Prevalence and impact of sarcopenia in individuals with heart failure with reduced ejection fraction (the SARC-HF study): A prospective observational study protocol

Sarcopenia, a clinical syndrome primarily associated with reduced muscle mass in the elderly, has a negative impact on quality of life and survival. It can occur secondarily to other diseases such as heart failure (HF), a complex clinical syndrome with high morbidity and mortality. The simultaneous occurrence of these two conditions can worsen the prognosis of their carriers, especially in the most severe cases of HF, as in patients with reduced left ventricular ejection fraction (LVEF). However, due to the heterogeneous diagnostic criteria for sarcopenia, estimates of its prevalence present a wide variation, leading to new criteria having been recently proposed for its diagnosis, emphasizing muscle strength and function rather than skeletal muscle mass. The primary objective of this study is to evaluate the prevalence of sarcopenia and/or dynapenia in individuals with HF with reduced LVEF according to the most recent criteria, and compare the gene and protein expression of those patients with and without sarcopenia. The secondary objectives are to evaluate the association of sarcopenia and/or dynapenia with the risk of clinical events and death, quality of life, cardiorespiratory capacity, ventilatory efficiency, and respiratory muscle strength. The participants will answer questionnaires to evaluate sarcopenia and quality of life, and will undergo the following tests: handgrip strength, gait speed, dual-energy X-ray absorptiometry, respiratory muscle strength, cardiopulmonary exercise, as well as genomic and proteomic analysis, and dosage of N-terminal pro-B-type natriuretic peptide and growth differentiation factor-15. An association between sarcopenia and/or dynapenia with unfavorable clinical evolution is expected to be found, in addition to reduced quality of life, cardiorespiratory capacity, ventilatory efficiency, and respiratory muscle strength.

Generation of patient-specific induced pluripotent stem cell lines from one patient with Jervell and Lange-Nielsen syndrome, one with type 1 long QT syndrome and two healthy relatives

Four human iPSC cell lines (one Jervell and Lange-Nielsen Syndrome, one Long QT Syndrome-type 1 and two healthy controls) were generated from peripheral blood obtained from donors belonging to the same family. CytoTune™-iPS 2.0 Sendai Reprogramming Kit (containing OCT3/4, KLF4, SOX2 and cMYC as reprogramming factors) was used to generate all cell lines. The four iPSCs have normal karyotype, express pluripotency markers as determined by RT-PCR and flow cytometry and differentiated spontaneously in vitro into cells of the three germ layers, confirming their pluripotent capacity.

Cardiosphere-derived cells do not improve cardiac function in rats with cardiac failure

BACKGROUND

Heart failure represents an important public health issue due to its high costs and growing incidence worldwide. Evidence showing the regenerative potential of postmitotic heart tissue has suggested the existence of endogenous cardiac stem cells in adult hearts. Cardiosphere-derived cells (CDC) constitute a candidate pool of such cardiac stem cells. Previous studies using acute myocardial infarction (MI) models in rodents demonstrated an improvement in cardiac function after cell therapy with CDC. We evaluated the therapeutic potential of CDC 60 days after MI in a rat model.

METHODS

CDC were obtained from human discarded myocardial tissue and rat hearts by enzymatic digestion with collagenase II. At 10-15 days after isolation, small, round, phase-bright cells (PBCs) appeared on top of the adherent fibroblast-like cells. The PBCs were collected and placed on a nonadherent plate for 2 days, where they formed cardiospheres which were then transferred to adherent plates, giving rise to CDC. These CDC were characterized by flow cytometry. Wistar rats were submitted to MI through permanent occlusion of the anterior descending coronary artery. After 60 days, they were immunosuppressed with cyclosporine A during 10 days. On the third day, infarcted animals were treated with 5 × 10⁵ human CDC (hCDC) or placebo through intramyocardial injection guided by echocardiogram. Another group of animals was treated with rat CDC (rCDC) without immunosuppression. hCDC and rCDC were stably transduced with a viral construct expressing luciferase under control of a constitutive promoter. CDC were then used in a bioluminescence assay. Functional parameters were evaluated by echocardiogram 90 and 120 days after MI and by Langendorff at 120 days.

RESULTS

CDC had a predominantly mesenchymal phenotype. Cell tracking by bioluminescence demonstrated over 85% decrease in signal at 5-7 days after cell therapy. Cardiac function evaluation by echocardiography showed no differences in ejection fraction, end-diastolic volume, or end-systolic volume between groups receiving human cells, rat cells, or placebo. Hemodynamic analyses and infarct area quantification confirmed that there was no improvement in cardiac remodeling after cell therapy with CDC.

CONCLUSION

Our study challenges the effectiveness of CDC in post-ischemic heart failure.

Adipose-derived stem-cell treatment of skeletal muscle injury

BACKGROUND

The aim of the present study was to investigate whether adipose-derived stem cells could contribute to skeletal muscle-healing.

METHODS

Adipose-derived stem cells of male rats were cultured and injected into the soleus muscles of female rats. Two and four weeks after injections, muscles were tested for tetanic force (50 Hz). Histological analysis was performed to evaluate muscle collagen deposition and the number of centronucleated muscle fibers. In order to track donor cells, chimerism was detected with use of real-time polymerase chain reaction targeting the male sex-determining region Y (SRY) gene.

RESULTS

Two weeks after cell injection, tetanus strength and the number of centronucleated regenerating myofibers, as well as the number of centronucleated regenerating myofibers, were higher in the treated group than they were in the control group (mean and standard error of the mean, 79.2 ± 5.0% versus 58.3 ± 8.1%, respectively [p < 0.05]; and 145 ± 36 versus 273 ± 18 per 10³ myofibers, respectively [p < 0.05]). However, there were no significant differences at four weeks. Treatment did not decrease collagen deposition. Male gene was not detected in female host tissue at two and four weeks after engraftment by polymerase chain reaction analysis.

CONCLUSIONS

Adipose-derived stem-cell therapy increased muscle repair and force at two weeks, but not four weeks, after injection, suggesting that adipose-derived stem-cell administration may accelerate muscle repair; however, the rapid disappearance of injected cells suggests a paracrine mechanism of action.