Cellular and Molecular Myology
Prof. Guglielmo Sorci
Dept. Medicine and Surgery
University of Perugia
IIM (Interuniversity Institute of Myology)
Our Research Aims
- Investigating the biology of muscle precursor cells, muscle regeneration, muscle atrophy (including sarcopenia and cancer cachexia), muscular dystrophy, and rhabdomyosarcoma, with particular regards to RAGE (receptor for advanced glycation end-products) and the calcium-binding protein S100B
- Investigating the intraperitoneal injection of microencapsulated Sertoli cells as a treatment to Duchenne muscular dystrophy.
- Investigating the alterations induced by microgravity in human satellite cells.
- Investigating the efficacy of herbal extracts in counteracting muscle atrophy.
Accelerating the use of microencapsulated Sertoli cells to treat DMD patients
Granted by Duchenne Parent Project NL
Sertoli cells (SeC) of the testes are endowed with trophic and anti-inflammatory properties and have been extensively used to protect co-grafted tissues or to take benefit from their released factors in many experimental models of diseases. A single intraperitoneal injection of biocompatible alginate-based microencapsulated porcine SeC (MC-SeC) into dystrophic mice translated into recovery of muscle morphology and performance in the absence of pharmacological immunosuppression. Injected MC-SeC behave as a drug-delivery system secreting a cocktail of factors that cross the peritoneum and reach all body muscles through the blood flow, thus restraining muscle inflammation and upregulating utrophin expression. Moreover, SeC exert promyogenic, antifibrotic and anti-atrophic effects on myoblasts/myotubes, and induce utrophin expression in human DMD myotubes irrespective of the mutation in a heregulin β1/ErbB2/ERK1/2-dependent manner. Thus, the SeC-based approach appears as a potential universal treatment to DMD. Based on the evaluation of the TREAT NMD Advisory Committee for Therapeutics (TACT), the project is aimed to evaluate in mdx mice: i) subcutaneous vs intraperitoneal engraftment of MC-SeC; ii) the effects of MC-SeC on the heart and tissues other than muscles; iii) the effects of MC-SeC on muscle physiology and performance; iv) the factors mainly involved in the beneficial effects of MC-SeC and their mechanism of action; v) the use of MC-SeC in combination with steroids. This investigation will improve the translational potential of SeC-based treatments to DMD and Becker muscular dystrophy (BMD) patients, endowed with several advantages over the therapeutic approaches currently under evaluation and substantially devoid of side effects.
Preclinical targeting of RAGE (receptor for advanced glycation end-products)
to counteract cancer cachexia
Granted by AIRC (Associazione Italiana per la Ricerca sul Cancro); Project #24762 (2021-2026)
Cachexia, a multifactorial syndrome affecting more than half patients with advanced cancer and responsible for ~20% of cancer-associated deaths, is still poorly understood and no standard cures are available. Muscle atrophy due to systemic inflammation and tumor-released factors is a major clinical feature of cachexia leading to weight loss, and worsening quality of life and patients’ response to anti-cancer therapy. The identification of valuable biomarkers of early cachexia is of great importance to treat patients in the reversible phase of the syndrome. RAGE (receptor for advanced glycation end-products) signaling concurs to muscle development and homeostasis, however in cancer conditions RAGE sustains hallmarks of cancer cachexia due to hyperstimulation by high serum levels of its ligands, S100B and HMGB1, which also induce muscle wasting per se.
Genetic ablation of RAGE in tumor-bearing mice translates into reduced serum levels of cachexia-inducing factors, delayed loss of muscle mass and strength, reduced tumor progression, and increased survival. Thus, molecular targeting of RAGE might represent a therapeutic strategy to counteract the cachectic syndrome.
Our project is aimed to: i) dissect the mechanism(s) used by RAGE to sustain cachexia in tumor, immune and muscle components; ii) investigate the effects of FPS-ZM1 (RAGE inhibitor) or pentamidine (S100B inhibitor) in comparison with glucocorticoids or ghrelin treatment or physical exercise, in adult, aged and under-chemotherapy tumor-bearing mice; iii) establish a correlation between preclinical models of cachexia and cachectic patients with respect to muscle RAGE and serum levels of RAGE ligands.
We expect: i) to identify the mechanism(s) through which RAGE sustains cachexia and in which component(s) (muscular or non-muscular); ii) that inactivation of RAGE using FPS-ZM1 and/or pentamidine reduces systemic inflammation and favours the maintenance of muscle mass and functionality in cancer conditions, even under chemotherapy treatment or during aging; and iii) to find a positive correlation between the severity of cachexia, RAGE expression in muscles and the serum levels of RAGE ligands in preclinical models and in cancer patients.
Pharmacological inhibition of RAGE activity might represent a promising approach to counteract muscle wasting in cancer conditions, and might be used as an exercise-mimetics in cachectic patients with elevated muscle weakness.
RAGE, sRAGE and/or RAGE ligands might represent potential biomarkers to monitor the cachectic stage and the efficacy of anti-cachectic treatments, which is of great importance as reliable biomarkers of cachexia are still lacking.
Use of microencapsulated Sertoli cells in Duchenne muscular dystrophy. Towards an application to human patients
Granted by Parent Project Onlus, Italy
Duchenne muscular dystrophy (DMD) is an X-linked disease due to lack of dystrophin, leading to progressive muscle degeneration, impaired locomotion and premature death. Persistent muscle degeneration is associated with a condition of chronic inflammation causing muscle necrosis and fibrosis.
Sertoli cells (SeC) have the ability to produce immunomodulatory and trophic factors. SeC have been long used to create an ectopic immune-privileged environment to prolong survival of co-transplanted cells. Encapsulation has represented an improvement for the use of SeC.
We reported that a single intraperitoneal injection of microencapsulated SeC (SeC-MC) is beneficial to dystrophic mdx mice. Injected SeC-MC behave as a drug-delivery system secreting factors that reach muscle tissue through the circulation, where reduce the inflammation and induce the expression of the dystrophin paralogue, utrophin, leading to rescue of muscle morphology and performance.
Although this novel therapeutic approach to DMD has translational potential (SeC are isolated from specific pathogens-free pigs, encapsulated in clinical grade alginate, injected with non-invasive procedure, and without any immunosuppression), further aspects need to be investigated that is the aim of this project: i) SeC-MC dose-response; ii) effects of SeC on canine and human dystrophic myoblasts in vitro; iii) morphology of SeC inside the microcapsules over time; iv) the role of SeC in inflammation using utrophin-deficient mdx (mdx/Utrn-/-) mice; and v) the safety of SeC treatment by the use of experimental models of infection and cancer.
The results will give us important information about SeC biology necessary in view of their possible application to DMD patients.
Multidisciplinary approach to the analysis of the functional alterations induced by microgravity in human satellite cells, and study of possible countermeasures
Granted by ASI (Italian Space Agency)
Long-time exposure to microgravity induces alteration of homeostasis in organs and tissues including skeletal muscles, which undergo atrophy with loss of mass and strength due to loss of muscle fibers and alteration of their composition. Particularly for long time flights such condition is of paramount relevance. Investigating the molecular mechanisms of muscle atrophy induced by microgravity is essential for establishing clinical approach/intervention.
Satellite cells (SC) are responsible for growth, maintenance and repair of the muscle tissue. The adult SC of muscle tissue that reside between the basal lamina and the sarcolemma have the ability to activate, proliferate and form new muscle fibers or repair damaged ones. The activity of SC is under the control of intracellular and extracellular factors that are spatially and temporally organized. Microgravity conditions may be able to induce muscle atrophy by influencing the biology and the functionality of the SC. The research objectives are: 1) to study the changes induced by microgravity in the biology of human SC; 2) to compare the effects induced in human SC during the simulated microgravity on Ground with those induced by the real microgravity onboard the International Space Station (ISS); 3) to evaluate the effects in murine muscle cells of muscle-specific overexpression of IGF-1 as countermeasure to microgravity-induced muscle atrophy.
The results of this project can be useful to understand any alterations at the level of property of SC of human skeletal muscle induced by exposure to microgravity, both simulated and real. The knowledge of the changes in the properties of SC, combined with changes in the ability of SC to respond to certain extracellular factors, will allow to design future interventions (nutritional and/or pharmacological) to fight the muscle wasting process induced by microgravity and encourage growth and maintenance of muscle mass during long-term space travel.
(The project is coordinated by Prof. Stefania Fulle, University of Chieti-Pescara, Italy, and involves the University Sapienza of Rome and the University of L'Aquila)
Inhibition of RAGE as a therapeutic approach to Duchenne muscular dystrophy
Granted by Duchenne Parent Project, the Netherlands
Duchenne muscular dystrophy (DMD) is an X-linked pathology characterized by progressive muscle degeneration and chronic inflammation that causes muscle necrosis and fibrosis. Indeed, DMD patients are treated with antiinflammatory steroids, despite their limited efficacy and undesired side effects. RAGE, a multiligand receptor involved in inflammation and myogenesis, is not expressed in adult muscle tissue, but it is highly expressed in immune cells, regenerating myofibers during muscle regeneration, and dystrophic muscle tissue.
To establish the effective role of RAGE in DMD muscles we generated a dystrophic (mdx) mouse lacking RAGE (mdx/Ager-/- mouse), which shows significantly reduced necrotic myofibers and immune cell infiltrate suggesting that targeting RAGE might result beneficial to DMD muscles.
The aims of the project are to characterize the mdx/Ager-/- mouse, and to test the effects of RAGE inhibition by the specific inhibitor, FPS-ZM1, in DMD animals as a therapeutic approach.
We will analyze muscles of mdx/Ager-/- mice at different ages, with particular focus on inflammatory cells. In mdx mice, we will analyze the effects in vitro and in vivo (i.p. injections) of different doses and durations of FPS-ZM1 treatment in comparison with glucocorticoids treatment to find an optimal condition for recovery of muscle morphology and performance. We will perform histological, immunohistochemical, western blot, FACS and PCR analyses of markers of inflammation, muscle differentiation, fibrosis, necrosis and autophagy, and functional evaluation. We expect that inhibition of RAGE in DMD animals by FPS-ZM1 results in reduced muscle inflammation, necrosis and fibrosis, and favors muscle functionality.
Evaluation of the efficacy of herbal preparations to counter induced muscular atrophy and sarcopenia. Formulation of a suitable herbal product.
Granted by Regione Umbria (A.R.CO. Fellowship)
In collaboration with Laboratori Biokyma Srl (Anghiari, Italy) (www.biokyma.com), leader in the production of officinal plants, and the research groups of Prof. Ferruccio Poli, University of Bologna (Bologna, Italy) and Prof. Stefania Fulle, University of Chieti-Pescara (Chieti, Italy). The project is aimed at developing herbal formulations useful in counteracting muscle atrophy associated with inflammatory diseases, use of steroid drugs or physiologically associated with aging.