[Perspectives of cell therapy for myocardial infarction and heart failure based on cardiosphere cells]

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide. In recent years, researchers are attracted to the use of cell therapy based on stem cell and progenitor cells, which has been a promising strategy for cardiac repair after injury. However, conducted research using intracoronary or intramyocardial transplantation of various types of stem/progenitor cells as a cell suspension showed modest efficiency. This is due to the low degree of integration and cell survival after transplantation. To overcome these limitations, the concept of the use of multicellular spheroids modeling the natural microenvironment of cells has been proposed, which allows maintaining their viability and therapeutic properties. It is of great interest to use so-called cardial spheroids (cardiospheres) spontaneously forming three-dimensional structures under low-adhesive conditions, consisting of a heterogeneous population of myocardial progenitor cells and extracellular matrix proteins. This review presents data on methods for creating cardiospheres, directed regulation of their properties and reparative potential, as well as the results of preclinical and clinical studies on their use for the treatment of heart diseases.

Oxygen Tension Regulates Human Mesenchymal Stem Cell Paracrine Functions

: Mesenchymal stem cells (MSCs) have captured the attention and research endeavors of the scientific world because of their differentiation potential. However, there is accumulating evidence suggesting that the beneficial effects of MSCs are predominantly due to the multitude of bioactive mediators secreted by these cells. Because the paracrine potential of MSCs is closely related to their microenvironment, the present study investigated and characterized select aspects of the human MSC (hMSC) secretome and assessed its in vitro and in vivo bioactivity as a function of oxygen tension, specifically near anoxia (0.1% O2) and hypoxia (5% O2), conditions that reflect the environment to which MSCs are exposed during MSC-based therapies in vivo. In contrast to supernatant conditioned media (CM) obtained from hMSCs cultured at either 5% or 21% of O2, CM from hMSCs cultured under near anoxia exhibited significantly (p < .05) enhanced chemotactic and proangiogenic properties and a significant (p < .05) decrease in the inflammatory mediator content. An analysis of the hMSC secretome revealed a specific profile under near anoxia: hMSCs increase their paracrine expression of the angiogenic mediators vascular endothelial growth factor (VEGF)-A, VEGF-C, interleukin-8, RANTES, and monocyte chemoattractant protein 1 but significantly decrease expression of several inflammatory/immunomodulatory mediators. These findings provide new evidence that elucidates aspects of great importance for the use of MSCs in regenerative medicine and could contribute to improving the efficacy of such therapies.

SIGNIFICANCE

The present study investigated and characterized select aspects of the human mesenchymal stem cell (hMSC) secretome and assessed its in vitro and in vivo biological bioactivity as a function of oxygen tension, specifically near anoxia (0.1% O2) and hypoxia (5% O2), conditions that reflect the environment to which MSCs are exposed during MSC-based therapies in vivo. The present study provided the first evidence of a shift of the hMSC cytokine signature induced by oxygen tension, particularly near anoxia (0.1% O2). Conditioned media obtained from hMSCs cultured under near anoxia exhibited significantly enhanced chemotactic and proangiogenic properties and a significant decrease in the inflammatory mediator content. These findings provide new evidence that elucidates aspects of great importance for the use of MSCs in regenerative medicine, could contribute to improving the efficacy of such therapies, and most importantly highlighted the interest in using conditioned media in therapeutic modalities.

Clinical efficacy of autologous stem cell transplantation for the treatment of patients with type 2 diabetes mellitus: a meta-analysis

BACKGROUND AIMS

In this study, we investigate whether bone marrow mononuclear cells (BM-MNC) or peripheral blood mononuclear cells (PB-MNC) have therapeutic efficacy in type 2 diabetes (T2D).

METHODS

Search terms included stem cell, bone marrow cell, peripheral blood cell, umbilical cord blood and T2D in MEDLINE, the Cochrane Controlled Trials Register, EMBASE, the Wanfang Database, the China Science and Technology Periodical Database and China Journal Net.

RESULTS

Fifteen trials met our inclusion criteria (n = 497). One group included 266 cases with BM-MNC therapy and the other group contained 231 cases with PB-MNC treatment. Glycosylated hemoglobin was decreased after BM-MNC or PB-MNC therapy compared with that before (12 months: P < 0.001; 6 months: P < 0.001; 3 months: P < 0.05). Fasting plasma glucose was reduced in BM-MNC therapy group compared with control after 12-month follow-up (P < 0.001) and after BM-MNC therapy compared with that before (9 months: P < 0.001) but was not obvious in other stages. Meanwhile, the analysis showed that C-peptide level increased after BM-MNC and PB-MNC therapy compared with the control therapy (12 months: P < 0.001) and with that before therapy (6 months: P < 0.05). Insulin requirement reduction was also observed in patients receiving BM-MNC therapy (3, 6, 9 and 12 months: P < 0.05).

CONCLUSIONS

To a certain extent, BM-MNC or PB-MNC therapy for T2D demonstrated superiority of glycemic control, increased insulin biosynthesis and elevated insulin secretion from existing β-cells and might prevent islet cell loss.

Enhancing spontaneous stem cell healing (Review)

Adult stem cells are distributed throughout the human body and are responsible to a great extent for the body's ability to maintain and heal itself. Accumulating data since the 1990s regarding stem cells have demonstrated that the beneficial effects of stem cells are not restricted to their ability to differentiate and are more likely due to their ability to release a multitude of molecules. Recent studies indicated that ≤80% of the therapeutic benefit of adult stem cells is manifested by the stem cell released molecules (SRM) rather than the differentiation of the stem cells into mature tissue. Stem cells may release potent combinations of factors that modulate the molecular composition of the cellular milieu to evoke a multitude of responses from neighboring cells. A multitude of pathways are involved in cellular and tissue function and, when the body is in a state of disease or trauma, a multitude of pathways are involved in the underlying mechanisms of that disease or trauma. Therefore, stem cells represent a natural systems-based biological factory for the production and release of a multitude of molecules that interact with the system of biomolecular circuits underlying disease or tissue damage. Currently, efforts are aimed at defining, stimulating, enhancing and harnessing SRM mechanisms, in order to develop systems-based methods for tissue regeneration, develop drugs/biologics or other therapeutics and enhance the release of SRM into the body for natural healing through proper dietary, exercise and other lifestyle strategies.

Using a systems-based approach to overcome reductionist strategies in the development of diagnostics

Systems biology is a recent addition to the necessary but insufficient reductionist approach used in biological research. Systems biology is focused on understanding living things as a function of their various interactions at multiple levels: not simply as a sum of all their individual parts at any one level. This integrative approach yields predictive models of the normal state, the disease state and therapeutic actions. Although molecular biology has collected an enormous amount of information, including the sequencing of the entire human genome in the year 2000, few real-world applications have resulted from this molecular approach. The pharmaceutical industry's R&D expenditure has increased substantially since 2000, but the number of approved therapeutics has dropped simultaneously, due in part to over-reliance on reductionist genomic, and not systems, approaches. Instead of using reductionist genomics approaches alone, genomics should be incorporated into a multi-level systems biology approach to develop diagnostics and therapeutics.

Stem cell therapy without the cells

As an example of the burgeoning importance of stem cell therapy, this past month the California Institute for Regenerative Medicine (CIRM) has approved $70 million to create a new network of stem cell clinical trial centers. Much work in the last decade has been devoted to developing the use of autologous and allogeneic adult stem cell transplants to treat a number of conditions, including heart attack, dementia, wounds, and immune system-related diseases. The standard model teaches us that adult stem cells exists throughout most of the body and provide a means to regenerate and repair most tissues through replication and differentiation. Although we have often witnessed the medical cart placed in front of the scientific horse in the development of stem cell therapies outside of academic circles, great strides have been made, such as the use of purified stem cells¹ instead of whole bone marrow transplants in cancer patients, where physicians avoid re-injecting the patients with their own cancer cells.² We most often think of stem cell therapy acting to regenerate tissue through replication and then differentiation, but recent studies point to the dramatic effects adult stem cells exert in the repair of various tissues through the release of paracrine and autocrine substances, and not simply through differentiation. Indeed, up to 80% of the therapeutic effect of adult stem cells has been shown to be through paracrine mediated actions.³ That is, the collected types of molecules released by the stem cells, called the secretome, or stem cell released molecules (SRM), number in the 100s, including proteins, microRNA, growth factors, antioxidants, proteasomes, and exosomes, and target a multitude of biological pathways through paracrine actions. The composition of the different molecule types in SRM is state dependent, and varies with cell type and conditions such as age and environment.