Murine and Chinese cobra venom‑derived nerve growth factor stimulate chondrogenic differentiation of BMSCs in vitro: A comparative study

NGF/TrkA promotes the vitality, migration and adhesion of bone marrow stromal cells in hypoxia by regulating the Nrf2 pathway

BACKGROUND

Bone marrow stromal cells (BMSCs) transplantation is a treatment strategy for ischemic stroke (IS) with great potential. However, the vitality, migration and adhesion of BMSCs are greatly impaired due to the harsh environment of the ischemic area, which affects the therapeutic effects. Herein, we aimed to investigate the roles of nerve growth factor (NGF) in regulating cell behaviors of BMSCs in IS.

METHODS

The mRNA and protein expressions were assessed using qRT-PCR and western blot, respectively. To simulate ischemic-like conditions in vitro, Brain microvascular (bEnd.3) cells were exposed to oxygen and glucose deprivation (OGD). Cell viability and cell proliferation were evaluated by MTT assay and BrdU assay, respectively. Transwell migration and cell adhesion assays were carried out to determine cell migration and adhesion of BMSCs, respectively, coupled with flow cytometry to evaluate cell apoptosis of bEnd.3 cells. Finally, angiogenesis assay was performed to assess the angiogenesis ability of bEnd.3 cells.

RESULTS

NGF overexpression resulted in increased cell vitality, adhesion and migration of BMSCs, while NGF knockdown presented the opposite effects. We subsequently discovered that TrkA was a receptor for NGF, and TrkA knockdown significantly inhibited the cell viability, migration and adhesion of BMSCs. Besides, Nrf2 was confirmed as the downstream target of NGF/TrkA to promote the viability, adhesion and migration of BMSC cells. Finally, NGF-silenced BMSCs could not effectively restore the OGD-induced brain microvascular cell damage.

CONCLUSIONS

NGF/TrkA promoted the viability, migration and adhesion of BMSCs in IS via activating Nrf2 pathway.

Nerve growth factor (NGF) and NGF receptors in mesenchymal stem/stromal cells: Impact on potential therapies

Mesenchymal stem/stromal cells (MSCs) are promising for the treatment of degenerative diseases and traumatic injuries. However, MSC engraftment is not always successful and requires a strong comprehension of the cytokines and their receptors that mediate the biological behaviors of MSCs. The effects of nerve growth factor (NGF) and its two receptors, TrkA and p75NTR, on neural cells are well studied. Increasing evidence shows that NGF, TrkA, and p75NTR are also involved in various aspects of MSC function, including their survival, growth, differentiation, and angiogenesis. The regulatory effect of NGF on MSCs is thought to be achieved mainly through its binding to TrkA. p75NTR, another receptor of NGF, is regarded as a novel surface marker of MSCs. This review provides an overview of advances in understanding the roles of NGF and its receptors in MSCs as well as the effects of MSC‐derived NGF on other cell types, which will provide new insight for the optimization of MSC‐based therapy.

Anthelminthic Activity of Assassin Bug Venom against the Blood Fluke Schistosoma mansoni

Helminths such as the blood fluke Schistosoma mansoni represent a major global health challenge due to limited availability of drugs. Most anthelminthic drug candidates are derived from plants, whereas insect-derived compounds have received little attention. This includes venom from assassin bugs, which contains numerous bioactive compounds. Here, we investigated whether venom from the European predatory assassin bug Rhynocoris iracundus has antischistosomal activity. Venom concentrations of 10–50 µg/mL inhibited the motility and pairing of S. mansoni adult worms in vitro and their capacity to produce eggs. We used EdU-proliferation assays to measure the effect of venom against parasite stem cells, which are essential for survival and reproduction. We found that venom depleted proliferating stem cells in different tissues of the male parasite, including neoblasts in the parenchyma and gonadal stem cells. Certain insect venoms are known to lyse eukaryotic cells, thus limiting their therapeutic potential. We therefore carried out hemolytic activity assays using porcine red blood cells, revealing that the venom had no significant effect at a concentration of 43 µg/mL. The observed anthelminthic activity and absence of hemolytic side effects suggest that the components of R. iracundus venom should be investigated in more detail as potential antischistosomal leads.