TNF-α-stimulated nucleus pulposus cells induce cell apoptosis through the release of exosomal miR-16 targeting IGF-1 and IGF-1R in rats

Cellular senescence in acute kidney injury: Target and opportunity

Acute kidney injury (AKI) is a common clinical disease with a high incidence and mortality rate. It typically arises from hemodynamic alterations, sepsis, contrast agents, and toxic drugs, instigating a series of events that culminate in tissue and renal damage. This sequence of processes often leads to acute renal impairment, prompting the initiation of a repair response. Cellular senescence is an irreversible arrest of the cell cycle. Studies have shown that renal cellular senescence is closely associated with AKI through several mechanisms, including the promotion of oxidative stress and inflammatory response, telomere shortening, and the down-regulation of klotho expression. Exploring the role of cellular senescence in AKI provides innovative therapeutic ideas for both the prevention and treatment of AKI. Furthermore, it has been observed that targeted removal of senescent cells in vivo can efficiently postpone senescence, resulting in an enhanced prognosis for diseases associated with senescence. This article explores the effects of common anti-senescence drugs senolytics and senostatic and lifestyle interventions on renal diseases, and mentions the rapid development of mesenchymal stem cells (MSCs). These studies have taken senescence-related research to a new level. Overall, this article comprehensively summarizes the studies on cellular senescence in AKI, aiming is to elucidate the relationship between cellular senescence and AKI, and explore treatment strategies to improve the prognosis of AKI.

Can extracellular vesicles be considered as a potential frontier in the treatment of intervertebral disc disease?

As a global public health problem, low back pain (LBP) caused by intervertebral disc degeneration (IDD) seriously affects patients' quality of life. In addition, the prevalence of IDD tends to be younger, which brings a huge burden to individuals and society economically. Current treatments do not delay or reverse the progression of IDD. The emergence of biologic therapies has brought new hope for the treatment of IDD. Among them, extracellular vesicles (EVs), as nanoscale bioactive substances that mediate cellular communication, have now produced many surprising results in the research of the treatment of IDD. This article reviews the mechanisms and roles of EVs in delaying IDD and describes the prospects and challenges of EVs.

Degenerated nucleus pulposus cells derived exosome carrying miR-27a-3p aggravates intervertebral disc degeneration by inducing M1 polarization of macrophages

BACKGROUND

Intervertebral disc degeneration (IVDD) is a major contributor to spinal disorders. Previous studies have indicated that the infiltration of immunocytes, specifically macrophages, plays a crucial role in the advancement of IVDD. Exosomes (exo) are believed to play a significant role in intercellular communication. This study aims to investigate the role of exosomes derived from degenerated nucleus pulposus (dNPc) in the process of macrophages M1 polarization.

METHODS

Nucleus pulposus (NP) tissue and nucleus pulposus cells (NPc) were collected from patients with intervertebral disc degeneration (IVDD) and idiopathic scoliosis. Immunohistochemistry analysis was performed to determine the number of M1 macrophages in NP tissue. Subsequently, exosomes derived from degenerated NP cells (dNPc-exo) and non-degenerated NP cells (nNPc-exo) were collected and co-cultured with M0 macrophages, which were induced from THP-1 cells. The M1 phenotype was assessed using western blot, flow cytometry, immunofluorescence staining, and qRT-PCR. RNA-sequencing analysis was conducted to examine the expression levels of microRNAs in the dNPc-exo and nNPc-exo groups, and qRT-PCR was performed to investigate the effect pf different microRNA to induce macrophage polarization. Furthermore, western blot and qRT-PCR were employed to demonstrate the regulatory effect of microRNAs carried by dNPc-exo on downstream target signaling pathways in macrophages. Finally, an animal model of IVDD was utilized to investigate the impact of dNPc-exo on inducing M1 polarization of macrophages and its role in the IVDD process.

RESULTS

In this study, we observed an increase in the number of M1 macrophages as the intervertebral disc (IVD) degraded. Additionally, we discovered that dNPc releases exosomes (dNPc-exo) could promote the polarization of macrophages towards the M1 phenotype. Notably, through RNA-sequencing analysis of dNPc-exo and nNPc-exo groups, we identified miR-27a-3p as a highly expressed miRNA in the dNPc-exo group, which significantly influences the induction of M1 polarization of macrophages. And then, we discovered that dNPc-exo has the ability to transport miR-27a-3p and target the PPARγ/NFκB/PI3K/AKT signaling pathway, thereby influencing the M1 polarization of macrophages. We conducted experiments using rat model of IVDD and observed that the exosomes carrying miR-27a-3p actually induced the M1 polarization of macrophages and exacerbated the degradation of IVD.

CONCLUSION

In conclusion, our findings highlight the significant role of dNPc-exo in IVDD process and provide a basis for further investigation into the mechanism of IVDD and the potential of exosome-based therapy.

N6-Methyladenosine-induced miR-143-3p promotes intervertebral disc degeneration by regulating SOX5

Intervertebral disc degeneration is the basic cause of lumbocrural pain, which not only causes pain and but also serious economic burdens on patients. Increasingly more evidence has shown that tumor necrosis factor-α (TNF-α) is involved in the pathological process of intervertebral disc degeneration, but the specific molecular mechanism is still unclear. This study investigated the potential mechanism and function of methyltransferase-like 3 (METTL3)/miR-143-3p/SOX5 regulatory axis in nucleus pulposus cells under the action of TNF-α. Human nucleus pulposus cells were treated with TNF-α to construct an in vitro model of intervertebral disc degeneration. Flow cytometry, quantitative reverse-transcription PCR (RT-qPCR), Western blot (WB) and luciferase assays were used to identify the mechanism of action of miR-143-3p in the course of intervertebral disc degeneration in vitro and the downstream targeted regulatory molecules. The role of miR-143-3p in intervertebral disc degeneration was also validated by in vivo. RT-qPCR, WB, coimmunoprecipitation (Co-IP) and flow cytometry were used to verify the regulatory effect of METTL3 on miR-143-3p maturation. RT-qPCR and WB were adopted to detect differences in METTL3, miR-143-3p and SOX5 expression in human nucleus pulposus tissue. miR-143-3p in nucleus pulposus cells was involved in the regulation of extracellular matrix metabolism and apoptosis after TNF-α stimulation, and intervertebral disc degeneration was relieved by effectively regulating miR-143-3p expression. Subsequent experiments showed that the downstream direct target gene of miR-143-3p was SOX5 and that miR-143-3p negatively regulated the expression of SOX5. In addition, METTL3 promoted miR-143-3p maturation, and METTL3 and miR-143-3p were significantly upregulated in degenerative nucleus pulposus, an effect that was significantly negatively correlated with low SOX5 expression. In conclusion, TNF-α upregulates METTL3, METTL3 promotes miR-143-3p maturation, and miR-143-3p inhibits the transcriptional activity of SOX5 through targeted binding, thereby inducing intervertebral disc degeneration. The inhibition of METTL3 or miR-143-3p expression may be an effective way to treat intervertebral disc degeneration.

Exosomes and exosomal miRNAs: A new therapy for intervertebral disc degeneration

Low back pain has been found as a major cause of global disease burden and disability. Intervertebral disc degeneration is recognized as the vital factor causing low back pain. Intervertebral disc degeneration has a complex mechanism and cannot be avoided. Traditional strategies for the treatment of intervertebral disc degeneration cannot meet the needs of intervertebral disc regeneration, so novel treatment methods are urgently required. Exosomes refer to extracellular vesicles that can be released by most cells, and play major roles in intercellular material transport and information transmission. MicroRNAs have been identified as essential components in exosomes, which can be selectively ingested by exosomes and delivered to receptor cells for the regulation of the physiological activities and functions of receptor cells. Existing studies have progressively focused on the role of exosomes and exosomal microRNAs in the treatment of intervertebral disc degeneration. The focus on this paper is placed on the changes of microenvironment during intervertebral disc degeneration and the biogenesis and mechanism of action of exosomes and exosomal microRNAs. The research results and deficiencies of exosomes and exosomal microRNAs in the regulation of apoptosis, extracellular matrix homeostasis, inflammatory response, oxidative stress, and angiogenesis in intervertebral disc degeneration are primarily investigated. The aim of this paper is to identify the latest research results, potential applications and challenges of this emerging treatment strategy.

RNA-Seq analysis of duck embryo fibroblast cells gene expression during duck Tembusu virus infection

Duck Tembusu virus (DTMUV), a member of the family Flaviviridae and an economically important pathogen with a broad host range, leads to markedly decreased egg production. However, the molecular mechanism underlying the host-DTMUV interaction remains unclear. Here, we performed high-throughput RNA sequencing (RNA-Seq) to study the dynamic changes in host gene expression at 12, 24, 36, 48 and 60 h post-infection (hpi) in duck embryo fibroblasts (DEF) infected with DTMUV. A total of 3129 differentially expressed genes (DEG) were identified after DTMUV infection. Gene Ontology (GO) category and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that these DEG were associated with multiple biological functions, including signal transduction, host immunity, virus infection, cell apoptosis, cell proliferation, and pathogenicity-related and metabolic process signaling pathways. This study analyzed viral infection and host immunity induced by DTMUV infection from a novel perspective, and the results provide valuable information regarding the mechanisms underlying host-DTMUV interactions, which will prove useful for the future development of antiviral drugs or vaccines for poultry, thus benefiting the entire poultry industry.

Immune Modulation Using Extracellular Vesicles Encapsulated with MicroRNAs as Novel Drug Delivery Systems

Self-tolerance involves protection from self-reactive B and T cells via negative selection during differentiation, programmed cell death, and inhibition of regulatory T cells. The breakdown of immune tolerance triggers various autoimmune diseases, owing to a lack of distinction between self-antigens and non-self-antigens. Exosomes are non-particles that are approximately 50–130 nm in diameter. Extracellular vesicles can be used for in vivo cell-free transmission to enable intracellular delivery of proteins and nucleic acids, including microRNAs (miRNAs). miRNAs encapsulated in exosomes can regulate the molecular pathways involved in the immune response through post-transcriptional regulation. Herein, we sought to summarize and review the molecular mechanisms whereby exosomal miRNAs modulate the expression of genes involved in the immune response.

Insights into Exosome in the Intervertebral Disc: Emerging Role for Disc Homeostasis and Normal Function

Low back pain (LBP) is a chronic condition that causes great individual suffering and economic burden. The major contributor of LBP is intervertebral disc degeneration (IDD), which is caused by a spectrum of homeostasis alteration, including the apoptosis of nucleus pulposus (NP) and annulus fibrosus (AF) cells, degradation of extracellular matrix (ECM), calcification of cartilaginous endplates (CEP) and so on. Currently, the therapeutic strategy for IDD includes conservative and surgery treatment. Nevertheless, none of them could reverse the progressive destruction of the intervertebral disc. Hence, it is pivotal to pursue a new therapeutic approach. Exosomes, nano-sized substances with diameters of 30-150 nm, can be synthesized and secreted by various types of cells. They play an important role in intercellular communication. Increasing evidence implicates that exosomes could impact the intracellular transcription activities, thereby inhibiting or accelerating the proliferation and apoptosis of cells. Thus, it is a new therapeutic source for IDD. This review chiefly focuses on generalizing and clarifying the roles of exosomes in the onset and deterioration of IDD, and their therapeutic potential.