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The stem cell field has grown very rapidly during the last decade, offering the promise of innovative therapies to treat disease. Different stem cell populations have been isolated from various human adult tissues, mainly from bone marrow and adipose tissue, but many other body tissues harbor a stem cell population. Adult tissue stem cells are invariably found in discrete microenvironments termed niches, where they play key roles in tissue homeostasis by enabling lifelong optimization of organ form and function. Some diseases are known to strike at the stem cell population, through alterations in their specific microenvironments, making them non-viable. Furthermore, it has been shown that a transformed stem cell population could prompt the development of certain cancers. This review focuses on the potential negative aspects of a range of diseases on the activity of stem cells and how their potential use in cell therapies may be affected. [ABSTRACT FROM AUTHOR]

Regulation of membrane-type 1 matrix metalloproteinase (MT1-MMP) by different extracellular matrices (ECMs) on human endothelial cells (ECs) has been investigated. First, MT1-MMP is found at the intercellular contacts of confluent ECs grown on β1 integrin-dependent matrix such as type 1 collagen (COL I), fibronectin (FN), or fibrinogen (FG), but not on gelatin (GEL) or vitronectin (VN). The novel localization of MT1-MMP at cell-cell contacts is assessed by confocal videomicroscopy of MT1MMP-GFP-transfected ECs. Moreover, MT1-MMP colocalizes with β1 integrins at the intercellular contacts, whereas it is preferentially found with αvβ3 integrin at motility-associated structures on migrating ECs. In addition, clustered integrins recruit MT1-MMP and neutralizing anti-β1 or anti-αv integrin mAb displace MT1-MMP from its specific sites, pointing to a biochemical association that is finally demonstrated by coimmunoprecipitation assays. On the other hand, COL I, FN, or FG up-regulate cell surface MT1-MMP on confluent ECs by an impairment of its internalization, whereas expression and internalization are not modified on GEL or VN. In addition, MT1-MMP activity is diminished in confluent ECs on COL I, FN, or FG. Finally, MT1-MMP participates and cooperates with β1 and αvβ3 integrins in the migration of ECs on different ECM. These data show a novel mechanism by which FCM regulates MT1-MMP association with β1 or αvβ3 integrins at distinct cellular compartments, thus modulating its internalization, activity, and function on human ECs. [ABSTRACT FROM AUTHOR]

We explored the association between aerobic capacity (AC) and the skeletal muscle proteome of McArdle (n = 10) and wild‐type (n = 8) mice, as models of intrinsically ‘low’ and ‘normal’ AC, respectively. AC was determined as total distance achieved in treadmill running until exhaustion. The quadriceps muscle proteome was studied using liquid chromatography with tandem mass spectrometry, with the Search Tool for the Retrieval of Interacting Genes/Proteins database used to generate protein–protein interaction (PPI) networks and enrichment analyses. AC was significantly associated (P‐values ranging from 0.0002 to 0.049) with 73 (McArdle) and 61 (wild‐type) proteins (r‐values from −0.90 to 0.94). These proteins were connected in PPI networks that enriched biological processes involved in skeletal muscle structure/function in both groups (false discovery rate <0.05). In McArdle mice, the proteins associated with AC were involved in skeletal muscle fibre differentiation/development, lipid oxidation, mitochondrial function and calcium homeostasis, whereas in wild‐type animals AC‐associated proteins were related to cytoskeleton structure (intermediate filaments), cell cycle regulation and endocytic trafficking. Two proteins (WEE2, THYG) were associated with AC (negatively and positively, respectively) in both groups. Only 14 of the 132 proteins (∼11%) associated with AC in McArdle or wild‐type mice were also associated with those previously reported to be modified by aerobic training in these mice, providing preliminary evidence for a large divergence in the muscle proteome signature linked to aerobic training or AC, irrespective of AC (intrinsically low or normal) levels. Our findings might help to gain insight into the molecular mechanisms underlying AC at the muscle tissue level. [ABSTRACT FROM AUTHOR]

Objectives: The effects of acute physical exercise in patients with resistant hypertension remain largely unexplored compared with hypertensive patients in general. We assessed the short-term effects of acute moderate-intensity (MICE) and high-intensity interval exercise (HIIE) on the clinic (BP) and 24-h ambulatory blood pressure (ABP) of patients with resistant hypertension., Methods: Using a crossover randomized controlled design, 10 participants (56 ± 7 years) with resistant hypertension performed three experimental sessions: MICE, HIIE, and control. MICE consisted of continuous treadmill exercise at an intensity of 3-4 metabolic equivalents of energy (METs) until completing 3 kcal/kg and was energy-matched to HIIE (which included six to eight intervals of 3 min duration at 6-7 METs interspersed with 1.5-min rests at 3 METs). In the control session, participants remained seated for 50 min. Flow-mediated vasodilation, autonomic nervous system balance (heart rate variability), exerkines [interleukin (IL)-6, IL-8, IL-15, vascular endothelial growth factor A, irisin, adiponectin, and angiopoietin] and 71 inflammatory-related proteins were also measured., Results: Compared with baseline, HIIE and MICE reduced clinic SBP immediately (P < 0.001 for both) and 90 min (P = 0.001 and P = 0.041, respectively) postexercise. HIIE and MICE also reduced clinic DBP immediately postexercise (P = 0.003 and P = 0.025). By contrast, no changes were found in the control session. On the other hand, no significant effects were noted for 24 h ABP measures or for the rest of variables., Conclusion: Although in patients with resistant hypertension, acute aerobic exercise induces short-term reductions in clinic BP, this stimulus does not suffice to reduce 24 h ABP or to impact on potential biological mechanisms., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

It has been described that adult tissues contain mesenchymal stem cell populations. The specific areas where stem cells reside are known as niches. Crosstalk between cells and their niche is essential to maintain the correct functionality of stem cell. MSCs present a set of abilities such as migration, invasion, and angiogenic potentials, which make them ideal candidates for cell-based therapies. In order to test the regenerative capacity of these cells, we have described a methodology for the collection and for the evaluation of these mesenchymal precursors from different niches.

Depression is a major medical and social problem. Here we review current body of knowledge on the benefits of exercise as an effective strategy for both the prevention and treatment of this condition. We also analyze the biological pathways involved in such potential benefits, which include changes in neurotrophic factors, oxidative stress and inflammation, telomere length, brain volume and microvessels, neurotransmitters or hormones. We also identify major caveats in this field of research: further studies are needed to identify which are the most appropriate types of exercise interventions (intensity, duration, or frequency) to treat and prevent depression.

The use of adult stem cells for tissue and organ regeneration constitutes a promising alternative therapy in many human diseases that are currently not treatable. We have isolated a new cell type from mouse adult uterine biopsies (murine adult myometrial precursors or mAMPs) by means of using a simple and non-invasive approach. These cells have been characterized by surface markers, being positive for CD31, CD34, CD44, CD117, Stro-1 and Sca-1. A similar cell population (hAMPs) was isolated from human biopsies. AMPs can differentiate in vitro into a number of mesodermal (smooth and skeletal muscle, osteoblasts and adipocytes) as well as epidermal lineages (all neural lineages). AMPs are unusual adult stem cells as they still express some embryonic antigens and remain undifferentiated through a high number of passages before entering senescence. Importantly, when injected into animal models of muscular disease, AMPs can regenerate new muscle fibers, and promote functional muscular recovery. Moreover, these cells can regenerate the uterine lining after wound healing, reconstructing the uterine muscular architecture. In addition, these cells can form new vessels both in vitro and in vivo. We believe that these cells have superior features to other known adult stem cells and, consequently, their use holds great promise for regenerative medicine, drug development and basic research.

Regulation of membrane-type 1 matrix metalloproteinase (MT1-MMP) by different extracellular matrices (ECMs) on human endothelial cells (ECs) has been investigated. First, MT1-MMP is found at the intercellular contacts of confluent ECs grown on beta1 integrin-dependent matrix such as type 1 collagen (COL I), fibronectin (FN), or fibrinogen (FG), but not on gelatin (GEL) or vitronectin (VN). The novel localization of MT1-MMP at cell-cell contacts is assessed by confocal videomicroscopy of MT1-MMP-GFP-transfected ECs. Moreover, MT1-MMP colocalizes with beta1 integrins at the intercellular contacts, whereas it is preferentially found with alphavbeta3 integrin at motility-associated structures on migrating ECs. In addition, clustered integrins recruit MT1-MMP and neutralizing anti-beta1 or anti-alphav integrin mAb displace MT1-MMP from its specific sites, pointing to a biochemical association that is finally demonstrated by coimmunoprecipitation assays. On the other hand, COL I, FN, or FG up-regulate cell surface MT1-MMP on confluent ECs by an impairment of its internalization, whereas expression and internalization are not modified on GEL or VN. In addition, MT1-MMP activity is diminished in confluent ECs on COL I, FN, or FG. Finally, MT1-MMP participates and cooperates with beta1 and alphavbeta3 integrins in the migration of ECs on different ECM. These data show a novel mechanism by which ECM regulates MT1-MMP association with beta1 or alphavbeta3 integrins at distinct cellular compartments, thus modulating its internalization, activity, and function on human ECs.