Metabolic degradation of polysaccharides from Lentinus edodes by Kupffer cells via the Dectin-1/Syk signaling pathway

Lentinan mitigates ulcerative colitis via the IL-22 pathway to repair the compromised mucosal barrier and enhance antimicrobial defense

Ulcerative colitis (UC) involves chronic, complex pathology of the intestinal mucosa. Current treatments are limited in efficacy and associated with adverse effects, highlighting the urgent need for improved therapeutic options. Lentinan (LNT), a polysaccharide drug commonly used in clinical immune modulation therapies, shows potential for UC treatment, though its specific targets and mechanisms remain unclear. In this study, LNT administration effectively mitigated DSS-induced colitis in mice, enhanced mucosal barrier function and antimicrobial defense. Specifically, LNT modulated the balance between tissue-resident and infiltrating macrophages, thereby improving pathogen clearance and enhancing the immunological barrier. Notably, we identified a novel effect of LNT in regulating the macrophage Dectin-1-ILC3 axis to increase IL-22 secretion. This led to the modulation of epithelial O-glycan fucosylation, antimicrobial peptides, and epithelial stem cells, thereby strengthening antimicrobial defenses and the physicochemical barrier. Neutralization with anti-IL-22 antibodies diminished the therapeutic effect of LNT in UC, underscoring the critical role of IL-22 in LNT-mediated treatment. Overall, this study highlights the potential of LNT as a novel therapeutic agent for UC, offering new insights into its molecular mechanisms and clinical application.

The Protective Effects of Burdock Fructooligosaccharide on Preterm Labor Through Its Anti-Inflammatory Action

Most pharmacotherapeutic chemicals/interventions used to manage preterm labor (PTL) often cause neonatal morbidity and maternal adverse reactions. Fructooligosaccharides, extracted from traditional Chinese medicine, can alleviate inflammation, demonstrate antiviral capabilities, and protect against antioxidant stress, implying a potential effective PTL treatment. In this study, we explored the protective effects of the purified burdock fructooligosaccharide (BFO), a Gfn-type fructose polymer, on inflammation-induced PTL. It was found that two doses of 30 mg/kg mouse BFO administration to pregnant mice at a 6 h interval can effectively ameliorate lipopolysaccharide (LPS)-induced PTL. Drug dynamic distribution analysis revealed that BFO was rather highly enriched in myometrial tissues, could inhibit oxytocin-induced uterine smooth muscle contraction, and could bind toll-like receptor 4 (TLR4) on the membrane of uterine smooth muscle cells, downregulating the expression of downstream genes, attenuating the upregulation of inflammatory cytokines in serum and the myometrium, as well as reversing the increased macrophage and neutrophil infiltration into the myometrium induced by LPS. It can also interfere with the levels of estrogen and progesterone, alleviating the occurrence of premature birth. These findings collectively suggest that BFO might serve as a promising therapeutic agent for inflammation-related preterm labor to safeguard the health of both the mother and fetus.

Intestinal lymphatic transport of Smilax china L. pectic polysaccharide via Peyer's patches and its uptake and transport mechanisms in mononuclear phagocytes

Recently, the intestinal lymphatic transport based on Peyer's patches (PPs) is emerging as a promising absorption pathway for natural polysaccharides. Herein, the aim of this study is to investigate the PP-based oral absorption of a pectic polysaccharide from Smilax china L. (SCLP), as well as its uptake and transport mechanisms in related immune cells. Taking advantages of the traceability of fluorescently labeled SCLP, we confirmed that SCLP could be absorbed into PPs and captured by their mononuclear phagocytes (dendritic cells and macrophages) following oral administration. Subsequently, the systematic in vitro study suggested that the endocytic mechanisms of SCLP by model mononuclear phagocytes (BMDCs and RAW264.7 cells) mainly involved caveolae-mediated endocytosis, macropinocytosis and phagocytosis. More importantly, SCLP directly binds and interacts with toll-like receptor 2 (TLR2) and galectin 3 (Gal-3) receptor, and was taken up by mononuclear phagocytes in receptor-mediated manner. After internalization, SCLP was intracellularly transported primarily through endolysosomal pathway and ultimately localized in lysosomes. In summary, this work reveals novel information and perspectives about the in vivo fate of SCLP, which will contribute to further research and utilization of SCLP and other pectic polysaccharides.

Lentinan-loaded GelMA hydrogel accelerates diabetic wound healing through enhanced angiogenesis and immune microenvironment modulation

Diabetic wound healing is a substantial clinical challenge, characterized by delayed angiogenesis and unresolved inflammation. Lentinan, a polysaccharide extracted from shiitake mushrooms, has the potential to regulate both macrophage polarization and angiogenesis, though this aspect remains inadequately explored. To facilitate lentinan's clinical utility, we have developed a GelMA hydrogel encapsulated with lentinan (10 μM), offering a controlled release mechanism for sustained lentinan delivery at the wound site. Application of the lentinan-encapsulated delivery system topically significantly expedites wound closure compared to control groups. Furthermore, histological examination demonstrates enhanced neovascularization and reduced inflammation in lentinan-treated wounds, as evidenced by increased M2 macrophage infiltration. Moreover, our results indicated that lentinan-induced AMPK activation promotes DAF16 expression, enhancing the resistance of macrophages and HUVECs to oxidative stress in high-glucose environments, thereby promoting M2 macrophage polarization and angiogenesis. All these findings underscore lentinan's capacity to modulate macrophage polarization and angiogenesis via the AMPK/DAF16 pathway, ultimately facilitating the healing of diabetic wounds.

Allosteric switch for electrochemical aptasensor toward heavy metals pollution of Lentinus edodes sensitized with porphyrinic metal-organic frameworks

BACKGROUND

Lentinan medicament from Lentinus edodes has been considered as natural medicinal products with minimal side effects for cancer therapy, but Lentinus edodes are easily polluted by nonbiodegradable heavy metals, especially silver ion (Ag+). Therefore, it is highly desirable to monitor Ag + pollution in Lentinus edodes considering their adverse impact on lentinan medicament. Electrochemical sensor isn't affected from the interference of matrix turbidity and color, and offers a powerful means for determination of variant analytes. As for electrochemical sensing toward Ag+, there is a great need to design efficient signal probes for specific recognition and signal generation.

RESULTS

We present an appropriate electrochemical aptasensor for Ag + assay based on biomimetic catalysis of porphyrin-encapsulated MOF (PorMOF) and allosteric switch of C-rich DNA. Thanks to the excellent biocompatibility, PorMOFs as nanozyme are used to design signal probes by loading duplex-like DNA scaffold. Owing to the specific recognition of Ag+ toward cytosine (C) base-rich DNA, PorMOF at the distal end was close to the underlying electrode via C-Ag+-C formation, leading to an enhanced current of catalytic hydroxylamine oxidation for signal generation. Using the positive correlation between current response and Ag+ level, the electrochemical system provides a promising means for on-line monitoring of Ag+ in Lentinus edodes with recoveries from 92.8% to 106.4% and relative standard deviation from 3.98% to 8.24%, verifying the applicability of the electrochemical aptasensor toward Ag+ in Lentinus edodes.

SIGNIFICANCE AND NOVELTY

With merits of portability, simple operation, and rapid response, the electrochemical pattern offers a useful solution for on-line monitoring of Ag+ in Lentinus edodes. By altering the DNA sequence, the proposed aptasensor provides a powerful way for monitoring other heavy metals, capable of protecting medicament production from heavy metal pollution.