Intestinal Metrnl released into the gut lumen acts as a local regulator for gut antimicrobial peptides

The Novel Cytokine Interleukin-41/Meteorin-like Is Reduced in Diffuse Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune connective tissue disease with a triad of features that include vascular abnormalities, inflammation and skin and lung fibrosis. At the core of the disease is the activation of myofibroblasts from quiescent fibroblasts and this can be modified by various cytokines. IL-41 is a recently described cytokine that was initially characterised as an adipokine as it was highly expressed in adipocytes and adipose tissue. However, it has recently been identified as being widely expressed and has immunomodulatory functions. This study examined the circulating levels of IL-41 and its expression in skin biopsies. We demonstrated significantly reduced levels of IL-41 in diffuse SSc that was also mirrored in the skin of SSc patients. AMPK has been proposed as a downstream target of IL-41, so we also measure mammalian target of rapamycin in skin and found that this is elevated in SSc patients. We speculate that IL-41 maybe an antifibrotic cytokine and its reduction may facilitate the activation of fibroblasts.

Chronic vascular pathogenesis results in the reduced serum Metrnl levels in ischemic stroke patients

Metrnl is a secreted protein involved in neurite outgrowth, insulin sensitivity, immunoinflammatory responses, blood lipids and endothelial protection. In this study, we investigated the role of Metrnl in ischemic stroke. Fifty-eight ischemic stroke patients (28 inpatient patients within 2 weeks of onset and 30 emergency patients within 24 h of onset) and 20 healthy controls were enrolled. Serum Metrnl was measured by enzyme-linked immunosorbent assay. We showed that serum Metrnl levels were significantly reduced in both inpatient and emergency patient groups compared with the controls. Different pathological causes for ischemic stroke such as large artery atherosclerosis and small artery occlusion exhibited similar reduced serum Metrnl levels. Transient ischemic attack caused by large artery atherosclerosis without brain infarction also had lower serum Metrnl levels. Metrnl was correlated with some metabolic, inflammatory and clotting parameters. Reduced serum Metrnl was associated with the severity of intracranial arterial stenosis and the presence of ischemic stroke. In order to elucidate the mechanisms underlying the reduced serum Metrnl levels, we established animal models of ischemic stroke in normal mice, atherosclerotic apolipoprotein E-knockout mice and Metrnl-knockout mice by middle cerebral artery occlusion (MCAO) using intraluminal filament or electrocoagulation. We demonstrated that serum Metrnl levels were significantly lower in atherosclerosis mice than normal mice, whereas acute ischemic stroke injury in normal mice and atherosclerosis mice did not alter serum Metrnl levels. Metrnl knockout did not affect acute ischemic stroke injury and death. We conclude that reduced serum Metrnl levels are attributed to the chronic vascular pathogenesis before the onset of ischemic stroke. Metrnl is a potential target for prevention of ischemic stroke.

Immunomodulation through Nutrition Should Be a Key Trend in Type 2 Diabetes Treatment

An organism's ability to function properly depends not solely on its diet but also on the intake of nutrients and non-nutritive bioactive compounds that exert immunomodulatory effects. This principle applies both to healthy individuals and, in particular, to those with concomitant chronic conditions, such as type 2 diabetes. However, the current food industry and the widespread use of highly processed foods often lead to nutritional deficiencies. Numerous studies have confirmed the occurrence of immune system dysfunction in patients with type 2 diabetes. This article elucidates the impact of specific nutrients on the immune system function, which maintains homeostasis of the organism, with a particular emphasis on type 2 diabetes. The role of macronutrients, micronutrients, vitamins, and selected substances, such as omega-3 fatty acids, coenzyme Q10, and alpha-lipoic acid, was taken into consideration, which outlined the minimum range of tests that ought to be performed on patients in order to either directly or indirectly determine the severity of malnutrition in this group of patients.

The Function and Mechanism of Anti-Inflammatory Factor Metrnl Prevents the Progression of Inflammatory-Mediated Pathological Bone Osteolytic Diseases

Metrnl, recently identified as an adipokine, is a secreted protein notably expressed in white adipose tissue, barrier tissues, and activated macrophages. This adipokine plays a pivotal role in counteracting obesity-induced insulin resistance. It enhances adipose tissue functionality by promoting adipocyte differentiation, activating metabolic pathways, and exerting anti-inflammatory effects. Extensive research has identified Metrnl as a key player in modulating inflammatory responses and as an integral regulator of muscle regeneration. These findings position Metrnl as a promising biomarker and potential therapeutic target in treating inflammation-associated pathologies. Despite this, the specific anti-inflammatory mechanisms of Metrnl in immune-mediated osteolysis and arthritis remain elusive, warranting further investigation. In this review, we will briefly elaborate on the role of Metrnl in anti-inflammation function in inflammation-related osteolysis, arthritis, and pathological bone resorption, which could facilitate Metrnl's clinical application as a novel therapeutic strategy to prevent bone loss. While the pathogenesis of elbow stiffness remains elusive, current literature suggests that Metrnl likely exerts a pivotal role in its development.

N-Acetylcysteine may exert hepatoprotective effect by regulating Meteorin-Like levels in Adriamycin-induced liver injury

Adriamycin (ADR) is an important chemotherapeutic drug, but it has serious side effects such as hepatotoxicity. This study aimed to evaluate whether N-acetylcysteine (NAC) has hepatoprotective effects against ADR-induced hepatotoxicity in rats. In addition, it was aimed to determine how Meteorin-Like (MtrnL), which has pleiotropic effects on immunology, inflammation, and metabolism, is affected by ADR and/or NAC applications in liver tissue. 28 rats were randomly assigned to one of four equal groups in the study: control (no treatment), NAC (150 mg/kg/day of NAC intraperitoneally (i.p), ADR (15 mg/kg only on the first day of the experiment), and ADR + NAC (ADR 15 mg/kg on the first day of the experiment + 150 mg/kg/day NAC i.p). After 15 days, liver enzyme levels in serum, oxidant/antioxidant parameters in liver tissue, histopathological changes, caspase 3 (Casp3) and heat shock protein 70 (HSP-70) immunoreactivities, and MtrnL levels were examined. Histopathological changes, liver enzyme levels, as well as HSP-70, and Casp3 immunoreactivities increased due to ADR application. Additionally, MtrnL levels in liver tissue were significantly increased as a result of ADR application. However, it was detected that the NAC application significantly regulated the ADR-induced changes. Furthermore, it was determined that NAC administration regulated the changes in ADR-induced oxidative stress parameters. We propose that NAC may exert a hepatoprotective effect by regulating ADR-induced altered oxidative stress parameters, MtrnL levels, Casp3, and HSP-70 immunoreactivities in the liver.

Plasma Bacterial DNA Load as a Potential Biomarker for the Early Detection of Colorectal Cancer: A Case-Control Study

The gut microbiota has gained increasing attention in recent years due to its significant impact on colorectal cancer (CRC) development and progression. The recent detection of bacterial DNA load in plasma holds promise as a potential non-invasive approach for early cancer detection. The aim of this study was to examine the quantity of bacterial DNA present in the plasma of 50 patients who have CRC in comparison to 40 neoplastic disease-free patients, as well as to determine if there is a correlation between the amount of plasma bacterial DNA and various clinical parameters. Plasma bacterial DNA levels were found to be elevated in the CRC group compared to the control group. As it emerged from the logistic analysis (adjusted for age and gender), these levels were strongly associated with the risk of CRC (OR = 1.02, p < 0.001, 95% C.I.: 1.01-1.03). Moreover, an association was identified between a reduction in tumor mass and the highest tertile of plasma bacterial DNA. Our findings indicate that individuals with CRC displayed a higher plasma bacterial DNA load compared to healthy controls. This observation lends support to the theory of heightened bacterial migration from the gastrointestinal tract to the bloodstream in CRC. Furthermore, our results establish a link between this phenomenon and the size of the tumor mass.

Protective role of the novel cytokine Metrnl/ interleukin-41 in host immunity defense during sepsis by promoting macrophage recruitment and modulating Treg/Th17 immune cell balance

BACKGROUND

Metrnl play an immunocytokine-like role in several diseases, which is also known as meteorin-like because it is homologous to the neurotrophic factor meteorin (Metrn). Although the expression and function of Metrnl, including neurotrophic, immunomodulatory, and insulin resistance functions in different tissues have been extensively studied, its role in sepsis has remained largely limited.

METHODS

The present work analyzed the levels of Metrnl and cytokines in the circulation, such as tumor necrosis factor (TNF-α), interleukin (IL-1)β, IL-6, IL-8, together with IL-10 among septic adult patients. Clinical information was obtained from such patients, including sofa score, procalcitonin(PCT)count, and C-reactive count (CRP) within 24 h when entering the intensive care unit (ICU). We constructed a sepsis model in Metrnl-deficient or normal wild-type mice using cecal ligation and perforation to study its functions in bacterial burden, survival, cytokine/chemokine generation, peritoneal lavage fluid neutrophils, macrophage and lymphocyte recruitment, and Treg/Th17 immune cell balance after CLP-induced sepsis.

RESULTS

The expression of Metrnl was remarkably elevated in the early phase of sepsis clinically. Its serum content in patients dying of sepsis slightly decreased relative to that in survivors. Furthermore, the concentration of Metrnl in septic cases when entering the ICU independently predicted the 28-day mortality. For septic patients who had low serum Metrnl content (≤ 274.40 pg/mL), the death risk increased by 2.3 folds relative to those who had a high serum content. It is reported that Metrnl is probably insufficient among patients dying of sepsis. Additionally, the content of Metrnl in the serum of septic patients when entering the ICU is markedly and negatively related to the levels of TNF-α, IL-1β, IL-6, IL-8, IL-17, PCT, and Sofa score. Collectively, Metrnl could be a potential therapeutic target for sepsis. A low-lethality non-severe sepsis (NSS) model was constructed, which suggested that Metrnl insufficiency elevated the death rate and reduced bacterial clearance during sepsis. For Metrnl-deficient mice, impaired sepsis immunity defense might be related to decreased macrophage recruitment and Treg/Th17 lymphocyte imbalance. Recombinant Metrnl administered to Metrnl-deficient mice abolished the immunity defense impairment following NSS while protecting the high-lethality severe sepsis (SS) model in wild-type (WT) mice. In addition, Metrnl-induced sepsis prevention was intricately associated with the increased recruitment of peritoneal macrophages and modulation of the Treg/TH17 immune cell balance. Furthermore, CCL3 exposure in Metrnl-deficient mice reduced peritoneal bacterial loads while improving survival during sepsis partially by promoting the recruitment of peritoneal macrophages. Furthermore, Metrnl regulated the polarization of M1 macrophages through the ROS signaling pathway and promoted macrophage phagocytosis, thereby killing Escherichia coli.

CONCLUSIONS

The present proof-of-concept work suggests that Metrnl-mediated recruitment of macrophages significantly affects sepsis defense in the host and modulates the Treg/Th17 immune cell balance. Findings in this work shed more light on the development of host-directed treatments that can be used to manipulate host immunity to treat sepsis.

Metrnl deficiency retards skin wound healing in mice by inhibiting AKT/eNOS signaling and angiogenesis

Meteorin-like (Metrnl) is a novel secreted protein with various biological activities. In this study, we investigated whether and how Metrnl regulated skin wound healing in mice. Global Metrnl gene knockout mice (Metrnl-/-) and endothelial cell-specific Metrnl gene knockout mice (EC-Metrnl-/-) were generated. Eight-mm-diameter full-thickness excisional wound was made on the dorsum of each mouse. The skin wounds were photographed and analyzed. In C57BL/6 mice, we observed that Metrnl expression levels were markedly increased in skin wound tissues. We found that both global and endothelial cell-specific Metrnl gene knockout significantly retarded mouse skin wound healing, and endothelial Metrnl was the key factor affecting wound healing and angiogenesis. The proliferation, migration and tube formation ability of primary human umbilical vein endothelial cells (HUVECs) were inhibited by Metrnl knockdown, but significantly promoted by addition of recombinant Metrnl (10 ng/mL). Metrnl knockdown abolished the proliferation of endothelial cells stimulated by recombinant VEGFA (10 ng/mL) but not by recombinant bFGF (10 ng/mL). We further revealed that Metrnl deficiency impaired VEGFA downstream AKT/eNOS activation in vitro and in vivo. The damaged angiogenetic activity in Metrnl knockdown HUVECs was partly rescued by addition of AKT activator SC79 (10 μM). In conclusion, Metrnl deficiency retards skin wound healing in mice, which is related to impaired endothelial Metrnl-mediated angiogenesis. Metrnl deficiency impairs angiogenesis by inhibiting AKT/eNOS signaling pathway.

The Meteorin-like cytokine is upregulated in grass carp after infection with Aeromonas hydrophila

Meteorin-like (Metrnl) is a novel immune regulatory factor or adipokine which is mainly produced by activated macrophages. In teleost fish, two homologs are present. In this study, monoclonal antibodies were prepared against recombinant grass carp (Ctenopharyngodon idella, Ci) Metrnl-a in mice and characterized by Western blotting, flow cytometry and immunofluorescent microscopy. In grass carp infected with Aeromonus hydrophila (A. hydrophila), the cells expressing CiMetrnl-a markedly increased in the gills, head kidney and intestine. In the inflamed intestine caused by A. hydrophila infection, the CiMetrnl-a producing cells were detected mainly in the mucosal layer of anterior, middle and posterior segments. Consistently, qRT-PCR analysis showed that the mRNA expression of CiMetrnl-a was markedly induced. Our results suggest that CiMetrnl-a is involved in regulating intestine inflammation caused by bacterial infection.

Investigation of IL-35 and IL-39, New Members of the IL-12 Family, in Different Clinical Presentations of Brucellosis

Brucellosis is significantly influenced by the interactions between the causative Brucella bacteria and host immunity. Recently identified cytokines have been described for their immunomodulatory effects in numerous inflammatory, autoimmune and infectious diseases. Some of them are new members of cytokine superfamilies, including several members of the IL-12 superfamily (IL-35, IL-39). The major purpose of the present study was to investigate the role of these new immunomodulatory cytokines in Brucella infections. The levels of IL-35 and IL-39 in the serum of 40 acute and 40 chronic brucellosis patients and 40 healthy controls were measured by ELISA. The mRNA levels of IL-35 and IL-39 in PBMCs were detected by RT-qPCR. Both IL-35 and IL-39 serum concentrations were significantly higher in healthy control subjects than in brucellosis patients, and IL-35 and IL-39 serum levels of chronic brucellosis patients were higher than those of acute cases. It was also found that the expression of Ebi3/IL-12A (IL-35 genes) and Ebi3/IL-23A (IL-39 genes) was upregulated in chronic brucellosis patients compared to healthy controls. Moreover, the expression of the Ebi3/IL-12A and Ebi3/IL-23A genes was lower in patients with acute brucellosis than in patients with chronic brucellosis. Overall, this study showed that IL-35 and IL-39 are positively correlated in brucellosis and significantly decreased during the disease. Significantly lower levels of IL-35 and IL-39 in acute brucellosis than in chronic brucellosis and healthy controls suggest that these cytokines may play a key role in suppressing the immune response to brucellosis and its progression to chronicity.

Meteorin-like/Metrnl, a novel secreted protein implicated in inflammation, immunology, and metabolism: A comprehensive review of preclinical and clinical studies

Meteorin-like, also known as Metrnl, Meteorin-β, Subfatin, and Cometin, is a novel secreted protein exerting pleiotropic effects on inflammation, immunology, and metabolism. Earlier research on this hormone focused on regulating energy expenditure and glucose homeostasis. Consequently, several studies attempted to characterize the molecule mechanism of Metrnl in glucose metabolism and obesity-related disorders but reported contradictory clinical results. Recent studies gradually noticed its multiple protective functions in inflammatory immune regulations and cardiometabolic diseases, such as inducing macrophage activation, angiogenesis, tissue remodeling, bone formation, and preventing dyslipidemias. A comprehensive understanding of this novel protein is essential to identify its significance as a potential therapeutic drug or a biomarker of certain diseases. In this review, we present the current knowledge on the physiology of Metrnl and its roles in inflammation, immunology, and metabolism, including animal/cell interventional preclinical studies and human clinical studies. We also describe controversies regarding the data of circulation Metrnl in different disease states to determine its clinical application better.

Endothelial METRNL determines circulating METRNL level and maintains endothelial function against atherosclerosis

METRNL is a recently identified secreted protein with emerging functions. This study is to find major cellular source of circulating METRNL and to determine METRNL novel function. Here, we show METRNL is abundant in human and mouse vascular endothelium and released by endothelial cells using endoplasmic reticulum-Golgi apparatus pathway. By creating endothelial cell-specific Metrnl knockout mice, combined with bone marrow transplantation to produce bone marrow-specific deletion of Metrnl, we demonstrate that most of circulating METRNL (approximately 75%) originates from the endothelial cells. Both endothelial and circulating METRNL decrease in atherosclerosis mice and patients. By generating endothelial cell-specific Metrnl knockout in apolipoprotein E-deficient mice, combined with bone marrow-specific deletion of Metrnl in apolipoprotein E-deficient mice, we further demonstrate that endothelial METRNL deficiency accelerates atherosclerosis. Mechanically, endothelial METRNL deficiency causes vascular endothelial dysfunction including vasodilation impairment via reducing eNOS phosphorylation at Ser1177 and inflammation activation via enhancing NFκB pathway, which promotes the susceptibility of atherosclerosis. Exogenous METRNL rescues METRNL deficiency induced endothelial dysfunction. These findings reveal that METRNL is a new endothelial substance not only determining the circulating METRNL level but also regulating endothelial function for vascular health and disease. METRNL is a therapeutic target against endothelial dysfunction and atherosclerosis.

Meteorin-like/Meteorin-β upregulates proinflammatory cytokines via NF-κB pathway in grass carp Ctenopharyngodon idella

Meteorin-like (Metrnl) is a newly discovered cytokine but whether it exists in fish is unclear. In this study, we identified two Meteorin-like (Metrnl) homologues in grass carp Ctenopharyngodon idella (termed CiMetrnl-a and CiMetrnl-b) which share high sequence homology and conserved genomic organization of 4 exons and 3 introns with known Metrnl molecules. Also, gene synteny of Metrnl genes is well conserved in vertebrates. Expression analyses showed that the CiMetrnl-a gene was constitutively expressed in tissues of healthy fish whilst the levels of CiMetrnl-b transcripts were too low to be detected. The CiMetrnl-a gene was inducible by Flavobacterium columnare, grass carp reovirus and PAMPs. Recombinant CiMetrnl-a produced in the CHO-S cells was active in up-regulating the expression of cytokines involved in promoting inflammation (IL-1β, IL-6, IL-8, IL-17A and TNF-α), type 1 immune response (IFN-γ and IL-2) and NF-κB signaling pathway (NF-κBp65 and NF-κBp52) in the primary head kidney leukocytes. Furthermore, luciferase reporter assay showed that CiMetrnl-a was able to activate the NF-κB promoter in the EPC cells, suggesting that CiMetrnl-a may upregulate pro-inflammatory cytokines via NF-κB dependent pathway.

Roux-en-Y gastric bypass potentially improved intestinal permeability by regulating gut innate immunity in diet-induced obese mice

Roux-en-Y gastric bypass (RYGB) has been demonstrated to be the most effective treatment for morbid obesity, yet the impact of RYGB on intestinal permeability is not fully known. In this work, we subjected obese mice to RYGB and sham operation procedures. Serum lipopolysaccharide (LPS) level, inflammatory cytokines and intestinal permeability were measured at 8 weeks post surgery. In contrast to sham surgery, RYGB reduced body weight, improved glucose tolerance and insulin resistance, and decreased serum levels of LPS, IL6 and TNFα. Intestinal permeability of the common limb and colon was significantly improved in the RYGB group compared to the sham group. The mRNA levels of IL1β, IL6, and TLR4 in the intestine were significantly decreased in the RYGB group compared with the sham group. The expression levels of intestinal islet-derived 3β (REG3β), islet-derived 3γ (REG3γ) and intestinal alkaline phosphatase (IAP) were higher in the RYGB group than in the sham group. In conclusion, in a diet-induced obesity (DIO) mouse model, both decreased intestinal permeability and attenuated systemic inflammation after RYGB surgery were associated with improved innate immunity, which might result from enhanced production of IAP and antimicrobial peptides.

Involvement of the secreted protein Metrnl in human diseases

Metrnl, a secreted protein expressed in white adipose tissue, has been identified as a novel adipokine. It is also highly expressed in barrier tissues, including the skin, intestinal and respiratory tract epithelium in both mice and humans. Research shows that its expression is upregulated by inflammation, chronic high-fat diets, exercise, cold exposure, etc., and it plays important roles in promoting neurite extension, enhancing white fat browning, improving insulin sensitivity, modulating lipid metabolism and regulating inflammatory response, the latter implying Metrnl is a new cytokine. These studies suggest that Metrnl could be a promising biomarker and a potential therapeutic target for the related diseases. For proving this, clinical studies need to be performed to bridge the gap between bench and bedside. In this paper, we summarize the progress in recent clinical research on Metrnl. Most of these clinical studies are designed to confirm the relationship between circulating Metrnl and metabolic or cardiovascular disease (type 2 diabetes and coronary heart disease), or immune inflammation-related diseases, such as colitis, psoriasis and arthritis. Although blood Metrnl seems to fluctuate and are affected by many factors, such as drugs, physical exercise, and cold exposure, these clinical studies provide reliable clues that Metrnl is associated with coronary heart disease, inflammation-related diseases, etc. Nevertheless, the roles of Metrnl in some diseases such as nervous system diseases remain unclear, and its putative involvement should be further clarified. These studies could promote the application of Metrnl in clinic as a new therapeutic target.

Metrnl deficiency decreases blood HDL cholesterol and increases blood triglyceride

Dyslipidemia is a risk factor for cardiovascular diseases and type 2 diabetes. Several adipokines play important roles in modulation of blood lipids. Metrnl is a recently identified adipokine, and adipose Metrnl participates in regulation of blood triglyceride (TG). In this study, we generated Metrnl global, intestine-specific and liver-specific knockout mice, and explored the effects of Metrnl on serum lipid parameters. Global knockout of Metrnl had no effects on serum lipid parameters under normal chow diet, but increased blood TG by 14%, and decreased total cholesterol (TC) by 16% and high density lipoprotein cholesterol (HDL-C) by 24% under high fat diet. Nevertheless, intestine-specific knockout of Metrnl did not alter the serum lipids parameters under normal chow diet or high fat diet. Notably, liver-specific knockout of Metrnl decreased HDL-C by 24%, TC by 20% and low density lipoprotein cholesterol (LDL-C) by 16% without alterations of blood TG and nonesterified fatty acids (NEFA) under high fat diet. But deficiency of Metrnl in liver did not change VLDL secretion and expression of lipid synthetic and metabolic genes. We conclude that tissue-specific Metrnl controls different components of blood lipids. In addition to modulation of blood TG by adipose Metrnl, blood HDL-C is regulated by liver Metrnl.

Integrated analysis of concomitant medications and oncological outcomes from PD-1/PD-L1 checkpoint inhibitors in clinical practice

Background

Concomitant medications, such as steroids, proton pump inhibitors (PPI) and antibiotics, might affect clinical outcomes with immune checkpoint inhibitors.

Methods

We conducted a multicenter observational retrospective study aimed at evaluating the impact of concomitant medications on clinical outcomes, by weighing their associations with baseline clinical characteristics (including performance status, burden of disease and body mass index) and the underlying causes for their prescription. This analysis included consecutive stage IV patients with cancer, who underwent treatment with single agent antiprogrammed death-1/programmed death ligand-1 (PD-1/PD-L1) with standard doses and schedules at the medical oncology departments of 20 Italian institutions. Each medication taken at the immunotherapy initiation was screened and collected into key categories as follows: corticosteroids, antibiotics, gastric acid suppressants (including proton pump inhibitors - PPIs), statins and other lipid-lowering agents, aspirin, anticoagulants, non-steroidal anti-inflammatory drugs (NSAIDs), ACE inhibitors/Angiotensin II receptor blockers, calcium antagonists, β-blockers, metformin and other oral antidiabetics, opioids.

Results

From June 2014 to March 2020, 1012 patients were included in the analysis. Primary tumors were: non-small cell lung cancer (52.2%), melanoma (26%), renal cell carcinoma (18.3%) and others (3.6%). Baseline statins (HR 1.60 (95% CI 1.14 to 2.25), p=0.0064), aspirin (HR 1.47 (95% CI 1.04 to 2.08, p=0.0267) and β-blockers (HR 1.76 (95% CI 1.16 to 2.69), p=0.0080) were confirmed to be independently related to an increased objective response rate. Patients receiving cancer-related steroids (HR 1.72 (95% CI 1.43 to 2.07), p<0.0001), prophylactic systemic antibiotics (HR 1.85 (95% CI 1.23 to 2.78), p=0.0030), prophylactic gastric acid suppressants (HR 1.29 (95% CI 1.09 to 1.53), p=0.0021), PPIs (HR 1.26 (95% CI 1.07 to 1.48), p=0.0050), anticoagulants (HR 1.43 (95% CI: 1.16 to 1.77), p=0.0007) and opioids (HR 1.71 (95% CI 1.28 to 2.28), p=0.0002) were confirmed to have a significantly higher risk of disease progression. Patients receiving cancer-related steroids (HR 2.16 (95% CI 1.76 to 2.65), p<0.0001), prophylactic systemic antibiotics (HR 1.93 (95% CI 1.25 to 2.98), p=0.0030), prophylactic gastric acid suppressants (HR 1.29 (95% CI 1.06 to 1.57), p=0.0091), PPI (HR 1.26 (95% CI 1.04 to 1.52), p=0.0172), anticoagulants (HR 1.45 (95% CI 1.14 to 1.84), p=0.0024) and opioids (HR 1.53 (95% CI 1.11 to 2.11), p=0.0098) were confirmed to have a significantly higher risk of death.

Conclusion

We confirmed the association between baseline steroids administered for cancer-related indication, systemic antibiotics, PPIs and worse clinical outcomes with PD-1/PD-L1 checkpoint inhibitors, which can be assumed to have immune-modulating detrimental effects.

Characterization of the serum levels of Meteorin-like in patients with inflammatory bowel disease and its association with inflammatory cytokines

Background

Meteorin-like (Metrnl) is an adipokine with insulin sensitizing and anti-inflammatory properties that has been discovered recently. The relation among Metrnl, Inflammatory Bowel Disease (IBD), and obesity has been unexplored yet.

Methods

The present study was conducted on 54 healthy control, 42 Ulcerative Colitis (UC), and 43 Crohn’s disease (CD) patients who were diagnosed by pathological examination. In all participants, serum levels of adiponectin, Metrnl, interleukin (IL)-6, and Tumor necrosis factor (TNF-α) were measured using ELISA kits.

Results

Metrnl concentration was considerably lower in both UC (85.25 ± 36.55 pg/mL) and CD (76.93 ± 27.92 pg/mL) patients in comparison to control (107.52 ± 35.33 pg/mL). In addition, it was seen that both patient groups have a decreased level of adiponectin compared to the controls. Besides that, the level of IL-6 and TNF-α were significantly greater in the patient groups. Moreover, the result showed that the level of Metrnl is inversely correlated with body mass index (BMI) in the controls and the patients. Metrnl levels are also inversely associated with IL-6, and TNF-α in both of the patient groups.

Conclusions

The current study is the first one reporting the decreased levels of Metrnl in serum among patients with IBD, which is inversely related with BMI, TNF-α, and IL-6. These results suggested a possible relation of Metrnl with the pathogenesis of IBD, particularly through inflammatory process, although further studies are warranted to dissect the possible mechanism.

Aggravated ulcerative colitis caused by intestinal Metrnl deficiency is associated with reduced autophagy in epithelial cells

Metrnl is a newly identified secreted protein highly expressed in the intestinal epithelium. This study aimed to explore the role and mechanism of intestinal epithelial Metrnl in ulcerative colitis. Metrnl^-/- (intestinal epithelial cell-specific Metrnl knockout) mice did not display any phenotypes of colitis under basal conditions. However, under administration of 3% dextran sodium sulfate (DSS) drinking water, colitis was more severe in Metrnl^-/- mice than in WT mice, as indicated by comparisons of body weight loss, the presence of occult or gross blood per rectum, stool consistency, shrinkage in the colon, intestinal damage, and serum levels of inflammatory factors. DSS-induced colitis activated autophagy in the colon. This activation was partially inhibited by intestinal epithelial Metrnl deficiency, as indicated by a decrease in Beclin-1 and LC3-II/I and an increase in p62 in DSS-treated Metrnl^-/- mice compared with WT mice. These phenomena were further confirmed by observation of autophagosomes and immunofluorescence staining for LC3 in epithelial cells. The autophagy-related AMPK-mTOR-p70S6K pathway was also activated in DSS-induced colitis, and this pathway was partially blocked by intestinal epithelial Metrnl deficiency, as indicated by a decrease in AMPK phosphorylation and an increase in mTOR and p70S6K phosphorylation in DSS-treated Metrnl^-/- mice compared with WT mice. Therefore, Metrnl deficiency deteriorated ulcerative colitis at least partially through inhibition of autophagy via the AMPK-mTOR-p70S6K pathway, suggesting that Metrnl is a therapeutic target for ulcerative colitis.

Alterations of the Gut Microbiota Associated With Promoting Efficacy of Prednisone by Bromofuranone in MRL/lpr Mice

Gut microbiota played an important role in systemic lupus erythematosus (SLE) and glucocorticoids were prone to cause alterations in gut microbiota. This study addressed the effect of bromofuranone on the treatment of SLE with prednisone, since bromofuranone could regulate gut microbiota by inhibiting the AI-2/LuxS quorum-sensing. Remarkably, bromofuranone did not alleviate lupus but promoted the efficacy of prednisone in the treatment of lupus. The alterations in the gut microbiota, including decreased Mucispirillum, Oscillospira, Bilophila and Rikenella, and increased Anaerostipes, were associated with prednisone treatment for SLE. In addition, the increase of Lactobacillus, Allobaculum, Sutterella, and Adlercreutzia was positively associated with the bromofuranone-mediated promotion for the treatment of lupus. This was the first study demonstrating that the efficacy of glucocorticoids could be affected by the interventions in gut microbiota.

IL-39 acts as a friend to pancreatic cancer

Pancreatic cancer is the most lethal digestive cancer and the fourth leading cause of cancer death in the US. IL-39, a heterodimer of p19 and EBI3, is a newly found cytokine and its role in the pathogenesis of neoplasia has not been studied yet. This study was designed to investigate the direct role of IL-39 in the growth of pancreatic cancer. Clonogenic survival assay, cell proliferation, and caspase-3 activity kits were used to evaluate the direct effects of IL-39 on cell survival, proliferation and apoptosis of the widely studied pancreatic cancer cell line MiaPaCa-2. We further investigated the possible molecular mechanisms by using RT-PCR and IHC. The percentage of colonies of pancreatic cancer cells increased significantly in the presence of IL-39. This was paralleled with the increase in the OD value of cancer cells in the presence of IL-39. Interestingly, the relative caspase-3 activity in cancer cells decreased significantly in the presence of IL-39. Furthermore, the pro-tumor effect of IL-39 on pancreatic cancer cells correlated with decreased anti-proliferative molecule p21.The anti-apoptotic effect of IL-39 correlated with decreased pro-apoptotic molecule TRAILR1. These results suggest that IL-39 favors growth of pancreatic cancer by promoting growth and inhibiting apoptosis of cancer cells. This suggests that IL-39 acts as a friend to pancreatic cancer. Thus, inhibition of effect of IL-39 on cells might be a promising strategy to treat pancreatic cancer.

Meteorin-like/Meteorin-β Is a Novel Immunoregulatory Cytokine Associated with Inflammation

We have described a novel cytokine encoded by a gene called Meteorin-like (Metrnl). Metrnl is a small (∼28 kDa) secreted protein expressed by activated macrophages and barrier tissues (mucosa and skin). Metrnl production by bone marrow macrophages is induced by several cytokines including TNF-α, IL-17α, IL-12, and IL-4 and inhibited by IFN-γ and TGF-β. Metrnl expression in macrophages is also induced by LPS, and its levels in circulation are associated with inflammatory responses in vivo. Furthermore, Metrnl regulates the production of several cytokines and chemokines in macrophages. We have produced a Metrnl^-/- mouse, which is viable and shows normal development. However, it exhibits dysregulated cytokine production, alterations in IgG production, and is highly susceptible to LPS in a sepsis model. Furthermore, older Metrnl^-/- mice develop inflammatory lesions, suggesting that Metrnl participates in the control of inflammatory responses. Taken together, these observations indicate that Metrnl encodes a novel immunoregulatory cytokine associated with inflammatory responses that we have designated Meteorin-β.

Chronic glucocorticoid treatment induced circadian clock disorder leads to lipid metabolism and gut microbiota alterations in rats

AIM

Glucocorticoids (GCs), steroid hormones synthetized by the adrenal gland, are regulated by circadian cycles, and dysregulation of GC signaling can lead to the development of metabolic syndrome. The effects and potential mechanism of GCs in physiology were investigated in the present study.

MAIN METHODS

Male Wistar rats were orally administered dexamethasone sodium phosphate (DEX, 0.01 and 0.05mg/kg body weight per day) for 7weeks.

KEY FINDING

DEX treatment attenuated body weight gain and reduced food intake, whereas it induced the accumulation of fat. Administration of DEX induced dysregulation of the expression of lipogenic genes in both fat and liver. Moreover, the mRNA levels of genes related to mitochondrial biogenesis and function were significantly downregulated in the liver and fat of DEX-treated rats. Furthermore, DEX treatment caused a significant reduction in the richness and diversity of the microbiota in the colon, as assessed using high-throughput sequencing of the 16s rRNA gene V3-V4 region, an increase in inflammatory cell infiltration, and a decrease in mucus secretion in the colon. Additionally, DEX administration induced phase shift or loss of circadian rhythmicity of clock-related genes in peripheral tissues. These results were associated with higher serum corticosterone levels and upregulation of GC receptor (GR) expression in peripheral tissues.

SIGNIFICANCE

Our findings indicate that long-term administration of GC caused lipid accumulation, changes in the structure of the intestinal flora, and reduced colonic mucus secretion in vivo. The mechanism of these physiological changes may involve a circadian rhythm disorder and dysregulation of GR expression.

Influence of Microbiota on Intestinal Immune System in Ulcerative Colitis and Its Intervention

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) with chronic and recurrent characteristics caused by multiple reasons. Although the pathogenic factors have not been clarified yet, recent studies have demonstrated that intestinal microbiota plays a major role in UC, especially in the immune system. This review focuses on the description of several major microbiota communities that affect UC and their interactions with the host. In this review, eight kinds of microbiota that are highly related to IBD, including Faecalibacterium prausnitzii, Clostridium clusters IV and XIVa, Bacteroides, Roseburia species, Eubacterium rectale, Escherichia coli, Fusobacterium, and Candida albicans are demonstrated on the changes in amount and roles in the onset and progression of IBD. In addition, potential therapeutic targets for UC involved in the regulation of microbiota, including NLRPs, vitamin D receptor as well as secreted proteins, are discussed in this review.