Differential Effects of Halofuginone Enantiomers on Muscle Fibrosis and Histopathology in Duchenne Muscular Dystrophy.

Progressive loss of muscle and muscle function is associated with significant fibrosis in Duchenne muscular dystrophy (DMD) patients. Halofuginone, an analog of febrifugine, prevents fibrosis in various animal models, including those of muscular dystrophies. Effects of (+)/(-)-halofuginone enantiomers on motor coordination and diaphragm histopathology in mice, the mouse model for DMD, were examined.

Early pathological signs in young dysf mice are improved by halofuginone.

Dysferlinopathies are a non-lethal group of late-onset muscular dystrophies. Here, we evaluated the fusion ability of primary myoblasts from young dysf mice and the muscle histopathology prior to, and during early stages of disease onset. The ability of primary myoblasts of 5-week-old dysf mice to form large myotubes was delayed compared to their wild-type counterparts, as evaluated by scanning electron microscopy.

Hydroxy group requirement for halofuginone-dependent inhibition of muscle fibrosis and improvement of histopathology in the mdx mouse model for Duchenne muscular dystrophy.

In Duchenne muscular dystrophy (DMD), the progressive loss of muscle and its ability to function is associated with significant fibrosis, representing the major disease complication in patients. Halofuginone, a halogenated analog of the naturally occurring febrifugine, has been shown to prevent fibrosis in various animal models, including those of muscular dystrophies. Here, two optically active enantiomers of deoxyhalofuginone - a halofuginone analogue in which the hydroxy group in position 3 was removed from the piperidinyl entity - were evaluated with respect to their effect on muscle histopathology in mdx mice.

A promotive effect for halofuginone on membrane repair and synaptotagmin-7 levels in muscle cells of dysferlin-null mice.

In the absence of dysferlin, skeletal muscle cells fail to reseal properly after injury, resulting in slow progress of the dysferlinopathy muscular dystrophy (MD). Halofuginone, a leading agent in preventing fibrosis in MDs, was tested for its effects on membrane resealing post-injury. A hypo-osmotic shock assay on myotubes derived from wild-type (Wt) and dysferlin-null (dysf-/-) mice revealed that pre-treatment with halofuginone reduces the percentage of membrane-ruptured myotubes only in dysf-/- myotubes.

Elevated Expression of Moesin in Muscular Dystrophies.

Fibrosis is the main complication of muscular dystrophies. We identified moesin, a member of the ezrin-radixin-moesin family, in dystrophic muscles of mice representing Duchenne and congenital muscular dystrophies (DMD and CMD, respectively) and dysferlinopathy, but not in the wild type. High levels of moesin were also observed in muscle biopsy specimens from DMD, Ullrich CMD, and merosin-deficient CMD patients, all of which present high levels of fibrosis.

Halofuginone promotes satellite cell activation and survival in muscular dystrophies.

Halofuginone is a leading agent in preventing fibrosis and inflammation in various muscular dystrophies. We hypothesized that in addition to these actions, halofuginone directly promotes the cell-cycle events of satellite cells in the mdx and dysf(-/-) mouse models of early-onset Duchenne muscular dystrophy and late-onset dysferlinopathy, respectively. In both models, addition of halofuginone to freshly prepared single gastrocnemius myofibers derived from 6-week-old mice increased BrdU incorporation at as early as 18h of incubation, as well as phospho-histone H3 (PHH3) and MyoD protein expression in the attached satellite cells, while having no apparent effect on myofibers derived from wild-type mice.

Strigolactone analogs act as new anti-cancer agents in inhibition of breast cancer in xenograft model.

Strigolactones (SLs) are a novel class of plant hormones. Previously, we found that analogs of SLs induce growth arrest and apoptosis in breast cancer cell lines. These compounds also inhibited the growth of breast cancer stem cell enriched-mammospheres with increased potency.

The role of iNOS in cholesterol-induced liver fibrosis.

Accumulation of cholesterol in the liver is associated with the development of non-alcoholic steatohepatitis-related fibrosis. However, underlying mechanisms are not well understood. The present study investigated the role of inducible nitric oxide synthase (iNOS) in cholesterol-induced liver fibrosis by feeding wild-type (WT) and iNOS-deficient mice with control or high-cholesterol diet (HCD) for 6 weeks.

Inhibition of muscle fibrosis results in increases in both utrophin levels and the number of revertant myofibers in Duchenne muscular dystrophy.

Duchenne Muscular Dystrophy is characterized by: near absence of dystrophin in skeletal muscles; low percentage of revertant myofibers; up-regulation of utrophin synthesis; and a high degree of muscle fibrosis. In patient quadriceps femoris biopsies (n = 6, ages between 3-9 years) an inverse correlation was observed between the levels of collagen type I - representing fibrosis - and the levels of utrophin. This correlation was independent of the patient's age and was observed in the entire muscle biopsy sections.

Halofuginone - the multifaceted molecule.

Halofuginone is an analog of febrifugine-an alkaloid originally isolated from the plant Dichroa febrifuga. During recent years, halofuginone has attracted much attention because of its wide range of beneficial biological activities, which encompass malaria, cancer, and fibrosis-related and autoimmune diseases. At present two modes of halofuginone actions have been described: (1) Inhibition of Smad3 phosphorylation downstream of the TGFβ signaling pathway results in inhibition of fibroblasts-to-myofibroblasts transition and fibrosis.

Halofuginone for fibrosis, regeneration and cancer in the gastrointestinal tract.

Organ fibrosis and architectural remodeling can severely disrupt tissue function, often with fatal consequences. Fibrosis is the end result of chronic inflammatory reactions induced by a variety of stimuli, and the key cellular mediator of fibrosis comprises the myofibroblasts which, when activated, serve as the primary collagen-producing cells. Complex links exist between fibrosis, regeneration and carcinogenesis, and the concept that all organs contain common tissue fibrosis pathways that could be potential therapeutic targets is an attractive one.

Halofuginone improves muscle-cell survival in muscular dystrophies.

Halofuginone has been shown to prevent fibrosis via the transforming growth factor-β/Smad3 pathway in muscular dystrophies. We hypothesized that halofuginone would reduce apoptosis--the presumed cause of satellite-cell depletion during muscle degradation-in the mdx mouse model of Duchenne muscular dystrophy. Six-week-old mdx mouse diaphragm exhibited fourfold higher numbers of apoptotic nuclei compared with wild-type mice as determined by a TUNEL assay.

The chemistry and biology of febrifugine and halofuginone.

The trans-2,3-disubstituted piperidine, quinazolinone-containing natural product febrifugine (also known as dichroine B) and its synthetic analogue, halofuginone, possess antimalarial activity. More recently studies have also shown that halofuginone acts as an agent capable of reducing fibrosis, an indication with clinical relevance for several disease states. This review summarizes historical isolation studies and the chemistry performed which culminated in the correct structural elucidation of naturally occurring febrifugine and its isomer isofebrifugine.

Inhibition of muscle fibrosis and improvement of muscle histopathology in dysferlin knock-out mice treated with halofuginone.

Absence of, or loss-of-function mutations in the dysferlin gene (dysf) result in dysferlinopathy, characterized by increased muscle inflammation, collagen deposition and deterioration in muscle function. We evaluated halofuginone efficacy in improving muscle histopathology in mice with deleted dysf transmembrane domain. Quadriceps sublumbar and longissimus muscles of 9-month-old dysf-/- mice treated with halofuginone for 4 months exhibited a reduction in centrally-nucleated myofibers, inflammatory infiltrates and collagen content.

The involvement of collagen triple helix repeat containing 1 in muscular dystrophies.

Fibrosis is the main complication of muscular dystrophies. We identified collagen triple helix repeat containing 1 (Cthrc1) in skeletal and cardiac muscles of mice, representing Duchenne and congenital muscle dystrophies (DMD and CMD, respectively), and dysferlinopathy. In all of the mice, Cthrc1 was associated with high collagen type I levels; no Cthrc1 or collagen was observed in muscles of control mice.

Involvement of host stroma cells and tissue fibrosis in pancreatic tumor development in transgenic mice.

Introduction: Stroma cells and extracellular matrix (ECM) components provide the pivotal microenvironment for tumor development. The study aimed to evaluate the importance of the pancreatic stroma for tumor development.

Methods: Pancreatic tumor cells were implanted subcutaneously into green fluorescent protein transgenic mice, and stroma cells invading the tumors were identified through immunohistochemistry.

Halofuginone inhibits multiple myeloma growth in vitro and in vivo and enhances cytotoxicity of conventional and novel agents.

Multiple Myeloma (MM), a malignancy of plasma cells, remains incurable despite the use of conventional and novel therapies. Halofuginone (HF), a synthetic derivative of quinazolinone alkaloid, has recently been shown to have anti-cancer activity in various preclinical settings. This study demonstrated the anti-tumour activity of HF against a panel of human MM cell lines and primary patient-derived MM cells, regardless of their sensitivity to conventional therapy or novel agents.

Losartan reduces trinitrobenzene sulphonic acid-induced colorectal fibrosis in rats.

Background: Intestinal fibrosis is a challenging clinical condition in several fibrostenosing enteropathies, particularly Crohn's disease. Currently, no effective preventive measures or medical therapies are available for intestinal fibrosis. Fibrosis, due to an abnormal accumulation of extracellular matrix proteins, is a chronic and progressive process mediated by cell⁄matrix⁄cytokine and growth factor interactions, but may be a reversible phenomenon.

Th17 cells and IL-17 in protective immunity to vaginal candidiasis.

Background: Th17 cells play a major role in coordinating the host defence in oropharyngeal candidiasis. In this study we investigated the involvement of the Th17 response in an animal model of vulvovaginal candidiasis (VVC).

Methods: To monitor the course of infection we exploited a new in vivo imaging technique.

Hsp90 and angiogenesis in bone disorders--lessons from the avian growth plate.

Thiram-induced tibial dyschondroplasia (TD) and vitamin-D deficiency rickets are avian bone disorders of different etiologies characterized by abnormal chondrocyte differentiation, enlarged and unvascularized growth plates, and lameness. Heat-shock protein 90 (Hsp90) is a proangiogenic factor in mammalian tissues and in tumors; therefore, Hsp90 inhibitors were developed as antiangiogenic factors. In this study, we evaluated the association between Hsp90, hypoxia, and angiogenesis in the chick growth plate.

Halofuginone and muscular dystrophy.

Muscular dystrophies (MDs) include different inherited diseases that all result in progressive muscle degeneration, impaired locomotion and often premature death. The major focus of MD research has been on alleviating the primary genetic deficit - using gene therapy and myoblast-transfer approaches to promote expression of the deficient or mutated genes in the muscle fibers. Although promising, these approaches have not yet entered into clinical practice and unfortunately for MD patients, there is currently no cure.

Fibrosis inhibition and muscle histopathology improvement in laminin-alpha2-deficient mice.

In muscular dystrophies (MD) the loss of muscle and its ability to function are associated with fibrosis. We evaluated the efficacy of halofuginone in reducing fibrosis in the dy(2J)/dy(2J) mouse model of congenital MD. Mice were injected intraperitoneally with 5 microg of halofuginone 3 times a week for 5 or 15 weeks, starting at the age of 3 weeks.

Inhibition of pancreatic stellate cell activation by halofuginone prevents pancreatic xenograft tumor development.

Objectives: Most solid tumors consist of neoplastic and nonneoplastic cells and extracellular matrix components. In the pancreas, activated stellate cells (PSCs) are the source of the extracellular matrix proteins. We evaluated the significance of PSC activation in tumor establishment and development in mouse xenografts.

Halofuginone inhibits Smad3 phosphorylation via the PI3K/Akt and MAPK/ERK pathways in muscle cells: effect on myotube fusion.

Halofuginone, a novel inhibitor of Smad3 phosphorylation, has been shown to inhibit muscle fibrosis and to improve cardiac and skeletal muscle functions in the mdx mouse model of Duchenne muscular dystrophy. Here, we demonstrate that halofuginone promotes the phosphorylation of Akt and mitogen-activated protein kinase (MAPK) family members in a C2 muscle cell line and in primary myoblasts derived from wild-type and mdx mice diaphragms. Halofuginone enhanced the association of phosphorylated Akt and MAPK/extracellular signal-regulated protein kinase (ERK) with the non-phosphorylated form of Smad3, accompanied by a reduction in Smad3 phosphorylation levels.

Inhibition of transforming growth factor beta signaling by halofuginone as a modality for pancreas fibrosis prevention.

Objectives: Chronic pancreatitis is characterized by inflammation and fibrosis. We evaluated the efficacy of halofuginone, an inhibitor of collagen synthesis and myofibroblast activation, in preventing cerulein-induced pancreas fibrosis.

Methods: Collagen synthesis was evaluated by in situ hybridization and staining.