Genome-wide sequencing identified extrachromosomal circular DNA as a transcription factor-binding motif of the senescence genes that govern replicative senescence in human mesenchymal stem cells.

Introduction: Mesenchymal stem cells (MSCs) have long been postulated as an important source cell in regenerative medicine. During subculture expansion, mesenchymal stem cell (MSC) senescence diminishes their multi-differentiation capabilities, leading to a loss of therapeutic potential. Up to date, the extrachromosomal circular DNAs (eccDNAs) have been demonstrated to be involved in senescence but the roles of eccDNAs during MSC. Methods: Here we explored eccDNA profiles in human bone marrow MSCs (BM-MSCs). EccDNA and mRNA was purified and sequenced, followed by quantification and functional annotation. Moreover, we mapped our datasets with the downloading enhancer and transcription factor-regulated genes to explore the potential role of eccDNAs. Results: Sequentially, gene annotation analysis revealed that the majority of eccDNA were mapped in the intron regions with limited BM-MSC enhancer overlaps. We discovered that these eccDNA motifs in senescent BMSCs acted as motifs for binding transcription factors (TFs) of senescence-related genes. Discussion: These findings are highly significant for identifying biomarkers of senescence and therapeutic targets in mesenchymal stem cells (MSCs) for future clinical applications. The potential of eccDNA as a stable therapeutic target for senescence-related disorders warrants further investigation, particularly exploring chemically synthesized eccDNAs as transcription factor regulatory elements to reverse cellular senescence.

Adjuvant activity of cordycepin, a natural derivative of adenosine from Cordyceps militaris, on an inactivated rabies vaccine in an animal model.

Vaccination is the most feasible way of preventing rabies, an ancient zoonosis that remains a major public health concern globally. However, administration of inactivated rabies vaccination without adjuvants is always inefficient and necessitates four to five injections. In the current study, we explored the adjuvant characteristics of cordycepin, a major bioactive component of Cordyceps militaris, to boost immune responses against a commercially available rabies vaccine. We found that cordycepin could stimulate stronger phenotypic and functional maturation of dendritic cells (DCs). For animal experiments, mice were immunized 3 times with rabies vaccine in the presence or absence of cordycepin at 1-week interval. Analysis of T cell differentiation and serum antibody isotypes showed that humoral immunity was dominant with a Th2 biased immune response. These results were also supported by the raised ratio of follicular helper T cells (TFH) and germinal center B cells (GCB). Thus, titer of rabies virus neutralizing antibody (RVNAb) and rabies virus-specific memory B cells were both raised as a result. Furthermore, administration of cordycepin did not cause pathological phenomena or body weight loss. The findings indicate that cordycepin could be used as a promising adjuvant for rabies vaccines to get a higher range of protection without any side effects.

The impact of the monetary gold principle on the determination of jurisdiction in the mixed maritime disputes.

Mixed maritime disputes are maritime disputes that involve the concurrent consideration of any dispute concerning sovereignty or other rights over continental or insular land territory, which according to Article 298(1)(a)(i) of United Nations Convention on the Law of the Sea, should be excluded from the jurisdiction of a court or tribunal referred to in Article 287. However, by means of treaty interpretation or consensus of two parties, International Tribunal for the Law of the Sea and other Annex VII tribunals have increasingly broken through the limits to actively exercise jurisdiction. Judgements under the influence of this tendency will be firmly resisted by states whose sovereign interests are damaged. Moreover, these judgements will not only fail to resolve disputes, but will create more serious international law and international political disputes, such as the judgement on preliminary objections of Mauritius v. Maldives delimitation case. In this judgement, the Special Chamber of International Tribunal for the Law of the Sea circumvented the Monetary Gold principle by citing the International Court of Justice advisory opinion and United Nations General Assembly resolution, which had no legally binding force. It is proposed that this judgement could open Pandora's box of challenges to general principles of international law and jurisdiction over sovereignty disputes. For States with mixed maritime disputes to resolve the issues mentioned above, it is necessary to respond to lawsuits actively, avoid adverse consequences caused by default judgements and reach regional consensus, and avoid unfavourable International Court of Justice advisory opinions and United Nations General Assembly resolutions.

Radiotherapy orchestrates natural killer cell dependent antitumor immune responses through CXCL8.

Radiotherapy is a mainstay cancer therapy whose antitumor effects partially depend on T cell responses. However, the role of Natural Killer (NK) cells in radiotherapy remains unclear. Here, using a reverse translational approach, we show a central role of NK cells in the radiation-induced immune response involving a CXCL8/IL-8-dependent mechanism. In a randomized controlled pancreatic cancer trial, CXCL8 increased under radiotherapy, and NK cell positively correlated with prolonged overall survival. Accordingly, NK cells preferentially infiltrated irradiated pancreatic tumors and exhibited CD56dim-like cytotoxic transcriptomic states. In experimental models, NF-κB and mTOR orchestrated radiation-induced CXCL8 secretion from tumor cells with senescence features causing directional migration of CD56dim NK cells, thus linking senescence-associated CXCL8 release to innate immune surveillance of human tumors. Moreover, combined high-dose radiotherapy and adoptive NK cell transfer improved tumor control over monotherapies in xenografted mice, suggesting NK cells combined with radiotherapy as a rational cancer treatment strategy.

Platelet-rich plasma in combination with adipose-derived stem cells promotes skin wound healing through activating Rho GTPase-mediated signaling pathway.

Adipose-derived stem cells (ADSCs) are multipotent stromal cells that provide an abundant source of cells for skin tissue engineering and wound healing. Platelet-rich plasma (PRP) is a concentrate of platelet-rich plasma protein, which contains several different growth factors and other cytokines. In this study, we combined ADSCs with PRP for wound healing. Herein, we found ADSCs in combination with PRP was able to promote wound healing, granulation formation, collagen deposition and re-epithelialization. The mechanism exploration discovered that PRP promoted stress fiber formation in ADSCs, leading to cell migration. Then, we demonstrated that PRP enhanced the expression of Rho GTP family proteins, including Cdc 42, Rac 1 and Rho A. Moreover, it promoted the expression of downstream Rho GTP signaling molecules, including PAK 1, ROCK 2, LIMK 1 and Cofilin. When PRP was used in combination with the Cdc 42 inhibitor ZCL278, the Rho A inhibitor CT04, Rac 1 inhibitor NSC23766, PAK inhibitor FRAX597, or Rock 2 inhibitor Y27632 to treat ADSCs, stress fiber formation was significantly reduced, resulting in decreased cell migration. Our findings may provide a promising approach to promote wound healing.

Disturbance of the let-7/LIN28 double-negative feedback loop is associated with radio- and chemo-resistance in non-small cell lung cancer.

Radio- and chemo-resistance represent major obstacles in the therapy of non-small-cell lung cancer (NSCLC) and the underlying molecular mechanisms are not known. In the present study, during induction of radio- or chemo-resistance in NSCLC cells, dynamic analyses revealed that decreased expression of let-7 induced by irradiation or cisplatin resulted in increased expression of its target gene LIN28, and increased expression of LIN28 then contributed to further decreased expression of let-7 by inhibiting its maturation and biogenesis. Moreover, we showed that down-regulation of let-7 and up-regulation of LIN28 expression promoted resistance to irradiation or cisplatin by regulating the single-cell proliferative capability of NSCLC cells. Consequently, in NSCLC cells, let-7 and LIN28 can form a double-negative feedback loop through mutual inhibition, and disturbance of the let-7/LIN28 double-negative feedback loop induced by irradiation or chemotherapeutic drugs can result in radio- and chemo-resistance. In addition, low expression of let-7 and high expression of LIN28 in NSCLC patients was associated significantly with resistance to radiotherapy or chemotherapy. Therefore, our study demonstrated that disturbance of the let-7/LIN28 double-negative feedback loop is involved in the regulation of radio- and chemo-resistance, and that let-7 and LIN28 could be employed as predictive biomarkers of response to radiotherapy or chemotherapy in NSCLC patients.