Comparison of Individual and Combined Effects of Four Endocrine Disruptors on Estrogen Receptor Beta Transcription in Cerebellar Cell Culture: The Modulatory Role of Estradiol and Triiodo-Thyronine

Analysis of arsenic-modulated expression of hypothalamic estrogen receptor, thyroid receptor, and peroxisome proliferator-activated receptor gamma mRNA and simultaneous mitochondrial morphology and respiration rates in the mouse

Arsenic has been identified as an environmental toxicant acting through various mechanisms, including the disruption of endocrine pathways. The present study assessed the ability of a single intraperitoneal injection of arsenic, to modify the mRNA expression levels of estrogen- and thyroid hormone receptors (ERα,β; TRα,β) and peroxisome proliferator-activated receptor gamma (PPARγ) in hypothalamic tissue homogenates of prepubertal mice in vivo. Mitochondrial respiration (MRR) was also measured, and the corresponding mitochondrial ultrastructure was analyzed. Results show that ERα,β, and TRα expression was significantly increased by arsenic, in all concentrations examined. In contrast, TRβ and PPARγ remained unaffected after arsenic injection. Arsenic-induced dose-dependent changes in state 4 mitochondrial respiration (St4). Mitochondrial morphology was affected by arsenic in that the 5 mg dose increased the size but decreased the number of mitochondria in agouti-related protein- (AgRP), while increasing the size without affecting the number of mitochondria in pro-opiomelanocortin (POMC) neurons. Arsenic also increased the size of the mitochondrial matrix per host mitochondrion. Complex analysis of dose-dependent response patterns between receptor mRNA, mitochondrial morphology, and mitochondrial respiration in the neuroendocrine hypothalamus suggests that instant arsenic effects on receptor mRNAs may not be directly reflected in St3-4 values, however, mitochondrial dynamics is affected, which predicts more pronounced effects in hypothalamus-regulated homeostatic processes after long-term arsenic exposure.

Espousing the innocence of paediatric patients: an innocent act?

Since the 19th century, innocence has been a hallmark of childhood. The innocence of children is seen as both a sanctity worth defending and a feature that excuses the unavoidable mistakes of adolescence. While beneficial in many settings, notions of childhood innocence are often entangled with values judgements. Inherent in innocence is the notion that that which we are innocent of is undesirable. Further, attributing innocence to some implies the tolerability of blame for others. This has unique implications in a medical setting. This essay explores the implications of espousing the innocence of paediatric patients. Ultimately, because attribution of innocence is both prone to bias and rooted in the same framework as blame, it degrades patient-centred care and compromises the patient-provider relationship. I argue that avoiding such characterisations may allow providers to more effectively promote paediatric health.

Potential of paracetamol for reproductive disruption: Molecular interaction, dynamics and MM-PBSA based In-silico assessment

Paracetamol is generally recommended for pain and fever. However, as per experimental and epidemiological data, widespread and irrational or long-term use of paracetamol may be harmful to human endocrine homeostasis, especially during pregnancy. Some researchers suggest that prenatal exposure to paracetamol might alter foetal development and also enhance the risk of reproductive disorders. An imbalance in the levels of these hormones may play a significant role in the emergence of various diseases, including infertility. Therefore, in this study, the interaction mechanism of paracetamol with reproductive hormone receptors was investigated by molecular docking, molecular dynamics (MD) simulations, and poisson-Boltzmann surface area (MM-PBSA) for assessing paracetamol's potency to disrupt reproductive hormones. The results indicate that paracetamol has the ability to interact with reproductive hormone receptors (estrogen 1XP9; 1QKM with binding energy of -5.61 kcal/mol; -5.77 kcal/mol; androgen 5CJ6 -5.63 kcal/mol; and progesterone 4OAR-5.60 kcal/mol) by hydrogen bonds as well as hydrophobic and van der Waals interactions to maintain its stability. In addition, the results of the MD simulations and MM-PBSA confirm that paracetamol and reproductive receptor complexes are stable. This research provides a molecular and atomic level understanding of how paracetamols disrupt reproductive hormone synthesis. The root mean square deviation (RMSD), root mean square fluctuation (RMSF), Radius of Gyration and hydrogen bonding exhibited that paracetamol mimic at various attribute to bisphenol and native ligand.

Endocrine Disruptors Induced Distinct Expression of Thyroid and Estrogen Receptors in Rat versus Mouse Primary Cerebellar Cell Cultures

The endocrine system of animals consists of fine-tuned self-regulating mechanisms that maintain the hormonal and neuronal milieu during tissue development. This complex system can be influenced by endocrine disruptors (ED)—substances that can alter the hormonal regulation even in small concentrations. By now, thousands of substances—either synthesized by the plastic, cosmetic, agricultural, or medical industry or occurring naturally in plants or in polluted groundwater—can act as EDs. Their identification and testing has been a hard-to-solve problem; Recent indications that the ED effects may be species-specific just further complicated the determination of biological ED effects. Here we compare the effects of bisphenol-A, zearalenone, and arsenic (well-known EDs) exerted on mouse and rat neural cell cultures by measuring the differences of the ED-affected neural estrogen- and thyroid receptors. EDs alters the receptor expression in a species-like manner detectable in the magnitude as well as in the nature of biological responses. It is concluded that the interspecies differences (or species specificity) in ED effects should be considered in the future testing of ED effects.

Comparative Analysis of Zearalenone Effects on Thyroid Receptor Alpha (TRα) and Beta (TRβ) Expression in Rat Primary Cerebellar Cell Cultures

Thyroid receptors play an important role in postnatal brain development. Zearalenone (ZEN), a major mycotoxin of Fusarium fungi, is well known to cause serious health problems in animals and humans through various mechanisms, including the physiological pathways of thyroid hormone (TH). In the present study, we aimed to investigate the expression of thyroid receptors α (TRα) and β (TRβ) in primary cerebellar neurons in the presence or absence of glia and following ZEN treatment, using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. Primary cerebellar granule cells were treated with low doses of ZEN (0.1 nM) in combination with physiologically relevant concentrations of l-thyroxine (T4), 3,3′,5-triiodo-l-thyronine (T3) and 17β-estradiol (E2). Expression levels of TRα and TRβ at mRNA and protein levels were slightly modified by ZEN administered alone; however, along with thyroid and steroid hormones, modelling the physiological conditions, expression levels of TRs varied highly depending on the given treatment. Gene expression levels were also highly modulated by the presence or absence of glial cells, with mostly contrasting effects. Our results demonstrate divergent transcriptional and translational mechanisms involved in the expression of TRs implied by ZEN and hormonal milieu, as well as culturing conditions.

The Influence of Low Doses of Zearalenone and T-2 Toxin on Calcitonin Gene Related Peptide-Like Immunoreactive (CGRP-LI) Neurons in the ENS of the Porcine Descending Colon

The enteric nervous system (ENS) can undergo adaptive and reparative changes in response to physiological and pathological stimuli. These manifest primarily as alterations in the levels of active substances expressed by the enteric neuron. While it is known that mycotoxins can affect the function of the central and peripheral nervous systems, knowledge about their influence on the ENS is limited. Therefore, the aim of the present study was to investigate the influence of low doses of zearalenone (ZEN) and T-2 toxin on calcitonin gene related peptide-like immunoreactive (CGRP-LI) neurons in the ENS of the porcine descending colon using a double immunofluorescence technique. Both mycotoxins led to an increase in the percentage of CGRP-LI neurons in all types of enteric plexuses and changed the degree of co-localization of CGRP with other neuronal active substances, such as substance P, galanin, nitric oxide synthase, and cocaine- and amphetamine-regulated transcript peptide. The obtained results demonstrate that even low doses of ZEN and T-2 can affect living organisms and cause changes in the neurochemical profile of enteric neurons.