Neutralization of IL-1α ameliorates Crohn's disease-like ileitis by functional alterations of the gut microbiome

Lactiplantibacillus argentoratensis AGMB00912 protects weaning mice from ETEC infection and enhances gut health

Maintaining a healthy intestinal environment, optimal epithelial barrier integrity, and balanced gut microbiota composition are essential for the growth performance of weaning pigs. We identified Lactiplantibacillus argentoratensis AGMB00912 (LA) in healthy porcine feces as having antimicrobial activity against pathogens and enhanced short-chain fatty acid (SCFA) production. Herein, we assess the protective role of LA using a weaning mouse model with enterotoxigenic Escherichia coli (ETEC) infection. LA treatment improves feed intake and weight gain and alleviates colon shortening. Furthermore, LA inhibits intestinal damage, increases the small intestine villus height compared with the ETEC group, and enhances SCFA production. Using the Kyoto Encyclopedia of Genes and Genomes and other bioinformatic tools, including InterProScan and COGNIZER, we validated the presence of SCFA-producing pathways of LA and Lactiplantibacillus after whole genome sequencing. LA mitigates ETEC-induced shifts in the gut microbiota, decreasing the proportion of Escherichia and Enterococcus and increasing SCFA-producing bacteria, including Kineothrix, Lachnoclostridium, Roseuburia, Lacrimispora, Jutongia, and Blautia. Metabolic functional prediction analysis revealed enhanced functions linked to carbohydrate, amino acid, and vitamin biosynthesis, along with decreased functions associated with infectious bacterial diseases compared to the ETEC group. LA mitigates the adverse effects of ETEC infection in weaning mice, enhances growth performance and intestinal integrity, rebalances gut microbiota, and promotes beneficial metabolic functions. These findings validate the functionality of LA in a small animal model, supporting its potential application in improving the health and growth performance of weaning pigs.

Anti-Inflammatory Effect of Dietary Pentadecanoic Fatty Acid Supplementation on Inflammatory Bowel Disease in SAMP1/YitFc Mice

BACKGROUND/OBJECTIVES

Dietary fats have been linked to the increasing incidence of chronic diseases, including inflammatory bowel diseases (IBD), namely, Crohn's disease (CD).

METHODS

This study investigated the impact of pentadecanoic acid (C15:0), a type of an odd-numbered chain saturated fatty acid, for its potential anti-inflammatory properties in different mouse models of experimental IBD using the SAMP1/YitFc (SAMP) mouse line (14- or 24-week-old), including chronic ileitis and DSS-induced colitis. To quantitively assess the effect of C:15, we tested two dosages of C:15 in selected experiments in comparison to control mice. Intestinal inflammation and intestinal permeability were used as primary outcomes.

RESULTS

In ileitis, C:15 supplementation showed an anti-inflammatory effect in SAMP mice (e.g., a reduction in ileitis severity vs. control p < 0.0043), which was reproducible when mice were tested in the DSS model of colitis (e.g., reduced permeability vs. control p < 0.0006). Of relevance, even the short-term C:15 therapy prevented colitis in mice by maintaining body weight, decreasing inflammation, preserving gut integrity, and alleviating colitis signs.

CONCLUSIONS

Collectively, the findings from both ileitis and colitis in SAMP mice indicate that C:15 may have therapeutic effects in the treatment of IBD (colitis in the short term). This promising effect has major translational potential for the alleviation of IBD in humans.

Interleukin-1 family cytokines at the crossroads of microbiome regulation in barrier health and disease

Recent advances in understanding how the microbiome can influence both the physiology and the pathogenesis of disease in humans have highlighted the importance of gaining a deeper insight into the complexities of the host-microbial dialogue. In tandem with this progress, has been a greater understanding of the biological pathways which regulate both homeostasis and inflammation at barrier tissue sites, such as the skin and the gut. In this regard, the Interleukin-1 family of cytokines, which can be segregated into IL-1, IL-18 and IL-36 subfamilies, have emerged as important custodians of barrier health and immunity. With established roles as orchestrators of various inflammatory diseases in both the skin and intestine, it is now becoming clear that IL-1 family cytokine activity is not only directly influenced by external microbes, but can also play important roles in shaping the composition of the microbiome at barrier sites. This review explores the current knowledge surrounding the evidence that places these cytokines as key mediators at the interface between the microbiome and human health and disease at the skin and intestinal barrier tissues.

Clonal Parabacteroides from Gut Microfistulous Tracts as Transmissible Cytotoxic Succinate-Commensal Model of Crohn's Disease Complications

Crohn's disease (CD) has been traditionally viewed as a chronic inflammatory disease that cause gut wall thickening and complications, including fistulas, by mechanisms not understood. By focusing on Parabacteroides distasonis (presumed modern succinate-producing commensal probiotic), recovered from intestinal microfistulous tracts (cavernous fistulous micropathologies CavFT proposed as intermediate between 'mucosal fissures' and 'fistulas') in two patients that required surgery to remove CD-damaged ilea, we demonstrate that such isolates exert pathogenic/pathobiont roles in mouse models of CD. Our isolates are clonally-related; potentially emerging as transmissible in the community and mice; proinflammatory and adapted to the ileum of germ-free mice prone to CD-like ileitis (SAMP1/YitFc) but not healthy mice (C57BL/6J), and cytotoxic/ATP-depleting to HoxB8-immortalized bone marrow derived myeloid cells from SAMP1/YitFc mice when concurrently exposed to succinate and extracts from CavFT-derived E. coli , but not to cells from healthy mice. With unique genomic features supporting recent genetic exchange with Bacteroides fragilis -BGF539, evidence of international presence in primarily human metagenome databases, these CavFT Pdis isolates could represent to a new opportunistic Parabacteroides species, or subspecies (' cavitamuralis' ) adapted to microfistulous niches in CD.

Fusobacterium nucleatum infection activates the noncanonical inflammasome and exacerbates inflammatory response in DSS-induced colitis

Caspase activation results in pyroptosis, an inflammatory cell death that contributes to several inflammatory diseases by releasing inflammatory cytokines and cellular contents. Fusobacterium nucleatum is a periodontal pathogen frequently detected in human cancer and inflammatory bowel diseases. Studies have reported that F. nucleatum infection leads to NLRP3 activation and pyroptosis, but the precise activation process and disease association remain poorly understood. This study demonstrated that F. nucleatum infection exacerbates acute colitis in mice and activates pyroptosis through caspase-11-mediated gasdermin D cleavage in macrophages. Furthermore, F. nucleatum infection in colitis mice induces the enhancement of IL-1⍺ secretion from the colon, affecting weight loss and severe disease activities. Neutralization of IL-1⍺ protects F. nucleatum infected mice from severe colitis. Therefore, F. nucleatum infection facilitates inflammation in acute colitis with IL-1⍺ from colon tissue by activating noncanonical inflammasome through gasdermin D cleavage.

Discovery of indole analogues from Periplaneta americana extract and their activities on cell proliferation and recovery of ulcerative colitis in mice

Background: As an important medicinal insect, Periplaneta americana (PA) has been applied for the treatment of wounds, burns, and ulcers with fewer side effects and a reduced recurrence rate, which provides great potential for developing new drugs based on its active constituents. Materials and methods: The main chromatographic peaks determined by high performance liquid chromatography (HPLC) in the PA concentrated ethanol-extract liquid (PACEL) were separated, purified, and identified by semi-preparative LC, mass spectrum, and 1H NMR spectroscopic analysis. The biological activities of the identified compounds were investigated by methylthiazolyldiphenyl-tetrazolium bromide (MTT) method based on in vitro human skin fibroblasts (HSF) and in vivo experiments based on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mouse model. Furthermore, RT-qPCR of six genes related to inflammation or intestinal epithelial cell proliferation was employed to investigate the molecular mechanism of the indole analogues recovering UC in mice. Results: Five indole analogues were purified and identified from PACEL, including tryptophan (Trp), tryptamine (pa01), 1,2,3,4-tetrahydrogen-β-carboline-3-carboxylic acid (pa02), (1S, 3S)-1-methyl-1,2,3,4-tetrahydrogen-β-carboline-3-carboxylic acid (pa03), and (1R, 3S)-1-methyl-1,2,3,4-tetrahydrogen-β-carboline-3-carboxylic acid (pa04), among which the pa02 and pa04 were reported in PA for the first time. In vitro and in vivo experiments showed that PACEL, Trp, and pa02 had promoting HSF proliferation activity and intragastric administration of them could alleviate symptoms of weight loss and colon length shortening in the UC mice. Although recovery activity of the compound pa01 on the colon length was not as obvious as other compounds, it showed anti-inflammatory activity in histological analysis. In addition, The RT-qPCR results indicated that the three indole analogues could alleviate DSS-induced intestinal inflammation in mice by inhibiting pro-inflammatory cytokines (MMP7, IL1α) and down-regulating BMP8B expression. Conclusion: This study reported the isolation, purification, structure identification, and biological activity of the active indole analogues in PACEL. It was found for the first time that the PA extract contained many indole analogues and Trp, which exhibited good proliferation activity on HSF fibroblasts as well as anti-UC activity in mice. These indole analogues probably are important components related to the pharmacological activity in PA.

IEC-intrinsic IL-1R signaling holds dual roles in regulating intestinal homeostasis and inflammation

Intestinal epithelial cells (IECs) constitute a critical first line of defense against microbes. While IECs are known to respond to various microbial signals, the precise upstream cues regulating diverse IEC responses are not clear. Here, we discover a dual role for IEC-intrinsic interleukin-1 receptor (IL-1R) signaling in regulating intestinal homeostasis and inflammation. Absence of IL-1R in epithelial cells abrogates a homeostatic antimicrobial program including production of antimicrobial peptides (AMPs). Mice deficient for IEC-intrinsic IL-1R are unable to clear Citrobacter rodentium (C. rodentium) but are protected from DSS-induced colitis. Mechanistically, IL-1R signaling enhances IL-22R-induced signal transducer and activator of transcription 3 (STAT3) phosphorylation in IECs leading to elevated production of AMPs. IL-1R signaling in IECs also directly induces expression of chemokines as well as genes involved in the production of reactive oxygen species. Our findings establish a protective role for IEC-intrinsic IL-1R signaling in combating infections but a detrimental role during colitis induced by epithelial damage.

EFFECT OF ABDOMINAL IRRADIATION IN MICE MODEL OF INFLAMMATORY BOWEL DISEASE

Inflammatory bowel diseases could be diagnosed in major measure by diagnostic imaging; however, radiation exposure in the intestine may also contribute to the progression of these pathologies. To better understand the impact of radiation in the presence of bowel disease, we administered dextran sodium sulfate (DSS) to C57BL/6 mice to induce colitis and exposed to radiation at abdominal area. We observed that abdominal irradiation (13 Gy) aggravates the DSS-induced decrease in survival rate (0%), body weight (74.54 ± 3.59%) and colon length (4.98 ± 0.14 cm). Additionally, abdominal irradiation markedly increased in colonic inflammation levels (3.16 ± 0.16) compared with that of DSS-induced sham mice. Furthermore, abdominal irradiation also increased the mRNA expression levels of inflammatory genes, such as cyclooxygenase-2 (13.10 folds), interleukin-6 (48.83 folds) and tumor necrosis factor-alpha (42.97 folds). We conclude that abdominal irradiation aggravates the detrimental effects of DSS-induced colitis in mice, which might be a useful guideline for inflammatory bowel disease patients.

Lactobacillus salivarius WZ1 Inhibits the Inflammatory Injury of Mouse Jejunum Caused by Enterotoxigenic Escherichia coli K88 by Regulating the TLR4/NF-κB/MyD88 Inflammatory Pathway and Gut Microbiota

Replacing antibiotics with probiotics has become an important way to safely and effectively prevent and treat some gastrointestinal diseases. This study was conducted to investigate whether Lactobacillus salivarius WZ1 (L.S) could reduce the inflammatory injury to the mouse jejunum induced by Escherichia coli (ETEC) K88. Forty Kunming mice were randomly divided into four groups with 10 mice in each group. From day 1 to day 14, the control group and the E. coli group were administered with normal saline each day, while the L.S group and the L.S + E. coli group were gavaged with Lactobacillus salivarius WZ1 1 × 108 CFU/mL each day. On the 15th day, the E. coli group and the L.S + E. coli group were intragastrically administered ETEC K88 1 × 109 CFU/mL and sacrificed 24 h later. Our results show that pretreatment with Lactobacillus salivarius WZ1 can dramatically protect the jejunum morphological structure from the changes caused by ETEC K88 and relieve the morphological lesions of the jejunum, inhibiting changes in the mRNA expressions of TNF-α, IL-1β and IL-6 and the protein expressions of TLR4, NF-κB and MyD88 in the intestinal tissue of mice caused by ETEC K88. Moreover, pretreatment with Lactobacillus salivarius WZ1 also increased the relative abundance of beneficial genera such as Lactobacillus and Bifidobacterium and decreased the abundance of harmful genera such as Ralstonia and Helicobacter in the gut. These results demonstrate that Lactobacillus salivarius WZ1 can inhibit the inflammatory damage caused by ETEC K88 in mouse jejunum by regulating the TLR4/NF-κB/MyD88 inflammatory pathway and gut microbiota.

Dietary Intake and Systemic Inflammation: Can We Use Food as Medicine?

PURPOSE OF REVIEW

This review summarizes the current literature regarding the association between diet and systemic inflammation.

RECENT FINDINGS

Data in humans suggests that consumption of plant-based nutrients is associated with a reduction in systemic inflammation, while consumption of red meat and excessive dairy has the opposite effect and may increase risk of acute flares in those that suffer from certain chronic diseases like inflammatory bowel disease or psoriasis and certain cancers. There is a known association between diet and systemic inflammation; thus, we recommend that clinicians discuss plant-based, whole food diets with patients, particularly those that suffer from chronic inflammatory diseases as an adjunct treatment for these conditions. Future research should evaluate whether adherence to these types of diets is sustainable in the long term and how these changes affect important quality of life concerns.

The Cytokine Network in Colorectal Cancer: Implications for New Treatment Strategies

Colorectal cancer (CRC) is one of the most frequent tumor entities worldwide with only limited therapeutic options. CRC is not only a genetic disease with several mutations in specific oncogenes and/or tumor suppressor genes such as APC, KRAS, PIC3CA, BRAF, SMAD4 or TP53 but also a multifactorial disease including environmental factors. Cancer cells communicate with their environment mostly via soluble factors such as cytokines, chemokines or growth factors to generate a favorable tumor microenvironment (TME). The TME, a heterogeneous population of differentiated and progenitor cells, plays a critical role in regulating tumor development, growth, invasion, metastasis and therapy resistance. In this context, cytokines from cancer cells and cells of the TME influence each other, eliciting an inflammatory milieu that can either enhance or suppress tumor growth and metastasis. Additionally, several lines of evidence exist that the composition of the microbiota regulates inflammatory processes, controlled by cytokine secretion, that play a role in carcinogenesis and tumor progression. In this review, we discuss the cytokine networks between cancer cells and the TME and microbiome in colorectal cancer and the related treatment strategies, with the goal to discuss cytokine-mediated strategies that could overcome the common therapeutic resistance of CRC tumors.

Electrolyzed Hydrogen Water Alleviates Abdominal Pain through Suppression of Colonic Tissue Inflammation in a Rat Model of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the digestive tract and is typically accompanied by characteristic symptoms, such as abdominal pain, diarrhea, and bloody stool, severely deteriorating the quality of the patient's life. Electrolyzed hydrogen water (EHW) has been shown to alleviate inflammation in several diseases, such as renal disease and polymyositis/dermatomyositis. To investigate whether and how daily EHW consumption alleviates abdominal pain, the most common symptom of IBD, we examined the antioxidative and anti-inflammatory effects of EHW in an IBD rat model, wherein colonic inflammation was induced by colorectal administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS). We found that EHW significantly alleviated TNBS-induced abdominal pain and tissue inflammation. Moreover, the production of proinflammatory cytokines in inflamed colon tissue was also decreased significantly. Meanwhile, the overproduction of reactive oxygen species (ROS), which is intricately involved in intestinal inflammation, was significantly suppressed by EHW. Additionally, expression of S100A9, an inflammatory biomarker of IBD, was significantly suppressed by EHW. These results suggest that the EHW prevented the overproduction of ROS due to its powerful free-radical scavenging ability and blocked the crosstalk between oxidative stress and inflammation, thereby suppressing colonic inflammation and alleviating abdominal pain.

Huoxiang Zhengqi alleviates azoxymethane/dextran sulfate sodium-induced colitis-associated cancer by regulating Nrf2/NF-κB/NLRP3 signaling

Colitis-associated cancer (CAC) is a subtype of inflammatory bowel disease (IBD)-associated colorectal cancer. Huoxiang Zhengqi (HXZQ) is a classical Chinese herbal medicine and has been used to treat intestinal disorders, however, anti-CAC effects and underlying mechanisms of HXZQ have not been reported. An azoxymethane/dextran sulfate sodium-induced CAC mice model was used to investigate the anti-CAC effect of HXZQ. HXZQ significantly reduced colonic inflammation, suppressed the size and number of tumors, and reduced the levels of pro-inflammatory cytokines (interleukin [IL]-1α, IL-1β, IL-6, IL-17A, IL-21, IL-23, granulocyte macrophage-colony stimulating factor, and tumor necrosis factor-α) and oxidative stress markers (reactive oxygen species and malondialdehyde), and increased the levels of anti-inflammatory cytokines (IL-10 and IL-27) in CAC mice. Intestinal microbiota and serum metabolomics analyses indicated that HXZQ altered the gut microbial composition and the abundance of 29 serum metabolites in CAC mice. Additionally, HXZQ activated the nuclear factor-erythroid factor 2-related factor 2 (Nrf2) signaling pathway and increased the levels of antioxidants such as catalase (CAT), heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductases-1 (NQO-1), and superoxide dismutase-1 (SOD-1). HXZQ inhibited the activation of the nuclear factor kappa-B (NF-κB) signaling pathway and decreased the expression of NLR family pyrin domain containing 3 (NLRP3) by inhibiting the phosphorylation of inhibitor of nuclear factor kappa-B (IκB), inhibitor of nuclear factor kappa-B kinase (IKK), and NF-κB. In conclusion, HXZQ alleviated CAC in mice by modulating the intestinal microbiota and metabolism, activating Nrf2-mediated antioxidant response, and inhibiting NF-κB-mediated NLRP3 inflammasome activation against inflammation. The present data provide a reference for the use of HXZQ as a therapeutic or combination agent for clinical CAC treatment.

Changes of gut microbiota structure in rats infected with Toxoplasma gondii

Toxoplasma gondii (T. gondii) infection can cause intestinal inflammation in rodents and significantly alters the structure of gut microbiota. However, the effects of different T. gondii genotypes on the gut microbiota of rats remain unclear. In this study, acute and chronic T. gondii infection in Fischer 344 rats was induced artificially by intraperitoneal injection of tachyzoites PYS (Chinese 1 ToxoDB#9) and PRU (Type II). Fecal 16S rRNA gene amplicon sequencing was employed to analyze the gut microbiota structure at different stages of infection, and to compare the effects of infection by two T. gondii genotypes. Our results suggested that the infection led to structural changes of gut microbiota in rats. At the acute infection stage, the microbiota diversity increased, while both diversity and abundance of beneficial bacteria decreased at the chronic infection stage. The differences of microbiota structure were caused by strains of different genotypes. However, the diversity changes were consistent. This study demonstrates that the gut microbiota plays an important role in T. gondii infection in rats. The data will improve our understanding of the association between T. gondii infection and gut microbiota in rodents.

Immune suppressive function of IL-1α release in the tumor microenvironment regulated by calpain 1

Interleukin-1α (IL-1α) plays an important role in inflammation and hematopoiesis. Many tumors have increased IL-1α expression. However, the immune regulatory role of secreted IL-1α in tumor development and whether it can be targeted for cancer therapy are still unclear. Here, we found that tumoral-secreted IL-1α significantly promoted hepatocellular carcinoma (HCC) development in vivo. Tumoral-released IL-1α were found to inhibit T and NK cell activation, and the killing capacity of CD8⁺ T cells. Moreover, MDSCs were dramatically increased by tumoral-released IL-1α in both spleens and tumors. Indeed, higher tumoral IL-1α expression is associated with increased tumoral infiltration of MDSCs in HCC patients. Further studies showed that tumoral-released IL-1α promoted MDSC recruitment to the tumor microenvironment through a CXCR2-dependent mechanism. Depletion of MDSCs could diminish the tumor-promoting effect of tumoral-released IL-1α. On the contrary, systemic administration of recombinant IL-1α protein significantly inhibited tumor development by activating T cells. In fact, IL-1α protein could promote T cell activation and enhance the cytotoxicity of CD8⁺ T cells in vitro. Thus, our study demonstrated that tumoral-released IL-1α promoted tumor development through recruiting MDSCs to inhibit T cell activation, while systemic IL-1α directly promoted anti-tumor T cell responses. We further identified calpain 1 as the major intracellular protease mediating tumoral IL-1α secretion. Calpain 1 KO tumors had diminished IL-1α release and reduced tumor development. Thus, our findings provide new insights into the functions of secreted IL-1α in tumor immunity and its implications for immunotherapy.

Intestinal inflammation alters the antigen-specific immune response to a skin commensal

Resident microbes in skin and gut predominantly impact local immune cell function during homeostasis. However, colitis-associated neutrophilic skin disorders suggest possible breakdown of this compartmentalization with disease. Using a model wherein neonatal skin colonization by Staphylococcus epidermidis facilitates generation of commensal-specific tolerance and CD4⁺ regulatory T cells (Tregs), we ask whether this response is perturbed by gut inflammation. Chemically induced colitis is accompanied by intestinal expansion of S. epidermidis and reduces gut-draining lymph node (dLN) commensal-specific Tregs. It also results in reduced commensal-specific Tregs in skin and skin-dLNs and increased skin neutrophils. Increased CD4⁺ circulation between gut and skin dLN suggests that the altered cutaneous response is initiated in the colon, and resistance to colitis-induced effects in Cd4^creIl1r1^fl/fl mice implicate interleukin (IL)-1 in mediating the altered commensal-specific response. These findings provide mechanistic insight into observed connections between inflammatory skin and intestinal diseases.

Gut microbiota composition does not associate with Toxoplasma infection in rats

Toxoplasma infection in intermediate host species closely associates with inflammation. This association has led to suggestions that the behavioural changes associated with infection may be indirectly driven by the resulting sustained inflammation rather than a direct behavioural manipulation by the parasite. If this is correct, sustained inflammation in chronically infected rodents should present as widespread differences in the gastrointestinal microbiota due to the dependency between the composition of these microbiota and sustained inflammation. We conducted a randomized controlled experiment in rats that were assigned to a Toxoplasma‐treatment, placebo‐treatment or negative control group. We euthanised rats during the chronic phase of infection, collected their caecal stool samples and sequenced the V3‐V4 region of the 16S rRNA gene to characterize the bacterial community in these samples. Toxoplasma infection did not induce widespread differences in the bacterial community composition of the gastrointestinal tract of rats. Rather, we found sex differences in the bacterial community composition of rats. We conclude that it is unlikely that sustained inflammation is the mechanism driving the highly specific behavioural changes observed in Toxoplasma‐positive rats.

IL-38 Gene Deletion Worsens Murine Colitis

IL-38 is a recently discovered cytokine and member of the IL-1 Family. In the IL-1 Family, IL-38 is unique because the cytokine is primarily a B lymphocyte product and functions to suppress inflammation. Studies in humans with inflammatory bowel disease (IBD) suggest that IL-38 may be protective for ulcerative colitis or Crohn’s disease, and that IL-38 acts to maintain homeostasis in the intestinal tract. Here we investigated the role of endogenous IL-38 in experimental colitis in mice deficient in IL-38 by deletion of exons 1-4 in C57 BL/6 mice. Compared to WT mice, IL-38 deficient mice subjected to dextran sulfate sodium (DSS) showed greater severity of disease, more weight loss, increased intestinal permeability, and a worse histological phenotype including increased neutrophil influx in the colon. Mice lacking IL-38 exhibited elevated colonic Nlrp3 mRNA and protein levels, increased caspase-1 activation, and the concomitant increased processing of IL-1β precursor into active IL-1β. Expression of IL-1α, an exacerbator of IBD, was also upregulated. Colonic myleloperoxidase protein and Il17a, and Il17f mRNA levels were higher in the IL-38 deficient mice. Daily treatment of IL-38 deficient mice with an NLRP3 inhibitor attenuated diarrhea and weight loss during the recovery phase. These data implicate endogenous IL-38 as an anti-inflammatory cytokine that reduces DSS colitis severity. We propose that a relative deficiency of IL-38 contributes to IBD by disinhibition of the NLRP3 inflammasome.

Protective Effects of a Novel Probiotic Bifidobacterium pseudolongum on the Intestinal Barrier of Colitis Mice via Modulating the Pparγ/STAT3 Pathway and Intestinal Microbiota

Colitis has become a major health concern worldwide. The objective of the present study was to determine the probiotic influence of different strains of B. pseudolongum (Bp7 and Bp8) on alleviating colitis and to explore its possible potential mechanisms. Our results displayed that Bp7 and Bp8 intervention effectively reduced dextran sodium sulfate (DSS)-caused body weight loss and the release of several pro-inflammatory factors (interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α)) and increased the activities of antioxidant enzymes (T-AOC, SOD, and GSH) and the concentrations of tight junction proteins (occludin, claudin-1, and ZO-1). Moreover, Bp7 and Bp8 intervention drastically down-regulated the expression of colonic MyD88, NF-κB, iNOS and COX2 and drastically elevated the expression of colonic STAT3, Nrf2, and PPARγ. Gas chromatography-mass spectrometry results revealed that the cecal levels of isobutyric, butyric, and isovaleric acids were drastically increased in colitis mice intervened with Bp7 and Bp8. Moreover, 16S rRNA sequencing revealed that Bp7 and Bp8 intervention modulated the intestinal microbiota structure, particularly by enhancing the proportion of Eubacterium coprostanoligenes group, Marvinbryantia, Enterorhabdus, Faecalibaculum, Coriobacteriaceae UCG 002, Alistipes, and Bifidobacterium, which are relevant to the levels of cecal isobutyric acid, butyric acid, isovaleric acid, and inflammatory cytokines. Collectively, these findings suggest that Bp7 and Bp8 intervention alleviates the intestinal barrier function, possibly by blocking the secretion of proinflammatory cytokines, maintaining the intestinal physical barrier integrity, activating the PPARγ/STAT3 pathway, and modulating intestinal microbiota composition. Our study also suggested that B. pseudolongum is a promising probiotic for colitis treatment.

Sweeteners Maintain Epithelial Barrier Function Through the miR-15b/RECK/MMP-9 Axis, Remodel Microbial Homeostasis, and Attenuate Dextran Sodium Sulfate-Induced Colitis in Mice

Non-nutritive sweeteners are the most widely used food additives designed to provide sweetness and reduce caloric intake. Studies have confirmed a link between sweeteners and colitis, yet supporting scientific data remain exiguous and controversial. In this study, three common sweeteners (Saccharin sodium, Stevioside, and Sucralose) in acceptable daily intake dosage were added to water in order to determine their effects on dextran sodium sulfate-induced colitis in mice. Our results show that the three sweeteners meliorate colitis to varying degrees─Saccharin exerts the most pronounced effect, followed by Stevioside and Sucralose. Intake of sweeteners alleviates colitis symptoms, alters gut microbiota, reshapes the TH17/Treg balance, protects the intestinal barrier, and reduces inflammation. Most significantly, sweeteners can enhance the abundance of Mucispirillum and Alistipes, which are conducive to colitis recovery, and upregulate the expression of E-cadherin through the miR-15b/RECK/MMP-9 axis to improve intestinal barrier integrity. Moreover, by inhibiting the MMP-9/AKT/NF-κB pathway, inflammation is relieved, as reflected in the restoration of the Th17/Treg balance. Our results link the consumption of sweeteners to the remission of colitis, which provides new scientific evidence for the safe use of sweeteners.

Harnessing murine models of Crohn's disease ileitis to advance concepts of pathophysiology and treatment

Crohn's disease (CD) and ulcerative colitis (UC) are both characterized by chronic inflammation and severe dysfunction of the gastrointestinal tract. These two forms of inflammatory bowel disease (IBD) represent distinct clinical disorders with diverse driving mechanisms; however, this divergence is not reflected in currently approved therapeutics that commonly target general proinflammatory pathways. A compelling need therefore remains to understand factors that differentiate the topology and the distinct clinical manifestations of CD versus UC, in order to develop more effective and specialized therapies. Animal models provide valuable platforms for studying IBD heterogeneity and deciphering disease-specific mechanisms. Both the established and the newly developed ileitis mouse models are characterized by various disease initiating mechanisms and diverse phenotypic outcomes that reflect the complexity of human CD-ileitis. Microbial dysbiosis, destruction of epithelial barrier integrity, immune cell deregulation, as well as the recently described genome instability and stromal cell activation have all been proposed as the triggering factors for the development of ileitis-associated pathology. In this review, we aim to critically evaluate the mechanistic underpinnings of murine models of CD-ileitis, discuss their phenotypic similarities to human disease, and envisage their further exploitation for the development of novel targeted and personalized therapeutics.

Ketogenic diet aggravates colitis, impairs intestinal barrier and alters gut microbiota and metabolism in DSS-induced mice

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disease with a high incidence. Multiple factors including dietary composition contribute to its occurrence. Recently, ketogenic diet which consists of a high proportion of fat and low carbohydrates has gained great popularity. Our study is aimed to explore the effect of ketogenic diet on IBD and its potential mechanisms. C57BL/6 mice were given a ketogenic diet or a control diet for a month and IBD was induced by 2% DSS in drinking water in the last week. Gut histology, inflammatory cytokines and chemokines, gut microbiota and metabolism were assessed. Ketogenic diet substantially worsened colitis, in terms of higher body weight loss, DAI scores and histological scores as well as colon length shortening. Levels of serum and colon inflammatory cytokines and chemokines (IL-1α, IL-6, TNF-α, IL-17, GM-CSF and IL-10) were significantly up-regulated in mice treated with ketogenic diet and DSS. Increased intestinal permeability and decreased expressions of intestinal epithelial barrier associated genes were observed due to ketogenic diet administration. Pretreatment with ketogenic diet alters the bacterial abundance, increasing pathogenic taxa such as Proteobacteria, Enterobacteriaceae, Helicobacter and Escherichia-Shigella and decreasing potential beneficial taxa such as Erysipelotrichaceae. Ketogenic diet also modified gut metabolism, increasing metabolites in the bile secretion such as ouabain, taurochenodeoxycholic acid, quinine, cholic acid and glycocholic acid, and decreasing metabolites associated with the biosynthesis of unsaturated fatty acids including stearic acid, arachidic acid, erucic acid, and docosanoic acid. These results suggest that ketogenic diet aggravates DSS-induced colitis in mice by increasing intestinal and systemic inflammation, and disrupting the intestinal barrier, which results from modulated gut microbiota and metabolism.

Abnormalities of the composition of the gut microbiota and short-chain fatty acids in mice after splenectomy

The brain–gut–microbiota axis is a complex multi-organ bidirectional signaling system between the brain and microbiota that participates in the host immune system. The spleen, as the largest immune organ in the body, has a key role in the brain–gut–microbiota axis. Here, we investigated whether splenectomy could affect depression-like phenotypes and the composition of the gut microbiota in adult mice. In behavioral tests, splenectomy did not cause depression-like behaviors in mice. Conversely, splenectomy led to significant alterations in the diversity of gut microbes compared with the findings in control (no surgery) and sham-operated mice. In an unweighted UniFrac distance analysis, the boxplots representing the splenectomy group were distant from those representing the other two groups. We found differences in abundance for several bacteria in the splenectomy group at the taxonomic level compared with the other two groups. Finally, splenectomy induced significant changes in lactic acid and n-butyric acid levels compared with those in the other groups. Interestingly, there were significant correlations between the counts of certain bacteria and lactic acid (or n-butyric acid) levels in all groups. These data suggest that splenectomy leads to an abnormal composition of the gut microbiota. It is likely that the spleen–gut–microbiota axis plays a crucial role in the composition of the gut microbiota by regulating immune homeostasis.

The Gut Microbiota-Bile Acids-TGR5 Axis Mediates Eucommia ulmoides Leaf Extract Alleviation of Injury to Colonic Epithelium Integrity

Eucommia ulmoides leaves (EL) are rich in phenolic acids and flavonoids, showing enhancing intestinal health effects. The intestinal microbiota-bile acid axis plays important roles in the occurrence and recovery of inflammatory bowel disease (IBD). However, whether EL extract (ELE) has regulatory effects on the intestinal microbiota, bile acid metabolism, and IBD is still unclear. To fill this gap, 2% dextran sulfate sodium (DSS)-induced mild IBD in a C57BL/6J mouse model that was treated with 200 or 400 mg/kg (intake dose/body weight) ELE was used. Oral ELE supplementation alleviated DSS-induced shortening of colon and colonic epithelial injury. Compared with the DSS group, ELE supplementation significantly decreased Toll-like receptor 4 (TLR4) and interlukin-6 (IL-6) and increased occludin and claudin-1 mRNA expression level in the colon (p < 0.05). Combined 16S rRNA gene sequencing and targeted metabolomic analyses demonstrated that ELE significantly improved the diversity and richness of the intestinal microbiota, decreased the abundance of Bacteroidaceae, and increased Akkermansiaceae and Ruminococcaceae abundance (p < 0.05) compared with DSS-induced IBD mice. Moreover, ELE significantly increased the serum contents of deoxycholic acid (DCA) and tauroursodeoxycholic acid (TUDCA), which were highly positively correlated with Akkermansia and unidentified_Ruminococccaceae relative to the DSS group. We then found that ELE increased Takeda G-protein coupled receptor 5 (TGR5), claudin-1, and occludin mRNA expression levels in the colon. In the Caco-2 cell model, we confirmed that activation of TGR5 improved the reduction in transepithelial electoral resistance (TEER) and decreased the permeability of FITC-dextran on monolayer cells induced by LPS (p < 0.05). siRNA interference assays showed that the decrease in TGR5 expression led to the decrease in TEER, an increase in FITC-dextran permeability, and a decrease in claudin-1 protein expression in Caco-2 cells. In summary, ELE alleviated IBD by influencing the intestinal microbiota structure and composition of bile acids, which in turn activated the colonic TGR5 gene expression in the colon and promoted the expression of tight junction proteins. These findings provide new insight for using ELE as a functional food with adjuvant therapeutic effects in IBD.

Non-autophagy Role of Atg5 and NBR1 in Unconventional Secretion of IL-12 Prevents Gut Dysbiosis and Inflammation

Intestinal myeloid cells play a critical role in balancing intestinal homeostasis and inflammation. Here, we report that expression of the autophagy-related 5 [Atg5] protein in myeloid cells prevents dysbiosis and excessive intestinal inflammation by limiting IL-12 production. Mice with a selective genetic deletion of Atg5 in myeloid cells [Atg5ΔMye] showed signs of dysbiosis preceding colitis, and exhibited severe intestinal inflammation upon colitis induction that was characterised by increased IFNγ production. The exacerbated colitis was linked to excess IL-12 secretion from Atg5-deficient myeloid cells and gut dysbiosis. Restoration of the intestinal microbiota or genetic deletion of IL-12 in Atg5ΔMye mice attenuated the intestinal inflammation in Atg5ΔMye mice. Additionally, Atg5 functions to limit IL-12 secretion through modulation of late endosome [LE] acidity. Last, the autophagy cargo receptor NBR1, which accumulates in Atg5-deficient cells, played a role by delivering IL-12 to LE. In summary, Atg5 expression in intestinal myeloid cells acts as an anti-inflammatory brake to regulate IL-12, thus preventing dysbiosis and uncontrolled IFNγ-driven intestinal inflammation.

Changes in the gut microbiota: a possible factor influencing peripheral blood immune indexes in non-obese diabetic mice

Intestinal flora changes were found in patients and animals with type 1 diabetes (T1D). However, few studies have provided any explicit clues of changes in highly disease related commensal microbiota before disease onset and their relationships with disordered peripheral immune cells. We conducted 16S rRNA microbiota analysis of non-obese diabetic (NOD) mice from weaning to diabetes onset to identify highly disease related microbes and performed Spearman correlation analysis between anomalous flora and peripheral immune cells. We found NOD mice had increased exclusive bacteria and decreased community richness or diversity, besides, with the features of decreased abundance of Bacteroidetes and increased abundance of Firmicutes, Proteobacteria or Deferribacteres and remarkable fluctuations of genus relative abundance. Furthermore, kinds of highly T1D related genus and their strong correlations with peripheral immune cells, especially neutrophils, were discovered. Microbial changes in NOD mice differed from that of ICR mice and highly disease associated microbes have strong correlations with the peripheral neutrophil ratio, which provide evidence that neutrophils are possibly involved in the pathogenesis of T1D.

Novel trends with biologics in inflammatory bowel disease: sequential and combined approaches

Inflammatory bowel disease (IBD) management has changed dramatically over the past 20 years, after the introduction of targeted biological therapies. However, the impact of these new drugs in changing the natural history of disease is still under debate. Recent evidence seems to suggest that the extent of their efficacy might be, at least partially, dependent on the timing of their introduction and on the subsequent management strategy. In this complex landscape, the potential role for a more dynamic approach with treatments based on sequencing and combining targeted therapies has been explored only minimally so far. In this review, we aim to explore the potential biological rationale behind the use of sequential and combination therapies in IBD, to summarise the current knowledge on this topic and to propose a management algorithm that combines these notions.

Replacing Animal Protein with Soy-Pea Protein in an "American Diet" Controls Murine Crohn Disease-Like Ileitis Regardless of Firmicutes: Bacteroidetes Ratio

BACKGROUND

The current nutritional composition of the "American diet" (AD; also known as Western diet) has been linked to the increasing incidence of chronic diseases, including inflammatory bowel disease (IBD), namely Crohn disease (CD).

OBJECTIVES

This study investigated which of the 3 major macronutrients (protein, fat, carbohydrates) in the AD has the greatest impact on preventing chronic inflammation in experimental IBD mouse models.

METHODS

We compared 5 rodent diets designed to mirror the 2011-2012 "What We Eat in America" NHANES. Each diet had 1 macronutrient dietary source replaced. The formulated diets were AD, AD-soy-pea (animal protein replaced by soy + pea protein), AD-CHO ("refined carbohydrate" by polysaccharides), AD-fat [redistribution of the ω-6:ω-3 (n-6:n-3) PUFA ratio; ∼10:1 to 1:1], and AD-mix (all 3 "healthier" macronutrients combined). In 3 separate experiments, 8-wk-old germ-free SAMP1/YitFC mice (SAMP) colonized with human gut microbiota ("hGF-SAMP") from CD or healthy donors were fed an AD, an AD-"modified," or laboratory rodent diet for 24 wk. Two subsequent dextran sodium sulfate-colitis experiments in hGF-SAMP (12-wk-old) and specific-pathogen-free (SPF) C57BL/6 (20-wk-old) mice, and a 6-wk feeding trial in 24-wk-old SPF SAMP were performed. Intestinal inflammation, gut metagenomics, and MS profiles were assessed.

RESULTS

The AD-soy-pea diet resulted in lower histology scores [mean ± SD (56.1% ± 20.7% reduction)] in all feeding trials and IBD mouse models than did other diets (P < 0.05). Compared with the AD, the AD-soy-pea correlated with increased abundance in Lactobacillaceae and Leuconostraceae (1.5-4.7 log2 and 3.0-5.1 log2 difference, respectively), glutamine (6.5 ± 0.8 compared with 3.9 ± 0.3 ng/μg stool, P = 0.0005) and butyric acid (4:0; 3.3 ± 0.5 compared with 2.54 ± 0.4 ng/μg stool, P = 0.006) concentrations, and decreased linoleic acid (18:2n-6; 5.4 ± 0.4 compared with 8.6 ± 0.3 ng/μL plasma, P = 0.01).

CONCLUSIONS

Replacement of animal protein in an AD by plant-based sources reduced the severity of experimental IBD in all mouse models studied, suggesting that similar, feasible adjustments to the daily human diet could help control/prevent IBD in humans.

Modeling microbe-host interaction in the pathogenesis of Crohn's disease

Alterations in the gut microbiota structure and function are thought to play an important role in the pathogenesis of Crohn's disease (CD). The rapid advancement of high-throughput sequencing technologies led to the identification of microbiome risk signatures associated with distinct disease phenotypes and progressing disease entities. Functional validation of the identified microbiome signatures is essential to understand the underlying mechanisms of microbe-host interactions. Germfree mouse models are available to study the functional role of disease-conditioning complex gut microbial ecosystems (dysbiosis) or pathobionts (single bacteria) in the pathogenesis of CD-like inflammation. Here, we discuss the clinical and mechanistic relevance and limitations of gnotobiotic mouse models in the context of CD. In addition, we will address the role of diet as an essential external factor modulating microbiome changes, potentially underlying disease initiation and development.

A Review of Selected IBD Biomarkers: From Animal Models to Bedside

Inflammatory bowel disease (IBD) is a dysregulated inflammatory condition induced by multiple factors. The etiology of IBD is largely unknown, and the disease progression and prognosis are variable and unpredictable with uncontrolled disease behavior. Monitoring the status of chronic colitis closely is challenging for physicians, because the assessment of disease activity and severity require invasive methods. Using laboratory biomarkers may provide a useful alternative to invasive methods in the diagnosis and management of IBD. Furthermore, patients with ulcerative colitis or Crohn’s disease are also at risk of developing cancer. Annual colonoscopies can help lower the risk for developing colorectal cancer. However, laboratory biomarkers may also be helpful as non-invasive indicators in predicting treatment responses, improving prognosis, and predicting possible tumors. This review addresses selected laboratory biomarkers (including ANCA, chitinase 3-like 1, S100A12/RAGE, calprotectin, and TNF/TNFR2), which are identified by utilizing two well-accepted animal models of colitis, dextran sodium sulfate-induced and T cell receptor alpha knockout colitis models. In addition to being useful for monitoring disease severity, these biomarkers are associated with therapeutic strategies. The factors may regulate the initiation and perpetuation of inflammatory factors in the gut.

Interleukin 1α: a comprehensive review on the role of IL-1α in the pathogenesis and treatment of autoimmune and inflammatory diseases

The interleukin (IL)-1 family member IL-1α is a ubiquitous and pivotal pro-inflammatory cytokine. The IL-1α precursor is constitutively present in nearly all cell types in health, but is released upon necrotic cell death as a bioactive mediator. IL-1α is also expressed by infiltrating myeloid cells within injured tissues. The cytokine binds the IL-1 receptor 1 (IL-1R1), as does IL-1β, and induces the same pro-inflammatory effects. Being a bioactive precursor released upon tissue damage and necrotic cell death, IL-1α is central to the pathogenesis of numerous conditions characterized by organ or tissue inflammation. These include conditions affecting the lung and respiratory tract, dermatoses and inflammatory skin disorders, systemic sclerosis, myocarditis, pericarditis, myocardial infarction, coronary artery disease, inflammatory thrombosis, as well as complex multifactorial conditions such as COVID-19, vasculitis and Kawasaki disease, Behcet's syndrome, Sjogren Syndrome, and cancer. This review illustrates the clinical relevance of IL-1α to the pathogenesis of inflammatory diseases, as well as the rationale for the targeted inhibition of this cytokine for treatment of these conditions. Three biologics are available to reduce the activities of IL-1α; the monoclonal antibody bermekimab, the IL-1 soluble receptor rilonacept, and the IL-1 receptor antagonist anakinra. These advances in mechanistic understanding and therapeutic management make it incumbent on physicians to be aware of IL-1α and of the opportunity for therapeutic inhibition of this cytokine in a broad spectrum of diseases.

Salidroside Attenuates Cognitive Dysfunction in Senescence-Accelerated Mouse Prone 8 (SAMP8) Mice and Modulates Inflammation of the Gut-Brain Axis

Background: Alzheimer's disease (AD) is a fatal neurodegenerative disease characterized by progressive cognitive decline and memory loss. However, several therapeutic approaches have shown unsatisfactory outcomes in the clinical setting. Thus, developing alternative therapies for the prevention and treatment of AD is critical. Salidroside (SAL) is critical, an herb-derived phenylpropanoid glycoside compound, has been shown to attenuate lipopolysaccharide (LPS)-induced cognitive impairment. However, the mechanism underlying its neuroprotective effects remains unclear. Here, we show that SAL has a therapeutic effect in the senescence-accelerated mouse prone 8 (SAMP8) strain, a reliable and stable mouse model of AD. Methods: SAMP8 mice were treated with SAL, donepezil (DNP) or saline, and cognitive behavioral impairments were assessed using the Morris water maze (MWM), Y maze, and open field test (OFT). Fecal samples were collected and analyzed by 16S rRNA sequencing on an Illumina MiSeq system. Brain samples were analyzed to detect beta-amyloid (Aβ) 1-42 (Aβ1-42) deposition by immunohistochemistry (IHC) and western blotting. The activation of microglia and neuroinflammatory cytokines was detected by immunofluorescence (IF), western blotting and qPCR. Serum was analyzed by a Mouse High Sensitivity T Cell Magnetic Bead Panel on a Luminex-MAGPIX multiplex immunoassay system. Results: Our results suggest that SAL effectively alleviated hippocampus-dependent memory impairment in the SAMP8 mice. SAL significantly 1) reduced toxic Aβ1-42 deposition; 2) reduced microglial activation and attenuated the levels of the proinflammatory factors IL-1β, IL-6, and TNF-α in the brain; 3) improved the gut barrier integrity and modified the gut microbiota (reversed the ratio of Bacteroidetes to Firmicutes and eliminated Clostridiales and Streptococcaceae, which may be associated with cognitive deficits); and 4) decreased the levels of proinflammatory cytokines, particularly IL-1α, IL-6, IL-17A and IL-12, in the peripheral circulation, as determined by a multiplex immunoassay. Conclusion: In summary, SAL reversed AD-related changes in SAMP8 mice, potentially by regulating the microbiota-gut-brain axis and modulating inflammation in both the peripheral circulation and central nervous system. Our results strongly suggest that SAL has a preventive effect on cognition-related changes in SAMP8 mice and highlight its value as a potential agent for drug development.

Nuclear Alarmin Cytokines in Inflammation

Pathogen-associated molecular patterns (PAMPs) are some nonspecific and highly conserved molecular structures of exogenous specific microbial pathogens, whose products can be recognized by pattern recognition receptor (PRR) on innate immune cells and induce an inflammatory response. Under physiological stress, activated or damaged cells might release some endogenous proteins that can also bind to PRR and cause a harmful aseptic inflammatory response. These endogenous proteins were named damage-associated molecular patterns (DAMPs) or alarmins. Indeed, alarmins can also play a beneficial role in the tissue repair in certain environments. Besides, some alarmin cytokines have been reported to have both nuclear and extracellular effects. This group of proteins includes high-mobility group box-1 protein (HMGB1), interleukin (IL)-33, IL-1α, IL-1F7b, and IL-16. In this article, we review the involvement of nuclear alarmins such as HMGB1, IL-33, and IL-1α under physiological state or stress state and suggest a novel activity of these molecules as central initiators in the development of sterile inflammation.

Curing piglets from diarrhea and preparation of a healthy microbiome with Bacillus treatment for industrial animal breeding

High-throughput farming of animals for an essential purpose such as large scale health and production of hogs is a challenge for the food industry in the modern world. The problem is that the breeding of livestock for fast growth or high yields of meat is often associated with illness and microbial infection that develop under the breeding conditions. Piglet diarrhea is most common pig disease, leading to heavy mortality and thereby economic loss. We proved that chemical drugs can relieve the symptoms of diarrhea in ill piglets, but they do not treat the underlying cause, i.e. significantly altered bacterial gut flora. Using Illumina sequencing of fecal DNA, we showed that the bacterial gut flora of piglets treated with antibiotics remain close to the ill conditions. However, using Illumina sequencing of fecal DNA from piglets treated with a specific Bacillus (Bacillus subtilis Y-15, B. amyloliquefaciens DN6502 and B. licheniformis SDZD02) demonstrated the efficiency of natural bioproducts not only on curing diarrhea, but also on beneficial bacteria to re-establish in the piglet gut. We therefore propose a new natural “medicine” to be explored by the world farm animal agriculture industry, particularly for sustainable improvement of swine livestock production and health.

Gut microbiota-derived short-chain fatty acids and hypertension: Mechanism and treatment

Hypertension (HTN) is an growing emerging health issue around across the world. In recent years, increasing attention has been paid to the role of dysbacteriosis in HTN and its underlying mechanism. Short-chain fatty acids (SCFAs), which are novel metabolites of intestinal flora, exert substantial regulatory effects on HTN, providing an exciting avenue for novel therapies for this disease. They function primarily by activating transmembrane G protein-coupled receptors and inhibiting histone acetylation. In this review, we discuss the mechanisms underlying the complex interaction between SCFAs and gut microbiota composition to lower blood pressure by regulating the brain-gut and kidney-gut axes, and the role of high-salt diet, immune system, oxidative stress, and inflammatory mechanism in the development of HTN. Furthermore, we also discuss the various treatment strategies for HTN, including diet, antibiotics, probiotics, fecal microflora transplantation, and traditional Chinese medicine. In conclusion, manipulation of SCFAs opens new avenues to improve treatment of HTN.

Endothelial-Derived Interleukin-1α Activates Innate Immunity by Promoting the Bactericidal Activity of Transendothelial Neutrophils

Migration of neutrophils across endothelial barriers to capture and eliminate bacteria is served as the first line of innate immunity. Bacterial virulence factors damage endothelium to produce inflammatory cytokines interacts with neutrophils. However, the mechanisms that behind endothelial-neutrophil interaction impact on the bactericidal activity remain unclear. Therefore, we aimed to find the target proteins on endothelial cells that triggered the bactericidal activity of transendothelial neutrophils. Herein, we built the infected models on rats and endothelial-neutrophil co-cultural system (Transwell) and discovered that endothelial-derived IL-1α promoted the survival of rats under Escherichia coli infection and enhanced the bactericidal activity of transendothelial neutrophils in vivo and in vitro. Results further showed that IL-1α was inhibited by lipopolysaccharide (LPS) in the endothelial-neutrophil interaction. We found that LPS mainly damaged cell membrane and induced cell necrosis to interrupt neutrophil migration from endothelial barrier. Thus, we used the isobaric tags for relative and absolute quantification (iTRAQ) method to identify different proteins of endothelial cells. Results showed that IL-1α targeted cellular plasma membrane, endoplasmic reticulum and mitochondrial envelope and triggered eleven common proteins to persistently regulate. During the early phase, IL-1α triggered the upregulation of cell adhesion molecules (CAMs) to promote neutrophil adhesion, while oxidative phosphorylation was involved in long time regulation to induce transmigration of neutrophils against bacteria. Our results highlight the critical mechanism of endothelial-derived IL-1α on promoting bactericidal activity of transendothelial neutrophils and the findings of IL-1α triggered proteins provide the potentially important targets on the regulation of innate immunity.

Artificial microbiome heterogeneity spurs six practical action themes and examples to increase study power-driven reproducibility

With >70,000 yearly publications using mouse data, mouse models represent the best engrained research system to address numerous biological questions across all fields of science. Concerns of poor study and microbiome reproducibility also abound in the literature. Despite the well-known, negative-effects of data clustering on interpretation and study power, it is unclear why scientists often house >4 mice/cage during experiments, instead of ≤2. We hypothesized that this high animal-cage-density  practice abounds in published literature because more mice/cage could be perceived as a strategy to reduce housing costs. Among other sources of 'artificial' confounding, including cyclical oscillations of the 'dirty-cage/excrement microbiome', we ranked by priority the heterogeneity of modern husbandry practices/perceptions across three professional organizations that we surveyed in the USA. Data integration (scoping-reviews, professional-surveys, expert-opinion, and 'implementability-score-statistics') identified Six-Actionable Recommendation Themes (SART) as a framework to re-launch emerging protocols and intuitive statistical strategies to use/increase study power. 'Cost-vs-science' discordance was a major aspect explaining heterogeneity, and scientists' reluctance to change. With a 'housing-density cost-calculator-simulator' and fully-annotated statistical examples/code, this themed-framework streamlines the rapid analysis of cage-clustered-data and promotes the use of 'study-power-statistics' to self-monitor the success/reproducibility of basic and translational research. Examples are provided to help scientists document analysis for study power-based sample size estimations using preclinical mouse data to support translational clinical trials, as requested in NIH/similar grants or publications.