Schwann Cell-Derived Exosomes Induce the Differentiation of Human Adipose-Derived Stem Cells Into Schwann Cells

Schwann cell-derived exosomes promote lung cancer progression via miRNA-21-5p

Schwann cells (SCs), the primary glial cells of the peripheral nervous system, which have been identified in many solid tumors, play an important role in cancer development and progression by shaping the tumor immunoenvironment and supporting the development of metastases. Using different cellular, molecular, and genetic approaches with integrated bioinformatics analysis and functional assays, we revealed the role of human SC-derived exosomal miRNAs in lung cancer progression in vitro and in vivo. We found that exosomal miRNA-21 from SCs up-regulated the proliferation, motility, and invasiveness of human lung cancer cells in vitro, which requires functional Rab small GTPases Rab27A and Rab27B in SCs for exosome release. We also revealed that SC exosomal miRNA-21-5p regulated the functional activation of tumor cells by targeting metalloprotease inhibitor RECK in tumor cells. Integrated bioinformatic analyses showed that hsa-miRNA-21-5p is associated with poor prognosis in patients with lung adenocarcinoma and can promote lung cancer progression through multiple signaling pathways including the MAPK, PI3K/Akt, and TNF signaling. Furthermore, in mouse xenograft models, SC exosomes and SC exosomal hsa-miRNA-21-5p augmented human lung cancer cell growth and lymph node metastasis in vivo. Together our data revealed, for the first time, that SC-secreted exosomes and exosomal miRNA-21-5p promoted the proliferation, motility, and spreading of human lung cancer cells in vitro and in vivo. Thus, exosomal miRNA-21 may play an oncogenic role in SC-accelerated progression of lung cancer and this pathway may serve as a new therapeutic target for further evaluation.

Inhibition of MiR-106b-5p mediated by exosomes mitigates acute kidney injury by modulating transmissible endoplasmic reticulum stress and M1 macrophage polarization

Acute kidney injury (AKI), mainly caused by Ischemia/reperfusion injury (IRI), is a common and severe life-threatening disease with high mortality. Accumulating evidence suggested a direct relationship between endoplasmic reticulum (ER) stress response and AKI progression. However, the role of the transmissible ER stress response, a new modulator of cell-to-cell communication, in influencing intercellular communication between renal tubular epithelial cells (TECs) and macrophages in the AKI microenvironment remains to be determined. To address this issue, we first demonstrate that TECs undergoing ER stress are able to transmit ER stress to macrophages via exosomes, promoting macrophage polarization towards the pro-inflammatory M1 phenotype in vitro and in vivo. Besides, the miR-106b-5p/ATL3 signalling axis plays a pivotal role in the transmission of ER stress in the intercellular crosstalk between TECs and macrophages. We observed an apparent increase in the expression of miR-106b-5p in ER-stressed TECs. Furthermore, we confirmed that ALT3 is a potential target protein of miR-106b-5p. Notably, the inhibition of miR-106b-5p expression in macrophages not only restores ATL3 protein level but also decreases transmissible ER stress and hinders M1 polarization, thus alleviating AKI progression. Additionally, our results suggest that the level of exosomal miR-106b-5p in urine is closely correlated with the severity of AKI patients. Taken together, our study sheds new light on the crucial role of transmissible ER stress in the treatment of AKI through the regulation of the miR-106b-5p/ATL3 axis, offering new ideas for treating AKI.

Human platelet lysate stimulates neurotrophic properties of human adipose-derived stem cells better than Schwann cell-like cells

BACKGROUND

Trauma-associated peripheral nerve injury is a widespread clinical problem causing sensory and motor disabilities. Schwann cells (SCs) contribute to nerve regeneration, mainly by secreting nerve growth factor (NGF) and brain-derived neurotrophic factor. In the last years, adipose-derived stem cells (ASCs) differentiated into SCs (SC-ASCs) were considered as promising cell therapy. However, the cell trans-differentiation process has not been effectively showed and presents several drawbacks, thus an alternative approach for increasing ASCs neurotrophic properties is highly demanded. In the context of human cell-based therapies, Good Manufacturing Practice directions indicate that FBS should be substituted with a xenogeneic-free supplement, such as Human Platelet Lysate (HPL). Previously, we demonstrated that neurotrophic properties of HPL-cultured ASCs were superior compared to undifferentiated FBS-cultured ASCs. Therefore, as following step, here we compared the neurotrophic properties of differentiated SC-like ASCs and HPL-cultured ASCs.

METHODS

Both cell groups were investigated for gene expression level of neurotrophic factors, their receptors and neuronal markers. Moreover, the expression of nestin was quantitatively evaluated by flow cytometry. The commitment toward the SC phenotype was assessed with immunofluorescence pictures. Proteomics analysis was performed on both cells and their conditioned media to compare the differential protein profile. Finally, neurotrophic abilities of both groups were evaluated with a functional co-culture assay, assessing dorsal root ganglia survival and neurite outgrowth.

RESULTS

HPL-cultured ASCs demonstrated higher gene expression of NGF and lower expression of S100B. Moreover, nestin was present in almost all HPL-cultured ASCs and only in one quarter of SC-ASCs. Immunofluorescence confirmed that S100B was not present in HPL-cultured ASCs. Proteomics analysis validated the higher expression of nestin and the increase in cytoskeletal and ECM proteins involved in neural regeneration processes. The co-culture assay highlighted that neurite outgrowth was higher in the presence of HPL-ASCs or their conditioned medium compared to SC-ASCs.

CONCLUSIONS

All together, our results show that HPL-ASCs were more neurotrophic than SC-ASCs. We highlighted that the HPL triggers an immature neuro-induction state of ASCs, while keeping their stem properties, paving the way for innovative therapies for nerve regeneration.

Improving Schwann Cell Differentiation from Human Adipose Stem Cells with Metabolic Glycoengineering

Schwann cells (SCs) are myelinating cells that promote peripheral nerve regeneration. When nerve lesions form, SCs are destroyed, ultimately hindering nerve repair. The difficulty in treating nerve repair is exacerbated due to SC's limited and slow expansion capacity. Therapeutic use of adipose-derived stem cells (ASCs) is emerging in combating peripheral nerve injury due to these cells' SC differentiation capability and can be harvested easily in large numbers. Despite ASC's therapeutic potential, their transdifferentiation period typically takes more than two weeks. In this study, we demonstrate that metabolic glycoengineering (MGE) technology enhances ASC differentiation into SCs. Specifically, the sugar analog Ac5ManNTProp (TProp), which modulates cell surface sialylation, significantly improved ASC differentiation with upregulated SC protein S100β and p75NGFR expression and elevated the neurotrophic factors nerve growth factor beta (NGFβ) and glial cell-line-derived neurotrophic factor (GDNF). TProp treatment remarkably reduced the SC transdifferentiation period from about two weeks to two days in vitro, which has the potential to improve neuronal regeneration and facilitate future use of ASCs in regenerative medicine.

The role of BMP4 in adipose-derived stem cell differentiation: A minireview

Bone morphogenetic protein 4 (BMP4) is a member of the transforming growth factor beta (TGF-β) superfamily of cytokines responsible for stem cells’ commitment to differentiation, proliferation, and maturation. To date, various studies have utilized BMP4 as a chemical inducer for in vitro differentiation of human mesenchymal stem cells (MSCs) based on its potential. BMP4 drives in vitro differentiation of ADSC via TGF-β signaling pathway by interactions with BMP receptors leading to the activation of smad-dependent and smad-independent pathways. The BMP4 signaling pathways are regulated by intracellular and extracellular BMP4 antagonists. Extracellular BMP4 antagonist prevents interaction between BMP4 ligand to its receptors, while intracellular BMP4 antagonist shutdowns the smad-dependent pathways through multiple mechanisms. BMP4 proved as one of the popular differentiation factors to induce ADSC differentiation into cell from mesodermal origin. However, addition of all-trans retinoic acid is also needed in trans-differentiation of ADSC into ectodermal lineage cells. Suggesting that both BMP4 and RA signaling pathways may be necessary to be activated for in vitro trans-differentiation of ADSC.

ADSCs Combined with Melatonin Promote Peripheral Nerve Regeneration through Autophagy

BACKGROUND

In the early stage of nerve injury, damaged tissue is cleared by autophagy. ADSCs can promote nerve axon regeneration. However, the microenvironment of the injury was changed, and ADSCs are easily apoptotic after transplantation. Mel plays a role in the apoptosis, proliferation, and differentiation of ADSCs. Therefore, we investigated whether Mel combined with ADSCs promoted peripheral nerve regeneration by enhancing early autophagy of injured nerves.

MATERIALS AND METHODS

SD rats were randomly split into the control group, model group, Mel group, ADSCs group, ADSCs + Mel group, and 3-MA group. On day 7, autophagy was observed and gait was detected on days 7, 14, 21, and 28. On the 28th day, the sciatic nerve of rats' renewal was detected.

RESULTS

After 1 w, compare with the model group, the number of autophagosomes and lysosomes and the expressions of protein of LC3-II/LC3-I and Beclin-1 in the ADSCs + Mel group were prominently increased, while the 3-MA group was significantly decreased. After 4 w, the function of the sciatic nerve in ADSCs + Mel was similar to that in the control group. Compared with the model group, the ADSCs + Mel group significantly increased myelin regeneration and the number of motor neurons and reduced gastrocnemius atrophy.

CONCLUSIONS

It was confirmed that ADSCs combined with Mel could promote sciatic nerve regeneration in rats by changing the early autophagy activity of the injured sciatic nerve.