RESUMO
INTRODUCTION: There is evidence that supports a role for Vitamin D (Vit. D) in muscle. The exact mechanism by which Vit. D deficiency impairs muscle strength and function is not clear. METHODS: Three-week-old mice were fed diets with varied combinations of Vit. D and Ca2+ deficiency. Behavioral testing, genomic and protein analysis, and muscle histology were performed with a focus on neuromuscular junction (NMJ) -related genes. RESULTS: Vit. D and Ca2+ deficient mice performed more poorly on given behavioral tasks than animals with Vit. D deficiency alone. Genomic and protein analysis of the soleus and tibialis anterior muscles revealed changes in several Vit. D metabolic, NMJ-related, and protein chaperoning and refolding genes. CONCLUSIONS: These data suggest that detrimental effects of a Vit. D deficient or a Vit. D and Ca2+ deficient diet may be a result of differential alterations in the structure and function of the NMJ and a lack of a sustained stress response in muscles. Muscle Nerve 54: 1120-1132, 2016.
Assuntos
Deficiência de Ácido Ascórbico/patologia , Dieta/efeitos adversos , Regulação da Expressão Gênica/fisiologia , Membro Posterior/patologia , Fibras Musculares Esqueléticas/fisiologia , Junção Neuromuscular/fisiopatologia , Fatores Etários , Animais , Deficiência de Ácido Ascórbico/sangue , Deficiência de Ácido Ascórbico/etiologia , Deficiência de Ácido Ascórbico/metabolismo , Cálcio/metabolismo , Modelos Animais de Doenças , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Locomoção , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Força Muscular , Hormônio Paratireóideo/sangue , Fósforo/sangue , Equilíbrio Postural , Desempenho Psicomotor , Vitamina D/metabolismoRESUMO
Activin A, a member of the transforming growth factor-ß superfamily, provides pleiotropic regulation of fibrosis and inflammation. We aimed at determining whether selective inhibition of activin A would provide a regenerative benefit. The introduction of activin A into normal muscle increased the expression of inflammatory and muscle atrophy genes Tnf, Tnfrsf12a, Trim63, and Fbxo32 by 3.5-, 10-, 2-, and 4-fold, respectively. The data indicate a sensitive response of muscle to activin A. Two hours after cardiotoxin-induced muscle damage, local activin A protein expression increased by threefold to ninefold. Neutralization of activin A with a specific monoclonal antibody in this muscle injury model decreased the muscle protein levels of lymphotoxin α and Il17a by 32% and 42%, respectively. Muscle histopathological features showed that activin A antibody-treated mice displayed an increase in muscle degradation, with the concomitant 9.2-fold elevation in F4/80-positive cells 3 days after injury. At the same time, the number of Pax7/Myod1-positive cells also increased, indicative of potentiated muscle precursor activation. Ultimately, activin A inhibition resulted in rapid recovery of muscle contractile properties indicated by a restoration of maximum and specific force. In summary, selective inhibition of activin A with a monoclonal antibody in muscle injury leads to the early onset of tissue degradation and subsequent enhanced myogenesis, thereby accelerating muscle repair and functional recovery.
Assuntos
Ativinas/antagonistas & inibidores , Contração Muscular/fisiologia , Músculo Esquelético/lesões , Músculo Esquelético/metabolismo , Animais , Eletroporação , Ensaio de Imunoadsorção Enzimática , Feminino , Imuno-Histoquímica , Camundongos Endogâmicos C57BL , Regeneração/fisiologia , TranscriptomaRESUMO
Follistatin (FST) is a member of the tissue growth factor ß family and is a secreted glycoprotein that antagonizes many members of the family, including activin A, growth differentiation factor 11, and myostatin. The objective of this study was to explore the use of an engineered follistatin therapeutic created by fusing FST315 lacking heparin binding activity to the N terminus of a murine IgG1 Fc (FST315-ΔHBS-Fc) as a systemic therapeutic agent in models of muscle injury. Systemic administration of this molecule was found to increase body weight and lean muscle mass after weekly administration in normal mice. Subsequently, we tested this agent in several models of muscle injury, which were chosen based on their severity of damage and their ability to reflect clinical settings. FST315-ΔHBS-Fc treatment proved to be a potent inducer of muscle remodeling and regeneration. FST315-ΔHBS-Fc induced improvements in muscle repair after injury/atrophy by modulating the early inflammatory phase allowing for increased macrophage density, and Pax7-positive cells leading to an accelerated restoration of myofibers and muscle function. Collectively, these data demonstrate the benefits of a therapeutically viable form of FST that can be leveraged as an alternate means of ameliorating muscle regeneration.
Assuntos
Folistatina/farmacologia , Fragmentos Fc das Imunoglobulinas/genética , Imunoglobulina G/genética , Músculo Esquelético/efeitos dos fármacos , Proteínas Recombinantes de Fusão/farmacologia , Regeneração , Animais , Folistatina/genética , Camundongos , Músculo Esquelético/fisiologia , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/genéticaRESUMO
The Th17 pathway has been implicated in autoimmune diseases. The retinoic acid receptor-related orphan receptor C2 (RORγt) is a master regulator of Th17 cells and controls the expression of IL-17A. RORγt is expressed primarily in IL-17A-producing lymphoid cells. Here we describe a virtual screen of the ligand-binding pocket and subsequent screen in a binding assay that identified the 1-benzyl-4',5'-dihydrospiro[piperidine-4,7'-thieno[2,3-c]pyran]-2'-carboxamide scaffold as a starting point for optimization of binding affinity and functional activity guided by structure-based design. Compound 12 demonstrated activity in a mouse PK/PD model and efficacy in an inflammatory arthritis mouse model that were used to define the level and duration of target engagement required for efficacy in vivo. Further optimization to improve ADME and physicochemical properties with guidance from simulations and modeling provided compound 22, which is projected to achieve the level and duration of target engagement required for efficacy in the clinic.
Assuntos
Ligantes , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Tiofenos/química , Animais , Artrite/induzido quimicamente , Artrite/tratamento farmacológico , Artrite/patologia , Sítios de Ligação , Cristalografia por Raios X , Modelos Animais de Doenças , Desenho de Fármacos , Feminino , Meia-Vida , Humanos , Interleucina-17/genética , Interleucina-17/metabolismo , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Camundongos , Simulação de Dinâmica Molecular , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/química , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Ligação Proteica , Relação Estrutura-Atividade , Tiofenos/metabolismo , Tiofenos/farmacologia , Tiofenos/uso terapêuticoRESUMO
A selective estrogen receptor modulator (SERM) for the potential treatment of hot flushes is described. (R)-(+)-7,9-difluoro-5-[4-(2-piperidin-1-ylethoxy)phenyl]-5H-6-oxachrysen-2-ol, LSN2120310, potently binds ERalpha and ERbeta and is an antagonist in MCF-7 breast adenocarcinoma and Ishikawa uterine cancer cell lines. The compound is a potent estrogen antagonist in the rat uterus. In ovariectomized rats, the compound lowers cholesterol, maintains bone mineral density, and is efficacious in a morphine dependent rat model of hot flush efficacy.
Assuntos
Benzopiranos/síntese química , Antagonistas de Estrogênios/síntese química , Fogachos/tratamento farmacológico , Naftalenos/síntese química , Moduladores Seletivos de Receptor Estrogênico/síntese química , Adenocarcinoma , Animais , Anticolesterolemiantes/síntese química , Anticolesterolemiantes/química , Anticolesterolemiantes/farmacologia , Benzopiranos/química , Benzopiranos/farmacologia , Densidade Óssea/efeitos dos fármacos , Neoplasias da Mama , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Colesterol/sangue , Antagonistas de Estrogênios/química , Antagonistas de Estrogênios/farmacologia , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Feminino , Humanos , Morfina/farmacologia , Naftalenos/química , Naftalenos/farmacologia , Ovariectomia , Ratos , Ratos Sprague-Dawley , Moduladores Seletivos de Receptor Estrogênico/química , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Estereoisomerismo , Neoplasias Uterinas , Útero/efeitos dos fármacos , Útero/crescimento & desenvolvimentoRESUMO
The high regenerative capacity of adult skeletal muscle relies on a self-renewing depot of adult stem cells, termed muscle satellite cells (MSCs). Androgens, known mediators of overall body composition and specifically skeletal muscle mass, have been shown to regulate MSCs. The possible overlapping function of androgen regulation of muscle growth and MSC activation has not been carefully investigated with regards to muscle regeneration.Therefore, the aim of this study was to examine coinciding androgen-mediated genetic changes in an in vitro MSC model and clinically relevant in vivo models. A gene signature was established via microarray analysis for androgen-mediated MSC engagement and highlighted several markers including follistatin (FST), IGF-1, C-X-C chemokine receptor 4 (CXCR4), hepatocyte growth factor (HGF) and glucocorticoid receptor (GR). In an in vivo muscle atrophy model, androgen re-supplementation significantly increased muscle size and expression of IGF-1, FST, and HGF, while significantly decreasing expression of GR. Biphasic gene expression profiles over the 7-day re-supplementation period identified temporal androgen regulation of molecular targets involved in satellite cell engagement into myogenesis. In a muscle injury model, removal of androgens resulted in delayed muscle recovery and regeneration. Modifications in the androgen signaling gene signature, along with reduced Pax7 and MyoD expression, suggested that limited MSC activation and increased inflammation contributed to the delayed regeneration. However, enhanced MSC activation in the androgen-deplete mouse injury model was driven by an androgen receptor (AR) agonist. These results provide novel in vitro and in vivo evidence describing molecular targets of androgen signaling, while also increasing support for translational use of AR agonists in skeletal muscle recovery and regeneration.
Assuntos
Androgênios/metabolismo , Músculo Esquelético/citologia , Músculo Esquelético/fisiologia , Regeneração , Transdução de Sinais , Animais , Biomarcadores/metabolismo , Linhagem Celular , Folistatina/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Ligantes , Masculino , Camundongos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/lesões , Ratos , Receptores Androgênicos/metabolismo , Receptores CXCR4/genética , Receptores de Glucocorticoides/genética , Regeneração/efeitos dos fármacos , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/efeitos dos fármacos , Células Satélites de Músculo Esquelético/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
We report the synthesis and characterization of novel 3-aryl indoles as potent and efficacious progesterone receptor (PR) antagonists with potential for the treatment of uterine fibroids. These compounds demonstrated excellent selectivity over other steroid nuclear hormone receptors such as the mineralocorticoid receptor (MR). They were prepared from 2-bromo-6-nitro indole in four to six steps using a Suzuki cross-coupling as the key step. Compound 8f was orally active in the complement 3 model of progesterone antagonism in the rat uterus and demonstrated partial antagonism in the McPhail model of progesterone activity.
RESUMO
For selective estrogen receptor modulators (SERMs), the orientation of the basic side chain relative to the SERM core has a significant impact on function. The synthesis and biological evaluation of two series of SERMs are disclosed, where the ligand side chain is constrained to adopt a defined orientation. Compounds where the side chain is forced into the plane of the SERM core have a different profile compared to those compounds where the side chain is pseudo-orthogonal, particularly with regard to antagonism of estradiol action on an Ishikawa uterine cell line.
Assuntos
Naftalenos/síntese química , Moduladores Seletivos de Receptor Estrogênico/síntese química , Tiofenos/síntese química , Animais , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Ligantes , Naftalenos/química , Naftalenos/farmacologia , Ensaio Radioligante , Ratos , Moduladores Seletivos de Receptor Estrogênico/química , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Relação Estrutura-Atividade , Tiofenos/química , Tiofenos/farmacologia , Útero/efeitos dos fármacos , Útero/fisiologiaRESUMO
The pharmacology and SAR of representative equine estogens is described. 17alpha-Dihydroequilenin was found to prevent bone loss after 5 weeks of oral administration to ovariectomized rats. The stereochemical significance of the D-ring and the C/D ring juncture was investigated with a series of benzothiophene-based equilenin analogues.