Modified Pulsatilla decoction alleviates 5-fluorouracil-induced intestinal mucositis by modulating the TLR4/MyD88/NF-κB pathway and gut microbiota

BACKGROUND Modified Pulsatilla decoction(PD),a PD with licorice and ejiao,is a classic Traditional Chinese Medicine formula with significant efficacy in treating intestinal mucositis(IM)induced by tumor therapy.However,its specific molecular and biological mechanisms remain unclear.AIM To investigate the therapeutic effect and mechanism of modified PD in IM.METHODS This study used an IM mouse model established using 5-fluorouracil injections to investigate the effects of the modified PD(3,6,and 12 g/kg)in IM.The primary chemical components of the modified PD were identified using liquid chromatography-mass spectrometry.Body weight loss,diarrhea scores,intestinal length,histopathological scores,and inflammatory cytokine levels were measured to evaluate the effects of the modified PD in IM.Effects on the TLR4/MyD88/NF-κB pathway were evaluated using western blot analysis.The intestinal microbiota was characterized using Illumina NovaSeq sequencing.RESULTS The results showed that modified PD significantly improved weight loss and diarrhea and shortened the intestines in IM mice.Mechanistically,modified PD suppressed the TLR4/MyD88/NF-κB pathway and downregulated the expression of reactive oxygen species,lipopolysaccharides,and pro-inflammatory cytokines(IL-1β,TNF-α,IFN-γ,IL-6,IL-8,and IL-17),while increasing the expression of the anti-inflammatory cytokine IL-10.Furthermore,modified PD protected the intestinal mucosal barrier by increasing the expression of tight junction proteins(occludin-1,claudin-1,and ZO-1)and mucin-2.Finally,16S rDNA sequencing revealed that modified PD improved intestinal dysbiosis.CONCLUSION Our research offers new insights into the potential mechanism of modified PD in alleviating IM and provides experimental evidence supporting its pharmaceutical application in clinical IM treatment.

Ramulus Cinnamomi extract attenuates neuroinflammatory responses via downregulating TLR4/MyD88 signaling pathway in BV2 cells

Ramulus Cinnamomi （RC）, a traditional Chinese herb, has been used to attenuate inflammatory responses. The purpose of this study was to investigate the effect of RC extract on lipopolysaccharide （LPS）-induced neuroinflammation in BV2 microglial cells and the underlying mechanisms involved. BV2 cells were incubated with normal medium （control group）, LPS, LPS plus 30 pg/mL RC extract, or LPS plus 100 pg/mL RC extract. The BV2 cell morphology was observed under an optical microscope and cell viability was detected by MTT assay. Nitric oxide level in BV2 cells was detected using Griess regents, and the levels of interleukin-6, interleukin-1 β, and tumor necrosis factor u in BV2 cells were determined by ELISA. The expression levels of cyclooxygenase-2, Toll-like receptor 4 and myeloid differentiation factor 88 proteins were detected by western blot assay. Compared with the LPS group, both 30 and 100 μg/mL RC extract had no significant effect on the viability of BV2 cells. The levels of nitric oxide, interleukin-6, interleukin-1β and tumor necrosis factor ct in BV2 cells were all significantly increased after LPS induction, and the levels were significantly reversed after treatment with 30 and 100 μg/mL RC extract. Furthermore, RC extract significantly inhibited the protein expression levels of cyclooxygenase-2, Toll-like receptor 4 and myeloid differentiation factor 88 in LPS-induced BV2 cells. Our findings suggest that RC extract alleviates neuroinflammation by downregulating the TLR4/MyD88 signaling pathway.

Bioinformatic Analysis and Experimental Verification of QJHGD on Caerulein-induced Inflammatory Response in SAP Model Rats Based on TLR4/NF-κB/My D88 Pathway

[Objectives]To conduct bioinformatic analysis and experimental verification of Qingjie Huagong Decoction(QJHGD)on caerulein-induced inflammatory response in severe acute pancreatitis(SAP)model rats based on TLR4/NF-κB/MyD88 pathway.[Methods]The effective component groups and potential targets of QJHGD were collected by the network pharmacology method.A drug-component-target network was constructed.The GO and KEGG of targets were enriched and analyzed with the aid of Metascape database,and the target pathway related to SAP inflammation was screened.The SAP rat model was established by caerulein combined with lipopolysaccharide,and QJHGD was intragastrically administered.Pancreatic tissue was observed by HE staining.In addition,enzyme-linked immunosorbent assay and immunohistochemistry were used to verify the anti-inflammatory effect of QJHGD on SAP rats and its regulatory effect on TLR4/NF-κB/MyD88 target pathway.[Results]A total of 105 active components of QJHGD and 148 key targets of SAP were predicted and screened;KEGG was enriched in 320 different pathways including toll-like receptor and NF-κB classical pathways.Animal experiment verified that QJHGD reduced serum amylase,serum lipase activity,IL-6,TNF-αlevels in SAP rats;HE staining showed the effect of QJHGD on the pathological changes of pancreas,and QJHGD inhibited the positive expression of key proteins of TLR4,NF-κB and MyD88 in the inflammatory transduction pathway.[Conclusions]The mechanism of QJHGD improving pancreatic injury in SAP rats may be related to down-regulating the expression of key proteins in the TLR4/NF-κB/MyD88 pathway.

Correlation of MyD88 expression in the peripheral blood and placenta with the inflammatory response and insulin signal transduction in the placenta of patients with GDM

Objective: To study the correlation of MyD88 expression in peripheral blood and placenta with the inflammatory response and insulin signal transduction in the placenta of patients with gestational diabetes mellitus (GDM). Methods: The patients with GDM and healthy pregnant women who accepted antenatal care and gave birth in Guangyuan First People's Hospital between March 2015 and June 2017 were selected as the research subjects and enrolled in the GDM group and control group for the study respectively;the peripheral blood was collected before delivery to determine the MyD88 mRNA expression, and the placental tissue was collected after delivery to determine the mRNA expression of MyD88, inflammatory response molecules and insulin signal transduction molecules. Results: MyD88 mRNA expression levels in the peripheral blood and placenta of GDM group were significantly higher than those of control group, and the MyD88 mRNA expression in the peripheral blood was positively correlated with the MyD88 mRNA expression in the placenta;IL-1β, IL-6, RBP4, Chemerin, Resistin and PTP1B mRNA expression levels in the placenta of GDM group were significantly higher than those of control group whereas IRS1, ISR2, p-PI3K and GLUT4 protein expression levels were significantly lower than those of control group;IL-1β, IL-6, RBP4, Chemerin, Resistin and PTP1B mRNA expression levels in the placenta of GDM group of patients with high MyD88 expression were significantly higher than those of patients with low MyD88 expression whereas IRS1, ISR2, p-PI3K and GLUT4 protein expression levels were significantly lower than those of patients with low MyD88 expression. Conclusion:The expression of MyD88 in peripheral blood and placenta increase in patients with GDM and the change of MyD88 expression in peripheral blood could reflect the abnormality of inflammatory response and insulin signal transduction in the placenta.

Novel compound FLZ alleviates rotenoneinduced PD mouse model by suppressing TLR4/MyD88/NF-kB pathway through microbiotaegutebrain axis

Parkinson’s disease(PD)is the second most common neurodegenerative disease,but none of the current treatments for PD can halt the progress of the disease due to the limited understanding of the pathogenesis.In PD development,the communication between the brain and the gastrointestinal system influenced by gut microbiota is known as microbiota-gut-brain axis.However,the explicit mechanisms of microbiota dysbiosis in PD development have not been well elucidated yet.FLZ,a novel squamosamide derivative,has been proved to be effective in many PD models and is undergoing the phase I clinical trial to treat PD in China.Moreover,our previous pharmacokinetic study revealed that gut microbiota could regulate the absorption of FLZ in vivo.The aims of our study were to assess the protective effects of FLZ treatment on PD and to further explore the underlying microbiota-related mechanisms of PD by using FLZ as a tool.In the current study,chronic oral administration of rotenone was utilized to induce a mouse model to mimic the pathological process of PD.Here we revealed that FLZ treatment alleviated gastrointestinal dysfunctions,motor symptoms,and dopaminergic neuron death in rotenone-challenged mice.16 S rRNA sequencing found that PD-related microbiota alterations induced by rotenone were reversed by FLZ treatment.Remarkably,FLZ administration attenuated intestinal inflammation and gut barrier destruction,which subsequently inhibited systemic inflammation.Eventually,FLZ treatment restored blood-brain barrier structure and suppressed neuroinflammation by inhibiting the activation of astrocytes and microglia in the substantia nigra(SN).Further mechanistic research demonstrated that FLZ treatment suppressed the TLR4/MyD88/NF-κB pathway both in the SN and colon.Collectively,FLZ treatment ameliorates microbiota dysbiosis to protect the PD model via inhibiting TLR4 pathway,which contributes to one of the underlying mechanisms beneath its neuroprotective effects.Our research also supports the importance of microbiota-gut-brain axis in PD pathogenesis,suggesting its potential role as a novel therapeutic target for PD treatment.

ATF4 is directly recruited by TLR4 signaling and positively regulates TLR4-trigged cytokine production in human monocytes

Toll-like receptors （TLRs） are sentinels of the host defense system, which recognize a large number of microbial pathogens. The host defense system may be inefficient or inflammatory diseases may develop if microbial recognition by TLRs and subsequent TLR-triggered cytokine production are deregulated. Activating transcription factor 4 （ATF4）, a member of the ATF/CREB transcription factor family, is an important factor that participates in several pathophysiological processes. In this report, we found that ATF4 is also involved in the TLR-mediated innate immune response, which participates in TLR4 signal transduction and mediates the secretion of a variety of cytokines. We observed that ATF4 is activated and translocates to the nucleus following l ipopolysaccharide （LPS） stimulation via the TLR4-MyD88-dependent pathway. Additionally, a cytokine array assay showed that some key inflammatory cytokines, such as I L-6, I L-8 and RANTES, are positively regulated by ATF4. We also demonstrate that c-Jun directly binds to ATF4, thereby promoting the secretion of inflammatory cytokines. Taken together, these results indicate that ATF4 acts as a positive regulator in TLR4-triggered cytokine production.

Discovery of novel aporphine alkaloid derivative as potent TLR2 antagonist reversing macrophage polarization and neutrophil infiltration against acute inflammation

Toll-like receptor 2(TLR2)mediated macrophages regulate the protective immune response to infectious microorganisms,but the aberrant activation of macrophages often leads to pathological inflammation,including tissue damage.In this study,we identified antagonists of TLR2 by screening2100 natural products and subsequently identified Taspine,an aporphine alkaloid,as an excellent candidate.Furthermore,analysis of the 10 steps chemical synthesis route and structural optimization yielded the Taspine derivative SMU-Y6,which has higher activity,better solubility,and improved drug-feasible property.Mechanistic studies and seq-RNA analysis revealed that SMU-Y6 inhibited TLR2 over other TLRs,hindered the formation of TLR2/MyD88 complex,and blocked the downstream NF-κB and MAPK signaling pathway,thus suppressing the release of inflammatory cytokines.SMU-Y6 could stabilize TLR2 and bind to TLR2 protein with a Kdof 0.18μmol/L.Additionally,SMU-Y6 could efficiently reverse the M1 phenotype macrophage polarization,reduce the production of cytokines as well as infiltration of neutrophiles and alleviate the local inflammation in mice with acute paw edema and colitis.Collectively,we reported the first aporphine alkaloid derivative that selectively inhibits TLR2 with high binding affinity and superior drug-feasible property,thus providing an urgently-needed molecular probe and potential drug candidate for inflammatory and autoimmune disease therapy.

Whey protein peptide PEW attenuates hyperuricemia and associated renal inflammation in potassium oxonate and hypoxanthine-induced rat

Pro-Glu-Trp(PEW),a whey protein-derived peptide,has been previously shown in vitro to have antihyperuricemic potential.The current study further evaluated the roles and the underlying mechanism of PEW in the management of hyperuricemia(HUA)in rat induced by potassium oxonate(PO)and hypoxanthine.Results revealed that PEW significantly reduced the levels of uric acid(UA),creatinine(Cr),and blood urea nitrogen(BUN)in serum,and effectively suppressed the activities of xanthine oxidase(XOD)associated with UA synthesis and modulated the expression of organic ion transporters related to UA excretion.Moreover,PEW alleviated UAinduced renal inflammation by regulating oxidative stress,suppressing the level of pro-inflammatory cytokines,and inhibiting the activation of NOD-like receptor family pyrin domain-containing 3(NLRP3)inflammasome and Toll-like receptor 4/myeloid differentiation factor 88/NF-kappaB(TLR4/MyD88/NF-κB)signaling pathway.Taken together,these relults indicated that PEW improved HUA and renal inflammation by inhibiting UA synthesis,promoting renal UA excretion and suppressing NLRP3 inflammasome and TLR4/MyD88/NF-κB signaling pathways.