Dihydrolipoic acid-coated gold nanocluster bioactivity against senescence and inflammation through the mitochondria-mediated JNK/AP-1 pathway

Multiscale Bioresponses of Metal Nanoclusters

Metal nanoclusters (NCs) are well-recognized novel nano-agents that hold great promise for applications in nanomedicine because of their ultrafine size, low toxicity, and high renal clearance. As foreign substances, however, an in-depth understanding of the bioresponses to metal NCs is necessary but is still far from being realized. Herein, this review is deployed to summarize the biofates of metal NCs at various biological levels, emphasizing their multiscale bioresponses at the molecular, cellular, and organismal levels. In the parts-to-whole schema, the interactions between biomolecules and metal NCs are discussed, presenting typical protein-dictated nano-bio interfaces, hierarchical structures, and in vivo trajectories. Then, the accumulation, internalization, and metabolic evolution of metal NCs in the cellular environment and as-imparted theranostic functionalization are demonstrated. The organismal metabolism and transportation processes of the metal NCs are subsequently distilled. Finally, this review ends with the conclusions and perspectives on the outstanding issues of metal NC-mediated bioresponses in the near future. This review is expected to provide inspiration for tailoring the customization of metal NC-based nano-agents to meet practical requirements in different sectors of nanomedicine.

Hsa-miR-409-3p regulates endothelial progenitor senescence via PP2A-P38 and is a potential ageing marker in humans

We explored the roles of hsa-microRNA (miR)-409-3p in senescence and signalling mechanism of human endothelial progenitor cells (EPCs). Hsa-miR-409-3p was found upregulated in senescent EPCs. Overexpression of miRNA mimics in young EPCs inhibited angiogenesis. In senescent EPCs, compared to young EPCs, protein phosphatase 2A (PP2A) was downregulated, with activation of p38/JNK by phosphorylation. Young EPCs treated with siPP2A caused inhibited angiogenesis with activation of p38/JNK, similar to findings in senescent EPCs. Time series analysis showed, in young EPCs treated with hsa-miR-409-3p mimics, PP2A was steadily downregulated for 72 h, while p38/JNK was activated with a peak at 48 hours. The inhibited angiogenesis of young EPCs after miRNA-409-3p mimics treatment was reversed by the p38 inhibitor. The effect of hsa-miR-409-3p on PP2A signalling was attenuated by exogenous VEGF. Analysis of human peripheral blood mononuclear cells (PBMCs) obtained from healthy people revealed hsa-miR-409-3p expression was higher in those older than 65 years, compared to those younger than 30 years, regardless of gender. In summary, hsa-miR-409-3p was upregulated in senescent EPCs and acted as a negative modulator of angiogenesis via targeting protein phosphatase 2 catalytic subunit alpha (PPP2CA) gene and regulating PP2A/p38 signalling. Data from human PBMCs suggested hsa-miR-409-3p a potential biomarker for human ageing.

Acute and Subacute Toxicity of Fluorescent Gold Nanoclusters Conjugated with α-Lipoic Acid

Fluorescent gold nanoclusters conjugated with α-lipoic acid (FANC) is a promising biocompatible fluorescent nanomaterial with a high potential for drug development. However, there is still no FANC-related research on toxicology, which is very important for future research and the development of healthy food supplements or drugs. This study uses oral administration of FANC to determine the most appropriate dose range in ICR mice for further evaluation. The in vivo acute and subacute toxicity study was conducted by oral administration of FANC to male and female ICR mice. Animal survival, body weight, daily food consumption, hematological profile, organ coefficient, serum biochemistry profile, and histopathological changes were analyzed. FANC did not show any form of morbidity or mortality at acute and subacute toxicity in both male and female ICR mice. Animal behavior, daily food consumption, hematological profile, organ coefficient, and histopathology showed no treatment-related malignant changes at single and repeated doses. Furthermore, serum glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), and creatinine (CRE) levels showed no significant malignant changes, which indicated that FANC does not cause liver and renal damage. The only change observed in this study was the change in body weight. The body weight of the FANC-treated group was slightly decreased in female mice but increased in male mice; however, the body weight decreases were below the threshold of concern, and there was no dose-response effect. In conclusion, no observed adverse effect level (NOAEL) in repeated doses was considered in 20 μM/100 μL/25 g male and female ICR mice.