Glucomannan from Aloe vera Gel Promotes Intestinal Stem Cell-Mediated Epithelial Regeneration via the Wnt/β-Catenin Pathway

Highland Barley β-Glucan Relieves Symptoms of Colitis via PPARα-Mediated Intestinal Stem Cell Proliferation

Intestinal stem cells (ISCs) are necessary to maintain intestinal renewal. Here, we found that the highland barley β-glucan (HBG) alleviated pathological symptoms and promoted the proliferation of intestinal stem cells in colitis mice. Notably, metabolomics studies showed that docosahexaenoic acid (DHA) was significantly increased by the HBG treatment. DHA is a ligand for peroxisome proliferator-activated receptor α (PPARα), which can promote ISC proliferation. Expectedly, HBG facilitated the expression of intestinal PPARα and the proliferation of ISCs in colitis mice. Further experiments verified that DHA significantly facilitated the expression of PPARα and the proliferation of ISCs in intestinal organoids. Intriguingly, the effect of DHA on ISC proliferation was reversed by the PPARα inhibitor. Together, our data indicate that HBG might accelerate PPARα-mediated ISC proliferation through DHA. This provides new insights into the effective application of polysaccharides in maintaining intestinal homeostasis.

Developing Chinese herbal-based functional biomaterials for tissue engineering

The role of traditional Chinese medicine (TCM) in treating diseases is receiving increasing attention. Chinese herbal medicine is an important part of TCM with various applications and the active ingredients extracted from Chinese herbal medicines have physiological and pathological effects. Tissue engineering combines cell biology and materials science to construct tissues or organs in vitro or in vivo. TCM has been proposed by the World Health Organization as an effective treatment modality. In recent years, the potential use of TCM in tissue engineering has been demonstrated. In this review, the classification and efficacy of TCM active ingredients and delivery systems are discussed based on the TCM theory. We also summarized the current application status and broad prospects of Chinese herbal active ingredients in different specialized biomaterials in the field of tissue engineering. This review provides novel insights into the integration of TCM and modern Western medicine through the application of Chinese medicine in tissue engineering and regenerative medicine.

Role of the GLP2-Wnt1 axis in silicon-rich alkaline mineral water maintaining intestinal epithelium regeneration in piglets under early-life stress

Stress-induced intestinal epithelial injury (IEI) and a delay in repair in infancy are predisposing factors for refractory gut diseases in adulthood, such as irritable bowel syndrome (IBS). Hence, it is necessary to develop appropriate mitigation methods for mammals when experiencing early-life stress (ELS). Weaning, as we all know, is a vital procedure that all mammalian newborns, including humans, must go through. Maternal separation (MS) stress in infancy (regarded as weaning stress in animal science) is a commonly used ELS paradigm. Drinking silicon-rich alkaline mineral water (AMW) has a therapeutic effect on enteric disease, but the specific mechanisms involved have not been reported. Herein, we discover the molecular mechanism by which silicon-rich AMW repairs ELS-induced IEI by maintaining intestinal stem cell (ISC) proliferation and differentiation through the glucagon-like peptide (GLP)2-Wnt1 axis. Mechanistic study showed that silicon-rich AMW activates GLP2-dependent Wnt1/β-catenin pathway, and drives ISC proliferation and differentiation by stimulating Lgr5+ ISC cell cycle passage through the G1-S-phase checkpoint, thereby maintaining intestinal epithelial regeneration and IEI repair. Using GLP2 antagonists (GLP23-33) and small interfering RNA (SiWnt1) in vitro, we found that the GLP2-Wnt1 axis is the target of silicon-rich AMW to promote intestinal epithelium regeneration. Therefore, silicon-rich AMW maintains intestinal epithelium regeneration through the GLP2-Wnt1 axis in piglets under ELS. Our research contributes to understanding the mechanism of silicon-rich AMW promoting gut epithelial regeneration and provides a new strategy for the alleviation of ELS-induced IEI.

Human gut homeostasis and regeneration: the role of the gut microbiota and its metabolites

The healthy human gut is a balanced ecosystem where host cells and representatives of the gut microbiota interact and communicate in a bidirectional manner at the gut epithelium. As a result of these interactions, many local and systemic processes necessary for host functionality, and ultimately health, take place. Impairment of the integrity of the gut epithelium diminishes its ability to act as an effective gut barrier, can contribute to conditions associated to inflammation processes and can have other negative consequences. Pathogens and pathobionts have been linked with damage of the integrity of the gut epithelium, but other components of the gut microbiota and some of their metabolites can contribute to its repair and regeneration. Here, we review what is known about the effect of bacterial metabolites on the gut epithelium and, more specifically, on the regulation of repair by intestinal stem cells and the regulation of the immune system in the gut. Additionally, we explore the potential therapeutic use of targeted modulation of the gut microbiota to maintain and improve gut homeostasis as a mean to improve health outcomes.

HucMSC-Exo Promote Mucosal Healing in Experimental Colitis by Accelerating Intestinal Stem Cells and Epithelium Regeneration via Wnt Signaling Pathway

Background

Mucosal healing has emerged as a crucial therapeutic goal for inflammatory bowel diseases (IBD). Exosomes (Exo) as a potential acellular candidate for stem cell therapy might be competent to promote mucosal healing, while its mechanism remains unexplored.

Methods

Exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs) were subjected to experimental colitis mice intraperitoneally to estimate the role in mucosal healing and the regeneration of intestinal stem cells (ISCs) and epithelium. The intestinal organoid model of IBD was constructed utilizing tumor necrosis factor (TNF)-α for subsequent function analysis in vitro. Transcriptome sequencing was performed to decipher the underlying mechanism and Wnt-C59, an oral Wnt inhibitor, was used to confirm that further. Finally, the potential specific components of hucMSC‑exo were investigated based on several existing miRNA expression datasets.

Results

HucMSC-exo showed striking potential for mucosal healing in colitis mice, characterized by decreased histopathological injuries and neutrophil infiltration as well as improved epithelial integrity. HucMSC-exo up-regulated the expression of leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5), a specific marker for ISCs and accelerated the proliferation of intestinal epithelium. HucMSC-exo endowed intestinal organoids with more excellent capacity to grow and bud under TNF-α stimulation. More than that, the fact that hucMSC-exo activated the canonical Wnt signaling pathway to promote mucosal healing was uncovered by not only RNA-sequencing but also relevant experimental data. Finally, bioinformatics analysis of the existing miRNA expression datasets indicated that several miRNAs abundant in hucMSC-exo involved widely in regeneration or repair related biological processes and Wnt signaling pathway might be one of the most important signal transduction pathways.

Conclusion

Our results suggested that hucMSC-exo could facilitate mucosal healing in experimental colitis by accelerating ISCs and intestinal epithelium regeneration via transferring key miRNAs, which was dependent on the activation of Wnt/β-catenin signaling pathway.

Encapsulation of Polyphenolic Compounds Based on Hemicelluloses to Enhance Treatment of Inflammatory Bowel Diseases and Colorectal Cancer

Inflammatory bowel diseases (IBD) and colorectal cancer (CRC) are difficult to cure, and available treatment is associated with troubling side effects. In addition, current therapies have limited efficacy and are characterized by high costs, and a large segment of the IBD and CRC patients are refractive to the treatment. Moreover, presently used anti-IBD therapies in the clinics are primarily aimed on the symptomatic control. That is why new agents with therapeutic potential against IBD and CRC are required. Currently, polyphenols have received great attention in the pharmaceutical industry and in medicine due to their health-promoting properties. They may exert anti-inflammatory, anti-oxidative, and anti-cancer activity, via inhibiting production of pro-inflammatory cytokines and enzymes or factors associated with carcinogenesis (e.g., matrix metalloproteinases, vascular endothelial growth factor), suggesting they may have therapeutic potential against IBD and CRC. However, their use is limited under both processing conditions or gastrointestinal interactions, reducing their stability and hence their bioaccessibility and bioavailability. Therefore, there is a need for more effective carriers that could be used for encapsulation of polyphenolic compounds. In recent years, natural polysaccharides have been proposed for creating carriers used in the synthesis of polyphenol encapsulates. Among these, hemicelluloses are particularly noteworthy, being characterized by good biocompatibility, biodegradation, low immunogenicity, and pro-health activity. They may also demonstrate synergy with the polyphenol payload. This review discusses the utility and potential of hemicellulose-based encapsulations of polyphenols as support for treatment of IBD and CRC.

Paeoniflorin promotes intestinal stem cell-mediated epithelial regeneration and repair via PI3K-AKT-mTOR signalling in ulcerative colitis

Ulcerative colitis (UC) is a chronic and immune-mediated inflammatory disorder characterized by abdominal pain, diarrhoea, and haematochezia. The goal of clinical therapy for UC is mucosal healing, accomplished by regenerating and repairing the intestinal epithelium. Paeoniflorin (PF) is a natural ingredient extracted from Paeonia lactiflora that has significant anti-inflammatory and immunoregulatory efficacy. In this study, we investigated how PF could regulate the renewal and differentiation of intestinal stem cells (ISCs) to improve the regeneration and repair of the intestinal epithelium in UC. Our experimental results showed that PF significantly alleviated colitis induced by dextran sulfate sodium (DSS) and ameliorated intestinal mucosal injury by regulating the renewal and differentiation of ISCs. The mechanism by which PF regulates ISCs was confirmed to be through PI3K-AKT-mTOR signalling. In vitro, we found that PF not only improved the growth of TNF-α-induced colon organoids but also increased the expression of genes and proteins related to the differentiation and regeneration of ISCs. Furthermore, PF promoted the repair ability of lipopolysaccharide (LPS)-induced IEC-6 cells. The mechanism by which PF regulates ISCs was further confirmed and was consistent with the in vivo results. Overall, these findings demonstrate that PF accelerates epithelial regeneration and repair by promoting the renewal and differentiation of ISCs, suggesting that PF treatment may be beneficial to mucosal healing in UC patients.

Glucomannan from Aloe vera gel maintains intestinal barrier integrity via mitigating anoikis mediated by Nrf2-mitochondria axis

Impairment of intestinal epithelium barrier is a hallmark of gut pathology. Cell death can compromise barrier function and impair epithelial restitution directly or indirectly in inflammatory bowel disease (IBD). Our previous work demonstrated that glucomannan from Aloe vera gel (AGP) protected mice from DSS-induced colitis, with unclear mechanism of AGP-intestinal barrier interactions. Here, AGP maintained the integrity of intestinal barrier in colitis mice. RNA-Sequencing results indicated that pathways related to anoikis (apoptosis induced by loss of cell-matrix interaction), mitochondrial function and oxidative stress were significantly altered in the process of AGP-intestinal barrier interaction. Further experiments confirmed that AGP activated Nrf2, decreased ROS levels, mitigated mitochondrial dysfunction and anoikis of colonic epithelial cells in mice. Intriguingly, AGP reversed oxidative stress and mitochondrial dysfunction induced by knockdown or inhibitor (ML385) of Nrf2 in IEC-6 cells, which indicated the essential role of Nrf2-mitochondrial axis in the intestinal protective function of AGP. In addition, AGP alleviated anoikis caused by impaired mitochondrial function. Hence, this current work indicated that AGP might maintain intestinal barrier integrity by mitigating anoikis mediated by Nrf2-mitochondria axis. These findings provide new evidence into the effect of polysaccharides maintaining intestinal barrier integrity.

Assessing Polysaccharides/Aloe Vera-Based Hydrogels for Tumor Spheroid Formation

In vitro tumor spheroids have proven to be useful 3D tumor culture models for drug testing, and determining the molecular mechanism of tumor progression and cellular interactions. Therefore, there is a continuous search for their industrial scalability and routine preparation. Considering that hydrogels are promising systems that can favor the formation of tumor spheroids, our study aimed to investigate and develop less expensive and easy-to-use amorphous and crosslinked hydrogels, based on natural compounds such as sodium alginate (NaAlg), aloe vera (AV) gel powder, and chitosan (CS) for tumor spheroid formation. The ability of the developed hydrogels to be a potential spheroid-forming system was evaluated using MDA-MB-231 and U87MG cancer cells. Spheroid abilities were influenced by pH, viscosity, and crosslinking of the hydrogel. Addition of either AV or chitosan to sodium alginate increased the viscosity at pH 5, resulting in amorphous hydrogels with a strong gel texture, as shown by rheologic analysis. Only the chitosan-based gel allowed formation of spheroids at pH 5. Among the variants of AV-based amorphous hydrogels tested, only hydrogels at pH 12 and with low viscosity promoted the formation of spheroids. The crosslinked NaAlg/AV, NaAlg/AV/glucose, and NaAlg/CS hydrogel variants favored more efficient spheroid formation. Additional studies would be needed to use AV in other physical forms and other formulations of hydrogels, as the current study is an initiation, in evaluating the potential use of AV gel in tumor spheroid formation systems.

Electrospinning of botanicals for skin wound healing

Being the first barrier between the human body and external environments, our skin is highly vulnerable to injuries. As one of the conventional therapies, botanicals prepared in different topical formulations have been applied as medical care for centuries. With the current increase of clinical requirements, applications of botanicals are heading towards nanotechnologies, typically fused with electrospinning that forms nanofibrous membranes suitable for skin wound healing. In this review, we first introduced the main process of wound healing, and then presented botanicals integrated into electrospun matrices as either loaded drugs, or carriers, or membrane coatings. In addition, by addressing functional features of individual botanicals in the healing of injured skin, we further discussed the bioactivity of botanical electrospun membranes in relevant to the medical issues solved in the process of wound healing. As achieved by pioneer studies, due to infrequent adverse effects and the diversity in resources of natural plants, the development of electrospun products based on botanicals is gaining greater attention. However, investigations in this field have mainly focused on different methodologies used in the preparation of nanofibrous membranes containing botanicals, their translation into clinical practices remains unaddressed. Accordingly, we propose that potential clinical applications of botanical electrospun membranes require not only the further expansion and understanding of botanicals, but also an establishment of standard criteria for the evaluation of wound healing and evolutions of technologies to support the large-scale manufacturing industry.