Nanotubules Link Damaged Heart Cells With Mesenchymal Stem Cells to Both of Their Benefit


Mesenchymal stem cells are found throughout the body in bone marrow, fat, tendons, muscle, skin, umbilical cord, and many other tissues. These cells have the capacity to readily differentiate into bone, fat, and cartilage, and can also form smooth muscles under particular conditions.

Several animal studies and clinical trials have demonstrated that mesenchymal stem cells can help heal the heart after a heart attack. Mesenchymal stem cells (MSCs) tend to help the heart by secreting a variety of particular molecules that stimulate heart muscle survival, proliferation, and healing.

Given these mechanisms of healing, is there a better way to get these healing molecules to the heart muscle cells?

A research group from INSERM in Creteil, France has examined the use of tunneling nanotubes to connect MSCs with heart muscle cells. These experiments have revealed something remarkable about MSCs.

Florence Figeac and her colleagues in the laboratory of Ann-Marie Rodriguez used a culture system that grew fat-derived MSCs and with mouse heart muscle cells. They induced damage in the heart muscle cells and then used tunneling nanotubes to connect the fat-based MSCs.

They discovered two things. First of all, the MSCs secreted a variety of healing molecules regardless of their culture situation. However, when the MSCs were co-cultured with damaged heart muscle cells with tunneling nanotubes, the secretion of healing molecules increased. The tunneling nanotubes somehow passed signals from the damaged heart muscle cells to the MSCs and these signals jacked up secretion of healing molecules by the MSCs.

The authors referred to this as “crosstalk” between the fat-derived MSCs and heart muscle cells through the tunneling nanotubes and it altered the secretion of heart protective soluble factors (e.g., VEGF, HGF, SDF-1α, and MCP-3). The increased secretion of these molecules also maximized the ability of these stem cells to promote the growth and formation of new blood vessels and recruit bone marrow stem cells.

After these experiments in cell culture, Figeac and her colleagues used these cells in a living animal. They discovered that the fat-based MSCs did a better job at healing the heart if they were previously co-cultured with heart muscle cells.

Exposure of the MSCs to damaged heart muscle cells jacked up the expression of healing molecules, and therefore, these previous exposures made these MSCs better at healing hearts in comparison to naive MSCs that were not previously exposed to damaged heart muscle.

Thus, these experiments show that crosstalk between MSCs and heart muscle cells, mediated by nanotubes, can optimize heart-based stem cells therapies.

Human Neural Stem Cells Heal Damaged Limbs


The term “ischemia” refers to conditions under which a part of your body, organ, or tissue is deprived of oxygen. Without life-giving cells begin to die. Therefore, ischemia is usually a very bad thing.

Critical limb ischemia or CLI results when blood vessels to the legs, feet or arms are severely obstructed. The results of CLI are never pretty, and CLI remains a medical condition that presents few treatment options.

A study from a research team and the University of Bristol’s School of Clinical Sciences has used stem cells in a trial that uses laboratory mice to treat CLI. The success of this study provides a new direction and new hope for procedures that relieve symptoms and prolong the life of the limb.

Autologous stem cells treatments, or those stem treatments that utilize a patient’s own stem cells care subject to clear limitations. After collection from bone marrow, fat, or other source, the stem cells must be expanded in culture after stimulation with chemicals called cytokines. After growth in culture, the cells typically contain a collection of different types of stem cells of variable quality and potency. Also, if the patients has had a heart attack or has diabetes, then the quality and potency of their own stem cells are seriously compromised.

To circumvent this problem, Paulo Madeddu and his team at the Bristol Heart Institute have used an immortalized human neural stem cell line called CTX to treat animals who suffered from diabetes mellitus and CLI.

The CTX cell line comes from a biotechnology company called ReNeuron. This company is using this cell line in a clinical trial for stoke patients, and wants to use the CTX cell line in a clinical trial for CLI patients in the future.

When CTX cells are injected into the muscle of diabetic mice with CLI, the cells promote recovery from CLI. The CTX cells do so by promoting the growth of new blood vessels.

Madeddu said, “There are not effective drug interventions to treat CLI. The consequences are a very poor quality of life, possible major amputation and a life expectancy of less than one year from diagnosis in 50 percent of all CLI patients.”

Dr. Madeddu continued: “Our findings have shown a remarkable advancement towards more effective treatments for CLI and we have also demonstrated the importance of collaborations between universities and industry that can have a social and medical impact.”