Cellular therapy promotes endogenous stem cell repair

The role of β-adrenergic receptors and p38MAPK signaling pathways in physiological processes of cardiosphere-derived cells

The effects of β adrenergic receptors (β-ARs) and p38 mitogen-activated protein kinases (MAPK) pathways on cardiosphere-derived cells (CDCs) are largely unknown. This study aimed to investigate the roles of β-ARs and p38MAPK pathways on the proliferation, apoptosis, and differentiation capacity of CDCs. The CDCs were treated with β1-AR blocker (Met group), β2-AR antagonist (ICI group), and p38MAPK inhibitor (SB group), non-selective β-AR blocker (PRO group), and β-AR agonist (ISO group). The viability, apoptotic rate and differentiation status of CDCs were determined by MST-1 assay, flow cytometery, and Western blot, respectively. The CDCs viability significantly reduced in ICI group (all P < 0.05), and SB group had a significant high viability after 48 h treatment (P < 0.05). Compared with control group, all treated groups had a low apoptotic rate. After treatment for 72 h, ISO treatment elevated the expression of Nkx2.5, and could partially or fully attenuate the inhibitory effects of β-AR antagonists and/or p38MAPK inhibitor. A similar overall trend of protein expression levels among all groups could be observed between protein pairs of cTnT and β1-AR as well as c-Kit and β2-AR, respectively. These results suggested that β-ARs and p38MAPK signaling pathways play crucial roles in the proliferation and differentiation of CDCs. Our findings should be helpful for better understanding the molecular mechanism underlying the physiological processes of CDCs.

Therapeutic potential of mesenchymal stem cells for pulmonary complications associated with preterm birth

Preterm infants frequently suffer from pulmonary complications resulting in significant morbidity and mortality. Physiological and structural lung immaturity impairs perinatal lung transition to air breathing resulting in respiratory distress. Mechanical ventilation and oxygen supplementation ensure sufficient oxygen supply but enhance inflammatory processes which might lead to the establishment of a chronic lung disease called bronchopulmonary dysplasia (BPD). Current therapeutic options to prevent or treat BPD are limited and have salient side effects, highlighting the need for new therapeutic approaches. Mesenchymal stem cells (MSCs) have demonstrated therapeutic potential in animal models of BPD. This review focuses on MSC-based therapeutic approaches to treat pulmonary complications and critically compares results obtained in BPD models. Thereby bottlenecks in the translational systems are identified that are preventing progress in combating BPD. Notably, current animal models closely resemble the so-called "old" BPD with profound inflammation and injury, whereas clinical improvements shifted disease pathology towards a "new" BPD in which arrest of lung maturation predominates. Future studies need to evaluate the utility of MSC-based therapies in animal models resembling the "new" BPD though promising in vitro evidence suggests that MSCs do possess the potential to stimulate lung maturation. Furthermore, we address the mode-of-action of MSC-based therapies with regard to lung development and inflammation/fibrosis. Their therapeutic efficacy is mainly attributed to an enhancement of regeneration and immunomodulation due to paracrine effects. In addition, we discuss current improvement strategies by genetic modifications or precondition of MSCs to enhance their therapeutic efficacy which could also prove beneficial for BPD therapies.

Dental stem cells: a future asset of ocular cell therapy

Regenerative medicine using patient's own stem cells (SCs) to repair dysfunctional tissues is an attractive approach to complement surgical and pharmacological treatments for aging and degenerative disorders. Recently, dental SCs have drawn much attention owing to their accessibility, plasticity and applicability for regenerative use not only for dental, but also other body tissues. In ophthalmology, there has been increasing interest to differentiate dental pulp SC and periodontal ligament SC (PDLSC) towards ocular lineage. Both can commit to retinal fate expressing eye field transcription factors and generate rhodopsin-positive photoreceptor-like cells. This proposes a novel therapeutic alternative for retinal degeneration diseases. Moreover, as PDLSC shares similar cranial neural crest origin and proteoglycan secretion with corneal stromal keratoctyes and corneal endothelial cells, this offers the possibility of differentiating PDLSC to these corneal cell types. The advance could lead to a shift in the medical management of corneal opacities and endothelial disorders from highly invasive corneal transplantation using limited donor tissue to cell therapy utilizing autologous cells. This article provides an overview of dental SC research and the perspective of utilizing dental SCs for ocular regenerative medicine.

The myeloid-binding peptide adenoviral vector enables multi-organ vascular endothelial gene targeting

Vascular endothelial cells (ECs) are ideal gene therapy targets as they provide widespread tissue access and are the first contact surfaces following intravenous vector administration. Human recombinant adenovirus serotype 5 (Ad5) is the most frequently used gene transfer system because of its appreciable transgene payload capacity and lack of somatic mutation risk. However, standard Ad5 vectors predominantly transduce liver but not the vasculature following intravenous administration. We recently developed an Ad5 vector with a myeloid cell-binding peptide (MBP) incorporated into the knob-deleted, T4 fibritin chimeric fiber (Ad.MBP). This vector was shown to transduce pulmonary ECs presumably via a vector handoff mechanism. Here we tested the body-wide tropism of the Ad.MBP vector, its myeloid cell necessity, and vector-EC expression dose response. Using comprehensive multi-organ co-immunofluorescence analysis, we discovered that Ad.MBP produced widespread EC transduction in the lung, heart, kidney, skeletal muscle, pancreas, small bowel, and brain. Surprisingly, Ad.MBP retained hepatocyte tropism albeit at a reduced frequency compared with the standard Ad5. While binding specifically to myeloid cells ex vivo, multi-organ Ad.MBP expression was not dependent on circulating monocytes or macrophages. Ad.MBP dose de-escalation maintained full lung-targeting capacity but drastically reduced transgene expression in other organs. Swapping the EC-specific ROBO4 for the CMV promoter/enhancer abrogated hepatocyte expression but also reduced gene expression in other organs. Collectively, our multilevel targeting strategy could enable therapeutic biological production in previously inaccessible organs that pertain to the most debilitating or lethal human diseases.