Exosomes Digest (3/4 April 2025)
- Lisa
- 20. Apr.
- 4 Min. Lesezeit
We have collected the most exciting new researches in the field of genetics and cellular research in the past week.
Mesenchymal stem cell exosomes therapy for the treatment of traumatic brain injury: mechanism, progress, challenges and prospects
Traumatic brain injury (TBI) is a heterogeneous disease characterized by brain damage and functional impairment caused by external forces. Under the influence of multiple mechanisms, TBI can cause synaptic dysfunction, protein aggregation, mitochondrial dysfunction, oxidative stress, and neuroinflammatory cascade reactions, resulting in a high disability and mortality rate for patients and a heavy burden on families and society. Exosomes are cell-derived vesicles that encapsulate a variety of molecules, including proteins, lipids, mRNAs, and other small biomolecules. Among these, exosomes derived from mesenchymal stem cells (MSCs) have garnered significant attention owing to their therapeutic potential in the nervous system, offering broad clinical applicability. Recent studies have demonstrated that MSC-derived exosome injections in traumatic brain injury models effectively mitigate local inflammatory damage and promote nerve regeneration following injury. Owing to their small size, challenging replication, ease of preservation, and low immunogenicity, MSC exosomes are emerging as a promising therapeutic strategy for traumatic brain injury. This review explores the pathogenesis of traumatic brain injury, the underlying mechanisms of MSC exosome action, and the potential clinical applications of MSC exosomes in the treatment of traumatic brain injury.
Comparative analysis of the therapeutic effects of mesenchymal stem cells and exosomes on cartilage regeneration: exploring their synergistic potential with hyaluronic acid for treating articular cartilage defects
Abstract
Purpose
Articular cartilage exhibits a low regenerative capacity and limited potential for self-renewal. Recent research has demonstrated that exosomes and mesenchymal stem cells (MSCs) significantly enhance cartilage repair by promoting cellular proliferation, increasing extracellular matrix synthesis, and modulating the immune response. Additionally, hyaluronic acid (HA), a critical component of synovial fluid, plays a key role in facilitating cell migration. This study aims to compare the regenerative effects of Wharton’s jelly-derived MSCs, MSC-derived exosomes, and their combination with hyaluronic acid in the treatment of cartilage defects. Additionally, we seek to evaluate the impact of hyaluronic acid when combined with MSCs and exosomes through histological analysis in a rat model.
Methods
In this study, full-thickness cartilage defects were created in the trochlear grooves of both distal femurs in 48 adult rats. The knees were randomly assigned to six groups:
Group I: Control—saline, Group II: Wharton’s jelly mesenchymal stem cells (MSCs), Group III: Wharton’s jelly MSC-derived exosomes (Exo), Group IV: Hyaluronic acid (HA), Group V: MSC and HA combination, and Group VI: Exo and HA combination.
Each rat received a total of three intra-articular injections at weekly intervals, beginning two weeks post-surgery. Four weeks following the final injection, all rats were euthanized, and their femurs were dissected for analysis. All groups were assessed macroscopically using the International Cartilage Repair Society (ICRS) scoring system, following histological staining with hematoxylin–eosin (HE) and toluidine blue, and immunohistochemical staining with type II collagen antibodies. The quality of the repaired cartilage was subsequently evaluated according to the ICRS histological grading system by an independent, blinded observer.
Results
Macroscopic evaluations indicated that the ICRS scores of the MSC group (8.2 ± 0.7) were significantly higher (P < 0.05) than those of the control group (4.3 ± 0.7). The cartilage defects in the MSC group showed substantial repair, displaying the most effective cartilage regeneration among all groups. Furthermore, comparison between groups revealed that both the MSC and Exo groups demonstrated a higher rate of defect depth repair, a smaller demarcation border, and a smoother cartilage surface.
Conclusions
This study demonstrates that exosomes are as effective as stem cell therapies in promoting cartilage repair, suggesting that exosomes may serve as a viable alternative to cell-based therapies for cartilage damage. However, the addition of hyaluronic acid to stem cells and exosomes showed no significant enhancement in cartilage repair. Our findings highlight a potentially effective therapeutic strategy for the treatment of osteochondral cartilage defects.
Exosome derived from human adipose-derived mesenchymal stem cells prevented bone loss induced by estrogen deficiency
Abstract
Objective: To investigate the effect of human adipose-derived mesenchymal stem cells (hASCs) exosomes on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) extracted from osteoporotic mice, and to evaluate the effect of hASCs exosomes on preventing bone loss induced by estrogen deficiency.
Methods: hASCs exosomes were extracted by ultracentrifugation. The osteoporotic mice were established by bilateral ovariectomy (OVX). BMSCs were isolated from osteo-porotic mice and cultured for further analysis. In the experimental group, these BMSCs were exposed to an osteogenic induction medium supplemented with hASCs exosomes to evaluate their potential effects on osteogenesis. In contrast, the control group was treated with the same osteogenic induction medium, but without the addition of hASCs exosomes, to serve as a baseline comparison for the study. To comprehensively assess the osteogenic differentiation of BMSCs influenced by hASCs exosomes, alkaline phosphatase (ALP) staining, ALP activity quantitative analysis and quantitative reverse transcription polymerase chain reaction (qPCR) were performed. These evaluations provided critical insights into the role of hASCs exosomes in promoting osteoblast differentiation and bone formation in osteoporotic conditions. The fluorescence labeled hASCs exosomes were injected via the tail vein to observe the biodistribution of exosomes. Two weeks after OVX, the mice were divided into three groups: The experimental group consisted of estrogen-deficient mice receiving hASCs exosome injections; the negative control group consisted of estrogen-deficient mice receiving phosphate-buffered saline (PBS) injections; and the positive control group consisted of mice that underwent Sham surgery and received PBS injections.The injections were administered once every 3 days, for a total of 8 injections. Afterward, the femurs were collected from the mice, and micro-computed tomography (micro-CT) was performed to measure bone mineral density and conduct bone morphometric analysis.
Results: hASCs exosomes were successfully extracted using ultracentrifugation. After the induction by hASCs exosomes, ALP staining and ALP activity in the BMSCs extracted from osteoporotic mice were significantly enhanced, the expression of osteogenesis related genes in BMSCs were significantly up-regulated. More trabecular bone and higher bone mineral density were observed in estrogen-deficient mice injected with hASCs exosomes compared with estrogen-deficient mice injected with PBS, and there was no significant decrease in bone mineral density compared with the Sham operation group.
Conclusion: hASCs exosomes promoted the osteogenic differentiation of BMSCs extracted from osteoporotic mice. hASCs exosomes prevented bone loss induced by estrogen deficiency.
