Pleurotus eryngii Polysaccharide Promotes Pluripotent Reprogramming via Facilitating Epigenetic Modification

Changing Fate: Reprogramming Cells via Engineered Nanoscale Delivery Materials

The incorporation of nanotechnology in regenerative medicine is at the nexus of fundamental innovations and early-stage breakthroughs, enabling exciting biomedical advances. One of the most exciting recent developments is the use of nanoscale constructs to influence the fate of cells, which are the basic building blocks of healthy function. Appropriate cell types can be effectively manipulated by direct cell reprogramming; a robust technique to manipulate cellular function and fate, underpinning burgeoning advances in drug delivery systems, regenerative medicine, and disease remodeling. Individual transcription factors, or combinations thereof, can be introduced into cells using both viral and nonviral delivery systems. Existing approaches have inherent limitations. Viral-based tools include issues of viral integration into the genome of the cells, the propensity for uncontrollable silencing, reduced copy potential and cell specificity, and neutralization via the immune response. Current nonviral cell reprogramming tools generally suffer from inferior expression efficiency. Nanomaterials are increasingly being explored to address these challenges and improve the efficacy of both viral and nonviral delivery because of their unique properties such as small size and high surface area. This review presents the state-of-the-art research in cell reprogramming, focused on recent breakthroughs in the deployment of nanomaterials as cell reprogramming delivery tools.

Dietary polysaccharides exert biological functions via epigenetic regulations: Advance and prospectives

Bioactive substances derived from natural products are valued for effective health-related activities. As extremely important component of plants, animal cell membrane and microbes cytoderm, polysaccharides have been applied as medications, foods and cosmetics stemming from their prominent biological functions and minor side-effects. Recent studies indicate that polysaccharides exert biological effects also through epigenetic mechanism. Through the intervention of DNA methylation, histone modification, and non-coding RNA, polysaccharides participatate in regulation of immunity/inflammation, glucose and lipid metabolism, antioxidant damage and anti-tumor, which presents novel mechanism of polysaccharide exerting various functions. In this review, the latest advances in the biological functions of dietary polysaccharides via epigenetic regulations were comprehensively summarized and discussed. From the view point of epigenetic regulation, investigating the relationship between polysaccharides and biological effects will enhance our understandings of polysaccharides and also means huge breakthrough of molecular mechanism in the polysaccharide research fields. The paper will provide important reference to these investigators of polysaccharide research and expand the applications of dietary polysaccharides in the functional food developments.

Transcriptome analysis reveals the role of nitric oxide in Pleurotus eryngii responses to Cd2+ stress

Pleurotus eryngii is widely cultivated in China. However, our understanding of its transcriptional response to heavy metal stress and the underlying mechanism of nitric oxide (NO) in enhancing its tolerance to heavy metals is limited. In the present study, RNA-seq was used to generate large transcript sequences from P. eryngii exposed to cadmium chloride (CdCl₂) and exogenous NO. A total of 45,833 unigenes were assembled from the P. eryngii transcriptome, of which 32,333 (70.54%) unigenes matched known proteins in the nr database. Transcriptional analysis revealed that putative genes encoding heat shock proteins (HSPs) and genes participating in glycerolipid metabolism and steroid biosynthesis were significantly up-regulated in P. eryngii exposed to 50 μM Cd (P < 0.05). P. eryngii mycelia exposed to extremely high levels of heavy metals showed an increase in biomass when exogenous NO was added to the culture. The collaboration of putative oxidoreductase, dehydrogenase, reductase, transferase genes and transcription factors such as "GTPase activator activity", "transcription factor complex", "ATP binding", "GTP binding", and "enzyme activator activity", which were significantly up-regulated in samples induced by exogenous NO, contributed to the enhancement of P. eryngii tolerance to extremely high levels of heavy metals. The study provides a new insight into the transcriptional response of P. eryngii to extremely high levels of heavy metals and the mechanism of NO in enhancing heavy metal tolerance.

Prolonged Three-Dimensional Co-Delivery of Yamanaka Factors for Cell Reprogramming

Reprogramming somatic cells into a pluripotent state has been widely investigated in two-dimensional (2D) systems but not described in the more biologically faithful three-dimensional (3D) scaffolds. Here, we devise a 3D porous tissue engineering scaffold that could achieve successful and efficient induction of pluripotency. To construct this 3D scaffold, nonviral hybrid nanoparticles were fabricated beforehand by employing calcium phosphate and cationized Pleurotus eryngii polysaccharide to codeliver plasmids OCT4, SOX2, KLF4 ,and C-MYC (pOSKM). These hybrid nanoparticles were then loaded into a 3D porous collagen scaffold to obtain the so-called pOSKM-activated 3D scaffold. This 3D scaffold could reprogram human umbilical cord mesenchymal stem cells (HUMSCs) into a pluripotent state, generating 3D cell spheres which showed positive expression of pluripotency markers in the 3D scaffolds and tightly packed colonies when transferred to 2D feeder layers. Besides sharing similar morphology, epigenetic modification, and expression of pluripotency genes with the embryonic stem cells, the 3D system-generated colonies could also be expanded on feeder layers for more than 20 passages, indicating the successful establishment of stable induced pluripotent stem cell (iPSC) lines. Our findings represent a first employment of porous 3D scaffolds to achieve successful reprogramming via a one-time transfection, offering a safe, simple, and effective alternative strategy for iPSC generation.