Sanguisorba officinalis ethyl acetate extract attenuates ulcerative colitis through inhibiting PI3K-AKT/NF-κB/ STAT3 pathway uncovered by single-cell RNA sequencing.

BACKGROUND: Ulcerative colitis (UC) accounts for the untreatable illness nowadays. Bloody stools are the primary symptom of UC, and the first-line drugs used to treat UC are associated with several drawbacks and negative side effects. S. officinalis has long been used as a medicine to treat intestinal infections and bloody stools. However, what the precise molecular mechanism, the exact etiology, and the material basis of the disease remain unclear. PURPOSE: This work aimed to comprehensively explore pharmacological effects as well as molecular mechanisms underlying the active fraction of S. officinalis, and to produce a comprehensive and brand-new guideline map of its chemical base and mechanism of action. METHODS: First, different polarity S. officinalis extracts were orally administered to the DSS-induced UC model mice for the sake of investigating its active constituents. Using the UPLC-orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap-HRMS) technique, the most active S. officinalis (S. officinalis ethyl acetate fraction, SOEA) extract was characterized. Subsequently, the effectiveness of its active fraction on UC was evaluated through phenotypic observation (such as weight loss, colon length, and stool characteristics), and histological examination of pathological injuries, mRNA and protein expression. Cell profile, cell-cell interactions and molecular mechanisms of SOEA in different cell types of the colon tissue from UC mice were described using single-cell RNA sequencing (scRNA-seq). As a final step, the molecular mechanisms were validated by appropriate molecular biological methods. RESULTS: For the first time, this study revealed the significant efficacy of SOEA in the treatment of UC. SOEA reduced DAI and body weight loss, recovered the colon length, and mitigated colonic pathological injuries along with mucosal barrier by promoting goblet cell proliferation. Following treatment with SOEA, inflammatory factors showed decreased mRNA and protein expression. SOEA restored the dynamic equilibrium of cell profile and cell-cell interactions in colon tissue. All of these results were attributed to the ability of SOEA to inhibit the PI3K-AKT/NF-κB/STATAT pathway. CONCLUSIONS: By integrating the chemical information of SOEA derived from UPLC-Q-Orbitrap-HRMS with single-cell transcriptomic data extracted from scRNA-seq, this study demonstrates that SOEA exerts the therapeutic effect through suppressing PI3K-AKT/NF-B/STAT3 pathway to improve clinical symptoms, inflammatory response, mucosal barrier, and intercellular interactions in UC, and effectively eliminates the interference of cellular heterogeneity.

Flooding duration affects the temperature sensitivity of soil extracellular enzyme activities in a lakeshore wetland in Poyang Lake, China.

Extracellular enzymes play central roles in the biogeochemical cycles in wetland ecosystems. Their activities are strongly impacted by hydrothermal conditions. Under the ongoing global change, many studies reported the individual effects of flooding and warming on extracellular enzyme activities, however, few researches investigated their interactive effects. Therefore, the current study aims to determine the responses of extracellular enzyme activities to warming in wetland soils under divergent flooding regimes. We investigated the temperature sensitivity of seven extracellular enzymes related to carbon (α-glucosidase, AG; ß-glucosidase, BG; cellobiohydrolase, CBH; ß-xylosidase, XYL), nitrogen (ß-N-acetyl -glucosaminidase, NAG; leucine aminopeptidase, LAP), and phosphorus (Phosphatase, PHOS) cycling along the flooding duration gradient in a lakeshore wetland of Poyang Lake, China. The Q10 value, calculated using a temperature gradient (10, 15, 20, 25, and 30 °C), was adopted to represent the temperature sensitivity. The average Q10 values of AG, BG, CBH, XYL, NAG, LAP, and PHOS in the lakeshore wetland were 2.75 ± 0.76, 2.91 ± 0.69, 3.34 ± 0.75, 3.01 ± 0.69, 3.02 ± 1.11, 2.21 ± 0.39, and 3.33 ± 0.72, respectively. The Q10 values of all the seven soil extracellular enzymes significantly and positively correlated with flooding duration. The Q10 values of NAG, AG and BG were more sensitive to the changes in flooding duration than other enzymes. The Q10 values of the carbon, nitrogen, and phosphorus-related enzymes were mainly determined by flooding duration, pH, clay, and substrate quality. Flooding duration was the most dominant driver for the Q10 of BG, XYL, NAG, LAP, and PHOS. In contrast, the Q10 values of AG and CBH were primarily affected by pH and clay content, respectively. This study indicated that flooding regime was a key factor regulating soil biogeochemical processes of wetland ecosystems under global warming.

N-acetyldopamine dimer inhibits neuroinflammation through the TLR4/NF-κB and NLRP3/Caspase-1 pathways.

Neuroinflammation mediated by microglia is an important pathophysiological mechanism in neurodegenerative diseases. However, there is a lack of effective drugs to treat neuroinflammation. N-acetyldopamine dimer (NADD) is a natural compound from the traditional Chinese medicine Isaria cicada. In our previous study, we found that NADD can attenuate DSS-induced ulcerative colitis by suppressing the NF-κB and MAPK pathways. Does NADD inhibit neuroinflammation, and what is the target of NADD? To answer this question, lipopolysaccharide (LPS)-stimulated BV-2 microglia was used as a cell model to investigate the effect of NADD on neuroinflammation. Nitric oxide (NO) detection, reactive oxygen species (ROS) detection and enzyme-linked immunosorbent assay (ELISA) results show that NADD attenuates inflammatory signals and proinflammatory cytokines in LPS-stimulated BV-2 microglia, including NO, ROS, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and interleukin-6 (IL-6). Western blot analysis show that NADD inhibits the protein levels of Toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), ASC and cysteinyl aspartate specific proteinase (Caspase)-1, indicating that NADD may inhibit neuroinflammation through the TLR4/NF-κB and NLRP3/Caspase-1 signaling pathways. In addition, surface plasmon resonance assays and molecular docking demonstrate that NADD binds with TLR4 directly. Our study reveals a new role of NADD in inhibiting the TLR4/NF-κB and NLRP3/Caspase-1 pathways, and shows that TLR4-MD2 is the direct target of NADD, which may provide a potential therapeutic candidate for the treatment of neuroinflammation.

N-Acetyldopamine Dimer Attenuates DSS-Induced Ulcerative Colitis by Suppressing NF-κB and MAPK Pathways.

Ulcerative Colitis (UC) is a major form of chronic inflammatory bowel disease of the colonic mucosa and exhibits progressive morbidity. There is still a substantial need of small molecules with greater efficacy and safety for UC treatment. Here, we report a N-acetyldopamine dimer (NADD) elucidated (2R,3S)-2-(3',4'-dihydroxyphenyl)-3-acetylamino-7-(N-acetyl-2″-aminoethyl)-1,4-benzodioxane, which is derived from traditional Chinese medicine Isaria cicadae, exhibits significant therapeutic efficacy against dextran sulfate sodium (DSS)-induced UC. Functionally, NADD treatment effectively relieves UC symptoms, including weight loss, colon length shortening, colonic tissue damage and expression of pro-inflammatory factors in pre-clinical models. Mechanistically, NADD treatment significantly inhibits the expression of genes in inflammation related NF-κB and MAPK signaling pathways by transcriptome analysis and western blot, which indicates that NADD inhibits the inflammation in UC might through these two pathways. Overall, this study identifies an effective small molecule for UC therapy.