Production of Cardiac Extracellular Matrix from Adult Human Fibroblasts for Culture Dish Coating.

The myocardium is composed of cardiomyocytes and an even greater number of fibroblasts, the latter being responsible for extracellular matrix production. From the early stages of heart development throughout the lifetime, in both normal and pathological conditions, the composition of the extracellular matrix changes and influences myocardium structure and function. The purpose of the method described here is to obtain the substrate for the culture of cardiac cells in vitro (termed cardiac ECM), mimicking the myocardial extracellular matrix in vivo. To this end, fibroblasts isolated from the adult human heart were cultured to confluence on gelatin-coated dishes to produce the myocardium-specific extracellular matrix. The subsequent removal of cardiac fibroblasts, while preserving the deposited cardiac ECM, produced the substrate for studying the influence of the myocardium-specific extracellular matrix on other cells. Importantly, the composition of the fibroblast-derived coating of the culture dish changes according to the in vivo activity of the fibroblasts isolated from the heart, allowing subsequent studies of cell-matrix interactions in different normal and pathological conditions.

Stem cell therapy in sports medicine: current applications, challenges and future perspectives.

Stem cells have demonstrated significant potential for tissue repair and regeneration, making them a promising therapeutic avenue in sports medicine. This review aims to provide a comprehensive overview of the current state of research on the application of stem cells in sports medicine. We will discuss the types of stem cells used, their mechanisms of action, and the clinical outcomes of stem cell therapy in different sports-related injuries. Furthermore, we will delve into the challenges and ethical considerations associated with stem cell therapy, as well as future directions and potential applications of stem cells in sports medicine.

Cardiac-derived extracellular matrix: A decellularization protocol for heart regeneration.

Extracellular matrix (ECM) is a fundamental component of the heart, guiding vital cellular processes during organ homeostasis. Most cardiovascular diseases lead to a remarkable remodeling of the ECM, accompanied by the formation of a fibrotic tissue that heavily compromises the heart function. Effective therapies for managing fibrosis and promoting physiological ECM repair are not yet available. The production of a decellularized extracellular matrix (d-ECM) serving as a three-dimensional and bioactive scaffold able to modulate cellular behavior and activities is considered crucial to achieve a successful regeneration. The protocol represents a step-by-step method to obtain a decellularized cardiac matrix through the combination of sodium dodecyl sulphate (SDS) and Triton X-100. Briefly, cardiac samples obtained from left ventricles of explanted, pathological human hearts were dissected and washed to remove residual body fluids. Samples were then snap-frozen and sliced by a cryostat into 350 µm thick sections. The sections obtained were decellularized using a solution containing 1% Triton X-100 and 1% SDS in combination, for 24 hours, until observing the color change from brownish-red to translucent-white. As a result, the protocol shows efficiency in preserving ECM architecture and protein composition during the whole process, suggesting that it is worthwhile, highly reproducible and produces a well- preserved decellularized extracellular matrix from cardiac samples. Notwithstanding, some limitations need to be addressed, such as the risk for microbial contamination and the unpredictable trend of the protocol when applied to decellularize samples other than myocardium, vessels, or skin. These issues require antibiotics mixture supplement during the procedure followed by UV sterilization, and appropriate adjustments for a tissue-specific utilization, respectively. The protocol is intended to produce a cardiac d-ECM for cell settlement, representing the ideal scaffold for tissue engineering purposes.

Generation and Characterization of a Tumor Stromal Microenvironment and Analysis of Its Interplay with Breast Cancer Cells: An In Vitro Model to Study Breast Cancer-Associated Fibroblast Inactivation.

Breast cancer-associated fibroblasts (BCAFs), the most abundant non-cancer stromal cells of the breast tumor microenvironment (TME), dramatically sustain breast cancer (BC) progression by interacting with BC cells. BCAFs, as well as myofibroblasts, display an up regulation of activation and inflammation markers represented by α-smooth muscle actin (α-SMA) and cyclooxygenase 2 (COX-2). BCAF aggregates have been identified in the peripheral blood of metastatic BC patients. We generated an in vitro stromal model consisting of human primary BCAFs grown as monolayers or 3D cell aggregates, namely spheroids and reverted BCAFs, obtained from BCAF spheroids reverted to 2D cell adhesion growth after 216 h of 3D culture. We firstly evaluated the state of activation and inflammation and the mesenchymal status of the BCAF monolayers, BCAF spheroids and reverted BCAFs. Then, we analyzed the MCF-7 cell viability and migration following treatment with conditioned media from the different BCAF cultures. After 216 h of 3D culture, the BCAFs acquired an inactivated phenotype, associated with a significant reduction in α-SMA and COX-2 protein expression. The deactivation of the BCAF spheroids at 216 h was further confirmed by the cytostatic effect exerted by their conditioned medium on MCF-7 cells. Interestingly, the reverted BCAFs also retained a less activated phenotype as indicated by α-SMA protein expression reduction. Furthermore, the reverted BCAFs exhibited a reduced pro-tumor phenotype as indicated by the anti-migratory effect exerted by their conditioned medium on MCF-7 cells. The deactivation of BCAFs without drug treatment is possible and leads to a reduced capability of BCAFs to sustain BC progression in vitro. Consequently, this study could be a starting point to develop new therapeutic strategies targeting BCAFs and their interactions with cancer cells.

Limited diagnostic value of questionnaire-based pre-participation screening algorithms: a "risk-exposed" approach to sports activity.

BACKGROUND: Several pre-participation screening algorithms (PPSAs) have been proposed to assess sports eligibility in different populations. They are usually based on self-administered questionnaires, without further medical assessment if no risk factors are documented. The Med-Ex "Formula Benessere" worksite program includes a complete cardiovascular (CV) screening for all participants. The purpose of this study was to assess PPSAs accuracy in detecting medical and/or CV abnormalities in the general population, comparing the results with the date derived from Med-Ex program. METHODS: The Med-Ex medical evaluation, consisting of medical history, physical examination (including body composition), resting electrocardiogram (ECG) and exercise stress test in 464 male subjects (38.4 aged) was analyzed and matched to several PPSAs - Physical Activity Readiness Questionnaire (PAR-Q) (2002-2020), American Heart Association (AHA)/American College of Sport Medicine (ACSM) (1998-2009-2014-2015), European Association of Cardiovascular Prevention and Rehabilitation (EACPR) (2011) - retrospectively simulated. RESULTS: Five-hundred and 67 abnormalities were detected though Med-Ex medical evaluation, and one-fourth (24%) would have been undetected applying PPSA alone. In particular 28% of high blood pressure, 21% of impaired fasting glycaemia, 21% of high Body Mass Index (BMI) values and 19% of ECG abnormalities would have been missed, on average, by all PPSAs. CONCLUSIONS: The simulation analysis model performed in this study allowed to highlight the limits of PPSAs in granting sport eligibility, compared to a medical-guided CV screening. These findings emphasize the importance of a more balanced approach to pre-participation screening that includes a thorough evaluation of the cost/benefit ratio.

Human Cardiac Progenitor Cell-Derived Extracellular Vesicles Exhibit Promising Potential for Supporting Cardiac Repair in Vitro.

Although human Cardiac Progenitor Cells (hCPCs) are not retained by host myocardium they still improve cardiac function when injected into ischemic heart. Emerging evidence supports the hypothesis that hCPC beneficial effects are induced by paracrine action on resident cells. Extracellular vesicles (EVs) are an intriguing mechanism of cell communication based on the transport and transfer of peptides, lipids, and nucleic acids that have the potential to modulate signaling pathways, cell growth, migration, and proliferation of recipient cells. We hypothesize that EVs are involved in the paracrine effects elicited by hCPCs and held accountable for the response of the infarcted myocardium to hCPC-based cell therapy. To test this theory, we collected EVs released by hCPCs isolated from healthy myocardium and evaluated the effects they elicited when administered to resident hCPC and cardiac fibroblasts (CFs) isolated from patients with post-ischemic end-stage heart failure. Evidence emerging from our study indicated that hCPC-derived EVs impacted upon proliferation and survival of hCPCs residing in the ischemic heart and regulated the synthesis and deposition of extracellular-matrix by CFs. These findings suggest that beneficial effects exerted by hCPC injection are, at least to some extent, ascribable to the delivery of signals conveyed by EVs.

Non-modified RNA-Based Reprogramming of Human Dermal Fibroblasts into Induced Pluripotent Stem Cells.

The generation of pluripotent stem cells from adult somatic cells by cell reprogramming has put a whole new perspective on stem cell biology and stem cell-based regenerative medicine. Cell reprogramming acts through the introduction of key genes that regulate and maintain the pluripotent cell state. In this chapter, we describe the optimized protocol for the efficient isolation of fibroblasts from a skin punch biopsy and the subsequent easy and effective generation of integration-free induced pluripotent stem cell (iPSC) colonies forcing the expression of specific factors by non-modified RNAs.

Decellularization for the Preparation of Highly Preserved Human Acellular Skin Matrix for Regenerative Medicine.

Extracellular matrix (ECM) provides biophysical and biochemical stimuli to support self-renewal, proliferation, survival, and differentiation of surrounding cells due to its content of diverse bioactive molecules. Due to these characteristics, the ECM has been recently considered a promising candidate for the creation of biological scaffolds to boost tissue regeneration. Emerging studies have demonstrated that decellularized human tissues could resemble the native ECM in their structural and biochemical profiles, preserving the three-dimensional (3D) architecture and the content of fundamental biological molecules. Hence, decellularized ECM can be employed to promote tissue remodeling, repair, and functional reconstruction of many organs. Selecting the appropriate decellularization procedure is crucial to obtain acellular tissues that retain the characteristics of the ideal microenvironment for cells. The protocol described here provides a detailed step-by-step description of the decellularization method to obtain a reproducible and effective cell-free biological ECM. Skin fragments from patients undergoing plastic surgery were scaled down and decellularized using a combination of sodium dodecylsulfate (SDS), Triton X-100, and antibiotics. To promote the regular and homogeneous transport of the solution through the samples, they were enclosed in embedding cassettes to ensure protection from mechanical insults. After the decellularization procedure, the snow-white color of skin fragments indicated complete and successful decellularization. Additionally, decellularized samples showed an intact and well-preserved architecture. The results suggest that the proposed decellularization method was effective, fast, and reproducible and protected samples from architectural damages.

Correlation between Official and Common Field-Based Fitness Tests in Elite Soccer Referees.

Official tests are used to assess the fitness status of soccer referees, and their results correlate with match performance. However, FIFA-approved tests expose the referees to high physical demands and are difficult to implement during the sportive year. The aim of our study was to evaluate the correlation between the 6 × 40-m sprint and Yo-Yo Intermittent Recovery Level 1 (IR1) official tests and other field-based tests that require no or little equipment, are not time-consuming, and impose low physical demands. All tests were performed by male referees from the Regional Section of the Italian Referee Association (n = 30). We observed a strong correlation between 6 × 40-m sprint and Illinois agility tests (r = 0.63, p = 0.001) and a moderate correlation between Yo-Yo IR1 and hand-grip strength in the dominant (r = 0.45, p = 0.014) and non-dominant hand (r = 0.41, p = 0.031). Interestingly, only a moderate correlation (r = -0.42, p = 0.025) was observed between the FIFA official tests, 6 × 40-m sprint and Yo-Yo IR1. These results suggest that Illinois agility and hand-grip tests could represent simple and low-physical-impact tools for repeated assessment and monitoring of referee fitness throughout the sportive season.

Influence of Tumor Microenvironment and Fibroblast Population Plasticity on Melanoma Growth, Therapy Resistance and Immunoescape.

Cutaneous melanoma (CM) tissue represents a network constituted by cancer cells and tumor microenvironment (TME). A key feature of CM is the high structural and cellular plasticity of TME, allowing its evolution with disease and adaptation to cancer cell and environmental alterations. In particular, during melanoma development and progression each component of TME by interacting with each other and with cancer cells is subjected to dramatic structural and cellular modifications. These alterations affect extracellular matrix (ECM) remodelling, phenotypic profile of stromal cells, cancer growth and therapeutic response. The stromal fibroblast populations of the TME include normal fibroblasts and melanoma-associated fibroblasts (MAFs) that are highly abundant and flexible cell types interacting with melanoma and stromal cells and differently influencing CM outcomes. The shift from the normal microenvironment to TME and from normal fibroblasts to MAFs deeply sustains CM growth. Hence, in this article we review the features of the normal microenvironment and TME and describe the phenotypic plasticity of normal dermal fibroblasts and MAFs, highlighting their roles in normal skin homeostasis and TME regulation. Moreover, we discuss the influence of MAFs and their secretory profiles on TME remodelling, melanoma progression, targeted therapy resistance and immunosurveillance, highlighting the cellular interactions, the signalling pathways and molecules involved in these processes.

The Microenvironment of Decellularized Extracellular Matrix from Heart Failure Myocardium Alters the Balance between Angiogenic and Fibrotic Signals from Stromal Primitive Cells.

Cardiac adverse remodeling is characterized by biological changes that affect the composition and architecture of the extracellular matrix (ECM). The consequently disrupted signaling can interfere with the balance between cardiogenic and pro-fibrotic phenotype of resident cardiac stromal primitive cells (CPCs). The latter are important players in cardiac homeostasis and can be exploited as therapeutic cells in regenerative medicine. Our aim was to compare the effects of human decellularized native ECM from normal (dECM-NH) or failing hearts (dECM-PH) on human CPCs. CPCs were cultured on dECM sections and characterized for gene expression, immunofluorescence, and paracrine profiles. When cultured on dECM-NH, CPCs significantly upregulated cardiac commitment markers (CX43, NKX2.5), cardioprotective cytokines (bFGF, HGF), and the angiogenesis mediator, NO. When seeded on dECM-PH, instead, CPCs upregulated pro-remodeling cytokines (IGF-2, PDGF-AA, TGF-ß) and the oxidative stress molecule H2O2. Interestingly, culture on dECM-PH was associated with impaired paracrine support to angiogenesis, and increased expression of the vascular endothelial growth factor (VEGF)-sequestering decoy isoform of the KDR/VEGFR2 receptor. Our results suggest that resident CPCs exposed to the pathological microenvironment of remodeling ECM partially lose their paracrine angiogenic properties and release more pro-fibrotic cytokines. These observations shed novel insights on the crosstalk between ECM and stromal CPCs, suggesting also a cautious use of non-healthy decellularized myocardium for cardiac tissue engineering approaches.

A low-cost scalable 3D-printed sample-holder for agitation-based decellularization of biological tissues.

Decellularized extracellular matrix is one of the most promising biological scaffold supporting in vitro tissue growth and in vivo tissue regeneration in both preclinical research and clinical practice. In case of thick tissues or even organs, conventional static decellularization methods based on chemical or enzymatic treatments are not effective in removing the native cellular material without affecting the extracellular matrix. To overcome this limitation, dynamic decellularization methods, mostly based on perfusion and agitation, have been proposed. In this study, we developed a low-cost scalable 3D-printed sample-holder for agitation-based decellularization purposes, designed for treating multiple specimens simultaneously and for improving efficiency, homogeneity and reproducibility of the decellularization treatment with respect to conventional agitation-based approaches. In detail, the proposed sample-holder is able to house up to four specimens and, immersed in the decellularizing solution within a beaker placed on a magnetic stirrer, to expose them to convective flow, enhancing the solution transport through the specimens while protecting them. Computational fluid dynamics analyses were performed to investigate the fluid phenomena establishing within the beaker and to support the sample-holder design. Exploratory biological tests performed on human skin specimens demonstrated that the sample-holder reduces process duration and increases treatment homogeneity and reproducibility.

Compact and tunable stretch bioreactor advancing tissue engineering implementation. Application to engineered cardiac constructs.

Physical stimuli are crucial for the structural and functional maturation of tissues both in vivo and in vitro. In tissue engineering applications, bioreactors have become fundamental and effective tools for providing biomimetic culture conditions that recapitulate the native physical stimuli. In addition, bioreactors play a key role in assuring strict control, automation, and standardization in the production process of cell-based products for future clinical application. In this study, a compact, easy-to-use, tunable stretch bioreactor is proposed. Based on customizable and low-cost technological solutions, the bioreactor was designed for providing tunable mechanical stretch for biomimetic dynamic culture of different engineered tissues. In-house validation tests demonstrated the accuracy and repeatability of the imposed mechanical stimulation. Proof of concepts biological tests performed on engineered cardiac constructs, based on decellularized human skin scaffolds seeded with human cardiac progenitor cells, confirmed the bioreactor Good Laboratory Practice compliance and ease of use, and the effectiveness of the delivered cyclic stretch stimulation on the cardiac construct maturation.

Guidelines for Physical Activity-A Cross-Sectional Study to Assess Their Application in the General Population. Have We Achieved Our Goal?

National and international healthcare organizations propose guidelines for physical activity worldwide, defining its characteristics. These guidelines' practical applications are difficult to estimate, since they are not fully followed. The aim of the present cross-sectional observational study was to assess awareness about guidelines for physical activity and to evaluate their practical applications in a sample of the Italian population. In total, 310 participants completed an online survey (mean age 29.10 ± 4.44), assessing the habits, beliefs and health effects of physical activity. In total, 39.35% of respondents were inactive. In total, 6.91% of active respondents did not perform a warm-up phase at the beginning of each training session and 77.14% did not check their own heart rate during the training session. Approximately half of respondents reported erroneous beliefs about the type, frequency and volume of physical activity, compared to data proposed by the guidelines. The preventive effect of physical activity was clearly perceived for cardiovascular diseases, diabetes, metabolic syndrome and depression. Several subjects misinterpreted the preventive role of physical activity in colon and breast cancers, and in femur and vertebral fractures. Habits and beliefs about physical activity in the general population are far from the guidelines and recommendations. Therefore, it is necessary to strengthen the conscious practice of physical activity further.

Decellularized Human Dermal Matrix as a Biological Scaffold for Cardiac Repair and Regeneration.

The complex and highly organized environment in which cells reside consists primarily of the extracellular matrix (ECM) that delivers biological signals and physical stimuli to resident cells. In the native myocardium, the ECM contributes to both heart compliance and cardiomyocyte maturation and function. Thus, myocardium regeneration cannot be accomplished if cardiac ECM is not restored. We hypothesize that decellularized human skin might make an easily accessible and viable alternate biological scaffold for cardiac tissue engineering (CTE). To test our hypothesis, we decellularized specimens of both human skin and human myocardium and analyzed and compared their composition by histological methods and quantitative assays. Decellularized dermal matrix was then cut into 600-µm-thick sections and either tested by uniaxial tensile stretching to characterize its mechanical behavior or used as three-dimensional scaffold to assess its capability to support regeneration by resident cardiac progenitor cells (hCPCs) in vitro. Histological and quantitative analyses of the dermal matrix provided evidence of both effective decellularization with preserved tissue architecture and retention of ECM proteins and growth factors typical of cardiac matrix. Further, the elastic modulus of the dermal matrix resulted comparable with that reported in literature for the human myocardium and, when tested in vitro, dermal matrix resulted a comfortable and protective substrate promoting and supporting hCPC engraftment, survival and cardiomyogenic potential. Our study provides compelling evidence that dermal matrix holds promise as a fully autologous and cost-effective biological scaffold for CTE.

Effectiveness of Tai Chi on Balance Improvement in Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis.

Balance impairments are a relevant problem in patients with diabetes, and interventions to manage this issue represent a public health need. This study reviewed the literature about the effectiveness of Tai Chi on balance improvement in patients with type 2 diabetes. Springerlink, MEDLINE, PubMed, CINAHL, Web of Science, Scopus, and Cochrane CENTRAL databases were screened. Randomized and nonrandomized controlled trials assessing balance in patients with type 2 diabetes enrolled in a Tai Chi program were considered eligible. Four studies were included in qualitative synthesis and in quantitative analysis (three randomized controlled trials and one pretest-posttest quasi-experimental study). Evidence supporting Tai Chi to improve balance in patients with type 2 diabetes was found (effect size: 0.52; 95% confidence interval [0.20, 0.84]); however, the analysis relied on a small number of studies, which raises concerns about the risk of bias. In conclusion, the results support the benefits of Tai Chi intervention to improve balance in patients with type 2 diabetes.

Isolation of Adult Human Dermal Fibroblasts from Abdominal Skin and Generation of Induced Pluripotent Stem Cells Using a Non-Integrating Method.

Induced pluripotent stem cells (iPSCs) could be considered, to date, a promising source of pluripotent cells for the management of currently untreatable diseases, for the reconstitution and regeneration of injured tissues and for the development of new drugs. Despite all the advantages related to the use of iPSCs, such as the low risk of rejection, the lessened ethical issues, and the possibility to obtain them from both young and old patients without any difference in their reprogramming potential, problems to overcome are still numerous. In fact, cell reprogramming conducted with viral and integrating viruses can cause infections and the introduction of required genes can induce a genomic instability of the recipient cell, impairing their use in clinic. In particular, there are many concerns about the use of c-Myc gene, well-known from several studies for its mutation-inducing activity. Fibroblasts have emerged as the suitable cell population for cellular reprogramming as they are easy to isolate and culture and are harvested by a minimally invasive skin punch biopsy. The protocol described here provides a detailed step-by-step description of the whole procedure, from sample processing to obtain cell cultures, choice of reagents and supplies, cleaning and preparation, to cell reprogramming by the means of a commercial non-modified RNAs (NM-RNAs)-based reprogramming kit. The chosen reprogramming kit allows an effective reprogramming of human dermal fibroblast to iPSCs and small colonies can be seen as early as 24 h after the first transfection, even with modifications with the respect to the standard datasheet. The reprogramming procedure used in this protocol offers the advantage of a safe reprogramming, without the risk of infections caused by viral vector-based methods, reduces the cellular defense mechanisms, and allows the generation of xeno-free iPSCs, all critical features that are mandatory for further clinical applications.

Brachial Plexus Injuries in Sport Medicine: Clinical Evaluation, Diagnostic Approaches, Treatment Options, and Rehabilitative Interventions.

The brachial plexus represents a complex anatomical structure in the upper limb. This "network" of peripheral nerves permits the rearrangement of motor efferent fibers, coming from different spinal nerves, in several terminal branches directed to upper limb muscles. Moreover, afferent information coming from different cutaneous regions in upper limb are sorted in different spinal nerves through the brachial plexus. Severe brachial plexus injuries are a rare clinical condition in the general population and in sport medicine, but with dramatic consequences on the motor and sensory functions of the upper limb. In some sports, like martial arts, milder injuries of the brachial plexus can occur, with transient symptoms and with a full recovery. Clinical evaluation represents the cornerstone in the assessment of the athletes with brachial plexus injuries. Electrodiagnostic studies and imaging techniques, like magnetic resonance and high-frequency ultrasound, could be useful to localize the lesion and to define an appropriate treatment and a functional prognosis. Several conservative and surgical techniques could be applied, and multidisciplinary rehabilitative programs could be performed to guide the athlete toward the recovery of the highest functional level, according to the type of injury.

Effect of Video Observation and Motor Imagery on Simple Reaction Time in Cadet Pilots.

Neuromotor training can improve motor performance in athletes and patients. However, few data are available about their effect on reaction time (RT). We investigated the influence of video observation/motor imagery (VO/MI) on simple RT to visual and auditory stimuli. The experimental group comprised 21 cadets who performed VO/MI training over 4 weeks. Nineteen cadets completed a sham intervention as control. The main outcome measure was RT to auditory and visual stimuli for the upper and lower limbs. The RT to auditory stimuli improved significantly post-intervention in both groups (control vs. experimental mean change for upper limbs: -40 ms vs. -40 ms, p = 0.0008; for lower limbs: -50 ms vs. -30 ms, p = 0.0174). A trend towards reduced RT to visual stimuli was observed (for upper limbs: -30 ms vs. -20 ms, p = 0.0876; for lower limbs: -30 ms vs. -20 ms, p = 0.0675). The interaction term was not significant. Only the specific VO/MI training produced a linear correlation between the improvement in the RT to auditory and visual stimuli for the upper (r = 0.703) and lower limbs (r = 0.473). In conclusion, VO/MI training does not improve RT when compared to control, but it may be useful in individuals who need to simultaneously develop a fast response to different types of stimuli.

Tendinopathy: Pathophysiology, Therapeutic Options, and Role of Nutraceutics. A Narrative Literature Review.

Tendinopathies are very common in general population and a huge number of tendon-related procedures take place annually worldwide, with significant socio-economic repercussions. Numerous treatment options are commonly used for tendon disorders. Besides pharmacological and physical therapy, nutrition could represent an additional tool for preventing and treating this complex pathology that deserve a multidisciplinary approach. In recent years, nutraceutical products are growing up in popularity since these seem to favor the prevention and the healing processes of tendon injuries. This narrative literature review aims to summarize current understanding and the areas of ongoing research about the management of tendinopathies with the help of oral supplementation.