EVs vs. EVs: MSCs and Tregs as a source of invisible possibilities

Extracellular vesicles therapy alleviates cisplatin-ınduced testicular tissue toxicity in a rat model

PURPOSE

Cisplatin is a commonly used chemotherapy agent effective against various cancers, however it induces significant gonadotoxicity and infertility due to its adverse effects on testicular function. The underlying mechanisms of cisplatin-induced testicular damage include oxidative stress and dysregulated autophagy. This study investigates the potential of extracellular vesicles (EVs) to mitigate cisplatin-induced testicular damage through their regenerative, antioxidant, and autophagy-modulating properties.

METHODS

In the testicular toxicity model, thirty-two male rats were randomly divided into four groups (n = 8): control, EVs-only, Cis-only, and Cis + EVs. A single intraperitoneal dose of 7.5mg/kg cisplatin was administered on the first day. On the six day, the EVs treatment group received a single dose of EVs (8x107/100μl) intravenously. Animals were sacrificed on day eight. Testicular histoarchitecture was assessed via hematoxylin and eosin staining. Sperm parameters, including motility and count, were measured using light microscopy. Hormone levels (testosterone and inhibin) were determined via enzyme-linked immunosorbent assay (ELISA). Oxidative stress markers, such as glutathione peroxidase (GSH-PX), superoxide dismutase (SOD), catalase (CAT), and is a metabolite malondialdehyde (MDA), were quantified using colorimetric assays. Autophagy and steroidogenesis were evaluated through immunohistochemical analysis of Beclin-1, p62, LC3-2, SF-1, and StAR.

RESULTS

Cisplatin exposure caused significant testicular damage, characterized by reduced germinal epithelium and degeneration of seminiferous tubules (p < 0.001). These structural changes led to hormonal imbalances, as evidenced by declines in testosterone (p < 0.005) and inhibin (p < 0.001). Additionally, sperm motility (p < 0.05) and count (p < 0.001) were adversely affected. Immunohistochemical analysis revealed upregulation of autophagy markers (p < 0.001), indicating heightened autophagic activity, alongside downregulation of steroidogenic factors (p < 0.001), which contributed to impaired steroidogenesis. Elevated levels of malondialdehyde (MDA) (p < 0.01) and decreased activities of antioxidant enzymes-GSH-PX, SOD, and CAT (p < 0.001) pointed to increased oxidative stress as a contributing mechanism. In contrast, treatment with extracellular vesicles (EVs) significantly improved testicular histoarchitecture (p < 0.001) and restored hormonal levels toward normal (testosterone p < 0.005, inhibin p < 0.001). Furthermore, EVs reduced the expression of autophagy markers (p < 0.001) and enhanced the levels of steroidogenic factors (p < 0.05). Notably, MDA levels decreased (p < 0.001), while antioxidant activities increased (p < 0.001), suggesting a protective effect of EVs against oxidative stress.

CONCLUSION

EVs protect against cisplatin-induced reproductive toxicity by modulating oxidative stress and autophagy pathways, preserving testicular function and fertility. These findings suggest that EVs may be a promising therapeutic strategy for mitigating cisplatin's negative effects on reproductive health. Further exploration of dosing regimens and localized applications is recommended for improved efficacy.

Exosome Source Matters: A Comprehensive Review from the Perspective of Diverse Cellular Origins

Exosomes have emerged as promising therapeutic agents in regenerative medicine. This review introduces a novel cell type-oriented perspective to systematically analyze exosomal properties in regenerative therapies. To our knowledge, this review is the first to comprehensively compare exosomes based on cellular source type, offering unprecedented insights into selecting optimal exosome producers for targeted regenerative applications. Factors beyond cellular origin influencing exosomal therapeutic efficacy, such as donor sites and collection methods, are also explored here. By synthesizing key advances, we propose promising research directions in the end. We aim to accelerate the development of more effective exosome-based regenerative therapies and highlight underexplored directions in this rapidly evolving field.

Extracellular vesicles derived from immune cells: Role in tumor therapy

Extracellular vesicles (EVs), which have a lipid nano-sized structure, are known to contain the active components of parental cells and play a crucial role in intercellular communication. The progression and metastasis of tumors are influenced by EVs derived from immune cells, which can simultaneously stimulate and suppress immune responses. In the past few decades, there has been a considerable focus on EVs due to their potential in various areas such as the development of vaccines, delivering drugs, making engineered modifications, and serving as biomarkers for diagnosis and prognosis. This review focuses on the substance information present in EVs derived from innate and adaptive immune cells, their effects on the immune system, and their applications in cancer treatment. While there are still challenges to overcome, it is important to explore the composition of immune cells released vesicles and their potential therapeutic role in tumor therapy. The review also highlights the current limitations and future prospects in utilizing EVs for treatment purposes.

Dual impacts of mesenchymal stem cell-derived exosomes on cancer cells: unravelling complex interactions

Mesenchymal stem cells (MSCs) are multipotent, self-renewing stromal cells found in a variety of adult tissues. MSCs possess a remarkable ability to migrate towards tumor sites, known as homing. This homing process is mediated by various factors, including chemokines, growth factors, and extracellular matrix components present in the tumor microenvironment. MSCs release extracellular vesicles known as exosomes (MSC-Exos), which have been suggested to serve a key role in mediating a wide variety of MSC activities. Through cell-cell communication, MSC-Exos have been shown to alter recipient cell phenotype or function and play as a novel cell-free alternative for MSC-based cell therapy. However, MSC recruitment to tumors allows for their interaction with cancer cells and subsequent regulation of tumor behavior. MSC-Exos act as tumor niche modulators via transferring exosomal contents, such as specific proteins or genetic materials, to the nearby cancer cells, leading to either promotion or suppression of tumorigenesis, angiogenesis, and metastasis, depending on the specific microenvironmental cues and recipient cell characteristics. Consequently, there is still a debate about the precise relationship between tumor cells and MSC-Exos, and it is unclear how MSC-Exos impacts tumor cells. Although the dysregulation of miRNAs is caused by the progression of cancer, they also play a direct role in either promoting or inhibiting tumor growth as they act as either oncogenes or tumor suppressors. The utilization of MSC-Exos may prove to be an effective method for restoring miRNA as a means of treating cancer. This review aimed to present the existing understanding of the impact that MSC-Exos could have on cancer. To begin with, we presented a brief explanation of exosomes, MSCs, and MSC-Exos. Following this, we delved into the impact of MSC-Exos on cancer growth, EMT, metastasis, angiogenesis, resistance to chemotherapy and radiotherapy, and modulation of the immune system. Opposing effects of mesenchymal stem cells-derived exosomes on cancer cells.

Large extracellular vesicles derived from human regulatory macrophages (L-EVMreg) attenuate CD3/CD28-induced T-cell activation in vitro

Macrophages belong to the innate immune system, and we have recently shown that in vitro differentiated human regulatory macrophages (Mreg) release large extracellular vesicles (L-EVMreg) with an average size of 7.5 μm which regulate wound healing and angiogenesis in vitro. The aim of this study was to investigate whether L-EVMreg also affect the CD3/CD28-mediated activation of T-cells. Mreg were differentiated using blood monocytes and L-EVMreg were isolated from culture supernatants by differential centrifugation. Activation of human T-cells was induced by CD3/CD28-coated beads in the absence or presence of Mreg or different concentrations of L-EVMreg. Inhibition of T-cell activation was quantified by flow cytometry and antibodies directed against the T-cell marker granzyme B. Phosphatidylserine (PS) exposure on the surface of Mreg and L-EVMreg was analyzed by fluorescence microscopy. Incubation of human lymphocytes with CD3/CD28 beads resulted in an increase of cell size, cell granularity, and number of granzyme B-positive cells (P < 0.05) which is indicative of T-cell activation. The presence of Mreg (0.5 × 106 Mreg/ml) led to a reduction of T-cell activation (number of granzyme B-positive cells; P < 0.001), and a similar but less pronounced effect was also observed when incubating activated T-cells with L-EVMreg (P < 0.05 for 3.2 × 106 L-EVMreg/ml). A differential analysis of the effects of Mreg and L-EVMreg on CD4+ and CD8+ T-cells showed an inhibition of CD4+ T-cells by Mreg (P < 0.01) and L-EVMreg (P < 0.05 for 1.6 × 106 L-EVMreg/ml; P < 0.01 for 3.2 × 106 L-EVMreg/ml). A moderate inhibition of CD8+ T-cells was observed by Mreg (P < 0.05) and by L-EVMreg (P < 0.01 for 1.6 × 106 L-EVMreg/ml and 3.2 × 106 L-EVMreg/ml). PS was restricted to confined regions of the Mreg surface, while L-EVMreg showed strong signals for PS in the exoplasmic leaflet. L-EVMreg attenuate CD3/CD28-mediated activation of CD4+ and CD8+ T-cells. L-EVMreg may have clinical relevance, particularly in the treatment of diseases associated with increased T-cell activity. KEY MESSAGES: Mreg release large extracellular vesicles (L-EVMreg) with an average size of 7.5 µm L-EVMreg exhibit phosphatidylserine positivity L-EVMreg suppress CD4+ and CD8+ T-cells L-EVMreg hold clinical potential in T-cell-related diseases.