Pregnancy-induced changes to the gut microbiota drive macrophage pyroptosis and exacerbate septic inflammation

Pregnane X receptor alleviates sepsis-induced liver injury through activation of yes-associated protein in mice

The severity of sepsis is attributed to excessive inflammatory responses leading to liver injury. Pregnane X receptor (PXR), a nuclear receptor that controls xenobiotic and endobiotic metabolism, has been implicated in regulating inflammation and liver regeneration. This study aimed to investigate the role of PXR in sepsis-induced liver injury and the underlying mechanisms. Sepsis models were established in mice, the mice were administered the typical mouse PXR agonist PCN (100 mg·kg-1·d-1, i.p.) for 3 consecutive days in advance, then subjected to CLP operation or LPS administration 1 h after the last administration of PCN. The results showed that PCN pretreatment significantly increased the survival rate of septic mice, while the survival rate was reduced after the knockout of Pxr. In addition, PCN pretreatment effectively alleviated sepsis-induced liver injury. In Pxr knockout mice, liver injury was more severe, whereas the protective effects of PCN pretreatment were abolished. Mechanistically, PCN pretreatment significantly upregulated the expression of yes-associated protein (YAP) and its downstream targets and decreased the level of phosphorylated nuclear factor-κB (NF-κB). Moreover, liver-specific knockdown of Yap blocked the protective effects of PCN pretreatment against sepsis-induced liver injury and downregulated the phosphorylation level of NF-κB. In summary, this study demonstrated that PXR activation protects against sepsis-induced liver injury through activation of the YAP signaling pathway, providing a new strategy for the diagnosis and treatment of sepsis-induced liver injury.

Gut microbiota regulates gut homeostasis, mucosal immunity and influences immune-related diseases

The intestinal microbiome constitutes a sophisticated and massive ecosystem pivotal for maintaining gastrointestinal equilibrium and mucosal immunity via diverse pathways. The gut microbiota is continuously reshaped by multiple environmental factors, thereby influencing overall wellbeing or predisposing individuals to disease state. Many observations reveal an altered microbiome composition in individuals with autoimmune conditions, coupled with shifts in metabolic profiles, which has spurred ongoing development of therapeutic interventions targeting the microbiome. This review delineates the microbial consortia of the intestine, their role in sustaining gastrointestinal stability, the association between the microbiome and immune-mediated pathologies, and therapeutic modalities focused on microbiome modulation. We emphasize the entire role of the intestinal microbiome in human health and recommend microbiome modulation as a viable strategy for disease prophylaxis and management. However, the application of gut microbiota modification for the treatment of immune-related diseases, such as fecal microbiota transplantation and probiotics, remain quite challenging. Therefore, more research is needed into the role and mechanisms of these therapeutics.

Spermidine restricts neonatal inflammation via metabolic shaping of polymorphonuclear myeloid-derived suppressor cells

Newborns exhibit a heightened vulnerability to inflammatory disorders due to their underdeveloped immune system, yet the underlying mechanisms remain poorly understood. Here we report that plasma spermidine is correlated with the maturity of human newborns and reduced risk of inflammation. Administration of spermidine led to the remission of neonatal inflammation in mice. Mechanistic studies revealed that spermidine enhanced the generation of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) via downstream eIF5A hypusination. Genetic deficiency or pharmacological inhibition of deoxyhypusine synthase (DHPS), a key enzyme of hypusinated eIF5A (eIF5AHyp), diminished the immunosuppressive activity of PMN-MDSCs, leading to aggravated neonatal inflammation. The eIF5AHyp pathway was found to enhance the immunosuppressive function via histone acetylation-mediated epigenetic transcription of immunosuppressive signatures in PMN-MDSCs. These findings demonstrate the spermidine-eIF5AHyp metabolic axis as a master switch to restrict neonatal inflammation.

Gut-derived macrophages link intestinal damage to brain injury after cardiac arrest through TREM1 signaling

Brain injury is the leading cause of death and disability in survivors of cardiac arrest, where neuroinflammation triggered by infiltrating macrophages plays a pivotal role. Here, we seek to elucidate the origin of macrophages infiltrating the brain and their mechanism of action after cardiac arrest/cardiopulmonary resuscitation (CA/CPR). Wild-type or photoconvertible Cd68-Cre:R26-LSL-KikGR mice were subjected to 10-min CA/CPR, and the migration of gut-derived macrophages into brain was assessed. Transcriptome sequencing was performed to identify the key proinflammatory signal of macrophages infiltrating the brain, triggering receptor expressed on myeloid cells 1 (TREM1). Upon drug intervention, the effects of TREM1 on post-CA/CPR brain injury were further evaluated. 16S rRNA sequencing was used to detect gut dysbiosis after CA/CPR. Through photoconversion experiments, we found that small intestine-derived macrophages infiltrated the brain and played a crucial role in triggering secondary brain injury after CA/CPR. The infiltrating peripheral macrophages showed upregulated TREM1 levels, and we further revealed the crucial role of gut-derived TREM1+ macrophages in post-CA/CPR brain injury through a drug intervention targeting TREM1. Moreover, a close correlation between upregulated TREM1 expression and poor neurological outcomes was observed in CA survivors. Mechanistically, CA/CPR caused a substantial expansion of Enterobacter at the early stage, which ignited intestinal TREM1 signaling via the activation of Toll-like receptor 4 on macrophages through the release of lipopolysaccharide. Our findings reveal essential crosstalk between the gut and brain after CA/CPR and underscore the potential of targeting TREM1+ small intestine-derived macrophages as a novel therapeutic strategy for mitigating post-CA/CPR brain injury.

Gut microbe-derived betulinic acid alleviates sepsis-induced acute liver injury by inhibiting macrophage NLRP3 inflammasome in mice

Sepsis-induced acute liver injury (SALI) is a prevalent and life-threatening complication associated with sepsis. The gut microbiota plays a crucial role in the maintenance of health and the development of diseases. The impact of physical exercise on gut microbiota modulation has been well-documented. However, the potential impact of gut microbiome on exercise training-induced protection against SALI remains uncertain. Here, we discovered exercise training ameliorated SALI and systemic inflammation in septic mice. Notably, gut microbiota pre-depletion abolished the protective effects of exercise training in SALI mice. Fecal microbiota transplantation treatment revealed that exercise training-associated gut microbiota contributed to the beneficial effect of exercise training on SALI. Exercise training modulated the metabolism of Ligilactobacillus and enriched betulinic acid (BA) levels in mice. Functionally, BA treatment conferred protection against SALI by inhibiting the hepatic inflammatory response in mice. BA bound and inactivated hnRNPA2B1, thus suppressing NLRP3 inflammasome activation in macrophages. Collectively, this study reveals gut microbiota is involved in the protective effects of exercise training against SALI, and gut microbiota-derived BA inhibits the hepatic inflammatory response via the hnRNPA2B1-NLRP3 axis, providing a potential therapeutic strategy for SALI.

IMPORTANCE

Sepsis is characterized by a dysregulated immune response to an infection that leads to multiple organ dysfunction. The occurrence of acute liver injury is frequently observed during the initial stage of sepsis and is directly linked to mortality in the intensive care unit. The preventive effect of physical exercise on SALI is well recognized, yet the underlying mechanism remains poorly elucidated. Exercise training alters the gut microbiome in mice, increasing the abundance of Ligilactobacillus and promoting the generation of BA. Additionally, BA supplementation can suppress the NLRP3 inflammasome activation in macrophages by directly binding to hnRNPA2B1, thereby mitigating SALI. These results highlight the beneficial role of gut microbiota-derived BA in inhibiting the hepatic inflammatory response, which represents a crucial stride toward implementing microbiome-based therapeutic strategies for the clinical management of sepsis.

Targeting GOLPH3L improves glioblastoma radiotherapy by regulating STING-NLRP3-mediated tumor immune microenvironment reprogramming

Radiotherapy (RT) has been the standard-of-care treatment for patients with glioblastoma (GBM); however, the clinical effectiveness is hindered by therapeutic resistance. Here, we demonstrated that the tumor immune microenvironment (TIME) exhibited immunosuppressive properties and high expression of Golgi phosphoprotein 3 like (GOLPH3L) in RT-resistant GBM. Our study showed that GOLPH3L interacted with stimulator of interferon genes (STING) at the aspartic acid residue 184 in Golgi after RT, leading to coat protein complex II-mediated retrograde transport of STING from Golgi to endoplasmic reticulum. This suppressed the STING-NOD-like receptor thermal protein domain associated protein 3 (NLRP3)-mediated pyroptosis, resulting in suppressive TIME, driving GBM resistance to RT. Genetic GOLPH3L ablation in RT-resistant GBM cells augmented antitumor immunity and overcame tumor resistance to RT. Moreover, we have identified a small molecular inhibitor of GOLPH3L, vitamin B5 calcium (VB5), which improved the therapeutic efficacy of RT and immune checkpoint blockade by inducing a robust antitumor immune response in mouse models. Clinically, patients with GBM treated with VB5 exhibited improved responses to RT. Thus, reprogramming the TIME by targeting GOLPH3L may offer a potential opportunity to improve RT in GBM.

HCAR2 Modulates the Crosstalk between Mammary Epithelial Cells and Macrophages to Mitigate Staphylococcus aureus Infection in the Mouse Mammary Gland

Staphylococcus aureus (S. aureus) is a major zoonotic pathogen, with mammary gland infections contributing to mastitis, a condition that poses significant health risks to lactating women and adversely affects the dairy industry. Therefore, understanding the immune mechanisms underlying mammary infections caused by S. aureus is essential for developing targeted therapeutic strategies against mastitis. This study identified hydroxycarboxylic acid receptor 2 (HCAR2) as a potential regulator of S. aureus infection in mammary glands. It is demonstrated that HCAR2 deficiency exacerbates the inflammatory response and disrupts the blood-milk barrier in the mammary gland during S. aureus infection, with NLRP3 inflammasome-mediated pyroptosis playing a central role. Activation of HCAR2, on the other hand, suppressed CMPK2 expression, thereby mitigating mitochondrial damage and pyroptosis in mouse mammary epithelial cells (mMECs) induced by S. aureus. Additionally, mitochondrial DNA (mtDNA) released from S. aureus-infected mMECs activates the cGAS/STING signaling pathway in macrophages, impairing their bactericidal activity. In conclusion, this study highlights the critical role of HCAR2 in S. aureus infection of the mammary gland and provides a theoretical basis for identifying potential therapeutic targets for such infections.

Gut microbiota mediates the anti-inflammatory effects of supplemental infrared irradiation in mice

In recent years, studies have shown that low-dose supplemental infrared (IR) irradiation exhibits systemic anti-inflammatory effects. The gut microbiota is increasingly recognized as a potential mediator of these effects due to its role in regulating host metabolism and inflammatory responses. To investigate the role of gut microbiota diversity and metabolite changes in the mechanism of light-emitting diodes (LED) infrared's anti-inflammatory action, we conducted IR irradiation on mice. Serum inflammatory cytokines were measured using ELISA, and fecal samples were subjected to metagenomic, untargeted, and targeted metabolomic analyses. Our results demonstrated a significant increase in the anti-inflammatory cytokine IL-10 in the IR group, accompanied by a declining trend in pro-inflammatory cytokines. Gut microbiome analysis revealed distinct alterations in composition and functional genes between the groups, including the enrichment of beneficial bacteria like various species of Parabacteroides and Akkermansia muciniphila in the IR group. Notably, the IR group exhibited enrichment in carbohydrate metabolism pathways and a reduction in DNA damage and repair pathways. Furthermore, targeted metabolomic analysis highlighted a notable increase in short-chain fatty acids (SCFAs), including butyric acid and isobutyric acid, which positively correlated with the abundance of several beneficial bacteria. These findings suggest a potential interplay between gut microbiota-derived SCFAs and the anti-inflammatory response. In conclusion, our study provides comprehensive insights into the changes in gut microbiota species and functions associated with IR irradiation. Moreover, we emphasize the significance of altered SCFAs levels in the IR group, which may contribute to the observed anti-inflammatory effects. Our findings contribute valuable evidence supporting the role of low-dose infrared light irradiation as an anti-inflammatory therapy.

MSCs Suppress Macrophage Necroptosis and Foster Liver Regeneration by Modulating SP1/SK1 Axis in Treating Acute Severe Autoimmune Hepatitis

Acute severe autoimmune hepatitis (AS-AIH) is characterized by rapid progression and poor prognosis, with a current lack of effective targeted treatments. Stem cell therapy has demonstrated significant therapeutic promise across various autoimmune diseases. However, the intricate pathogenesis of AS-AIH has hindered the widespread utilization of mesenchymal stem cells (MSCs) in this domain. Herein, it is demonstrated that necroptosis, as the primary mode of cell death in AIH, is crucial in causing AS-AIH. Inflammatory macrophages are the primary cell population involved in necroptosis. Inhibition of the specificity protein 1/sphingosine kinase 1/sphingosine-1-phosphate (SP1/SK1/S1P) axis is responsible for this phenomenon, leading to excessive activation of the intrahepatic immune system and aggravating liver damage. Furthermore, the S1P/S1PR2/YAP axis is the key pathway in initiating liver regeneration during AS-AIH. S1P synthesized by hepatocytes is the primary source, and this process is also regulated by the SP1/SK1 axis. MSCs promote S1P synthesis by macrophages through the delivery of SP1, which inhibits necroptosis and synergistically enhances liver regeneration. In addition, MSCs also promote S1P synthesis in hepatocytes through the same mechanism, further aiding liver regeneration. These findings unveil the core pathogenesis of AS-AIH and provide a theoretical foundation for using MSCs as a potential targeted therapeutic modality.

Piplartine alleviates sepsis-induced acute kidney injury by inhibiting TSPO-mediated macrophage pyroptosis

Sepsis-induced acute kidney injury (SI-AKI) is the most common organ dysfunction of sepsis, characterized with prolonged hospitalization periods and significantly elevated mortality rates. Piplartine (PLG), an alkaloid extracted from Piper longum within the Piperaceae family, has exhibited diverse pharmacological activities, including anti-inflammatory, anti-atherosclerotic, and anti-tumor effects. Herein, we investigated whether the PLG could reverse SI-AKI and explore its possible anti-inflammatory mechanisms. We constructed an SI-AKI model using cecal ligation and puncture (CLP) and systematically evaluated the protective effect of PLG administered by gavage in the SI-AKI mice. Subsequently, we performed proteomic sequencing of the kidney and integrated data from the GeneCards and SwissTargetPrediction databases to identify potential targets and mechanisms. Immunofluorescence and western blotting were used to examine the expression of relevant targets and pathways in vivo and in vitro. The influence of PLG on the predicted target and pathway was verified using an agonist of the target protein and a series of biochemical experiments. PLG exhibited significant efficacy against pathological damage, neutrophil and macrophage infiltration, and macrophage pyroptosis in kidneys at 30 mg/kg. An integrated analysis of proteomic data identified the translocator protein (TSPO) as a potential target for the renoprotective effects of PLG. Moreover, a TSPO agonist (RO5-4864) prominently reversed the protective effect of PLG in SI-AKI mice, as manifested by a deterioration in renal function, histopathological lesions and macrophage pyroptosis in the kidneys. Our results suggest that PLG may ameliorate SI-AKI, potentially through partial inhibition of the TSPO-macrophage pyroptosis pathway.

Characterization of the gut microbiota in urinary calculi patients with preoperative urinary tract infection

Background

Urinary tract infection is one of the most common comorbidities of urinary stones. Disorders of gut microbiota can affect various infectious diseases and the formation of the stones. Therefore, alterations in the gut bacteria profile may be a potential risk factor for the development of infections in patients with urinary tract stones.

Methods

We conducted a retrospective study to analyze the association of urinary tract infections with gut microbiota and serum metabolism in patients with stones.

Results

Patients with urolithiasis were predominantly in combination with diabetes mellitus (11.4% vs. 20%) and hypertension (36.4% vs. 50%). There were no statistically significant differences in hematological and urinary parameters. Compared to negative patients, IL-17A was significantly higher in the positive group (25.0 vs 21.1 pg/ml p = 0.038). The majority of pathogens detected in urine cultures were urease-negative bacteria, and urease-positive bacteria accounted for 15% of the total number of patients. We analyzed the community composition of the two groups of patients and found a significant difference in their β-diversity (p = 0.025), suggesting that dysbiosis of the gut bacteria may be associated with the combination of urinary tract infections in urolithiasis. For identification of crucial bacteria, we found changes in the abundance of both Intestinibacter (p = 0.036) and Dialister (p = 0.039), and abundance of Intestinibacter was positively correlated with IFN-α, IL-12P70 (p<0.05), and especially IL-17A (p<0.01), which may result from differences in translational, ribosomal structural and biosynthetic functions in stone patients (p < 0.05).

Conclusion

Urolithiasis with gut dysbiosis developed a higher incidence of urinary tract infections, which may be associated with the increasing of Intestinibacter and affect the expression of IL-17A by translational, ribosomal structural and biosynthetic function.

A gut Eggerthella lenta-derived metabolite impairs neutrophil function to aggravate bacterial lung infection

The composition of the gut microbiota in patients with bronchiectasis has been proven to be distinct from that of healthy individuals, and this disrupted gut microbiota can exacerbate lung infections. However, the responsible microbes and mechanisms in the "gut-lung" axis in bronchiectasis remain unknown. Here, we report that Eggerthella lenta was enriched in the gut, and taurine ursodeoxycholic acid (TUDCA) was enriched in both the guts and sera of patients with bronchiectasis, with both being associated with disease severity. Fecal microbiota transfer from patients with bronchiectasis as well as administration of E. lenta independently exacerbated pulmonary Pseudomonas aeruginosa infections in murine models. E. lenta-associated TUDCA bound adenosine monophosphate-activated protein kinase (AMPK) within neutrophils and interfered with the interaction between liver kinase B1 and AMPK, with a consequential decrease in AMPK phosphorylation. This ultimately reduced ATP production in neutrophils, inhibited their function, and compromised P. aeruginosa elimination from the lung, aggravating tissue injury. Metformin treatment improved disease severity and outcome in the mouse models. In sum, the gut bacterium E. lenta raises the stakes of bacterial lung infection because it causes dysfunction of neutrophils circulated from serum to lung via the metabolite TUDCA. Interventions targeting E. lenta or AMPK phosphorylation may serve as adjunctive strategies to complement existing approaches for managing chronic pulmonary infection in bronchiectasis and other chronic respiratory disease states.

The Complex Role of Gut Microbiota in Systemic Lupus Erythematosus and Lupus Nephritis: From Pathogenetic Factor to Therapeutic Target

The role of gut microbiota (GM) and intestinal dysbiosis in triggering the onset and/or modulating the severity and progression of lupus nephritis (LN) has been the object of intense research over the last few years. Some alterations at the phyla level, such as the abundance of Proteobacteria and reduction in Firmicutes/Bacteroidetes (F/B) ratio and in α-diversity have been consistently reported in systemic lupus erythematosus (SLE), whereas a more specific role has been ascribed to some species (Bacteroides thetaiotaomicron and Ruminococcus gnavus) in LN. Underlying mechanisms include microbial translocation through a "leaky gut" and subsequent molecular mimicry, immune dysregulation (alteration of IFNγ levels and of balance between Treg and Th17 subsets), and epigenetic interactions. Levels of bacterial metabolites, such as butyrate and other short-chain fatty acids (SCFAs), appear to play a key role in modulating LN. Beyond bacterial components of GM, virome and mycobiome are also increasingly recognized as important players in the modulation of an immune response. On the other hand, microbiota-based therapy appears promising and includes diet, prebiotics, probiotics, symbiotics, and fecal microbiota transplantation (FMT). The modulation of microbiota could correct critical alterations, such as F/B ratio and Treg/Th17 imbalance, and blunt production of autoantibodies and renal damage. Despite current limits, GM is emerging as a powerful environmental factor that could be harnessed to interfere with key mechanisms leading to SLE, preventing flares and organ damage, including LN. The aim of this review is to provide a state-of-the-art analysis of the role of GM in triggering and modulating SLE and LN on the one hand, while exploring possible therapeutic manipulation of GM to control the disease on the other hand.

Oral administration of astilbin mitigates acetaminophen-induced acute liver injury in mice by modulating the gut microbiota

Acetaminophen (APAP) overdose-induced acute liver injury (ALI) is characterized by extensive oxidative stress, and the clinical interventions for this adverse effect remain limited. Astilbin is an active compound found in the rhizome of Smilax glabra Roxb. with anti-inflammatory and antioxidant activities. Due to its low oral bioavailability, astilbin can accumulate in the intestine, which provides a basis for the interaction between astilbin and gut microbiota (GM). In the present study we investigated the protective effects of astilbin against APAP-induced ALI by focusing on the interaction between astilbin and GM. Mice were treated with astilbin (50 mg·kg-1·d-1, i.g.) for 7 days. After the last administration of astilbin for 2 h, the mice received APAP (300 mg/kg, i.g.) to induce ALI. We showed that oral administration of astilbin significantly alleviated APAP-induced ALI by altering the composition of GM and enriching beneficial metabolites including hydroxytyrosol (HT). GM depletion using an "antibiotics cocktail" or paraoral administration of astilbin abolished the hepatoprotective effects of astilbin. On the other hand, administration of HT (10 mg/kg, i.g.) caused similar protective effects in APAP-induced ALI mice. Transcriptomic analysis of the liver tissue revealed that HT inhibited reactive oxygen species and inflammation-related signaling in APAP-induced ALI; HT promoted activation of the Nrf2 signaling pathway to combat oxidative stress following APAP challenge in a sirtuin-6-dependent manner. These results highlight that oral astilbin ameliorates APAP-induced ALI by manipulating the GM and metabolites towards a more favorable profile, and provide an alternative therapeutic strategy for alleviating APAP-induced ALI.

Framework Nucleic Acid-Based and Neutrophil-Based Nanoplatform Loading Baicalin with Targeted Drug Delivery for Anti-Inflammation Treatment

Targeted drug delivery is a promising strategy for treating inflammatory diseases, with recent research focusing on the combination of neutrophils and nanomaterials. In this study, a targeted nanodrug delivery platform (Ac-PGP-tFNA, APT) was developed using tetrahedral framework nucleic acid (tFNA) along with a neutrophil hitchhiking mechanism to achieve precise delivery and anti-inflammatory effects. The tFNA structure, known for its excellent drug-loading capacity and cellular uptake efficiency, was used to carry a therapeutic agent─baicalin. The results demonstrate that the development of this drug delivery platform not only considerably enhances the bioavailability and effective concentration of the drug (baicalin) but also promotes the polarization of pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages by modulating the interactions between the neutrophils and macrophages. This targeted therapeutic method effectively treats inflammatory conditions such as sepsis and introduces a strategy for managing inflammatory diseases characterized by neutrophil infiltration.

Cellular Senescence Contributes to Colonic Barrier Integrity Impairment Induced by Toxoplasma gondii Infection

Toxoplasma gondii (T. gondii) induces gut barrier integrity impairment, which is crucial to the establishment of long-term infection in hosts. Cellular senescence is an imperative event that drives disease progression. Several studies have indicated that T. gondii induces oxidative stress and cell cycle blockade in the tissues of hosts, suggesting cellular senescence induced by the parasite. Here, we explored whether cell senescence is involved in T. gondii-mediated colonic barrier integrity damage in mice. C57BL/6J mice were infected with 10 cysts of T. gondii. Senolytic therapy (dasatinib and quercetin, DQ, a combination therapy for reducing senescent cells) was given by oral gavage 4 weeks post-infection. Alcian blue staining, immunofluorescence, western blot, quantitative PCR (qPCR), and enzyme-linked immunosorbent assay (ELISA) were employed to evaluate the thickness of the colonic mucus layer, the expression profiles of genes and proteins related to tight junction function and cellular senescence in the colonic tissues, and the levels of serum lipopolysaccharides (LPS), respectively. T. gondii-infected mice exhibited deteriorated secreted mucus, shortened length, decreased expression of zonula occludens-1 (ZO-1) and occludin in the colon, accompanied by elevated levels of serum LPS. Moreover, the infection upregulated cell senescence-related markers (p16INK4A, p21CIP1) while inhibiting Lamin B1 expression. In addition, the expression levels of senescence-associated secretory phenotypes (SASPs), including IL-1β, TNF-α, IL-6, MMP9 and CXCL10, were upregulated post-infection. Notably, reducing cell senescence with DQ administration, significantly ameliorated the colonic pathological alterations induced by T. gondii infection. This study uncovers for the first time that cellular senescence contributes to the colonic barrier integrity damage induced by chronic T. gondii infection. Importantly, we provide evidence that senolytic therapy exerts a therapeutic effect on the intestinal pathological lesions.

Non-SCFA microbial metabolites associated with fiber fermentation and host health

Dietary fiber is degraded by commensal gut microbes to yield host-beneficial short-chain fatty acids (SCFAs), but personalized responses to fiber supplementation highlight a role for other microbial metabolites in shaping host health. In this review we summarize recent findings from dietary fiber intervention studies describing health impacts attributed to microbial metabolites other than SCFAs, particularly secondary bile acids (2°BAs), aromatic amino acid derivatives, neurotransmitters, and B vitamins. We also discuss shifts in microbial metabolism occurring through altered maternal dietary fiber intake and agricultural practices, which warrant further investigation. To optimize the health benefits of dietary fibers, it is essential to survey a range of metabolites and adapt recommendations on a personalized basis, according to the different functional aspects of the microbiome.

Guizhi Shaoyao Zhimu decoction inhibits neutrophil extracellular traps formation to relieve rheumatoid arthritis via gut microbial outer membrane vesicles

BACKGROUND

Rheumatoid arthritis (RA) is a common autoimmune disease with a high disability rate. Accumulating studies suggest that neutrophil extracellular traps (NETs) play a crucial role in the pathogenesis of RA and targeting NETs has emerged as a potential therapeutic strategy for RA. As a traditional Chinese medicine, Guizhi-Shaoyao-Zhimu Decoction (GSZD) has exhibited good efficacy in the treatment of rheumatoid arthritis (RA), while the underly mechanism especially the possibility that GSZD alter NETs formation to relieve RA remains unknown.

PURPOSE

Our study aimed to investigate relationship between GSZD and NETs in RA treatment and revealed underlying mechanism.

METHODS

We constructed collagen-induced arthritis (CIA) model and treated CIA mice with GZSY to validate therapeutic effects of GSZD and examine whether GZSD could inhibit NETs formation in RA. And 16S rRNA sequencing and Fecal microbiota transplantation (FMT) experiment were performed to determine whether GSZD could reduce NETs formation to alleviate RA in gut microbiota-associated manner and identify crucial bacterium in response to GSZD administration. CIA mice treated with effective bacteria and its outer membrane vesicles (OMVs) with oral administration to investigate protective effect against RA and NETs regulative efficiency. We utilized small interfering RNA in vivo and vitro to silence gene mediating effect of GZSD-gut microbiota-NETs.

RESULTS

GSZD could inhibit NETs formation and relive arthritis in CIA mice. Additionally, GSZD alter gut microbiota composition and significantly increase intestinal Parabacteroides goldsteinii (P.goldsteinii) abundance. Mechanistically, P.goldsteinii enriched by GSZD secreted outer membrane vesicles (OMVs) to translocate into joints and activate Cav-1-Nrf2 axis, leading to reduced NETs formation and alleviate arthritis. In clinical, the abundance of P.goldsteinii exhibited negative correlation with NETs indexes and RA disease activities.

CONCLUSION

Our findings suggest that GSZD inhibits NETs formation to relieve RA in P.goldsteinii-Cav-1-Nrf2 associated manner, which could provide new sight of the prevention and treatment of RA.

CHS-Ⅳa activates the IGF1R/PI3K signal pathway with inhibited pyroptosis of endometrial stromal cells and progress of endometriosis

ETHNOPHARMACOLOGICAL RELEVANCE

Chikusetsusaponin IVa (CHS IVa) as a natural extract from the Panax japonicus (T.Nees) C.A.Mey (P. japonicus), can regulate the immune responses, such as anti-inflammation, which have been applied in treating various diseases. It is still unclear, nevertheless, whether the CHS IVa can target-able treat endometriosis (EMs) and what the possible mechanism would be.

PURPOSE OF THE STUDY

This work aims to investigate the possible mechanism and the impact of CHS IVa on EMs.

MATERIALS AND METHODS

The EMs models were established in mice by autologous transplantation or chemicals (lipopolysaccharide and adenosine triphosphate), inducing the pyroptotic endometrial stromal cells. Then the CHS IVa was used to treat the EMs mice. The therapeutic impact of CHS IVa was assessed by hematoxylin-eosin staining, immunofluorescent staining, western blot (WB), and enzyme-linked immunosorbent assay (ELISA).

RESULTS

The results of immunofluorescence and WB indicated that pyroptosis indicators, including Gasdermin-D (GSDMD), Caspase-1, NOD-like receptor thermal protein domain associated protein 3 (NLRP3), and interleukin (IL)-1β, were substantially expressed in the ectopic endometrial lesions of EMs mice. The ELISA results showed that the abdominal cavity of EMs mice had higher concentrations of IL-1β, IL-6, and TNF-α than the non-EMs animals (control group). As shown in the molecule docking experiments, CHS IVa exhibited high binding affinity with GSDMD, IL-1β, Caspase-1, and NLRP3. Moreover, after treatment with CHS IVa, the expression levels of GSDMD, IL-1β, Caspase-1, and NLRP3 decreased in the EMs mice. Meanwhile, the expression level of pain-related proteins, such as pro-nerve growth factor (pro-NGF) and transient receptor potential vanilloid-1 (TRPV1), was inhibited via the treatment of CHS IVa. According to the antibody chip analysis, the insulin-like growth factor 1 receptor/phosphatidylinositide 3-kinases (IGF1R/PI3K) signal pathway was essential to the CHS IVa's treatment of EMs. Finally, according to the WB experiments, after the treatment with CHS-Ⅳa, the expression of IGF1R, PI3K, and related phosphorylated proteins increased compared to the mice in lipopolysaccharide + adenosine triphosphate (LPS + ATP) groups.

CONCLUSION

CHS IVa can activate the IGF1R/PI3K signal pathway, inhibit the pyroptosis of endometrial stromal cells, and relieve the inflammation and EMs.

Quantitative evaluation of microenvironmental changes and efficacy of cupping therapy under different pressures based on photoacoustic imaging

Cupping therapy, a traditional Chinese medicinal practice, has been subjected to scientific scrutiny to validate its effects on local tissue microenvironments. This study provides a quantitative assessment of cupping therapy at different negative pressures using photoacoustic imaging. Low-pressure cupping (-20 kPa) significantly improved local blood circulation, evidenced by increased hemoglobin oxygen saturation and vessel dilation that normalized within two hours. In contrast, high-pressure cupping (-30 kPa) led to capillary rupture, bleeding, and tissue edema, similar to the clinical presentation of cupping bruises. Additionally, our research unveiled that -20 kPa cupping expedited the clearance of indocyanine green dye, suggesting enhanced lymphatic drainage, which was further supported by fluorescence imaging. This indicates a potential mechanism for cupping's pain relief effects. Moreover, cupping showed promising results in improving sepsis outcomes in mice, potentially due to its anti-inflammatory properties. This study establishes a foundation for the objective evaluation of cupping therapy, demonstrating that low-pressure cupping is effective in promoting blood and lymphatic flow while minimizing tissue damage, thereby offering a safer therapeutic approach.

PRDM16 suppresses ferroptosis to protect against sepsis-associated acute kidney injury by targeting the NRF2/GPX4 axis

Acute kidney injury (AKI) constitutes a significant public health issue. Sepsis accounts for over 50 % of AKI cases in the ICU. Recent findings from our research indicated that the PRD1-BF1-RIZ1 homeodomain protein 16 (PRDM16) inhibited the progression of diabetic kidney disease (DKD). However, its precise role and regulatory mechanism in sepsis-induced AKI remain obscure. This study reveals that lipopolysaccharide (LPS) and cecum ligation and puncture (CLP) instigated PRDM16 expression in Boston University mouse proximal tubule (BUMPT) cells and mouse kidneys, respectively. Functionally, PRDM16 curtailed LPS-induced ferroptosis. Mechanistically, PRDM16 associates with the promoter regions of nuclear factor-erythroid 2-related factor-2 (NRF2) and augments its expression, subsequently enhancing glutathione peroxidase 4 (GPX4) expression. Additionally, PRDM16 directly engages with the promoter regions of GPX4, stimulating its expression. Notably, these observations were corroborated in human renal tubular epithelial (HK-2) cells. Furthermore, the ablation of PRDM16 from kidney proximal tubules in mice inhibited NRF2 and GPX4 expression, leading to decreased glutathione (GSH)/oxidized glutathione (GSSG) ratio, increased Fe2+ and reactive oxygen species (ROS) production, exacerbated ferroptosis, and AKI progression. Conversely, PRDM16 knock-in exhibited the opposite effects. Ultimately, adenovirus (ADV)-PRDM16 plasmid or poly (lactide-glycolide acid) (PLGA)-encapsulated formononetin not only mitigated sepsis-induced AKI but also alleviated liver, cardiac, and lung injury. In summary, PRDM16 inhibits ferroptosis via the NRF2/GPX4 axis or GPX4 to prevent sepsis-induced multi-organ injury, including AKI. PLGA-encapsulated formononetin presents a promising therapeutic approach.

Astragaloside IV Reduces Lung Epithelial Cell Pyroptosis via TXNIP-NLRP3-GSDMD pathway

This study aimed to investigate the detrimental impact of cigarettes on lung cells and the potential effects of astragaloside IV on lung epithelial cell oxidative stress and pyroptosis. The research utilized cigarette smoke extract (CSE) to stimulate lung epithelial cells BEAS-2B, assessed cytotoxicity using the CCK-8 method, and measured changes in reactive oxygen species (ROS) and mitochondrial membrane potential with a probe method. Additionally, Seahorse XF24 was employed to analyze the impact of CSE on mitochondria in lung epithelial cells. Furthermore, LPS and cigarette combination-treated mice were created, alveolar damage was evaluated using HE staining, and changes in the key protein GSDMD of pyroptosis were detected using western blot (WB). The study also utilized the CCK-8 method to assess the potential toxic effects of astragaloside IV on lung epithelial cells, and the probe method to monitor changes in ROS and mitochondrial membrane potential. WB analysis was conducted to observe protein alterations in the TXNIP/NLRP3/GSDMD pathway. CSE concentration-dependently reduced cell activity, increased cellular ROS levels, and decreased mitochondrial membrane potential. CSE also decreases basal respiratory capacity, respiratory reserve capacity, and ATP production levels in cells. In LPS and cigarette combination-treated mice, cigarette smoke caused the alveolar septum to break and alveoli to enlarge, while increasing the expression of pyroptosis-related protein GSDMD. Astragaloside IV did not show significant cytotoxic effects within 48 h of treatment and could reduce CSE-induced ROS levels while increasing mitochondrial membrane potential. WB results indicated that astragaloside IV reduced the activation of the TXNIP/NLRP3/GSDMD signaling pathway in lung epithelial cells exposed to CSE. Our study demonstrates that CSE induces oxidative stress and impairs mitochondrial function in pulmonary epithelial cells, while astragaloside IV can potentially reverse these effects by inhibiting the TXNIP-NLRP3-GSDMD signaling pathway, thereby mitigating CSE-induced pulmonary disease and epithelial cell pyroptosis.

Ubiquitination in pyroptosis pathway: A potential therapeutic target for sepsis

Sepsis remains a significant clinical challenge, causing numerous deaths annually and representing a major global health burden. Pyroptosis, a unique form of programmed cell death characterized by cell lysis and the release of inflammatory mediators, is a crucial factor in the pathogenesis and progression of sepsis, septic shock, and organ dysfunction. Ubiquitination, a key post-translational modification influencing protein fate, has emerged as a promising target for managing various inflammatory conditions, including sepsis. This review integrates the current knowledge on sepsis, pyroptosis, and the ubiquitin system, focusing on the molecular mechanisms of ubiquitination within pyroptotic pathways activated during sepsis. By exploring how modulating ubiquitination can regulate pyroptosis and its associated inflammatory signaling pathways, this review provides insights into potential therapeutic strategies for sepsis, highlighting the need for further research into these complex molecular networks.

Gut microbiota in health and disease: advances and future prospects

The gut microbiota plays a critical role in maintaining human health, influencing a wide range of physiological processes, including immune regulation, metabolism, and neurological function. Recent studies have shown that imbalances in gut microbiota composition can contribute to the onset and progression of various diseases, such as metabolic disorders (e.g., obesity and diabetes) and neurodegenerative conditions (e.g., Alzheimer's and Parkinson's). These conditions are often accompanied by chronic inflammation and dysregulated immune responses, which are closely linked to specific forms of cell death, including pyroptosis and ferroptosis. Pathogenic bacteria in the gut can trigger these cell death pathways through toxin release, while probiotics have been found to mitigate these effects by modulating immune responses. Despite these insights, the precise mechanisms through which the gut microbiota influences these diseases remain insufficiently understood. This review consolidates recent findings on the impact of gut microbiota in these immune-mediated and inflammation-associated conditions. It also identifies gaps in current research and explores the potential of advanced technologies, such as organ-on-chip models and the microbiome-gut-organ axis, for deepening our understanding. Emerging tools, including single-bacterium omics and spatial metabolomics, are discussed for their promise in elucidating the microbiota's role in disease development.

Dietary-timing-induced gut microbiota diurnal oscillations modulate inflammatory rhythms in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune condition characterized by inflammatory activity with distinct rhythmic fluctuations. However, the precise mechanisms governing these inflammatory rhythms remain elusive. Here, we explore the interaction between dietary patterns, gut microbiota diurnal oscillations, and the rhythmicity of RA in both collagen-induced arthritis (CIA) mice and patients with RA and highlight the significance of dietary timing in modulating RA inflammatory rhythms linked to gut microbiota. Specifically, we discovered that Parabacteroides distasonis (P. distasonis) uses β-glucosidase (β-GC) to release glycitein (GLY) from the diet in response to daily nutritional cues, influencing RA inflammatory rhythms dependent on the sirtuin 5-nuclear factor-κB (SIRT5-NF-κB) axis. Notably, we validated the daily fluctuations of P. distasonis-β-GC-GLY in patients with RA through continuous sampling across day-night cycles. These findings underscore the crucial role of dietary timing in RA rhythmicity and propose potential clinical implications for novel therapeutic strategies to alleviate arthritis.

Factors affecting neutrophil functions during sepsis: human microbiome and epigenetics

Sepsis is a severe disease that occurs when the body's immune system reacts excessively to infection. The body's response, which includes an intense antibacterial reaction, can damage its tissues and organs. Neutrophils are the major components of white blood cells in circulation, play a vital role in innate immunity while fighting against infections, and are considered a feature determining sepsis classification. There is a plethora of basic research detailing neutrophil functioning, among which, the study of neutrophil extracellular traps is providing novel insights into mechanisms and treatments of sepsis. This review explores their functions, dysfunctions, and influences in the context of sepsis. The interplay between neutrophils and the human microbiome and the impact of DNA methylation on neutrophil function in sepsis are crucial areas of study. The interaction between neutrophils and the human microbiome is complex, particularly in the context of sepsis, where dysbiosis may occur. We highlight the importance of deciphering neutrophils' functional alterations and their epigenetic features in sepsis because it is critical for defining sepsis endotypes and opening up the possibility for novel diagnostic methods and therapy. Specifically, epigenetic signatures are pivotal since they will provide a novel implication for a sepsis diagnostic method when used in combination with the cell-free DNA. Research is exploring how specific patterns of DNA methylation in neutrophils, detectable in cell-free DNA, could serve as biomarkers for the early detection of sepsis.

Abelmoschi Corolla polysaccharides and related metabolite ameliorates colitis via modulating gut microbiota and regulating the FXR/STAT3 signaling pathway

Ulcerative Colitis (UC) is a chronic inflammatory disease of the intestinal tract with unknown definitive etiology. Polysaccharides are among the most important active components of Abelmoschi Corolla, exhibitings various pharmacological activities such as antioxidation and immunomodulation. However, no studies have yet reported the application of Abelmoschi Corolla Polysaccharides (ACP) in treating UC. This study aims to highlight the therapeutic efficacy of ACP in UC and reveal the underlying mechanism. The potential therapeutic effect is initially verified using a dextran sodium sulfate (DSS)-induced colitis model. 16S rRNA sequencing is performed using feces samples and untargeted metabolomics using serum samples to further reveal that ACP reprograms the dysbiosis triggered by UC progression, increases the abundance of Bacteroides spp., Blautia spp., and Parabacteroides spp. at the genus level and enriches the serum concentration of 7-ketodeoxycholic acid (7-KDA). Furthermore, using the FXR-/- mouse model, it is revealed that Farnesoid X Receptor (FXR) is a key target for ACP and the metabolite 7-KDA to block STAT3 phosphorylation by repairing the intestinal barrier to attenuate UC. Taken together, this work highlights the therapeutic potential of ACP against UC, mainly exerting its effects via modulating gut microbiota and regulating the FXR/STAT3 signaling pathway.

Indole-3-Carboxaldehyde Alleviates LPS-Induced Intestinal Inflammation by Inhibiting ROS Production and NLRP3 Inflammasome Activation

Indole-3-carboxaldehyde (IAld) is a tryptophan (Trp) metabolite derived from gut microbiota, which has a potential protective effect on intestinal inflammatory diseases. Abnormal activation of NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is an important cause of intestinal inflammation. However, the effect and mechanism of IAld on NLRP3 inflammasome activation remain unclear. Here, we found that IAld inhibited the activation of the NLRP3 inflammasome in intestinal epithelial cells, and effectively prevented intestinal epithelial barrier injury caused by lipopolysaccharide (LPS) stimulation. Mechanistically, we demonstrated that IAld activated the aryl hydrocarbon receptor (AhR), subsequently prevented reactive oxygen species (ROS) production, maintained mitochondrial membrane potential, and blocked the NF-κB/NLRP3 inflammatory pathway in intestinal epithelial cells. Also, the AhR-specific inhibitor CH-223191 effectively blocked the IAld-induced NLRP3 inhibition and intestinal epithelial barrier repairment. In addition, in vivo results showed that IAld prevented pro-inflammatory mediator production and intestinal inflammatory damage in LPS-induced mice, which is related to AhR activation and NLRP3 inflammasome inhibition. Collectively, our study unveiled that IAld is an effective endogenous antioxidant and suggested the AhR as a potential treatment target for NLRP3-induced intestinal inflammatory diseases.

Qi Huang Fang improves intestinal barrier function and intestinal microbes in septic mice through NLRP3 inflammasome-mediated cellular pyroptosis

OBJECTIVE

Sepsis has a high incidence, morbidity, and mortality rate and is a great threat to human safety. Gut health plays an important role in sepsis development. Qi Huang Fang (QHF) contains astragalus, rhubarb, zhishi, and atractylodes. It is used to treat syndromes of obstructive qi and deficiency of righteousness. This study aimed to investigate whether QHF improves intestinal barrier function and microorganisms in mice through NLRP3 inflammatory vesicle-mediated cellular focal death.

METHODS

A mouse model of sepsis was constructed by cecal ligation and puncture (CLP) of specific pathogen-free (SPF)-grade C57BL/6 mice after continuous gavage of low, medium, and high doses of astragalus formula or probiotics for 4 weeks. Twenty-four hours postoperatively, the mechanism of action of QHF in alleviating septic intestinal dysfunction and restoring intestinal microecology, thereby alleviating intestinal injury, was evaluated by pathological observation, immunohistochemistry, western blotting, ELISA, and 16S rDNA high-throughput sequencing.

RESULTS

Different doses of QHF and probiotics ameliorated intestinal injury and reduced colonic apoptosis in mice to varying degrees (P < 0.05). Meanwhile, different doses of QHF and probiotics were able to reduce the serum levels of IL-6, IL-1β, and TNF-α (P < 0.05); down-regulate the protein expression of NLRP3, caspase-1, and caspase-11 (P < 0.05); and up-regulate the protein expression of zonula occluden-1 (ZO-1) and occludin (P < 0.05), which improved the intestinal barrier function in mice. In addition, QHF decreased the relative abundance of harmful bacteria (Firmicutes, Muribaculaceae, Campilobacterota, Helicobacter, and Alistipes) and increased the relative abundance of beneficial bacteria (Bacteroidetes and Actinobacteria) (P < 0.05).

CONCLUSION

QHF improves intestinal barrier function and gut microbiology in mice via NLRP3 inflammasome-mediated cellular pyroptosis.

Natural product/diet-based regulation of macrophage polarization: Implications in treatment of inflammatory-related diseases and cancer

Macrophages are phagocytic cells with important physiological functions, including the digestion of cellular debris, foreign substances, and microbes, as well as tissue development and homeostasis. The tumor microenvironment (TME) shapes the aggressiveness of cancer, and the biological and cellular interactions in this complicated space can determine carcinogenesis. TME can determine the progression, biological behavior, and therapy resistance of human cancers. The macrophages are among the most abundant cells in the TME, and their functions and secretions can determine tumor progression. The education of macrophages to M2 polarization can accelerate cancer progression, and therefore, the re-education and reprogramming of these cells is promising. Moreover, macrophages can cause inflammation in aggravating pathological events, including cardiovascular diseases, diabetes, and neurological disorders. The natural products are pleiotropic and broad-spectrum functional compounds that have been deployed as ideal alternatives to conventional drugs in the treatment of cancer. The biological and cellular interactions in the TME can be regulated by natural products, and for this purpose, they enhance the M1 polarization of macrophages, and in addition to inhibiting proliferation and invasion, they impair the chemoresistance. Moreover, since macrophages and changes in the molecular pathways in these cells can cause inflammation, the natural products impair the pro-inflammatory function of macrophages to prevent the pathogenesis and progression of diseases. Even a reduction in macrophage-mediated inflammation can prevent organ fibrosis. Therefore, natural product-mediated macrophage targeting can alleviate both cancerous and non-cancerous diseases.

Investigating the association between gut microbiome and aortic aneurysm diseases: a bidirectional two-sample Mendelian randomization analysis

Objective

This study aims to investigate the associations between specific bacterial taxa of the gut microbiome and the development of aortic aneurysm diseases, utilizing Mendelian Randomization (MR) to explore these associations and overcome the confounding factors commonly present in observational studies.

Methods

Employing the largest available gut microbiome and aortic aneurysm Genome-Wide Association Study databases, including MiBioGen, Dutch Microbiome Project, FinnGen, UK Biobank, and Michigan Genomics Initiative, this study performs two-sample bidirectional MR analyses. Instrumental variables, linked to microbiome taxa at significant levels, were selected for identifying relationships with abdominal aortic aneurysms (AAA), thoracic aortic aneurysms (TAA), and aortic dissection (AD). Methods like inverse variance weighted, MR-PRESSO, MR-Egger, weighted median, simple mode, and mode-based estimate were used for MR analysis. Heterogeneity was assessed with the Cochran Q test. MR-Egger regression and MR-PRESSO addressed potential unbalanced horizontal pleiotropy.

Results

The analysis did not find any evidence of statistically significant associations between the gut microbiome and aortic aneurysm diseases after adjusting for the false discovery rate (FDR). Specifically, while initial results suggested correlations between 19 taxa and AAA, 25 taxa and TAA, and 13 taxa with AD, these suggested associations did not hold statistical significance post-FDR correction. Therefore, the role of individual gut microbial taxa as independent factors in the development and progression of aortic aneurysm diseases remains inconclusive. This finding underscores the necessity for larger sample sizes and more comprehensive studies to further investigate these potential links.

Conclusion

The study emphasizes the complex relationship between the gut microbiome and aortic aneurysm diseases. Although no statistically significant associations were found after FDR correction, the findings provide valuable insights and highlight the importance of considering gut microbiota in aortic aneurysm diseases research. Understanding these interactions may eventually contribute to identifying new therapeutic and preventive strategies for aortic aneurysm diseases.

Urolithin A Protects against Hypoxia-Induced Pulmonary Hypertension by Inhibiting Pulmonary Arterial Smooth Muscle Cell Pyroptosis via AMPK/NF-κB/NLRP3 Signaling

Recent studies confirmed that pyroptosis is involved in the progression of pulmonary hypertension (PH), which could promote pulmonary artery remodeling. Urolithin A (UA), an intestinal flora metabolite of ellagitannins (ETs) and ellagic acid (EA), has been proven to possess inhibitory effects on pyroptosis under various pathological conditions. However, its role on PH remained undetermined. To investigate the potential of UA in mitigating PH, mice were exposed to hypoxia (10% oxygen, 4 weeks) to induce PH, with or without UA treatment. Moreover, in vitro experiments were carried out to further uncover the underlying mechanisms. The in vivo treatment of UA suppressed the progression of PH via alleviating pulmonary remodeling. Pyroptosis-related genes were markedly upregulated in mice models of PH and reversed after the administration of UA. In accordance with that, UA treatment significantly inhibited hypoxia-induced pulmonary arterial smooth muscle cell (PASMC) pyroptosis via the AMPK/NF-κB/NLRP3 pathway. Our results revealed that UA treatment effectively mitigated PH progression through inhibiting PASMC pyroptosis, which represents an innovative therapeutic approach for PH.

Huang Lian Jie Du decoction attenuates inflammation in septic rats by activating autophagy and altering the intestinal microbiome

Aims

The aim of this study was to investigate the protective effect of HLJDD on septic rats and the underlying mechanisms.

Materials and methods

Adult male Sprague-Dawley (SD) adult rats (150-180 g) were randomly divided into the following 5 groups (n = 7 per group): the Sham group, caecal ligation and puncture (CLP) group, HLJDD + CLP (Huang Lian Jie Du Decoction, HLJDD) group (1 g/mL/100 g), HLJDD + Rap + CLP (H. Rap) group (Rap: 3 mg/kg), and HLJDD+3-MA + CLP (H. 3-MA) group (3-MA: 30 mg/kg). Rapamycin (Rap) and 3-methyladenosine (3-MA) were used to activate and inhibit autophagy, respectively. HLJDD was purchased from Beijing Tong Ren Tang Guiyang Branch and verified by experts as a genuine product. We used CLP to establish an animal model of sepsis in the last four groups. Survival was analysed by the Kaplan‒Meier method. Then, we examined autophagy-related genes (Atgs) and proteins using real-time PCR and Western blotting, respectively. The microstructure of the ileum and the number of autophagosomes were observed by transmission electron microscopy (TEM). Analyses of HE-stained pathological ileum and inflammatory factor levels were examined to assess the extent of septic injury. The effect of HLJDD on the gut microbiota was analysed by 16S rRNA gene sequencing of faeces.

Results

In this study, we identified the protective effects of HLJDD on mortality and inflammation in septic rats. Several key proteins, including LC3-II, Beclin-1 and p62, were examined and showed that HLJDD could effectively reverse the sepsis-induced decrease in autophagy. TEM was performed and the expression of Atgs was assessed to evaluate fluctuations in autophagy. Then, we examined the intestinal tight junction protein zona occludens (ZO-1), lipopolysaccharide (LPS) and inflammatory factors, and found that HLJDD effectively alleviated the increase in ZO-1 gene expression, the level of LPS and serum level of inflammatory factors caused by sepsis. These results were consistent with those obtained from pathological sectioning and TEM analysis. Moreover, autophagy activation effectively ameliorated sepsis, and autophagy inhibition exacerbated the systemic symptoms caused by infection. By examining the expression of key proteins upstream of the autophagy pathway, we found that HLJDD inhibited mTOR via the MAPK/PI3K signalling pathway to promote autophagy in septic rats. 16S rRNA sequencing revealed that HLJDD significantly affected the diversity and physiological function of the gut microbiota in septic rats.

Conclusions

The results of this study indicate that autophagy activation is a potential mechanism underlying the protective effect of HLJDD on the intestine in septic rats.

Superparamagnetic iron oxide nanoparticle regulates microbiota-gut-inner ear axis for hearing protection

Noise-induced hearing loss (NIHL) is a highly prevalent form of sensorineural hearing damage that has significant negative effects on individuals of all ages and there are no effective drugs approved by the US Food and Drug Administration. In this study, we unveil the potential of superparamagnetic iron oxide nanoparticle assembly (SPIOCA) to reshape the dysbiosis of gut microbiota for treating NIHL. This modulation inhibits intestinal inflammation and oxidative stress responses, protecting the integrity of the intestinal barrier. Consequently, it reduces the transportation of pathogens and inflammatory factors from the bloodstream to the cochlea. Additionally, gut microbiota-modulated SPIOCA-induced metabolic reprogramming in the gut-inner ear axis mainly depends on the regulation of the sphingolipid metabolic pathway, which further contributes to the restoration of hearing function. Our study confirms the role of the microbiota-gut-inner ear axis in NIHL and provides a novel alternative for the treatment of NIHL and other microbiota dysbiosis-related diseases.

Formononetin protects against Aspergillus fumigatus Keratitis: Targeting inflammation and fungal load

PURPOSE

To investigate the potential treatment of formononetin (FMN) on Aspergillus fumigatus (A. fumigatus) keratitis with anti-inflammatory and antifungal activity.

METHODS

The effects of FMN on mice with A. fumigatus keratitis were evaluated through keratitis clinical scores, hematoxylin-eosin (HE) staining, and plate counts. The expression of pro-inflammatory factors was measured using RT-PCR, ELISA, or Western blot. The distribution of macrophages and neutrophils was explored by immunofluorescence staining. The antifungal properties of FMN were assessed through minimum inhibitory concentration (MIC), propidium iodide (PI) staining, fungal spore adhesion, and biofilm formation assay.

RESULTS

In A. fumigatus keratitis mice, FMN decreased the keratitis clinical scores, macrophages and neutrophils migration, and the expression of TNF-α, IL-6, and IL-1β. In A. fumigatus-stimulated human corneal epithelial cells (HCECs), FMN reduced the expression of IL-6, TNF-α, IL-1β, and NLRP3. FMN also decreased the expression of thymic stromal lymphopoietin (TSLP) and thymic stromal lymphopoietin receptor (TSLPR). Moreover, FMN reduced the levels of reactive oxygen species (ROS) induced by A. fumigatus in HCECs. Furthermore, FMN inhibited A. fumigatus growth, prevented spore adhesion and disrupted fungal biofilm formation in vitro. In vivo, FMN treatment reduced the fungal load in mice cornea at 3 days post infection (p.i.).

CONCLUSION

FMN demonstrated anti-inflammatory and antifungal properties, and exhibited a protective effect on mouse A. fumigatus keratitis.

Magnesium alleviates extracellular histone-induced apoptosis and defective bacterial phagocytosis in macrophages by regulating intracellular calcium signal

Extracellular histones have been determined as important mediators of sepsis, which induce excessive inflammatory responses in macrophages and impair innate immunity. Magnesium (Mg2+), one of the essential nutrients of the human body, contributes to the proper regulation of immune function. However, no reports indicate whether extracellular histones affect survival and bacterial phagocytosis in macrophages and whether Mg2+ is protective against histone-induced macrophage damage. Our clinical data revealed a negative correlation between circulating histone and monocyte levels in septic patients, and in vitro experiments confirmed that histones induced mitochondria-associated apoptosis and defective bacterial phagocytosis in macrophages. Interestingly, our clinical data also indicated an association between lower serum Mg2+ levels and reduced monocyte levels in septic patients. Moreover, in vitro experiments demonstrated that Mg2+ attenuated histone-induced apoptosis and defective bacterial phagocytosis in macrophages through the PLC/IP3R/STIM-mediated calcium signaling pathway. Importantly, further animal experiments proved that Mg2+ significantly improved survival and attenuated histone-mediated lung injury and macrophage damage in histone-stimulated mice. Additionally, in a cecal ligation and puncture (CLP) + histone-induced injury mouse model, Mg2+ inhibited histone-mediated apoptosis and defective phagocytosis in macrophages and further reduced bacterial load. Overall, these results suggest that Mg2+ supplementation may be a promising treatment for extracellular histone-mediated macrophage damage in sepsis.

Acupoint Autohemotherapy Attenuates DNCB-Induced Atopic Dermatitis and Activates Regulatory T Cells in BALB/c Mice

Purpose

Acupoint autohemotherapy (A-AHT) has been proposed as an alternative and complementary treatment for atopic dermatitis (AD), yet the exact role of its blood component in terms of therapeutic efficacy and mechanism of action is still largely unknown.

Methods

This study aimed to evaluate the therapeutic efficacies and action mechanisms of intramuscular injections of autologous whole blood (AWB) and mouse immunoglobulin G (IgG) (autologous or heterologous) at acupoints on 2,4-dinitrochlorobenzene (DNCB)-induced AD mouse models. Serum levels of total immunoglobulin E (IgE), IgG, interleukin-10 (IL-10), and interferon-gamma (IFN-γ) were measured, as well as mRNA expression levels of Forkhead box P3 (FoxP3), IL-10 and IFN-γ in dorsal skin lesions, and IL-10+, IFN-γ+ and FoxP3+CD4+T cells in murine spleen.

Results

It showed that repeated acupoint injection of AWB, autologous total IgG (purified from autologous blood in AD mice) or heterologous total IgG (purified from healthy blood in normal mice) effectively reduced the severity of AD symptoms and decreased epidermal and dermal thickness as well as mast cells in skin lesions. Additionally, AWB acupoint injection was found to upregulate FoxP3+, IL-10+ and IFN-γ+ CD4+T cells in murine spleen, suppressing the production of IgE antibodies and increasing that of IgG antibodies in the serum. Furthermore, both AWB and autologous total IgG administrations significantly elevated FoxP3 expression, mRNA levels of IL-10 and IFN-γ in dorsal skin lesions. However, acupoint injection of heterologous total IgG had no effect on regulatory T (Treg) and Th1 cells modulation.

Conclusion

These findings suggest that the therapeutic effects of A-AHT on AD are mediated by IgG-induced activation of Treg cells.

Exploring ncRNA-mediated pathways in sepsis-induced pyroptosis

Sepsis, a potentially fatal illness caused by an improper host response to infection, remains a serious problem in the world of healthcare. In recent years, the role of ncRNA has emerged as a pivotal aspect in the intricate landscape of cellular regulation. The exploration of ncRNA-mediated regulatory networks reveals their profound influence on key molecular pathways orchestrating pyroptotic responses during septic conditions. Through a comprehensive analysis of current literature, we navigate the diverse classes of ncRNAs, including miRNAs, lncRNAs, and circRNAs, elucidating their roles as both facilitators and inhibitors in the modulation of pyroptotic processes. Furthermore, we highlight the potential diagnostic and therapeutic implications of targeting these ncRNAs in the context of sepsis, aiming to cover the method for novel and effective strategies to mitigate the devastating consequences of septic pathogenesis. As we unravel the complexities of this regulatory axis, a deeper understanding of the intricate crosstalk between ncRNAs and pyroptosis emerges, offering promising avenues for advancing our approach to sepsis intervention. The intricate pathophysiology of sepsis is examined in this review, which explores the dynamic interaction between ncRNAs and pyroptosis, a highly regulated kind of programmed cell death.

16S rRNA seq-identified Corynebacterium promotes pyroptosis to aggravate diabetic foot ulcer

BACKGROUND

Diabetic foot ulcer (DFU) is one of the main chronic complications caused by diabetes, leading to amputation in severe cases. Bacterial infection affects the wound healing in DFU.

METHODS

DFU patients who met the criteria were selected, and the clinical data were recorded in detail. The pus exudate from the patient's foot wound and venous blood were collected for biochemical analysis. The distribution of bacterial flora in pus exudates of patients was analyzed by 16S rRNA sequencing, and the correlation between DFU and pathogenic variables, pyroptosis and immunity was analyzed by statistical analysis. Then, the effects of key bacteria on the inflammation, proliferation, apoptosis, and pyroptosis of polymorphonuclear leukocytes were investigated by ELISA, CCK-8, flow cytometry, RT-qPCR and western blot.

RESULTS

Clinical data analysis showed that Wagner score was positively correlated with the level of inflammatory factors, and there was high CD3+, CD4+, and low CD8+ levels in DFU patients with high Wagner score. Through alpha, beta diversity analysis and species composition analysis, Corynebacterium accounted for a large proportion in DFU. Logistics regression model and Person correlation analysis demonstrated that mixed bacterial infections could aggravate foot ulcer, and the number of bacteria was closely related to inflammatory factors PCT, PRT, immune cells CD8+, and pyroptosis-related proteins GSDMD and NLRP3. Through in vitro experiments, Corynebacterium inhibited cell proliferation, promoted inflammation (TNF-α, PCT, CRP), apoptosis and pyroptosis (IL-1β, LDH, IL-18, GSDMD, NLRP3, and caspase-3).

CONCLUSION

Mixed bacterial infections exacerbate DFU progression with a high predominance of Corynebacterium, and Corynebacterium promotes inflammation, apoptosis and pyroptosis to inhibit DFU healing.

Intestinal flora and pregnancy complications: Current insights and future prospects

Numerous studies have demonstrated the pivotal roles of intestinal microbiota in many physiopathological processes through complex interactions with the host. As a unique period in a woman's lifespan, pregnancy is characterized by changes in hormones, immunity, and metabolism. The gut microbiota also changes during this period and plays a crucial role in maintaining a healthy pregnancy. Consequently, anomalies in the composition and function of the gut microbiota, namely, gut microbiota dysbiosis, can predispose individuals to various pregnancy complications, posing substantial risks to both maternal and neonatal health. However, there are still many controversies in this field, such as "sterile womb" versus "in utero colonization." Therefore, a thorough understanding of the roles and mechanisms of gut microbiota in pregnancy and its complications is essential to safeguard the health of both mother and child. This review provides a comprehensive overview of the changes in gut microbiota during pregnancy, its abnormalities in common pregnancy complications, and potential etiological implications. It also explores the potential of gut microbiota in diagnosing and treating pregnancy complications and examines the possibility of gut-derived bacteria residing in the uterus/placenta. Our aim is to expand knowledge in maternal and infant health from the gut microbiota perspective, aiding in developing new preventive and therapeutic strategies for pregnancy complications based on intestinal microecology.

CircMLH3 induces mononuclear macrophage pyroptosis in sepsis by sponging miR-590-3p to regulate TAK1 expression

Sepsis is a fatal syndrome characterized by uncontrolled systemic inflammatory responses. Circular RNAs (circRNAs) are involved in the modulation of various pathophysiological processes, but their potential role in sepsis has largely been unexplored. In this study, we observed differential expression of circMLH3 between healthy volunteers and septic patients, and revealed the value of circMLH3 for sepsis diagnosis and prognostic prediction. Interestingly, we discovered a correlation between the expression level of circMLH3 and the degree of pyroptosis, a critical mechanism contributing to uncontrolled inflammation in sepsis patients. Knocking down circMLH3 alleviated macrophage pyroptosis whereas overexpressing circMLH3 aggravated pyroptosis. circMLH3 regulated macrophage pyroptosis by sponging miR-590-3p and subsequently modulating TAK1 expression. Furthermore, we found that the miR-590-3p/TAK1 axis inhibited the activation of pro-caspase-1 and the NLRP3 inflammasome. miR-590-3p overexpression had a protective effect by reducing macrophage pyroptosis, thereby alleviating sepsis-induced lung injury and systemic inflammatory responses. In conclusion, our study elucidated the circMLH3/miR-590-3p/TAK1 signaling pathway and identified its role in regulating mononuclear macrophage pyroptosis, thus providing potential novel targets and strategies for sepsis diagnosis and therapy.

Propofol improves survival in a murine model of sepsis via inhibiting Rab5a-mediated intracellular trafficking of TLR4

BACKGROUND

Propofol is a widely used anesthetic and sedative, which has been reported to exert an anti-inflammatory effect. TLR4 plays a critical role in coordinating the immuno-inflammatory response during sepsis. Whether propofol can act as an immunomodulator through regulating TLR4 is still unclear. Given its potential as a sepsis therapy, we investigated the mechanisms underlying the immunomodulatory activity of propofol.

METHODS

The effects of propofol on TLR4 and Rab5a (a master regulator involved in intracellular trafficking of immune factors) were investigated in macrophage (from Rab5a-/- and WT mice) following treatment with lipopolysaccharide (LPS) or cecal ligation and puncture (CLP) in vitro and in vivo, and peripheral blood monocyte from sepsis patients and healthy volunteers.

RESULTS

We showed that propofol reduced membrane TLR4 expression on macrophages in vitro and in vivo. Rab5a participated in TLR4 intracellular trafficking and both Rab5a expression and the interaction between Rab5a and TLR4 were inhibited by propofol. We also showed Rab5a upregulation in peripheral blood monocytes of septic patients, accompanied by increased TLR4 expression on the cell surface. Propofol downregulated the expression of Rab5a and TLR4 in these cells.

CONCLUSIONS

We demonstrated that Rab5a regulates intracellular trafficking of TLR4 and that propofol reduces membrane TLR4 expression on macrophages by targeting Rab5a. Our study not only reveals a novel mechanism for the immunomodulatory effect of propofol but also indicates that Rab5a may be a potential therapeutic target against sepsis.

Inflammatory Dietary Potential Is Associated with Vitamin Depletion and Gut Microbial Dysbiosis in Early Pregnancy

Pregnancy alters many physiological systems, including the maternal gut microbiota. Diet is a key regulator of this system and can alter the host immune system to promote inflammation. Multiple perinatal disorders have been associated with inflammation, maternal metabolic alterations, and gut microbial dysbiosis, including gestational diabetes mellitus, pre-eclampsia, preterm birth, and mood disorders. However, the effects of high-inflammatory diets on the gut microbiota during pregnancy have yet to be fully explored. We aimed to address this gap using a system-based approach to characterize associations among dietary inflammatory potential, a measure of diet quality, and the gut microbiome during pregnancy. Forty-seven pregnant persons were recruited prior to 16 weeks of gestation. Participants completed a food frequency questionnaire (FFQ) and provided fecal samples. Dietary inflammatory potential was assessed using the Dietary Inflammatory Index (DII) from the FFQ data. Fecal samples were analyzed using 16S rRNA amplicon sequencing. Differential taxon abundances with respect to the DII score were identified, and the microbial metabolic potential was predicted using PICRUSt2. Inflammatory diets were associated with decreased vitamin and mineral intake and a dysbiotic gut microbiota structure and predicted metabolism. Gut microbial compositional differences revealed a decrease in short-chain fatty acid producers such as Faecalibacterium, and an increase in predicted vitamin B12 synthesis, methylglyoxal detoxification, galactose metabolism, and multidrug efflux systems in pregnant individuals with increased DII scores. Dietary inflammatory potential was associated with a reduction in the consumption of vitamins and minerals and predicted gut microbiota metabolic dysregulation.

Claudin-2 upregulation enhances intestinal permeability, immune activation, dysbiosis, and mortality in sepsis

Intestinal epithelial expression of the tight junction protein claudin-2, which forms paracellular cation and water channels, is precisely regulated during development and in disease. Here, we show that small intestinal epithelial claudin-2 expression is selectively upregulated in septic patients. Similar changes occurred in septic mice, where claudin-2 upregulation coincided with increased flux across the paracellular pore pathway. In order to define the significance of these changes, sepsis was induced in claudin-2 knockout (KO) and wild-type (WT) mice. Sepsis-induced increases in pore pathway permeability were prevented by claudin-2 KO. Moreover, claudin-2 deletion reduced interleukin-17 production and T cell activation and limited intestinal damage. These effects were associated with reduced numbers of neutrophils, macrophages, dendritic cells, and bacteria within the peritoneal fluid of septic claudin-2 KO mice. Most strikingly, claudin-2 deletion dramatically enhanced survival in sepsis. Finally, the microbial changes induced by sepsis were less pathogenic in claudin-2 KO mice as survival of healthy WT mice injected with cecal slurry collected from WT mice 24 h after sepsis was far worse than that of healthy WT mice injected with cecal slurry collected from claudin-2 KO mice 24 h after sepsis. Claudin-2 upregulation and increased pore pathway permeability are, therefore, key intermediates that contribute to development of dysbiosis, intestinal damage, inflammation, ineffective pathogen control, and increased mortality in sepsis. The striking impact of claudin-2 deletion on progression of the lethal cascade activated during sepsis suggests that claudin-2 may be an attractive therapeutic target in septic patients.

Fecal microbiota transplantation alleviates intestinal inflammatory diarrhea caused by oxidative stress and pyroptosis via reducing gut microbiota-derived lipopolysaccharides

Infancy is a critical period in the maturation of the gut microbiota and a phase of susceptibility to gut microbiota dysbiosis. Early disturbances in the gut microbiota can have long-lasting effects on host physiology, including intestinal injury and diarrhea. Fecal microbiota transplantation (FMT) can remodel gut microbiota and may be an effective way to treat infant diarrhea. However, limited research has been conducted on the mechanisms of infant diarrhea and the regulation of gut microbiota balance through FMT, primarily due to ethical challenges in testing on human infants. Our study demonstrated that elevated Lipopolysaccharides (LPS) levels in piglets with diarrhea were associated with colon microbiota dysbiosis induced by early weaning. Additionally, LPS upregulated NLRP3 levels by activating TLR4 and inducing ROS production, resulting in pyroptosis, disruption of the intestinal barrier, bacterial translocation, and subsequent inflammation, ultimately leading to diarrhea in piglets. Through microbiota regulation, FMT modulated β-PBD-2 secretion in the colon by increasing butyric acid levels. This modulation alleviated gut microbiota dysbiosis, reduced LPS levels, attenuated oxidative stress and pyroptosis, inhibited the inflammatory response, maintained the integrity of the intestinal barrier, and ultimately reduced diarrhea in piglets caused by colitis. These findings present a novel perspective on the pathogenesis, pathophysiology, prevention, and treatment of diarrhea diseases, underscoring the significance of the interaction between FMT and the gut microbiota as a critical strategy for treating diarrhea and intestinal diseases in infants and farm animals.

Gut microbiota and its metabolic products in acute respiratory distress syndrome

The prevalence rate of acute respiratory distress syndrome (ARDS) is estimated at approximately 10% in critically ill patients worldwide, with the mortality rate ranging from 17% to 39%. Currently, ARDS mortality is usually higher in patients with COVID-19, giving another challenge for ARDS treatment. However, the treatment efficacy for ARDS is far from satisfactory. The relationship between the gut microbiota and ARDS has been substantiated by relevant scientific studies. ARDS not only changes the distribution of gut microbiota, but also influences intestinal mucosal barrier through the alteration of gut microbiota. The modulation of gut microbiota can impact the onset and progression of ARDS by triggering dysfunctions in inflammatory response and immune cells, oxidative stress, cell apoptosis, autophagy, pyroptosis, and ferroptosis mechanisms. Meanwhile, ARDS may also influence the distribution of metabolic products of gut microbiota. In this review, we focus on the impact of ARDS on gut microbiota and how the alteration of gut microbiota further influences the immune function, cellular functions and related signaling pathways during ARDS. The roles of gut microbiota-derived metabolites in the development and occurrence of ARDS are also discussed.

Isofraxidin attenuates dextran sulfate sodium-induced ulcerative colitis through inhibiting pyroptosis by upregulating Nrf2 and reducing reactive oxidative species

BACKGROUND

Ulcerative colitis (UC), a non-specific gastrointestinal disease, is commonly managed with aminosalicylic acids and immunosuppressive agents to control inflammation and relieve symptoms, despite frequent relapses. Isofraxidin is a coumarin compound extracted from traditional Chinese medicine, exhibiting anti-inflammatory and antioxidant properties; however, its alleviating effect on UC remains unclear. Therefore, we investigated the mechanism of isofraxidin in lipopolysaccharide (LPS)-induced cell inflammation in human intestinal epithelial cell (HIEC) and human colorectal adenocarcinoma cells (Caco-2), as well as in dextran sulfate sodium (DSS)-induced UC in mice.

METHODS

We established colitis models in HIEC and Caco-2 cells and mice with LPS and DSS, respectively. Additionally, NLRP3 knockout mice and HIEC cells transfected with NLRP3 silencing gene and ML385 illustrated the role of isofraxidin in pyroptosis and oxidative stress. Data from cells and mice analyses were subjected to one-way analysis of variance or a paired t-test.

RESULTS

Isofraxidin significantly alleviated LPS-induced cell inflammation and reduced lactic dehydrogenase release. Isofraxidin also reversed DSS- or LPS-induced pyroptosis in vivo and in vitro, increasing the expression of pyroptosis-related proteins. Moreover, isofraxidin alleviated oxidative stress induced by DSS or LPS, reducing reactive oxidative species (ROS), upregulation nuclear factor erythroid 2-related factor 2 (Nrf2), and promoting its entry into the nucleus. Mechanistically, ML385 reversed the inhibitory effect of isofraxidin on ROS and increased pyroptosis.

CONCLUSION

Isofraxidin can inhibit pyroptosis through upregulating Nrf2, promoting its entry into the nucleus, and reducing ROS, thereby alleviating DSS-induced UC. Our results suggest isofraxidin as a promising therapeutic strategy for UC treatment.

The role of gut microbiota in intestinal disease: from an oxidative stress perspective

Recent studies have indicated that gut microbiota-mediated oxidative stress is significantly associated with intestinal diseases such as colorectal cancer, ulcerative colitis, and Crohn's disease. The level of reactive oxygen species (ROS) has been reported to increase when the gut microbiota is dysregulated, especially when several gut bacterial metabolites are present. Although healthy gut microbiota plays a vital role in defending against excessive oxidative stress, intestinal disease is significantly influenced by excessive ROS, and this process is controlled by gut microbiota-mediated immunological responses, DNA damage, and intestinal inflammation. In this review, we discuss the relationship between gut microbiota and intestinal disease from an oxidative stress perspective. In addition, we also provide a summary of the most recent therapeutic approaches for preventing or treating intestinal diseases by modifying gut microbiota.

Inflammatory dietary potential is associated with vitamin depletion and gut microbial dysbiosis in early pregnancy

Background

Pregnancy alters many physiological systems, including the maternal gut microbiota. Diet is a key regulator of this system and can alter the host immune system to promote inflammation. Multiple perinatal disorders have been associated with inflammation, maternal metabolic alterations, and gut microbial dysbiosis, including gestational diabetes mellitus, preeclampsia, preterm birth, and mood disorders. However, the effects of high inflammatory diets on the gut microbiota during pregnancy have yet to be fully explored.

Objective

To use a systems-based approach to characterize associations among dietary inflammatory potential, a measure of diet quality, and the gut microbiome during pregnancy.

Methods

Forty-nine pregnant persons were recruited prior to 16 weeks of gestation. Participants completed a food frequency questionnaire (FFQ) and provided fecal samples. Dietary inflammatory potential was assessed using the Dietary Inflammatory Index (DII) from FFQ data. Fecal samples were analyzed using 16S rRNA amplicon sequencing. Differential taxon abundance with respect to DII score were identified, and microbial metabolic potential was predicted using PICRUSt2.

Results

Inflammatory diets were associated with decreased vitamin and mineral intake and dysbiotic gut microbiota structure and predicted metabolism. Gut microbial compositional differences revealed a decrease in short chain fatty acid producers such as Faecalibacterium, and an increase in predicted vitamin B12 synthesis, methylglyoxal detoxification, galactose metabolism and multi drug efflux systems in pregnant individuals with increased DII scores.

Conclusions

Dietary inflammatory potential was associated with a reduction in the consumption of vitamins & minerals and predicted gut microbiota metabolic dysregulation.

MAGNESIUM SULFATE AMELIORATES HISTONE-INDUCED COAGULATION DYSFUNCTION AND LUNG DAMAGE IN MICE

ABSTRACT

Introduction: Extracellular histones have been determined as significant mediators of sepsis, which can induce endothelial cell injury and promote coagulation activation, and ultimately contribute to multiorgan failure. Evidence suggests that magnesium sulfate (MgSO 4 ) exerts a potential coagulation-modulating activity; however, whether MgSO 4 ameliorates histone-induced coagulation dysfunction and organ damage remains unclear. Methods: To measure circulating histone levels, blood specimens were collected from septic patients and mice, and the relationship between circulating histone levels, coagulation parameters, and Mg 2+ levels in sepsis was investigated. Furthermore, to explore the possible protective effects of MgSO 4 , we established a histone-induced coagulation model in mice by intravenous histone injection. The survival rate of mice was assessed, and the histopathological damage of the lungs (including endothelial cell injury and coagulation status) was evaluated using various methods, including hematoxylin and eosin staining, immunohistochemistry, immunofluorescence, electron microscopy, and quantitative polymerase chain reaction. Results: The circulating histone levels in septic patients and mice were significantly associated with several coagulation parameters. In septic patients, histone levels correlated negatively with platelet counts and positively with prothrombin time and D-dimer levels. Similarly, in cecal ligation and puncture mice, histones correlated negatively with platelet counts and positively with D-dimer levels. Interestingly, we also observed a positive link between histones and Mg 2+ levels, suggesting that Mg 2+ with anticoagulant activity is involved in histone-mediated coagulation alterations in sepsis. Further animal experiments confirmed that MgSO 4 administration significantly improved survival and attenuated histone-mediated endothelial cell injury, coagulation dysfunction, and lung damage in mice. Conclusion: These results suggest that therapeutic targeting of histone-mediated endothelial cell injury, coagulation dysfunction, and lung damage, for example, with MgSO 4 , may be protective in septic individuals with elevated circulating histone levels.