm of latent forms of hormone-active and potentially malignant formations in the adrenal glands using modern methods of laboratory diagnostics and radiation imaging is substantiated. In the clinic of a faculty of surgery and on its clinical base, experience in the examination and treatment of 1457 patients with various formations of the adrenal glands has been accumulated. Among them, 270 (14.9%) patients were selected, in whom precursor hormones of steroidogenesis and metabolites of catecholamines in the blood plasma were specially studied by high-performance liquid chromatography, tumor marker measurement, and three-phase computed tomography with intravenous contrast enhancement. Determination of steroidogenesis precursor hormones and catecholamine metabolites in the blood plasma by high-performance liquid chromatography in combination with traditional methods of laboratory diagnostics, use of computed tomography with intravenous contrast enhancement, construction of multiplanar reconstructions, and postprocessor image processing are the basis of a modified algorithm for verification of latent forms of hormone-active and potentially malignant tumors of the adrenal glands. The implementation of the diagnostic algorithm developed in the clinic made early diagnosis of the subclinical forms of NP neoplasms possible, as well as ensure the implementation of minimally invasive surgical interventions before the development of endocrine and metabolic disorders and consequently prevent the development of intraoperative and postoperative complications, which thereby reduce the duration of rehabilitation and disability of patients with good long-term treatment results and high quality of life.

Neurodegenerative Diseases and Cholesterol: Seeing the Field Through the Players.

Neurodegenerative diseases, namely Alzheimer’s (AD), Parkinson’s (PD), and Huntington’s disease (HD) together with amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS), devastate millions of lives per year worldwide and impose an increasing socio-economic burden across nations. Consequently, these diseases occupy a considerable portion of biomedical research aiming to understand mechanisms of neurodegeneration and to develop efficient treatments. A potential culprit is cholesterol serving as an essential component of cellular membranes, as a cofactor of signaling pathways, and as a precursor for oxysterols and hormones. This article uncovers the workforce studying research on neurodegeneration and cholesterol using the TeamTree analysis. This new bibliometric approach reveals the history and dynamics of the teams and exposes key players based on citation-independent metrics. The team-centered view reveals the players on an important field of biomedical research.

Early metabolic support for critically ill trauma patients: A prospective randomized controlled trial.

There is a lack of consensus regarding the optimal nutritional support for trauma patients. We hypothesize that early postinjury metabolic support focusing on adequate protein would modify the metabolic signature and alter the inflammatory environment for critically ill trauma patients. We conducted a prospective randomized controlled pilot trial for adult patients admitted to the surgical intensive care unit following traumatic injury. Patients were randomized to receive early metabolic support (EMS) (peripheral amino acid infusions) or standard of care (enteral nutrition as soon as feasible). Routine laboratory assessments, nitrogen balance, cytokines, and metabolomic analyses were assessed at baseline and day 5 after intervention. A total of 42 trauma patients were randomized into well-balanced groups with similar age (32 years), Injury Severity Score (25), and body mass index (27.4 kg/m2). Early metabolic support provided significantly more protein (1.43 g/kg vs. 0.35 g/kg; p < 0.0001) and more calories (12.6 kcal/kg vs. 7.5 g/kg; p = 0.0012) over the first 5 days as compared with the standard of care. Early metabolic support modified protein catabolism and synthesis as demonstrated by a larger median negative nitrogen balance (-16.3 g vs. -5.3 g; p = 0.03) and a unique metabolomic profile at day 5. The biochemical profile of patients who received EMS was defined by greater declines in circulating levels of stress hormone precursors and increased levels of amino acids. The inflammatory response following EMS resulted in a greater decrease in interleukin-1B (p = 0.02) and increase in soluble interleukin-6 receptor (p = 0.01) between baseline and day 5 as compared with the standard of care. The EMS group had a decreased length of stay (15 vs. 22 days) and decreased surgical intensive care unit length of stay (8 vs. 9 days); however, this disappeared after adjustment for Injury Severity Score in this small population. Early metabolic support with amino acid is safe, modifies metabolism, and may downregulate the inflammatory state associated with significant trauma, warranting a larger trial to assess for improved outcomes. Therapeutic/Care Management; Level II.

Biomarkers of Pulmonary Hypertension Are Altered in Children with Down Syndrome and Pulmonary Hypertension

To evaluate the performance of pulmonary hypertension (PH) biomarkers in children with Down syndrome, an independent risk factor for PH, in whom biomarker performance may differ compared with other populations. Serum endostatin, interleukin (IL)-1 receptor 1 (ST2), galectin-3, N-terminal pro hormone B-natriuretic peptide (NT-proBNP), IL-6, and hepatoma-derived growth factor (HDGF) were measured in subjects with Down syndrome and PH (n=29), subjects with Down syndrome and resolved PH (n=13), subjects with Down syndrome without PH (n=49), and subjects without Down syndrome with World Symposium on Pulmonary Hypertension group I pulmonary arterial hypertension (no Down syndrome PH group; n=173). Each biomarker was assessed to discriminate PH in Down syndrome. A classification tree was created to distinguish PH from resolved PH and no PH in children with Down syndrome. Endostatin, galectin-3, HDGF, and ST2 were elevated in subjects with Down syndrome regardless of PH status. Not all markers differed between subjects with Down syndrome and PH and subjects with Down syndrome and resolved PH. NT-proBNP and IL-6 levels were similar in the Down syndrome with PH group and the no Down syndrome PH group. A classification tree identified NT-proBNP and galectin-3 as the best markers for sequentially distinguishing PH, resolved PH, and no PH in subjects with Down syndrome. Proteomic markers are used to improve the diagnosis and prognosis of PH but, as demonstrated here, can be altered in genetically unique populations such as individuals with Down syndrome. This further suggests that clinical biomarkers should be evaluated in unique groups with the development of population-specific nomograms.

Mechanistic insights from a multiparametric magnetic resonance imaging study regarding the role of sodium glucose co-transporter 2 inhibitors

Abstract Background Type 2 diabetes (T2D) is associated with an increased risk of heart failure (HF) and cardiovascular (CV) mortality. Sodium–glucose-co transporter-2 (SGLT2) inhibitors reduce the risk of major adverse CV events and hospitalisation for HF in T2D patients with high cardiovascular risk, despite only a modest improvement in glycemic control. Restoring cellular energy homeostasis and reversing adverse cardiac remodelling in diabetes have been speculated as a potential metabolic modulatory effect of SGLT2 inhibitors leading to their beneficial CV outcomes. Myocardial energy deficient states can be detected non-invasively by 31-phosphorus magnetic resonance spectroscopy (31P-MRS). Objectives Utilising cardiovascular magnetic resonance imaging (CMR) and 31P-MRS in a single centre longitudinal cohort study, we aimed to investigate the effects of the selective SGLT2 inhibitor empagliflozin on myocardial energetics, function, perfusion, and myocardial cellular volume in patients with T2D. Methods Eighteen consecutive T2D patients who were commenced on empagliflozin in cardiometabolic optimisation clinics underwent CMR and 31P-MRS scans before and after twelve-week empagliflozin treatment, and plasma N-terminal pro hormone B-type natriuretic peptide (NT-proBNP) levels were measured. Ten controls with no diabetes underwent an identical 31P-MRS and CMR protocol on a single visit. Results When compared to controls, patients with T2D showed: lower myocardial energetics (1.52±0.40 vs 2.20±0.5, p=0.0005), lower stress myocardial blood flow (1.60±0.50 vs 2.10±0.50, p=0.02) and lower left ventricular ejection fraction (52±13% vs 63±4%, p=0.01). Treatment with empagliflozin led to significant improvements in myocardial energetics (PCr/ATP: 1.52 to 1.76, p=0.009). This was accompanied by a relative 13% improvement in left ventricular ejection fraction (p=0.001), 3% improvement in global longitudinal strain (p=0.01), 61% reduction in NTproBNP (p=0.05), and 9% reduction in myocardial cell volume (p=0.04). No significant change in myocardial blood flow or diastolic strain was detected. Conclusions For the first time, we demonstrate that empagliflizon improves myocardial energetics and function, reduces myocardial cellular volume, and reduces NT-proBNP levels in patients with T2D. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): British Heart Foundation PCr/ATPLVEF

Effect of Monoclonal Antibody Blockade of Long Fragment Neurotensin on Weight Loss, Behavior, and Metabolic Traits After High-Fat Diet Induced Obesity.

BackgroundObesity is a major public health problem of our time as a risk factor for cardiometabolic disease and the available pharmacological tools needed to tackle the obesity pandemic are insufficient. Neurotensin (NTS) is a 13 amino acid peptide, which is derived from a larger precursor hormone called proneurotensin or Long Form NTS (LF NTS). NTS modulates neuro-transmitter release in the central system nervous, and facilitates intestinal fat absorption in the gastrointestinal tract. Mice lacking LF NTS are protected from high fat diet (HFD) induced obesity, hepatic steatosis and glucose intolerance. In humans, increased levels of LF NTS strongly and independently predict the development of obesity, diabetes mellitus, cardiovascular disease and mortality. With the perspective to develop therapeutic tools to neutralize LF NTS, we developed a monoclonal antibody, specifically inhibiting the function of the LF NTS (LF NTS mAb). This antibody was tested for the effects on body weight, metabolic parameters and behavior in mice made obese by high-fat diet.MethodsC57bl/6j mice were subjected to high-fat diet (HFD) until they reached an obesity state, then food was switched to chow. Mice were treated with either PBS (control therapy) or LF NTS mAb at the dose of 5 mg/kg once a week (i.v.). Mice weight, plasma biochemical analysis, fat and muscle size and distribution and behavioral tests were performed during the losing weight period and the stabilization period.ResultsObese mice treated with the LF NTS mAb lost weight significantly faster than the control treated group. LF NTS mAb treatment also resulted in smaller fat depots, increased fecal cholesterol excretion, reduced liver fat and larger muscle fiber size. Moreover, mice on active therapy were also less stressed, more curious and more active, providing a possible explanation to their weight loss.ConclusionOur results demonstrate that in mice subjected to HFD-induced obesity, a blockade of LF NTS with a monoclonal antibody results in reduced body weight, adipocyte volume and increased muscle fiber size, possibly explained by beneficial effects on behavior. The underlying mechanisms as well as any future role of LF NTS mAb as an anti-obesity agent warrants further studies.

Cholesterol dyshomeostasis in amyotrophic lateral sclerosis: cause, consequence, or epiphenomenon?

Amyotrophic lateral sclerosis (ALS), the most common adult-onset motor neuron disease, is characterized by the selective degeneration of motor neurons leading to paralysis and eventual death. Multiple pathogenic mechanisms, including systemic dysmetabolism, have been proposed to contribute to ALS. Among them, dyslipidemia, i.e., abnormal level of cholesterol and other lipids in the circulation and central nervous system (CNS), has been reported in ALS patients, but without a consensus. Cholesterol is a constituent of cellular membranes and a precursor of steroid hormones, oxysterols, and bile acids. Consequently, optimal cholesterol levels are essential for health. Due to the blood-brain barrier (BBB), cholesterol cannot move between the CNS and the rest of the body. As such, cholesterol metabolism in the CNS is proposed to operate autonomously. Despite its importance, it remains elusive how cholesterol dyshomeostasis may contribute to ALS. In this review, we aim to describe the current state of cholesterol metabolism research in ALS, identify unresolved issues, and provide potential directions.

Diet modulates behaviour in house sparrows: insights into possible hormone-mediated mechanisms

Foraging animals usually select foods that balance the intake of key nutrients, for example essential amino acids that cannot be synthesized and must be obtained from the diet. However, the ability to gain optimal ratios, proportions and amounts of nutrients may be hampered by a changing environment, competitive conspecifics or species and predators. Here, we used an experimental system in which house sparrows, Passer domesticus , were fed a manipulated diet with different compositions of amino acids (in the experimental diet phenylalanine and tyrosine content was 42% of that in the control diet). Phenylalanine and tyrosine are precursors of coping hormones: dopamine, noradrenaline (norepinephrine) and adrenaline (epinephrine) which are involved mainly in the expression of stress and fear, but also in learning and long-term memory formation. Accordingly, birds fed a diet deficient in these amino acids learned to avoid unpalatable food markedly slower, coped worse with stress in the presence of a novel object and were more aggressive towards other sparrows than control birds. Surprisingly, circulating amounts of the catecholamines in blood plasma were higher in these birds than in sparrows on the control diet. This study provides the first evidence that variation in amino acid composition in the diet is associated with variation in behaviours and hormone levels in birds. We conclude that food, besides its nutritional function, seems to represent one of the modulators of behavioural expression making a balanced diet crucial for survival. • Animals balance the intake of key nutrients such as essential amino acids. • An imbalance of amino acids may result in behavioural changes. • Birds on an imbalanced diet learned slower and were more aggressive and stressed. • Food seems to represent one of the main modulators of behaviour.

Cochlear Fibrocyte and Osteoblast Lineages Expressing Type 2 Deiodinase Identified with a Dio2CreERt2 Allele.

Type 2 deiodinase (Dio2) amplifies levels of 3,5,3'-L-triiodothyronine (T3), the active form of thyroid hormone, and is essential for cochlear maturation and auditory development. However, cellular routes for endocrine signaling in the compartmentalized, anatomically complex cochlea are little understood. Dio2 generates T3 from thyroxine (T4), a more abundant thyroid hormone precursor in the circulation, and is dramatically induced in the cochlea before the onset of hearing. The evidence implies that specific Dio2-expressing cell types critically mediate T3 signaling but these cell types are poorly defined because Dio2 is expressed transiently at low levels. Here, using a Dio2CreERt2 knockin that activates a fluorescent reporter, we define Dio2-expressing cochlear cell types at high resolution in male or female mice. Dio2-positive cells were detected in vascularized supporting tissues but not in avascular internal epithelia, indicating segregation of T3-generating and T3-responding tissues. In the spiral ligament and spiral limbus, Dio2-positive fibrocytes clustered around vascular networks that convey T4 into cochlear tissues. In the otic capsule, Dio2-positive osteoblasts localized at cartilage surfaces as the bony labyrinth matures. We corroborated the identities of Dio2-positive lineages by RNA-sequencing of individual cells. The results suggest a previously unrecognized role for fibrocytes in mediating hormonal signaling. We discuss a model whereby fibrocytes mediate paracrine-like control of T3 signaling to the organ of Corti and epithelial target tissues.

Functional analyses of three different mutations in the AVP-NPII gene causing familial neurohypophyseal diabetes insipidus.

Familial neurohypophyseal diabetes insipidus (FNDI), a rare disorder, which is clinically characterized by polyuria and polydipsia, results from mutations in the arginine vasopressin-neurophysin II (AVP-NPII) gene. The aim of this study was to perform functional analyses of three different mutations (p.G45C, 207_209delGGC, and p.G88V) defined in the AVP-NPII gene of patients diagnosed with FNDI, which are not included in the literature. For functional analysis studies, the relevant mutations were created using PCR-based site-directed mutagenesis and restriction fragment replacement strategy and expressed in Neuro2A cells. AVP secretion into the cell culture medium was determined by radioimmunoassay (RIA) analysis. Fluorescence imaging studies were conducted to determine the differences in the intracellular trafficking of wild-type (WT) and mutant AVP-NPII precursors. Molecular dynamics (MD) simulations were performed to determine the changing of the conformational properties of domains for both WT and 207-209delGGC mutant structures and dynamics behavior of residues. Reduced levels of AVP in the supernatant culture medium of p.G45C and p.G88V transfected cells compared to 207_209delGGC and WT cells were found. Fluorescence imaging studies showed that a substantial portion of the mutant p.G45C and p.G88V AVP-NPII precursors appeared to be located in the endoplasmic reticulum (ER), whereas 207_209delGGC and WT AVP-NPII precursors were distributed throughout the cytoplasm. The mutations p.G45C and p.G88V cause a failure in the intracellular trafficking of mutant AVP-NPII precursors. However, 207_209delGGC mutation does not result in impaired cellular trafficking, probably due to not having any significant effect in processes such as the proper folding, gain of three-dimensional structure, or processing. These results will provide valuable information for understanding the influence of mutations on the function of the AVP precursor hormone and cellular trafficking. Therefore, this study will contribute to elucidate the mechanisms of the molecular pathology of AVP-NPII mutations.

Abstract 734: Macrophage tumor cell metabolic interactions induce therapeutic resistance in prostate cancer

Abstract Castration-resistant prostate cancer (CRPC) is a lethal stage of disease. A wealth of clinical and experimental data supports the persistence of androgen receptor (AR) signaling in many cases of CRPC, despite androgen-deprivation therapy (ADT). Here we sought to determine the role of macrophage cholesterol in CRPC and androgen signaling using a syngeneic model that reflected the mutational landscape of the disease. A transcriptomic analysis of prostate tumors following macrophage depletion revealed lower molecular signatures for steroid and bile acid metabolism, indicating perturbation of cholesterol transport. Since cholesterol is the precursor of steroid hormones, we reasoned that macrophages were regulating androgen biosynthesis within the prostate tumor microenvironment. Indeed, macrophage depletion reduced the levels of androgens within prostate tumors and restricted androgen receptor (AR) nuclear localization in vitro and in vivo. Macrophages were cholesterol rich and had the ability to transfer cholesterol to tumor cells in vitro, and AR nuclear translocation was inhibited by activation of Liver X Receptor (LXR)-β, the master regulator of cholesterol homeostasis. Finally, combining macrophage depletion with androgen deprivation therapy increased survival, supporting the therapeutic potential of targeting macrophages in CRPC. Citation Format: Asmaa El-Kenawi, William Dominguez Viqueira, Min Liu, Shivanshu Awasthi, Jasreman Dhillon, Kosj Yamoah, Xiaoqing Yu, John Koomen, Robert Gatenby, Brian Ruffell. Macrophage tumor cell metabolic interactions induce therapeutic resistance in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 734.