Effects of estrogen receptor modulators on cytoskeletal proteins in the central nervous system

Estrogen receptor modulators are compounds of interest because of their estrogenic agonistic/antagonistic effects and tissue specificity. These compounds have many clinical applications, particularly for breast cancer treatment and osteoporosis in postmenopausal women, as well as for the treatment of climacteric symptoms. Similar to estrogens, neuroprotective effects of estrogen receptor modulators have been described in different models. However, the mechanisms of action of these compounds in the central nervous system have not been fully described. We conducted a systematic search to investigate the effects of estrogen receptor modulators in the central nervous system, focusing on the modulation of cytoskeletal proteins. We found that raloxifene, tamoxifen, and tibolone modulate some cytoskeletal proteins such as tau, microtuble-associated protein 1（MAP1）, MAP2, neurofilament 38（NF38） by different mechanisms of action and at different levels： neuronal microfilaments, intermediate filaments, and microtubule-associated proteins. Finally, we emphasize the importance of the study of these compounds in the treatment of neurodegenerative diseases since they present the benefits of estrogens without their side effects.

Design, Synthesis and Biological Evaluation of 2-Aroyl-3-aryl-6,7-dihydro-5H-furo[3,2-g]chromen Derivatives as a Novel Series of Estrogen Receptor Modulators

Based on the principles of the bioisosterism, combination of the active substructures of selective estrogen receptor modulators which are currently therapeutic agents available for the prevention and treatment of various estrogen dependent diseases, and structural optimization, a novel series of 2-aroyl-3-aryl-6,7-dihydro-5H-furo[3,2-g]- chromen derivatives was designed as potent selective estrogen receptor modulators via molecular docking. The target compounds have been synthesized, and characterized by 1R, proton NMR, ESI-MS, elemental analysis and evaluated for their antitumor activity against human osteosarcoma U2OS-EGFP-4FI2G cell line. Some target compounds showed good inhibition effects on U2OS-EGFP-4F12G cell line and the preliminary structure-activity relationships were discussed.

FTY720,Sphingosine 1-Phosphate Receptor Modulator,Ameliorates Experimental Autoimmune Encephalomyelitis by Inhibition of T Cell Infiltration

FTY720, a sphingosine 1-phosphate receptor modulator, induces a marked decrease in the number of peripheral blood lymphocytes and exerts immunomodulating activity in various experimental allograft and autoimmune disease models. In this study, we evaluated the effect of FTY720 and its active metabolite, （S）-enantiomer of FTY720-phosphate [（S）-FTY720-P] on experimental autoimmune encephalomyelitis （EAE） in rats and mice. Prophylactic administration of FTY720 at 0.1 to 1 mg/kg almost completely prevented the development of EAE, and therapeutic treatment with FTY720 significantly inhibited the progression of EAE and EAE-associated histological change in the spinal cords of LEW rats induced by immunization with myelin basic protein. Consistent with rat EAE, the development of proteolipid protein-induced EAE in SJL/J mice was almost completely prevented and infiltration of CD4^＋ T cells into spinal cord was decreased by prophylactic treatment with FTY720 and （S）-FTY720-P. When FTY720 or （S）-FTY720-P was given after establishment of EAE in SJL/J mice, the relapse of EAE was markedly inhibited as compared with interferon-β, and the area of demyelination and the infiltration of CD4^＋ T cells were decreased in spinal cords of EAE mice. Similar therapeutic effect by FTY720 was obtained in myelin oligodendrocyte glycoprotein-induced EAE in C57BL/6 mice. These results indicate that FTY720 exhibits not only a prophylactic but also a therapeutic effect on EAE in rats and mice, and that the effect of FTY720 on EAE appears to be due to a reduction of the infiltration of myelin antigen-specific CD4^＋ T cells into the inflammation site. Cellular ＆ Molecular Immunology. 2005;2（6）：439-448.

Selective Estrogen Receptor Modulator: Raloxifene

Selective estrogen receptor modulators （SERMs） are structurally different com- pounds that interact with intracellular estrogen receptors in target organs as estrogen receptor agonists and antagonists. Raloxifene is the only SERM approved worldwide for the prevention and treatment of postmenopausal osteoporosis. Raloxifene, which has estrogen-like actions on bone, lipids and the coagulation system, and estrogen antagonist effects on the breast and uterus, has undergone very extensive prospective, placebo-controlled, randomized trial evaluation.

Approach to loss of response to advanced therapies in inflammatory bowel disease

BACKGROUND Remarkable progress over the last decade has equipped clinicians with many options in the treatment of inflammatory bowel disease.Clinicians now have the unique opportunity to provide individualized treatment that can achieve and sustain remission in many patients.However,issues of primary non-response(PNR)and secondary loss of response(SLOR)to non-tumour necrosis factor inhibitor(TNFi)therapies remains a common problem.Specific issues include the choice of optimization of therapy,identifying when dose optimization will recapture response,establishing optimal dose for escalation and when to switch therapy.AIM To explores the issues of PNR and SLOR to non-TNFi therapies.METHODS This review explores the current evidence and literature to elucidate management options in cases of PNR/SLOR.It will also explore potential predictors for response following SLOR/PNR to therapies including the role of therapeutic drug monitoring(TDM).RESULTS In the setting of PNR and loss of response to alpha-beta7-integrin inhibitors and interleukin(IL)-12 and IL-23 inhibitors dose optimization is a reasonable option to capture response.For Janus kinase inhibitors dose optimization can be utilized to recapture response with loss of response.CONCLUSION The role of TDM in the setting of advanced non-TNFi therapies to identify patients who require dose optimization and as a predictor for clinical remission is not yet established and this remains an area that should be addressed in the future.

Identification of neuron selective androgen receptor inhibitors

AIM To identify neuron-selective androgen receptor(AR) signaling inhibitors, which could be useful in the treatment of spinal and bulbar muscular atrophy(SBMA), or Kennedy's disease, a neuromuscular disorder in which deterioration of motor neurons leads to progressive muscle weakness. METHODS Cell lines representing prostate, kidney, neuron, adipose, and muscle tissue were developed that stably expressed the CFP-AR-YFP FRET reporter. We used these cells to screen a library of small molecules for cell typeselective AR inhibitors. Secondary screening in luciferase assays was used to identify the best cell-type specific AR inhibitors. The mechanism of action of a neuronselective AR inhibitor was examined in vitro using luciferase reporter assays, immunofluorescence microscopy, and immunoprecipitations. Rats were treated with the most potent compound and tissue-selective AR inhibition was examined using RT-q PCR of AR-regulated genes and immunohistochemistry.RESULTS We identified the thiazole class of antibiotics as com-pounds able to inhibit AR signaling in a neuronal cell line but not a muscle cell line. One of these antibiotics, thiostrepton is able to inhibit the activity of both wild type and polyglutamine expanded AR in neuronal GT1-7 cells with nanomolar potency. The thiazole antibiotics are known to inhibit FOXM1 activity and accordingly, a novel FOXM1 inhibitor FDI-6 also inhibited AR activity in a neuron-selective fashion. The selective inhibition of AR is likely indirect as the varied structures of these compounds would not suggest that they are competitive antagonists. Indeed, we found that FOXM1 expression correlates with cell-type selectivity, FOXM1 co-localizes with AR in the nucleus, and that sh RNA-mediated knock down of FOXM1 reduces AR activity and thiostrepton sensitivity in a neuronal cell line. Thiostrepton treatment reduces FOXM1 levels and the nuclear localization of beta-catenin, a known co-activator of both FOXM1 and AR, and reduces the association between beta-catenin and AR. Treatment of rats with thiostrepton demonstrated AR signaling inhibition in neurons, but not muscles. CONCLUSION Our results suggest that thiazole antibiotics, or other inhibitors of the AR-FOXM1 axis, can inhibit AR signaling selectively in motor neurons and may be useful in the treatment or prevention of SBMA symptoms.

Neuroactive alkaloids that modulate the neuronal nicotinic receptor and provide neuroprotection in an Alzheimer's disease model:the case of Teline monspessulana

Despite the advances in combinatorial or synthetic chemis- try and bioinformatics, recent literature has demonstrated the relevance of nature and biomass as a source of new molecules to treat different pathologies, i.e., bioactive com- pounds obtained from Ecteinascidia turbinate to treat some types of cancer or rapamycin from Streptomyces hygroscop- icus to prevent organ rejection after transplant. This trend will continue simply due to the fact that Mother Nature has been synthesizing molecules for millions of years. In our lab- oratory, we have characterized several compounds obtained from natural sources and that possess important neuronal effects,

Tamoxifen:an FDA approved drug with neuroprotective effects for spinal cord injury recovery

Spinal cord injury（SCI） is a condition without a cure,affecting sensory and/or motor functions.The physical trauma to the spinal cord initiates a cascade of molecular and cellular events that generates a non-permissive environment for cell survival and axonal regeneration.Among these complex set of events are damage of the blood-brain barrier,edema formation,inflammation,oxidative stress,demyelination,reactive gliosis and apoptosis.The multiple events activated after SCI require a multi-active drug that could target most of these events and produce a permissive environment for cell survival,regeneration,vascular reorganization and synaptic formation.Tamoxifen,a selective estrogen receptor modulator,is an FDA approved drug with several neuroprotective properties that should be considered for the treatment of this devastating condition.Various investigators using different animal models and injury parameters have demonstrated the beneficial effects of this drug to improve functional locomotor recovery after SCI.Results suggest that the mechanism of action of Tamoxifen administration is to modulate anti-oxidant,anti-inflammatory and anti-gliotic responses.A gap of knowledge exists regarding the sex differences in response to Tamoxifen and the therapeutic window available to administer this treatment.In addition,the effects of Tamoxifen in axonal outgrowth or synapse formation needs to be investigated.This review will address some of the mechanisms activated by Tamoxifen after SCI and the results recently published by investigators in the field.

选择性雄激素受体调节剂治疗迟发性男性性腺功能低下症

Several testosterone preparations are used in the treatment of hypogonadism in the ageing male. These therapies differ in their convenience, flexibility, regional availability and expense but share their pharmacokinetic basis of approval and dearth of long-term safety data. The brevity and relatively reduced cost of pharmacokinetic based registration trials provides little commercial incentive to develop improved novel therapies for the treatment of late onset male hypogonadism. Selective androgen receptor modulators （SARMs） have been shown to provide anabolic benefit in the absence of androgenic effects on prostate, hair and skin. Current clinical development for SARMs is focused on acute muscle wasting conditions with defined clinical endpoints of physical function and lean body mass. Similar regulatory clarity concerning clinical deficits in men with hypogonadism is required before the beneficial pharmacology and desirable pharmacokinetics of SARMs can be employed in the treatment of late onset male hypogonadism.

【特刊综述】雄激素对骨骼肌的作用：对乏力的发展和治疗的意义

Androgens have potent anabolic effects on skeletal muscle and decline with age in parallel to losses in muscle mass and strength. This loss of muscle mass and function, known as sarcopenia, is the central event in development of frailty, the vulnerable health status that presages adverse outcomes and rapid functional decline in older adults. The potential role of falling androgen levels in the development of frailty and their utility as function promoting therapies in older men has therefore attracted considerable attention. This review summarizes current concepts and definitions in muscle ageing, sarcopenia and frailty, and evaluates recent developments in the study of androgens and frailty. Current evidence from observational and interventional studies strongly supports an effect of androgens on muscle mass in ageing men, but effects on muscle strength and particularly physical function have been less clear. Androgen treatment has been generally well-tolerated in studies of older men, but concerns remain over higher dose treatments and use in populations with high cardiovascular risk. The first trials of selective androgen receptor modulators （SARMs） suggest similar effects on muscle mass and function to traditional androgen therapies in older adults. Important future directions include the use of these agents in combination with exercise training to promote functional ability across different populations of older adults, as well as more focus on the relationships between concurrent changes in hormone levels, body composition and physical function in observational studies.

Ulipristal Acetate (UPA): An Alternative Option to Surgery for Uterine Fibroids in Reproductive Age: A Review

Uterine fibroids are common in females of reproductive age and substantially affecting fertility and quality of life. Current management strategies mainly involve surgical interventions. For treatment, options available are surgical and non-surgical, but the mode of management leans on several factors, such as severity of symptoms, patient’s age, myoma characteristics, desire to preserve uterus and fertility. Alternative approach to surgery for the treatment of symptomatic females with uterine myomas has been recognized. Ulipristal acetate (UPA) has been the first selective progesterone-receptor modulator (SPRM) approved for the pre-operative and long-term management of uterine fibroids. There are evidences promoting an important role for progesterone pathways in the pathophysiology of uterine fibroids which supports the use of ulipristal acetate. The availability of alternative choices to surgical intervention is very necessary especially for those willing to preserve uterus and fertility. One of the alternatives is with ulipristal acetate, which has been proven to treat fibroid symptoms effectively.

Synthesis of Oligomer with N-(O,O-diisopropyl)-phosphoryl Arginine and Its Effect on 5-Hydroxytryptamine Receptor

Oligomer (OMPA) with N(O,Odiisopropyl) phosphoryl arginine (DIPPArg) has been synthesized and its structure has been identified by IR, 1H NMR,31P NMR, and elemental analysis. The functional conversion ratio of this reaction was found to be about 30%. The effect of OMPA on the 5hydroxytryptamine (5HT) receptor was studied by a functional test of constriction in rat blood vessels. The results showed that OMPA inhibited 5HT receptorinduced blood vessels constrictions with pD2 values of 565±021 (OMPA) and 745± 030 (DIPPArg) and exhibited significant pharmacological action of antagonism effect on the 5HT receptor.

性腺功能减退患者的生育能力保护：研究进展

An increasing number of young and middle-aged men are seeking treatment for symptoms related to deficient levels of androgens （hypogonadism） including depression, loss of libido, erectile dysfunction, and fatigue. The increase in prevalence of testosterone supplementation in general and anabolic steroid-induced hypogonadism specifically among younger athletes is creating a population of young men who are uniquely impacted by the testicular end-organ negative consequences of exogenous steroid use. Exogenous testosterone therapy can alter the natural regulation of the hypothalamic-pituitary-gonadal axis leading to impaired spermatoganesis with azoospermia being a serious possible result, thus rendering the individual infertile. For men of reproductive age who suffer from hypogonadal symptoms, preservation of fertility is an important aspect of their treatment paradigm. Treatment with human chorionic gonadotropin （hCG） has shown the ability not only to reverse azoospermia brought on by testosterone supplementation therapy but also to help maintain elevated intratesticular testosterone levels. In addition, selective estrogen receptor modulators, often used with hCG have been shown both to elevate total testosterone levels and to maintain spermatogenesis in hypogonadal men.

A critical role of the thioredoxin domain containing protein 5(TXNDC5) in redox homeostasis and cancer development

Correct folding of nascent peptides occurs in the endoplasmic reticulum(ER).It is a complicate process primarily accomplished by the coordination of multiple redox proteins including members of the protein disulfide isomerase(PDI)family.As a critical member of the PDI family,thioredoxin domain containing protein 5(TXNDC5)assists the folding of newly synthesized peptides to their mature form through series of disulfide bond exchange reactions.Interestingly,TXNDC5 is frequently found overexpressed in specimens of many human diseases including various types of cancer.In this review,we summarized the biochemical function of TXNDC5 in mammalian cells and the recent progress on the understanding of its role and molecular mechanisms in cancer development.Findings of TXNDC5 in the activation of intracellular signaling pathways,stimulation of cell growth&proliferation,facilitation of cell survival and modulation of extracellular matrix to affect cancer cell invasion and metastasis are reviewed.These published studies suggest that strategies of targeting TXNDC5 can be developed as potentially valuable methods for the treatment of certain types of cancer in patients.