Exosomes: A promising therapeutic strategy for intervertebral disc degeneration

Angiogenesis unveiled: Insights into its role and mechanisms in cartilage injury

Osteoarthritis (OA) commonly results in compromised mobility and disability, thereby imposing a significant burden on healthcare systems. Cartilage injury is a prevalent pathological manifestation in OA and constitutes a central focus for the development of treatment strategies. Despite the considerable number of studies aimed at delaying this degenerative process, their outcomes remain unvalidated in preclinical settings. Recently, therapeutic strategies focused on angiogenesis have attracted the growing interest from researchers. Thus, we conducted a comprehensive literature review to elucidate the current progress in research and pinpoint research gaps in this domain. Additionally, it provides theoretical guidance for future research endeavors and the development of treatment strategies.

Novel Therapeutic Mechanisms and Strategies for Intracerebral Hemorrhage: Focusing on Exosomes

Intracerebral hemorrhage (ICH) is a primary, non-traumatic cerebral event associated with substantial mortality and disability. Despite advancements in understanding its etiology and refining diagnostic techniques, a validated treatment to significantly improve ICH prognosis remains elusive. Exosomes, a subtype of extracellular vesicles, encapsulate bioactive components, predominantly microRNAs (miRNAs), facilitating and regulating intercellular communication. Currently, exosomes have garnered considerable interests in clinical transformation for their nanostructure, minimal immunogenicity, low toxicity, inherent stability, and the ability to traverse the blood-brain barrier. A wealth of studies has demonstrated that exosomes can improve the prognosis of ICH through anti-apoptosis, neurogenesis, angiogenesis, anti-inflammation, immunomodulation, and autophagy, primarily via the transportation or overexpression of selected miRNAs. More importantly, exosomes can be easily customized with specific miRNAs or bioactive compounds to establish delivery systems, broadening their potential applications. This review focuses on the therapeutic potential of exosomes in ICH, reviewing the mechanisms of molecular biology mediated by certain miRNAs, discussing the benefits, challenges, and future prospects in ICH treatment. We hope comprehensive understanding of exosomes based on miRNAs will provide new insights into the treatment of ICH and guide the translation of exosome's research from laboratory to clinical practice.

Regulating pyroptosis by mesenchymal stem cells and extracellular vesicles: A promising strategy to alleviate intervertebral disc degeneration

Intervertebral disc degeneration (IVDD) is a main cause of low back pain (LBP), which can lead to disability and thus generate a heavy burden on society. IVDD is characterized by a decrease in nucleus pulposus cells (NPCs) and endogenous mesenchymal stem cells (MSCs), degradation of the extracellular matrix, macrophage infiltration, and blood vessel and nerve ingrowth. To date, the therapeutic approaches regarding IVDD mainly include conservative treatment and surgical intervention. However, both can only relieve symptoms rather than stop or revert the progression of IVDD, since the pathogenesis of IVDD is not yet clear. Pyroptosis, which is characterized by Caspase family dependence and conducted by the Gasdermin family, is a newly discovered mode of programmed cell death. Pyroptosis has been observed in NPCs, annulus fibrosus cells (AFCs), chondrocytes, MSCs, macrophages, vascular endothelial cells and neurons and may contribute to IVDD. MSCs are a kind of pluripotent stem cell that can be found in almost all tissues. MSCs have a strong ability to secrete extracellular vesicles (EVs), which contain exosomes, microvesicles and apoptotic bodies. EVs derived from MSCs play an important role in pyroptosis regulation and could be beneficial for alleviating IVDD. This review focuses on clarifying the regulation of pyroptosis to improve IVDD by MSCs and EVs derived from MSCs.

Mesenchymal stem cell exosomes inhibit nucleus pulposus cell apoptosis via the miR-125b-5p/TRAF6/NF-κB pathway axis

Intervertebral disc degeneration (IVDD) is the pathological basis of a range of degenerative spinal diseases and is the primary cause of lower back pain. Mesenchymal stem cell (MSC) transplantation inhibits IVDD progression. However, the specific mechanisms that underlie these effects remain unclear. In this study, candidate microRNAs (miRNAs) are screened using bioinformatics and high-throughput sequencing. TNF-α is used to induce nucleus pulposus cell (NPC) degeneration. MSC-derived exosomes (MSC-exosomes) are obtained using high-speed centrifugation and identified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blot analysis. Cell viability is determined by CCK-8 assay. Flow cytometry and TUNEL assays are used to detect cell apoptosis. The expression levels of miR-125b-5p are detected by RT-qPCR, and a dual-luciferase gene reporter assay confirms the downstream target genes of miR-125b-5p. Protein expression is determined by western blot analysis. Rat models are used to validate the function of miR-125b-5p in MSC-exosomes. The results show that miR-125b-5p is expressed at low levels in degenerated disc tissues compared with that in normal disc tissues; however, it is highly expressed in MSC-exosomes. Furthermore, MSC-exosomes are efficiently taken up by NPCs while miR-125b-5p is delivered into NPCs; thus, MSC-exosomes act as inhibitors of apoptosis in NPCs. Overexpression of miR-125b-5p downregulates TRAF6 expression and inhibits NF-κB activation. However, TRAF6 overexpression reverses these effects of miR-125b-5p. We demonstrate that MSC-exosomes attenuate IVDD in vivo by delivering miR-125b-5p. MSC-exosomes can deliver miR-125b-5p to target TRAF6, inhibit NF-κB activation, and attenuate the progression of IVDD.

Mesenchymal stem cell-derived extracellular vesicles/exosome: A promising therapeutic strategy for intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is the second largest type of stroke with high mortality and morbidity. The vast majority of survivors suffer from serious neurological defects. Despite the well-established etiology and diagnose, there is still some controversy over the ideal treatment strategy. MSC-based therapy has become an attractive and promising strategy for the treatment of ICH through immune regulation and tissue regeneration. However, accumulating studies have revealed that MSC-based therapeutic effects are mainly attributed to the paracrine properties of MSC, especially small extracellular vesicles/exosome (EVs/exo) which are considered to be the key mediators of the protective efficacy from MSCs. Moreover, some papers reported that MSC-EVs/exo have better therapeutic effects than MSCs. Therefore, EVs/exo has become a new choice for the treatment of ICH stroke in recent years. In this review, we mainly concentrate on the current research progress on the use of MSC-EVs/exo in the treatment of ICH and the existing challenges in their transplation from lab to clinical practice.

Application of mesenchymal stem cell-derived exosomes from different sources in intervertebral disc degeneration

Intervertebral disc degeneration (IVDD) is a main cause of lower back pain, leading to psychological and economic burdens to patients. Physical therapy only delays pain in patients but cannot eliminate the cause of IVDD. Surgery is required when the patient cannot tolerate pain or has severe neurological symptoms. Although surgical resection of IVD or decompression of the laminae eliminates the diseased segment, it damages adjacent normal IVD. There is also a risk of re-protrusion after IVD removal. Cell therapy has played a crucial role in the development of regenerative medicine. Cell transplantation promotes regeneration of degenerative tissue. However, owing to the lack of vascular structure in IVD, sufficient nutrients cannot be provided for transplanted mesenchymal stem cells (MSCs). In addition, dead cells release harmful substances that aggravate IVDD. Extracellular vesicles (EVs) have been extensively studied as an emerging therapeutic approach. EVs generated by paracrine MSCs retain the potential of MSCs and serve as carriers to deliver their contents to target cells to regulate target cell activity. Owing to their double-layered membrane structure, EVs have a low immunogenicity and no immune rejection. Therefore, EVs are considered an emerging therapeutic modality in IVDD. However, they are limited by mass production and low loading rates. In this review, the structure of IVD and advantages of EVs are introduced, and the application of MSC-EVs in IVDD is discussed. The current limitations of EVs and future applications are described.

Mesenchymal Stem Cell-Derived Exosomes and Intervertebral Disc Regeneration: Review

Intervertebral disc degeneration (IVDD) is a common cause of lower back pain (LBP), which burdens individuals and society as a whole. IVDD occurs as a result of aging, mechanical trauma, lifestyle factors, and certain genetic abnormalities, leads to loss of nucleus pulposus, alteration in the composition of the extracellular matrix, excessive oxidative stress, and inflammation in the intervertebral disc. Pharmacological and surgical interventions are considered a boon for the treatment of IVDD, but the effectiveness of those strategies is limited. Mesenchymal stem cells (MSCs) have recently emerged as a possible promising regenerative therapy for IVDD due to their paracrine effect, restoration of the degenerated cells, and capacity for differentiation into disc cells. Recent investigations have shown that the pleiotropic effect of MSCs is not related to differentiation capacity but is mediated by the secretion of soluble paracrine factors. Early studies have demonstrated that MSC-derived exosomes have therapeutic potential for treating IVDD by promoting cell proliferation, tissue regeneration, modulation of the inflammatory response, and reduced apoptosis. This paper highlights the current state of MSC-derived exosomes in the field of treatment of IVDD with further possible future developments, applications, and challenges.

Recent Advances in Managing Spinal Intervertebral Discs Degeneration

Low back pain (LBP) represents a frequent and debilitating condition affecting a large part of the global population and posing a worldwide health and economic burden. The major cause of LBP is intervertebral disc degeneration (IDD), a complex disease that can further aggravate and give rise to severe spine problems. As most of the current treatments for IDD either only alleviate the associated symptoms or expose patients to the risk of intraoperative and postoperative complications, there is a pressing need to develop better therapeutic strategies. In this respect, the present paper first describes the pathogenesis and etiology of IDD to set the framework for what has to be combated to restore the normal state of intervertebral discs (IVDs), then further elaborates on the recent advances in managing IDD. Specifically, there are reviewed bioactive compounds and growth factors that have shown promising potential against underlying factors of IDD, cell-based therapies for IVD regeneration, biomimetic artificial IVDs, and several other emerging IDD therapeutic options (e.g., exosomes, RNA approaches, and artificial intelligence).