Hypothalamic Dysfunction and Multiple Sclerosis: Implications for Fatigue and Weight Dysregulation

Thyroid hormone action in adult neurogliogenic niches: the known and unknown

Over the last decades, thyroid hormones (THs) signaling has been established as a key signaling cue for the proper maintenance of brain functions in adult mammals, including humans. One of the most fascinating roles of THs in the mature mammalian brain is their ability to regulate adult neurogliogenic processes. In this respect, THs control the generation of new neuronal and glial progenitors from neural stem cells (NSCs) as well as their final differentiation and maturation programs. In this review, we summarize current knowledge on the cellular organization of adult rodent neurogliogenic niches encompassing well-established niches in the subventricular zone (SVZ) lining the lateral ventricles, the hippocampal subgranular zone (SGZ), and the hypothalamus, but also less characterized niches in the striatum and the cerebral cortex. We then discuss critical questions regarding how THs availability is regulated in the respective niches in rodents and larger mammals as well as how modulating THs availability in those niches interferes with lineage decision and progression at the molecular, cellular, and functional levels. Based on those alterations, we explore the novel therapeutic avenues aiming at harnessing THs regulatory influences on neurogliogenic output to stimulate repair processes by influencing the generation of either new neurons (i.e. Alzheimer's, Parkinson's diseases), oligodendrocytes (multiple sclerosis) or both (stroke). Finally, we point out future challenges, which will shape research in this exciting field in the upcoming years.

Understanding the spectrum of non-motor symptoms in multiple sclerosis: insights from animal models

Multiple sclerosis is a chronic autoimmune disease of the central nervous system and is generally considered to be a non-traumatic, physically debilitating neurological disorder. In addition to experiencing motor disability, patients with multiple sclerosis also experience a variety of non-motor symptoms, including cognitive deficits, anxiety, depression, sensory impairments, and pain. However, the pathogenesis and treatment of such non-motor symptoms in multiple sclerosis are still under research. Preclinical studies for multiple sclerosis benefit from the use of disease-appropriate animal models, including experimental autoimmune encephalomyelitis. Prior to understanding the pathophysiology and developing treatments for non-motor symptoms, it is critical to characterize the animal model in terms of its ability to replicate certain non-motor features of multiple sclerosis. As such, no single animal model can mimic the entire spectrum of symptoms. This review focuses on the non-motor symptoms that have been investigated in animal models of multiple sclerosis as well as possible underlying mechanisms. Further, we highlighted gaps in the literature to explain the non-motor aspects of multiple sclerosis in experimental animal models, which will serve as the basis for future studies.

Overview of the Current Pathophysiology of Fatigue in Multiple Sclerosis, Its Diagnosis and Treatment Options - Review Article

Fatigue is a common, debilitating and often underestimated symptom in patients with multiple sclerosis (MS). The exact pathophysiological mechanism of fatigue in MS is still unknown. However, there are many theories involving different immunological, metabolic and inflammatory mechanisms of fatigue. Owing to the subjective nature of this symptom, its diagnosis is still very limited and is still based only on diagnostic questionnaires. Although several therapeutic agents have been used in the past to try to influence fatigue in MS patients, no single effective approach for the treatment of fatigue has yet been found. This review article aims to provide the reader with information on the current theories on the origin and mechanism of fatigue in MS, as well as diagnostic procedures and, finally, current therapeutic strategies for the management of fatigue in MS patients.

Orexin pathway in Parkinson's disease: a review

Parkinson's disease (PD) is a progressive neurodegenerative disease (NDD) caused by dopaminergic neuron degeneration in the substantia nigra (SN). Orexin is a neuropeptide that plays a role in the pathogenesis of PD. Orexin has neuroprotective properties in dopaminergic neurons. In PD neuropathology, there is also degeneration of orexinergic neurons in the hypothalamus, in addition to dopaminergic neurons. However, the loss of orexinergic neurons in PD began after the degeneration of dopaminergic neurons. Reduced activity of orexinergic neurons has been linked to developing and progressing motor and non-motor symptoms in PD. In addition, the dysregulation of the orexin pathway is linked to the development of sleep disorders. The hypothalamic orexin pathway regulates various aspects of PD neuropathology at the cellular, subcellular, and molecular levels. Finally, non-motor symptoms, particularly insomnia and disturbed sleep, promote neuroinflammation and the accumulation of neurotoxic proteins as a result of defects in autophagy, endoplasmic reticulum (ER) stress, and the glymphatic system. As a result, this review aimed to highlight the potential role of orexin in PD neuropathology.

Volumetric changes in hypothalamic subunits in patients with relapsing remitting multiple sclerosis

PURPOSE

Studies on hypothalamic changes in patients with relapsing remitting multiple sclerosis (RRMS) are very scarce, despite the fact that the relationship with the hypothalamus is frequently reported. The aim of the study was to determine the volume of the hypothalamic subunits and the total hypothalamus and its relationship with the total demyelinating lesion volume (TLV) and expanded disability status scale (EDSS) in RRMS patients.

METHODS

In this cross-sectional study, anterior-superior, superior tubular, posterior hypothalamus, anterior-inferior, inferior tubular subunits of hypothalamus, and total hypothalamus volume were calculated, with fully automatic analysis methods using volumetric T1 images of 65 relapsed RRMS patients and 68 healthy controls (HC). Volume changes in the hypothalamus and its subunits in RRMS patients were examined using multivariate analysis of covariance (MANCOVA). The relationship of these volumes with EDSS and TLV was investigated by partial correlation analysis.

RESULTS

There is volume reduction in total hypothalamus (F = 13.87, p < 0.001), anterior-superior (F = 19.2, p < 0.001), superior tubular (F = 10.1, p = 0.002) subunits, and posterior hypothalamus (F = 19.2, p < 0.001) volume in RRMS patients. EDSS correlates negatively with anterior-superior (p = 0.017, r =  - 0.333), superior tubular subunits (p = 0.023, r =  - 0.439), posterior hypothalamus (p < 0.001, r =  - 0.511), and whole hypothalamus volume (p = 0.001, r =  - 0.439). TLV correlates negatively with anterior superior (p < 0.001, r =  - 0.565), anterior inferior (p = 0.002, r =  - 0.431), superior tubular subunits (p = 0.002, r =  - 0.432), posterior hypothalamus (p < 0.001, r =  - 0.703), and whole hypothalamus (p < 0.001, r =  - 0.627) volumes.

CONCLUSION

This study demonstrates a reduction in total hypothalamus volume, anterior-superior, superior tubular, and posterior hypothalamus in patients with RRMS. Anterior-superior and superior tubular subunit, posterior hypothalamus, and total hypothalamus volume were negatively correlated with TLV and EDSS scores.

Evaluation of the relationship between the morphometric structure of the pituitary gland and fatigue in patients with multiple sclerosis

BACKGROUND

The correlation between fatigue and disability in multiple sclerosis (MS) with the hypothalamus-pituitary-adrenal axis is known. This study aimed to investigate the relationship between the morphometric dimensions of the pituitary gland with fatigue and disability.

METHOD

This research, designed as a prospective and case-control study, included 85 MS patients and 45 healthy controls. The disability was evaluated using the expanded disability rating scale (EDSS), while fatigue was determined using the fatigue severity scale (FSS) and the neurological fatigue index (NFI-MS). The morphometric structure of the pituitary gland was measured using a coronal, T2-weighted, turbo-spin-echo sequence of magnetic resonance imaging.

RESULTS

FSS and NFI-MS scores were higher in MS patients than in the control group (p = 0.001). Patients with a progressive and moderate-to-severe disability had a higher FSS score (p = 0.015; p = 0.002, respectively). A positive correlation was determined between disease duration, attack frequency, and EDSS and physical fatigue subscale score (p = 0.001; r = 0.383; 0.373; 0.545, respectively). The height and width of the pituitary gland were higher in MS patients (p = 0.021; p = 0.001, respectively). Pituitary gland height was higher in fatigued patients (p = 0.041). A low-positive correlation was determined between the number of attacks and the height of the pituitary gland (p = 0.027, r = 0.231).

CONCLUSION

The difference in the dimensions of the pituitary gland in MS patients, especially in the fatigued group, supports the relationship of fatigue with morphometric features as well as the hypothalamus-pituitary-adrenal axis.

Ketogenic diet uncovers differential metabolic plasticity of brain cells

To maintain homeostasis, the body, including the brain, reprograms its metabolism in response to altered nutrition or disease. However, the consequences of these challenges for the energy metabolism of the different brain cell types remain unknown. Here, we generated a proteome atlas of the major central nervous system (CNS) cell types from young and adult mice, after feeding the therapeutically relevant low-carbohydrate, high-fat ketogenic diet (KD) and during neuroinflammation. Under steady-state conditions, CNS cell types prefer distinct modes of energy metabolism. Unexpectedly, the comparison with KD revealed distinct cell type-specific strategies to manage the altered availability of energy metabolites. Astrocytes and neurons but not oligodendrocytes demonstrated metabolic plasticity. Moreover, inflammatory demyelinating disease changed the neuronal metabolic signature in a similar direction as KD. Together, these findings highlight the importance of the metabolic cross-talk between CNS cells and between the periphery and the brain to manage altered nutrition and neurological disease.

Brain Structural and Functional Alterations in Multiple Sclerosis-Related Fatigue: A Systematic Review

Fatigue is one of the most disabling symptoms of multiple sclerosis (MS); it influences patients’ quality of life. The etiology of fatigue is complex, and its pathogenesis is still unclear and debated. The objective of this review was to describe potential brain structural and functional dysfunctions underlying fatigue symptoms in patients with MS. To reach this purpose, a systematic review was conducted of published studies comparing functional brain activation and structural brain in MS patients with and without fatigue. Electronic databases were searched until 24 February 2021. The structural and functional outcomes were extracted from eligible studies and tabulated. Fifty studies were included: 32 reported structural brain differences between patients with and without fatigue; 14 studies described functional alterations in patients with fatigue compared to patients without it; and four studies showed structural and functional brain alterations in patients. The results revealed structural and functional abnormalities that could correlate to the symptom of fatigue in patients with MS. Several studies reported the differences between patients with fatigue and patients without fatigue in terms of conventional magnetic resonance imaging (MRI) outcomes and brain atrophy, specifically in the thalamus. Functional studies showed abnormal activation in the thalamus and in some regions of the sensorimotor network in patients with fatigue compared to patients without it. Patients with fatigue present more structural and functional alterations compared to patients without fatigue. Specifically, abnormal activation and atrophy of the thalamus and some regions of the sensorimotor network seem linked to fatigue.

Exercise training improves memory and produces changes in the adrenal gland morphology in the experimental autoimmune encephalomyelitis

Objective. The present study sought to verify the effects of an exercise training on the memory along with the morphological assessment of the adrenal gland tissue in the rats with experimental autoimmune encephalomyelitis (EAE). Methods. Female Lewis rats were randomly divided into three groups: EAE group, EAE group with exercise (EAE+Ex), and control group (CO). Each group contained 10 rats. To evaluate the memory, all rats were subjected to the Morris water maze learning test for four consecutive days and one day for a prop test. EAE was induced by guinea pig spinal cord homogenate emulsified in incomplete Freund's adjuvant and heat-mycobacterium. The exercise training on a motorized treadmill was initiated 3 weeks before EAE induction and disconnected 2 weeks post-induction. Results. We found that exercise training for five weeks produced an improved swimming velocity related to memory improvement in EAE+Ex group in comparison with EAE group, but not an incurable adrenal gland tissue after EAE induction. Conclusions. The experimental design selected for this study appears to be an effective treatment for memory in rats with experimental autoimmune encephalomyelitis.

Orexins: A promising target to digestive cancers, inflammation, obesity and metabolism dysfunctions

Hypothalamic neuropeptides named hypocretin/orexins which were identified in 1998 regulate critical functions such as wakefulness in the central nervous system. These past 20 years had revealed that orexins/receptors system was also present in the peripheral nervous system where they participated to the regulation of multiple functions including blood pressure regulation, intestinal motility, hormone secretion, lipolyze and reproduction functions. Associated to these peripheral functions, it was found that orexins and their receptors were involved in various diseases such as acute/chronic inflammation, metabolic syndrome and cancers. The present review suggests that orexins or the orexin neural circuitry represent potential therapeutic targets for the treatment of multiple pathologies related to inflammation including intestinal bowel disease, multiple sclerosis and septic shock, obesity and digestive cancers.

Orexinergic System in Neurodegenerative Diseases

Orexinergic system consisting of orexins and orexin receptors plays an essential role in regulating sleep–wake states, whereas sleep disruption is a common symptom of a number of neurodegenerative diseases. Emerging evidence reveals that the orexinergic system is disturbed in various neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and multiple sclerosis (MS), whereas the dysregulation of orexins and/or orexin receptors contributes to the pathogenesis of these diseases. In this review, we summarized advanced knowledge of the orexinergic system and its role in sleep, and reviewed the dysregulation of the orexinergic system and its role in the pathogenesis of AD, PD, HD, and MS. Moreover, the therapeutic potential of targeting the orexinergic system for the treatment of these diseases was discussed.

The Role of Electroacupuncture in the Regulation of Appetite-Controlling Hormone and Inflammatory Response in Obesity

Objective: Obesity, a condition with serious complications, needs special attention. It is a complex and multifactorial problem and regulation of calorie balance involving various humoral and central factors is the main key for managing obesity. In addition, there is an increase in various proinflammatory cytokines and an increase in oxidative stress. There is a need to discover a useful therapy for obesity management. The goal of this review was to examine the literature on electroacupuncture (EA) as a potential therapy. Methods: This review explores the literature on EA, which has proven to be effective for inducing weight loss in experimental human and animal studies. Both continuous and dense-disperse EA waves have their own roles in hormone regulation of obesity using ST 25, CV 9, CV 12, CV 4, SP 6, ST 36, and ST 44; this is discussed the associated mechanism related to this is through suppression of various orexigenic peptides, enhancement of anorexigenic peptides, suppression of inflammatory factors, and improvement in the balance of pro-oxidants and antioxidants. Conclusions: The absence of another definitive therapy for obesity and EA's minimal side-effects make it a potential therapy for managing obesity.

Variant-to-Gene-Mapping Analyses Reveal a Role for the Hypothalamus in Genetic Susceptibility to Inflammatory Bowel Disease

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) is a polygenic disorder characterized principally by dysregulated inflammation impacting the gastrointestinal tract. However, there also is increasing evidence for a clinical association with stress and depression. Given the role of the hypothalamus in stress responses and in the pathogenesis of depression, useful insights could be gleaned from understanding its genetic role in IBD.

METHODS

We conducted genetic correlation analyses on publicly available genome-wide association study summary statistics for depression and IBD traits to identify genetic commonalities. We used partitioned linkage disequilibrium score regression, leveraging our ATAC sequencing and promoter-focused Capture C data, to measure enrichment of IBD single-nucleotide polymorphisms within promoter-interacting open chromatin regions of human embryonic stem cell-derived hypothalamic-like neurons (HNs). Using the same data sets, we performed variant-to-gene mapping to implicate putative IBD effector genes in HNs. To contrast these results, we similarly analyzed 3-dimensional genomic data generated in epithelium-derived colonoids from rectal biopsy specimens from donors without pathologic disease noted at the time of colonoscopy. Finally, we conducted enrichment pathway analyses on the implicated genes to identify putative IBD dysfunctional pathways.

RESULTS

We found significant genetic correlations (rg) of 0.122 with an adjusted P (Padj) = 1.4 × 10-4 for IBD: rg = 0.122; Padj = 2.5 × 10-3 for ulcerative colitis and genetic correlation (rg) = 0.094; Padj = 2.5 × 10-3 for Crohn's disease, and significant approximately 4-fold (P = .005) and approximately 7-fold (P = .03) enrichment of IBD single-nucleotide polymorphisms in HNs and colonoids, respectively. We implicated 25 associated genes in HNs, among which CREM, CNTF, and RHOA encode key regulators of stress. Seven genes also additionally were implicated in the colonoids. We observed an overall enrichment for immune and hormonal signaling pathways, and a colonoid-specific enrichment for microbiota-relevant terms.

CONCLUSIONS

Our results suggest that the hypothalamus warrants further study in the context of IBD pathogenesis.

Regional microglial activation in the substantia nigra is linked with fatigue in MS

OBJECTIVE

The goal of our study is to assess the role of microglial activation in MS-associated fatigue (MSAF) using [F-18]PBR06-PET.

METHODS

Fatigue severity was measured using the Modified Fatigue Impact Scale (MFIS) in 12 subjects with MS (7 relapsing-remitting and 5 secondary progressive) and 10 healthy control participants who underwent [F-18]PBR06-PET. The MFIS provides a total fatigue score as well as physical, cognitive, and psychosocial fatigue subscale scores. Standardized Uptake Value (SUV) 60-90 minute frame PET maps were coregistered to 3T MRI. Voxel-by-voxel analysis using Statistical Parametric Mapping and atlas-based regional analyses were performed. SUV ratios (SUVRs) were global brain normalized.

RESULTS

Peak voxel-based level of significance for correlation between total fatigue score and PET uptake was localized to the right substantia nigra (T-score 4.67, p = 0.001). Similarly, SUVRs derived from atlas-based segmentation of the substantia nigra showed significant correlation with MFIS (r = 0.76, p = 0.004). On multiple regression, the right substantia nigra was an independent predictor of total MFIS (p = 0.02) and cognitive MFIS subscale values (p = 0.007), after adjustment for age, disability, and depression. Several additional areas of significant correlations with fatigue scores were identified, including the right parahippocampal gyrus, right precuneus, and juxtacortical white matter (all p < 0.05). There was no correlation between fatigue scores and brain atrophy and lesion load in patients with MS.

CONCLUSION

Substantia nigra microglial activation is linked to fatigue in MS. Microglial activation across key brain regions may represent a unifying mechanism for MSAF, and further evaluation of neuroimmunologic basis of MSAF is warranted.

Insights into Endothelin-3 and Multiple Sclerosis

Endothelins are powerful vasoconstrictor peptides that play numerous other roles. Endothelin-1 (ET1) is the principal isoform produced by the endothelium in the human cardiovascular system. Endothelin-3 (ET3) and its rPptor affinity have been demonstrated to support neuronal repair mechanisms throughout life. In multiple sclerosis (MS), the role of vasoactive peptides are not well defined. Here we focus on ET3, specifically the plasma levels between MS patients and healthy subjects. Furthermore, we evaluated the changes in ET1 and ET3 plasma levels during different disease phases, the correlation between ET3 and cerebral circulation time, and the relationship between ET1 and ET3. In MS patients, the ET3 plasma levels were altered in a time-dependent manner. These results could support a putative role of ET3 in neuroprotection and/or neuroimmune modulation over time.

Insights into the Therapeutic Potential of Glucocorticoid Receptor Modulators for Neurodegenerative Diseases

Glucocorticoids are crucial for stress-coping, resilience, and adaptation. However, if the stress hormones become dysregulated, the vulnerability to stress-related diseases is enhanced. In this brief review, we discuss the role of glucocorticoids in the pathogenesis of neurodegenerative disorders in both human and animal models, and focus in particular on amyotrophic lateral sclerosis (ALS). For this purpose, we used the Wobbler animal model, which mimics much of the pathology of ALS including a dysfunctional hypothalamic–pituitary–adrenal axis. We discuss recent studies that demonstrated that the pathological cascade characteristic for motoneuron degeneration of ALS is mimicked in the genetically selected Wobbler mouse and can be attenuated by treatment with the selective glucocorticoid receptor antagonist (GRA) CORT113176. In long-term treatment (3 weeks) GRA attenuated progression of the behavioral, inflammatory, excitatory, and cell-death-signaling pathways while increasing the survival signal of serine–threonine kinase (pAkt). The action mechanism of the GRA may be either by interfering with GR deactivation or by restoring the balance between pro- and anti-inflammatory signaling pathways driven by the complementary mineralocorticoid receptor (MR)- and GR-mediated actions of corticosterone. Accordingly, GR antagonism may have clinical relevance for the treatment of neurodegenerative diseases.

Brain anatomical correlates of fatigue in multiple sclerosis

Fatigue is one of the most debilitating symptoms in patients with multiple sclerosis (MS). Despite its clinical significance, the aetiology and pathophysiology of MS-related fatigue are not well understood. Current evidence and understanding of the neuroanatomical underpinnings of MS-related fatigue are reviewed in this article. The aims of this paper are to (1) review the findings of previous structural neuroimaging studies on MS-related fatigue and summarize consistent findings regarding brain circuitry associated with fatigue in MS, (2) contextualize these findings with the neurochemistry of the relevant circuits and (3) discuss future perspectives with regard to impact on fatigue management of MS patients and methodological challenges towards improved understanding of fatigue pathogenesis. The detailed understanding of the neuroanatomical underpinnings of fatigue might contribute to the identification of novel treatment targets and factors determining treatment resistance to drugs used in current clinical practice.

Behavioural phenotypes in the cuprizone model of central nervous system demyelination

The feeding of cuprizone (CPZ) to animals has been extensively used to model the processes of demyelination and remyelination, with many papers adopting a narrative linked to demyelinating conditions like multiple sclerosis (MS), the aetiology of which is unknown. However, no current animal model faithfully replicates the myriad of symptoms seen in the clinical condition of MS. CPZ ingestion causes mitochondrial and endoplasmic reticulum stress and subsequent apoptosis of oligodendrocytes leads to central nervous system demyelination and glial cell activation. Although there are a wide variety of behavioural tests available for characterizing the functional deficits in animal models of disease, including that of CPZ-induced deficits, they have focused on a narrow subset of outcomes such as motor performance, cognition, and anxiety. The literature has not been systematically reviewed in relation to these or other symptoms associated with clinical MS. This paper reviews these tests and makes recommendations as to which are the most important in order to better understand the role of this model in examining aspects of demyelinating diseases like MS.

Interleukin-1-related activity and hypocretin-1 in cerebrospinal fluid contribute to fatigue in primary Sjögren's syndrome

BACKGROUND

Fatigue is a common and sometimes debilitating phenomenon in primary Sjögren's syndrome (pSS) and other chronic inflammatory diseases. We aimed to investigate how IL-1 β-related molecules and the neuropeptide hypocretin-1 (Hcrt1), a regulator of wakefulness, influence fatigue.

METHODS

Hcrt1 was measured by radioimmunoassay (RIA) in cerebrospinal fluid (CSF) from 49 patients with pSS. Interleukin-1 receptor antagonist (IL-1Ra), IL-1 receptor type 2 (IL-1RII), IL-6, and S100B protein were measured by enzyme-linked immunosorbent assay (ELISA). Fatigue was rated by the fatigue visual analog scale (fVAS).

RESULTS

Simple univariate regression and multiple regression analyses with fatigue as a dependent variable revealed that depression, pain, and the biochemical variable IL-1Ra had a significant association with fatigue. In PCA, two significant components were revealed. The first component (PC1) was dominated by variables related to IL-1β activity (IL-1Ra, IL-1RII, and S100B). PC2 showed a negative association between IL-6 and Hcrt1. fVAS was then introduced as an additional variable. This new model demonstrated that fatigue had a higher association with the IL-1β-related PC1 than to PC2. Additionally, a third component (PC3) became significant between low Hcrt1 concentrations and fVAS scores.

CONCLUSIONS

The main findings of this study indicate a functional network in which several IL-1β-related molecules in CSF influence fatigue in addition to the classical clinical factors of depression and pain. The neuropeptide Hcrt1 seems to participate in fatigue generation, but likely not through the IL-1 pathway.

Multiple sclerosis and sarcoidosis: A case for coexistence

Background

Patients with biopsy-proven systemic sarcoidosis who develop a chronic CNS disorder are often presumed to have neurosarcoidosis (NS), however, the possibility of comorbid neurologic disease, such as MS, must be considered if presentation and course are not typical for NS.

Methods

Retrospective chart review across 4 academic MS centers was undertaken to identify patients with diagnosis of MS (2017 McDonald criteria) and biopsy-confirmed extraneural sarcoidosis. Data were abstracted from each chart using a case report form that systematically queried for demographic, clinical, and paraclinical characteristics relevant to NS and MS.

Results

Ten patients met our inclusion criteria (mean age 47.7 [±5.9] years; 80% female). Noncaseating granulomas consistent with sarcoidosis were found on biopsy in all cases (lung 7/10, mediastinum 2/10, liver 1/10, spleen 1/10, and skin 1/10). Diagnosis of MS was based on clinical history of MS-like relapses and MRI findings characteristic of demyelination and typical disease evolution during follow-up (average of 7 years). No patient developed features of NS that could be considered a "red flag" against the diagnosis of MS (such as meningeal enhancement, hydrocephalus, and pituitary involvement). All patients were treated with disease-modifying therapy for MS.

Conclusions

We propose a rational diagnostic approach to patients with sarcoidosis who may have comorbid MS. When the clinical picture is equivocal, the presence of multiple "MS-typical lesions" and the absence of any "NS-typical lesions" on MRI favor diagnosis of MS. Close follow-up is required to ascertain whether clinical and radiologic disease evolution and response to MS therapies conform to the proposed diagnosis of MS.

Mechanisms of Acupuncture Therapy for Simple Obesity: An Evidence-Based Review of Clinical and Animal Studies on Simple Obesity

Simple obesity is a worldwide epidemic associated with rapidly growing morbidity and mortality which imposes an enormous burden on individual and public health. As a part of Traditional Chinese Medicine (TCM), acupuncture has shown the positive efficacy in the management of simple obesity. In this article, we comprehensively review the clinical and animal studies that demonstrated the potential mechanisms of acupuncture treatment for simple obesity. Clinical studies suggested that acupuncture regulates endocrine system, promotes digestion, attenuates oxidative stress, and modulates relevant molecules of metabolism in patients of simple obesity. Evidence from laboratory indicated that acupuncture regulates lipid metabolism, modulates inflammatory responses, and promotes white adipose tissue browning. Acupuncture also suppresses appetite through regulating appetite regulatory hormones and the downstream signaling pathway. The evidence from clinical and animal studies indicates that acupuncture induces multifaceted regulation through complex mechanisms and moreover a single factor may not be enough to explain the beneficial effects against simple obesity.

Localization of orexin B and orexin-2 receptor in the rat epididymis

The peptides orexin A (OXA) and orexin B (OXB) derived from the proteolytic cleavage of a common precursor molecule, prepro-orexin, were originally described in the rat hypothalamus. Successively, they have been found in many other brain regions as well as in peripheral organs of mammals and other less evolved animals. The widespread localization of orexins accounts for the multiple activities that they exert in the body, including the regulation of energy homeostasis, feeding, metabolism, sleep and arousal, stress, addiction, and cardiovascular and endocrine functions. Both OXA and OXB peptides bind to two G-coupled receptors, orexin-1 (OX1R) and orexin-2 (OX2R) receptor, though with different binding affinity. Altered expression/activity of orexins and their receptors has been associated with a large number of human diseases. Though at present evidence highlighted a role for orexins and cognate receptors in mammalian reproduction, their central and/or local effects on gonadal functions remain poorly known. Here, we investigated the localization of OXB and OX2R in the rat epididymis. Immunohistochemical staining of sections from caput, corpus and cauda segments of the organ showed intense signals for both OXB and OX2R in the principal cells of the lining epithelium, while no staining was detected in the other cell types. Negative results were obtained from immunohistochemical analysis of hypothalamic and testicular tissues from OX2R knock-out mice (OX2R^-/-) and OX1R/OX2R double knock-out (OX1R^-/-; OX2R^-/-) mice, thus demonstrating the specificity of the rabbit polyclonal anti-OX2R antibody used in our study. On contrary, the same antibody clearly showed the presence of OX2R in sections from hypothalamus and testis of normal mice and rats which are well known to express the receptor. Thus, our results provide the first definite evidence for the immunohistochemical localization of OXB and OX2R in the principal cells of rat epididymis.

High-dose biotin therapy leading to false biochemical endocrine profiles: validation of a simple method to overcome biotin interference

Background:

High-dose biotin therapy is beneficial in progressive multiple sclerosis (MS) and is expected to be adopted by a large number of patients. Biotin therapy leads to analytical interference in many immunoassays that utilize streptavidin-biotin capture techniques, yielding skewed results that can mimic various endocrine disorders. We aimed at exploring this interference, to be able to remove biotin and avoid misleading results.

Methods:

We measured free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), parathyroid homrone (PTH), 25-hydroxyvitamin D (25OHD), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, C-peptide, cortisol (Roche Diagnostics assays), biotin and its main metabolites (liquid chromatography tandem mass spectrometry) in 23 plasmas from MS patients and healthy volunteers receiving high-dose biotin, and in 39 biotin-unsupplemented patients, before and after a simple procedure (designated N5) designed to remove biotin by means of streptavidin-coated microparticles. We also assayed fT4, TSH and PTH in the 23 high-biotin plasmas using assays not employing streptavidin-biotin binding.

Results:

The biotin concentration ranged from 31.7 to 1160 µg/L in the 23 high-biotin plasmas samples. After the N5 protocol, the biotin concentration was below the detection limit in all but two samples (8.3 and 27.6 μg/L). Most hormones results were abnormal, but normalized after N5. All results with the alternative methods were normal except two slight PTH elevations. In the 39 biotin-unsupplemented patients, the N5 protocol did not affect the results for any of the hormones, apart from an 8.4% decrease in PTH.

Conclusions:

We confirm that most streptavidin-biotin hormone immunoassays are affected by high biotin concentrations, leading to a risk of misdiagnosis. Our simple neutralization method efficiently suppresses biotin interference.