Resistin-like Molecule Research Articles

Trimetazidine Alleviates Bleomycin-Induced Pulmonary Fibrosis by Targeting the Long Noncoding RNA CBR3-AS1-Mediated miRNA-29 and Resistin-Like Molecule alpha 1: Deciphering a Novel Trifecta Role of LncRNA CBR3-AS1/miRNA-29/FIZZ1 Axis in Lung Fibrosis.

Pulmonary fibrosis (PF) and tissue remodeling can greatly impair pulmonary function and often lead to fatal outcomes. In the present study, we explored a novel molecular interplay of long noncoding (Lnc) RNA CBR3-AS1/ miRNA-29/ FIZZ1 axis in moderating the inflammatory processes, immunological responses, and oxidative stress pathways in bleomycin (BLM)-induced lung fibrosis. Furthermore, we investigated the pharmacological potential of Trimetazidine (TMZ) in ameliorating lung fibrosis. Our results revealed that the BLM-treated group exhibited a significant upregulation in the expression of epigenetic regulators, lncRNA CBR3-AS1 and FIZZ1, compared to the control group (P<0.0001), along with the downregulation of miRNA-29 expression. Furthermore, Correlation analysis showed a significant positive association between lnc CBR3-AS1 and FIZZ1 (R=0.7723, p<0.05) and a significant negative association between miRNA-29 and FIZZ1 (R=-0.7535, p<0.05), suggesting lnc CBR3-AS1 as an epigenetic regulator of FIZZ1 in lung fibrosis. BLM treatment significantly increased the expression of Notch, Jagged1, Smad3, TGFB1, and hydroxyproline. Interestingly, the administration of TMZ demonstrated the ability to attenuate the deterioration effects caused by BLM treatment, as indicated by biochemical and histological analyses. Our investigations revealed that the therapeutic potential of TMZ as an antifibrotic drug could be ascribed to its ability to directly target the epigenetic regulators lncRNA CBR3-AS1/ miRNA-29/ FIZZ1, which in turn resulted in the mitigation of lung fibrosis. Histological and immunohistochemical analyses further validated the potential antifibrotic effects of TMZ by mitigating the structural damage associated with fibrosis. Taken together, our study showed for the first time the interplay between epigenetic lncRNAs CBR3-AS1 and miRNA-29 in lung fibrosis and demonstrated that FIZZ1 could be a downregulatory gene for lncRNA CBR3-AS1 and miRNA-29. Our key findings demonstrate that TMZ significantly reduces the expression of fibrotic, oxidative stress, immunomodulatory, and inflammatory markers, along with epigenetic regulators associated with lung fibrosis. This validates its potential as an effective antifibrotic agent by targeting the CBR3-AS1/miRNA-29/FIZZ1 axis.

MFN2-dependent mitochondrial dysfunction contributes to Relm-β-induced pulmonary arterial hypertension via USP18/Twist1/miR-214 pathway

Induction of resistin-like molecule β (Relm-β) and mitofusin 2 (MFN2) mediated aberrant mitochondrial fission have been found to be involved in the pathogenesis of pulmonary arterial hypertension (PAH). However, the molecular mechanisms underlying Relm-β regulation of MFN2 therefore mitochondrial fission remain unclear. This study aims to address these issues. Primary cultured PASMCs and monocrotaline (MCT)-induced PAH rats were applied in this study. The results showed that Relm-β promoted cells proliferation in PASMCs, this was accompanied with the upregulation of USP18, Twist1 and miR-214, and downregulation of MFN2. We found that Relm-β increased USP18 expression which in turn raised Twist1 by suppressing its proteasome degradation. Elevation of Twist1 increased miR-214 expression and then reduced MFN2 expression and mitochondrial fragmentation leading to PASMCs proliferation. In vivo study, we confirmed that Relm-β was elevated in MCT-induced PAH rat model, and USP18/Twist1/miR-214/MFN2 axis was altered similar as in vitro. Targeting this cascade by Relm-β receptor inhibitor Calhex231, proteasome inhibitor MG-132, Twist1 inhibitor Harmine or miR-214 antagomiR prevented the development of pulmonary vascular remodeling and therefore PAH in MCT-treated rats. In conclusion, we demonstrate that Relm-β promotes PASMCs proliferation and vascular remodeling by activating USP18/Twist1/miR-214 dependent MFN2 reduction and mitochondrial fission, suggesting that this signaling pathway might be a promising target for management of PAH.

Regulation of cardiac fibrosis in mice with TAC/DOCA-induced HFpEF by resistin-like molecule gamma and adenylate cyclase 1.

Heart failure with preserved ejection fraction (HFpEF) is one of the major subtypes of heart failure (HF) and no effective treatments for this common disease exist to date. Cardiac fibrosis is central to the pathology of HF and a potential avenue for the treatment of HFpEF. To explore key fibrosis-related genes and pathways in the pathophysiological process of HFpEF, a mouse model of HFpEF was constructed. The relevant gene expression profiles were downloaded from the Gene Expression Omnibus database, and single-sample Gene Set Enrichment Analysis (ssGSEA) was performed targeting fibrosis-related pathways to explore differentially expressed genes (DEGs) in healthy control and HFpEF heart tissues with cross-tabulation analysis of fibrosis-related genes. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed on the identified fibrosis-related genes. The two most significant DEGs were selected, and further validation was conducted in HFpEF mice. The results indicated that myocardial fibrosis was significantly upregulated in HFpEF mice compared to healthy controls, while the ssGSEA results revealed significant differences in the enrichment of nine fibrosis-related pathways in HFpEF myocardial tissue, with 112 out of 798 DEGs being related to fibrosis. The in vivo results demonstrated that expression levels of resistin-like molecule gamma (Relmg) and adenylate cyclase 1 (Adcy1) in the heart tissues of HFpEF mice were significantly higher and lower, respectively, compared to healthy controls. Taken together, these results suggest that Relmg and Acdy1 as well as the fibrosis process may be potential targets for HFpEF treatment.

Abstract 5669: Rare germline variants on SI gene and the possibility of colorectal cancer development

Abstract Research on cancer and germline variants has been ongoing. The germline variant in CPGs has been linked to cancer development. BRCA 1/2 is a typical case and oncometabolite production due to germline variants of the FH gene can affect the cancer progression. Among the genes related to IEMs, SI (Sucrase-isomaltase) is an enzyme that converts sucrose into glucose and fructose to allow normal metabolism in the small intestine. In addition, SI is highly specifically expressed in the gastrointestinal tract (nTPM = 435.9). So, we focused on and hypothesized the biological traits of the SI gene and alteration caused by germline variants could affect colorectal cancer progression. We used the public cancer databases PCAWG and TCGA and the healthy cohorts 1000G. We confirmed carriers with SI germline variants are the top gene with a high prevalence of IEM-related genes. We also established the hypothesis the SI gene may match “Knudson’s Two-hit hypothesis”. Depending on whether germline variants in IEM-related genes or not, we performed regression and utilized LOH (Loss of heterozygosity) information for each cancer sample from the public database. In COAD and STAD which are in the gastrointestinal tract, SI was confirmed to have a high tendency for LOH according to germline prevalence. Next, we performed DEG analysis and found SI germline carriers had upregulated genes related to the IFIT (Interferon-induced proteins with tetratricopeptide repeats) family. STRING network analysis also showed significance in pathways associated with “Interferon alpha/beta signaling (FDR = 0.00058)”, “Antiviral defense (FDR = 0.0016)”, “Innate immunity (FDR = 0.0317)”, and “Tetratricopeptide repeats (FDR = 0.0413)”. The following GSEA revealed that “KEGG_CYTOSOLIC DNA-SENSING PATHWAY” and “HALLMARK_INTERFERON_ALPHA_RESPONSE” were enriched in the SI germline carriers. In summary, it can be suggested immune regulation caused by SI germline variants may lead to cancer progression. We executed a follow-up analysis using the genes with low expression levels to the SI germline carriers. Among the down-regulated genes in the DEG, REG4 (Regenerating Family Member 4) and RELMβ (Resistin-Like Molecule Beta) genes were confirmed to express and function specifically only in the gastrointestinal tract. RELMβ is essential for preserving energy balance and glucose metabolism. As a validation at the protein level, we conducted IHC (Immunohistochemistry) on tissues from Korean colorectal cancer patients and confirmed lower REG4 and RELMβ expression were associated with poor prognosis. Our results suggest that SI germline carriers may cause colorectal cancer by affecting the immune system due to decreased SI enzyme function. Additionally, the decreased REG4 and RELMβ expression levels are associated with the SI germline variant and may affect cancer progression. Further analyses and experimental validations are still required. Citation Format: Seokhyeon Kim, Jeong Mo Bae, Youngil Koh, Sung-Soo Yoon. Rare germline variants on SI gene and the possibility of colorectal cancer development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5669.

Myeloid- and epithelial-derived RELMα contribute to tissue repair following lung helminth infection.

Soil-transmitted helminth (STH) infections impact billions of individuals globally; however, there is a need to clarify the long-term impacts of these infections on pulmonary health owing to their transient migration and subsequent damage to the lungs. In mouse models of these infections using Nippostrongylus brasiliensis, lung pathology persists at later time points post single infection. These studies also indicate the persistent transcriptional expression of resistin-like molecule α (RELMα), an immunomodulatory protein induced in type 2 immunity and alternatively activated macrophages. Using constitutive and tamoxifen-inducible cell-specific RELMα knockout mouse strains, we identified that epithelial- and myeloid-derived RELMα protein remained elevated at 30 days post infection and altered the immune cell signature and gene expression in lung compartments. Histopathological assessment of alveolar damage revealed a role for RELMα in tissue repair, suggesting the importance of sustained RELMα expression for lung recovery from helminth infection. Acellular three-dimensional (3D) lung scaffolds were prepared from the lungs of wild-type (WT), RELMα KO-naive, or 30 days post N. brasiliensis-infected mice to assess their ability to support epithelial cell growth. N. brasiliensis infection significantly altered the scaffold and impaired epithelial cell growth and metabolic activity, especially in the RELMα KO scaffolds. These findings underscore a need to identify the long-term impacts of helminth infection on human pulmonary disease, particularly as alveolar destruction can develop into chronic obstructive pulmonary disease (COPD), which remains among the top global causes of death. Translation of these findings to human protein resistin, with sequence homology to RELMα therapeutic opportunities in lung repair.

Chromofungin, a chromogranin A-derived peptide, protects against sepsis-induced acute lung injury by inhibiting LBP/TLR4-dependent inflammatory signaling

Chromofungin (CHR) is a biologically active peptide derived from chromogranin A that exhibits anti-inflammatory effects. However, it remains unclear whether and how CHR protects against sepsis-induced acute lung injury (ALI). A murine model of sepsis-induced ALI was established through cecal ligation and puncture, with intraperitoneal injection of CHR. Lung inflammation and macrophage polarization were examined by measuring the levels of cytokines and markers of M1 (CD86, inducible nitric oxide synthase [iNOS]) or M2 macrophages (arginase-1 [Arg1], resistin-like molecule α1 [Fizz1] and CD206). In vitro, mouse MH-S cells pretreated with CHR was employed to explore the interplay between the lipopolysaccharide-binding protein (LBP)/toll-like receptor 4 (TLR4) signaling pathway and M1/M2 polarity. The results revealed CHR's ability to enhance the 7-day survival rate and protect lung pathological injury in sepsis-induced ALI. CHR increased the expression of interleukin-4 and interleukin-10 but decreased the expression of tumour necrosis factor-α and interleukin-1β. In addition, CHR notably facilitated M2 macrophage polarization, while significantly suppressingM1 polarization of alveolar macrophages. Mechanistic investigations delineated CHR's role in macrophage polarization by downregulating nuclear factor-κB expression through modulation of the LBP/TLR4 signaling pathway. Therefore, CHR may represent a novel strategy for the prevention of sepsis-induced ALI.

The Mechanisms of Resistin-Like Molecule-β-Mediated Airway Inflammation in Chronic Obstructive Pulmonary Disease via Autophagy.

The role of irreversible airway inflammatory damage in chronic obstructive pulmonary disease (COPD) progression is evident. Autophagy is an essential process in the cellular material metabolic cycle, and a family of resistant vegetative molecules may be involved in the COPD autophagic process. In this study, we investigated the mechanism of resistin-like molecule β (RELMβ) in COPD smoking-induced autophagy. Firstly, the expression differences of RELMβ and autophagy markers between COPD and control groups were analyzed in the Gene Expression Omnibus (GEO) datasets and clinical specimens. Secondly, in vitro and in vivo experiments were conducted using immunoblotting, immunofluorescence, immunohistochemistry, and other methods to investigate the mechanism by which RELMβ promotes airway inflammation through autophagy in a cigarette smoke extract-induced 16HBE cell inflammation model and a cigarette smoke-induced COPD-like mouse model. In addition, immunoprecipitation was used to analyze the binding of RELMβ to the membrane protein TLR4. The expression of RELMβ and autophagy genes p62 and LC3B in lung tissue of COPD patients was significantly increased. RELMβ can mediate the activation of autophagy in 16HBE cells, and through autophagy, it increases the expression of inflammatory cytokines in a cigarette smoke extract-induced 16HBE cell inflammation model. RELMβ promotes cigarette smoke-induced COPD-like mouse airway inflammation through autophagy, and RELMβ can mediate signal transduction through the cell membrane receptor TLR4. The RELMβ binds to TLR4 to encourage signal transduction and that RELMβ can promote inflammation in smoky COPD lungs through autophagy.

Resistin-like Molecule α and Pulmonary Vascular Remodeling: A Multi-Strain Murine Model of Antigen and Urban Ambient Particulate Matter Co-Exposure.

Pulmonary hypertension (PH) has a high mortality and few treatment options. Adaptive immune mediators of PH in mice challenged with antigen/particulate matter (antigen/PM) has been the focus of our prior work. We identified key roles of type-2- and type-17 responses in C57BL/6 mice. Here, we focused on type-2-response-related cytokines, specifically resistin-like molecule (RELM)α, a critical mediator of hypoxia-induced PH. Because of strain differences in the immune responses to type 2 stimuli, we compared C57BL/6J and BALB/c mice. A model of intraperitoneal antigen sensitization with subsequent, intranasal challenges with antigen/PM (ovalbumin and urban ambient PM2.5) or saline was used in C57BL/6 and BALB/c wild-type or RELMα-/- mice. Vascular remodeling was assessed with histology; right ventricular (RV) pressure, RV weights and cytokines were quantified. Upon challenge with antigen/PM, both C57BL/6 and BALB/c mice developed pulmonary vascular remodeling; these changes were much more prominent in the C57BL/6 strain. Compared to wild-type mice, RELMα-/- had significantly reduced pulmonary vascular remodeling in BALB/c, but not in C57BL/6 mice. RV weights, RV IL-33 and RV IL-33-receptor were significantly increased in BALB/c wild-type mice, but not in BALB/c-RELMα-/- or in C57BL/6-wild-type or C57BL/6-RELMα-/- mice in response to antigen/PM2.5. RV systolic pressures (RVSP) were higher in BALB/c compared to C57BL/6J mice, and RELMα-/- mice were not different from their respective wild-type controls. The RELMα-/- animals demonstrated significantly decreased expression of RELMβ and RELMγ, which makes these mice comparable to a situation where human RELMβ levels would be significantly modified, as only humans have this single RELM molecule. In BALB/c mice, RELMα was a key contributor to pulmonary vascular remodeling, increase in RV weight and RV cytokine responses induced by exposure to antigen/PM2.5, highlighting the significance of the genetic background for the biological role of RELMα.

A172 THE LACK OF CHROMOGRANIN A PROTECTS THE COLONIC EPITHELIAL BARRIER FUNCTIONS FROM COLITIS IN MALE MICE AND EXACERBATES COLITIS IN FEMALE MICE

Abstract Background Ulcerative colitis (UC) is associated with compromised mucosal barrier function and colonic epithelial repair in a sex-dependent manner. Chromogranin A (CHGA), a pro-hormone, correlates positively with UC disease severity. In male mice, deletion of CHGA has been shown to decrease the inflammatory process; however, the effect of CHGA on mucosal barrier function and colonic epithelial repair between males and females is unknown. Purpose We investigated whether the lack of CHGA modulates gut barrier function, mucosa integrity, and colonic epithelial repair between males and females in a mice model of colitis. Method Male and female wild-type (WT) and CHGA (CHGA-/-) deficient mice (13-17 weeks old) were given 5% dextran sulfate sodium (DSS) to induce colitis or water for 5-days (n=5-8 mice per group). The disease activity index (DAI) was assessed. Colons were collected, and tumor necrosis factor (TNF)-α and IL-25 concentrations were measured by ELISA. Expression of structural and functional markers specific to epithelial cells, namely, colonocytes (Na-K-Cl cotransporter [Nkcc]1), goblet cells function (resistin-like molecule [Relm]β), and mucin [MUC]2) and stem cells (reserve Hopx, fast-cycling Lgr5, and fetal-like Ly6a cells) were evaluated by qRT-PCR. Result(s) Colitic male CHGA-/- did not show significant changes in DAI compared to WT mice. Conversely, female CHGA-/- mice demonstrated a trend toward higher susceptibility to colitis compared to female WT mice with increased weight loss and bleeding. This was associated with elevated levels of colonic TNF-α and IL-25 (p&amp;lt;0.05) in CHGA-/- females compared to CHGA-/- males. TNF-α levels were not different between female groups at baseline and during colitis. While colitic CHGA-/- female had elevated Relmβ expression (p&amp;lt;0.01) compared to WT mice. No significative change was noted in Relmβ expression between female WT mice at baseline and during colitis. Similarly, Nkcc1 and Muc2 expression was not different between female groups. By contrast, male CHGA-/- were less susceptible to colitis than male WT mice with elevated Nkcc1and a lower Relmβ and Muc2 expression (p&amp;lt;0.01). In colitis, expression of stem cell markers, Hopx and Lgr5, was markedly reduced in all groups, while male WT, CHGA-/-, and female WT had elevated Ly6a expression. However, the magnitude of Hopx and Ly6a expression was associated with sex. Thus, colitic male CHGA-/- mice had a higher Hopx expression than male WT and female CHGA-/ - mice, with a lower reduction of 1.9 compared to 4.9 and 6.6, respectively (p&amp;lt;0.05, 0.01, and 0.0001). While colitic male CHGA-/- mice had elevated Ly6a expression (p&amp;lt;0.05) in contrast to female CHGA-/- mice (p=0.5). The magnitude of the decrease in Lgr5 expression was not different between all groups. Conclusion(s) In the absence of CHGA, male mice preserved their colonic mucosa integrity and repair potential, while female mice suffered significant loss of mucosa integrity and repair potential during colitis. Disclosure of Interest None Declared

The Intestinal Adipokine Resistin-like Molecule Beta Is Dysregulated In Children With Food Allergy

Food allergy (FA) is increasing, yet accurate biomarkers and disease-modifying treatments are still lacking, reflecting incomplete understanding of FA pathogenesis. In a mouse model of FA, Resistin-like molecule beta (RELMb) – a gut-derived cytokine involved in both allergic responses and protection from pathogens - is dysregulated, and its deletion results in protection from food-induced anaphylaxis.

Fecal HBD-2 and Claudin-3 may be potential biomarkers to predict the deterioration of necrotizing enterocolitis: A prospective study.

Necrotizing enterocolitis (NEC) is a critical gastrointestinal disease. We aim to explore the value of fecal human β-defensin 2 (HBD-2), Claudin-3, high-mobility group box-1 protein (HMGB-1), and resistin-like molecule β (Relmβ) as well as some laboratory metrics to predict the deterioration of NEC. Infants diagnosed with NEC at Stage II were enrolled in our study. Those who progressed to Stage III were included in the Stage III group and the rest were included in the Stage II group. Clinical data and laboratory metrics of the infants were collected. Fecal samples of HBD2, HMGB-1, Claudin-3, and Relmβ collected during their enrollment were determined by using enzyme-linked immunosorbent assay (ELISA) kits. Student's t-test, the Mann-Whitney U test, the chi-square test, receiver operating characteristic (ROC), and logistic regression analysis were performed. Sixty infants diagnosed with NEC at Stage II were enrolled in our study, with 27 in the Stage III group (n = 27) and 33 in the Stage II group (n = 33). Although many of these NEC cases were late preterm and term infants, the infants in the Stage III group had a lower gestational age (P < 0.05). The incidence of gestational diabetes mellitus, peritonitis, intestinal adhesion, and sepsis was higher and more infants in the Stage III group underwent surgeries (P < 0.05). The levels of HBD-2 and Claudin-3 were higher and neutrophil count was lower in the Stage III group than in the Stage II Group, and the area under the curve (AUC) was 0.754, 0,755, and 0.666, respectively (P < 0.05). HBD-2 ≥ 1649.02 ng/g and Claudin-3 ≥ 2488.71 pg/g were included in the multivariate stepwise logistic regression analysis (P < 0.05), and the AUC of the model was 0.805 (95% CI: 0.688-0.922). Fecal HBD-2 and Claudin-3 may be potential biomarkers to predict the deterioration of NEC from Stage II to Stage III.

Resistin contributes perivascular adipose tissue dysfunction in a rheumatoid arthritis mouse model

BackgroundPatients with rheumatoid arthritis (RA) experience 50% more risk of mortality attributed to cardiovascular disease (CVD). PVAT dysfunction, which leads to vascular dysfunction, is driven by increased proinflammatory adipokines, and overactivation of immune cells. The proinflammatory adipokine resistin modulates vascular function, and circulating, synovial and serum resistin concentrations are increased in RA patients. We hypothesized that resistin causes PVAT dysfunction, inflammation and macrophage infiltration in a RA experimental model.MethodsAntigen‐induced arthritis (AIA) was induced in 12 weeks‐old C57BL/6 male mice. AIA immunized mice received mBSA (intraarterial injection, 10 µg in10 µl PBS/week) or PBS (10 µl) for 5 weeks. Disease activity was determined based on immune cells profile in lymph nodes, by flow cytometry, and measurement of the mediolateral knee joint diameter. Thoracic aorta, with or without PVAT, were isolated after five weeks of AIA onset for functional, cellular, and molecular assays. Data are represented as mean and standard error, and student´s T test (p&lt;0.05) was used for statistical analysis. All the experiments were approved by the Ethics Committee on Animal Research of the FMRP,USP (protocol nº 15/2020).ResultsInguinal lymph nodes of AIA showed increased CD4+/IL‐17 cells compared to control [(%) AIA: 10.4 ± 1.06 vs. CT 1.8 ± 1.06, n=6] and the mediolateral knee diameter was increased in AIA compared to control mice [(mm) AIA 4.38 ± 0.06 vs. CT 3.50 ± 0.04, n=6]. Aorta from AIA mice had a dysfunctional PVAT, decreased phenylephrine (Pe) maximum responses (Emax) and no changes in Pe logEC50 compared to CT [Emax (mN): CT ‐PVAT 10.6 ± 0.3 vs. CT +PVAT 8.7 ± 0.2; AIA ‐PVAT 6.8 ± 0.3 vs. CT +PVAT 7.0 ± 0.2, n=6‐8]. 40 ng/ml of resistin for 4 hours compromised aortic PVAT function [Emax (mN): WT–PVAT + Resistin = 5,8 ± 0,1 vs. WT+PVAT + Resistin = 6,0 ± 0,1; CT ‐PVAT= 10,6 ± 0,3 vs. CT +PVAT 8,7 ± 0,2, n=7‐8]. Resistin concentrations were increased in the PVAT, plasma, and knee of AIA mice vs. control [(pg/ml) Serum: AIA 899.2 ± 11 vs. CT 837.9 ± 18; PVAT: AIA 217.0 ± 24 vs. CT 121 ± 18; Knee: AIA 28.3 ± 1.7 vs. CT 19.5 ± 1.1, n=4‐8). mRNA genemarkers of type 1 (M1) macrophages, including monocyte chemoattractant protein‐1 (CCL2), interleukin‐1beta (IL‐1b), inducible nitric oxide synthase (iNOS), and tumor necrosis alpha (TNFα) were increased in AIA PVAT [(‐∆∆ct) CCL2: AIA 2.6 ± 0.3 vs. CT 0.82 ± 0.10; iNOS: AIA 2,5± 0,7 vs. CT 0,6 ± 0,1; IL‐1b: AIA 2.0 ± 0.4 vs. CT 1.0; TNFα: AIA 1,2 ± 0,1 vs. CT 0,5 ± 0,0; n=5‐8, 2]. mRNA gene markers of type 2 macrophages (M2) such as resistin‐like molecule alpha (Retnla), L‐arginase (Arg1), Mannose Receptor C‐Type 1 (Mrc1) was increased in PVAT from AIA mice vs. control [(‐∆∆ct) Arg1: AIA 3,4 ± 0,6 vs. CT 0,8 ± 0,1; Retna AIA 2,0 ± 0,6 vs. CT 1,0 ± 0,2; n=5‐7, 2]. Flow cytometry analysis confirmed increased M1 and M2 markers in the PVAT of AIA mice [(% of cells) M1:F4/80+CD11b+:AIA 11,8 ± 1,6 vs. Sham 6,0 vs. 1,1; M2: CD206+CD11b+ :AIA 20,4 ± 1,7 vs. Sham 11,8 ± 1,2; n=6‐8].ConclusionAIA‐associated PVAT dysfunction, i.e. loss of its anti‐contractile effect, is linked to increased resistin and an inflammation profile involving macrophages‐related cytokines and chemokines.

Retracted: Resistin-Like Molecule Beta (RELM-β) Regulates Proliferation of Human Diabetic Nephropathy Mesangial Cells via Mitogen-Activated Protein Kinases (MAPK) Signaling Pathway.

This publication has been retracted by the Editor due to the identification of non-original figure images and manuscript content that raise concerns regarding the credibility and originality of the study and the manuscript. Reference: Yun-Qian Wang, Cong-Cong Fan, Bao-Ping Chen, Jun Shi. Resistin-Like Molecule Beta (RELM-ß) Regulates Proliferation of Human Diabetic Nephropathy Mesangial Cells via Mitogen-Activated Protein Kinases (MAPK) Signaling Pathway.Med Sci Monit 2017; 23:3897-3903. DOI: 10.12659/MSM.905381.

A182 THE LACK OF CHROMOGRANIN A IMPACTS COLONIC EPITHELIAL CELLS MARKERS IN AN EXPERIMENTAL MODEL OF ULCERATIVE COLITIS

BackgroundUlcerative colitis (UC) is a chronic and acute inflammatory disorder of the colon linked to dysregulated gut mucosal immune response and compromised colonic epithelial barrier function and integrity. Chromogranin-A (CHGA), a pro-peptide secreted by enteroendocrine cells, is highly expressed in colonic tissues of patients with UC. Elevated CHGA has been shown to correlate with UC disease activity and severity. Moreover, complete deletion of CHGA was shown to result in a diminution of pro-inflammatory markers known to disrupt the colonic epithelial barrier function and gut mucosal healing process. However, little is known about the effect of the absence of CHGA on colonic epithelial barrier function and gut mucosal integrity.AimsHere, we characterized the impact of the lack of CHGA on the colonic mucosa and epithelial barrier structure and function using CHGA knockout (CHGA-/-) mice treated with dextran sulfate sodium (DSS) to induce colitis.Methods13–17 weeks old male C57BL/6 wild-type (CHGA+/+) and C57BL/6 CHGA-/- mice were treated for 5 days with 5% DSS to induced acute colitis, control mice received regular water. CHGA mRNA expression, disease activity index (DAI), and macroscopic score (MS) were analyzed. Distal colonic tissues were isolated, and mRNA expression of markers associated with regenerative stem cells (fast-cycling stem cells [Lgr5+] and reserve stem cells [HOPX+] and [LY6a+], Goblet cells functions mucus barrier mucin 2 [MUC2], resistin-like molecule β [RELMβ], WAP 4-disulphide core domain 2 [WFDC2]) and trefoil factor 3 (TFF3) was evaluated by qRT-PCR.ResultsWe validated a beneficial effect of the Lack of CHGA on colitis severity, associated with significantly lower DAI and MS. In colitic CHGA+/+ and CHGA-/- mice, Lgr5+ and HOPX+ were both highly down-regulated, although, compared to CHGA+/+, CHGA-/- mice presented a 10.5fold higher expression of HOPX+. Compared to non-colitic states, Ly6a+ expression was significantly elevated in both colitic CHGA+/+ and CHGA-/- mice, however, no differences in Lgr5+ and Ly6a+ expression were noted between CHGA+/+ and CHGA-/- mice in all conditions. In CHGA+/+ mice, inflammatory conditions led to higher MUC2 and RELMB expression, although, compared to CHGA+/+, these markers were significantly lower in CHGA-/- mice. In colitic conditions, compared to CHGA+/+, CHGA-/- had a significant increase of WFDC2. In non-colitic conditions, mRNA expressions of all markers evaluated between CHGA+/+ and CHGA-/- in this study were unaltered. Finally, no differences were observed in TFF3 gene expression.ConclusionsThese results indicate in the absence of CHGA, the colonic epithelial barrier integrity and function are maintained through the modulation of goblet cells functions and elevated gut mucosa regenerative potential, thus enhancing the mucosal protection to colitis damage.Funding AgenciesCIHR

The Inflammatory Response Induced by RELMβ Upregulates IL-8 and IL-1β Expression in Bronchial Epithelial Cells in COPD.

PurposeChronic obstructive pulmonary disease (COPD) is associated with a complex inflammatory regulatory network. Resistin-like molecule β (RELMβ) is highly expressed in the lungs of COPD patients. We aimed to investigate the proinflammatory effect of RELMβ on airway epithelial cells in COPD.MethodsFirst, a GEO dataset was used to analyze the expression of the RELMβ gene in the COPD and control groups as well as the protein levels of RELMβ in the sera of outpatients with COPD and normal control subjects in our hospital. We also stimulated 16HBE bronchial epithelial cells with recombinant RELMβ protein and analyzed the expression of IL-8 and IL-1β. We upregulated and downregulated the gene expression of RELMβ in 16HBE cells and analyzed the expression of the inflammatory cytokines IL-8 and IL-1β. In addition, we also examined the mechanism by which the p38 MAPK signaling pathway contributed to the regulation of IL-8 and IL-1β expression by RELMβ.ResultsRELMβ expression was increased in COPD tissues in different data sets and in the serum of COPD patients in our hospital. IL-8 and IL-1β expression was also increased in COPD tissues with high RELMβ gene expression in different data sets. The RELMβ gene was mainly related to inflammatory factors and inflammatory signaling pathways in the PPI regulatory network. Experiments at the cellular level showed that RELMβ promoted the expression of the inflammatory cytokines IL-8 and IL-1β, and this regulation was mediated by the p38 MAPK signaling pathway.ConclusionRELMβ can promote the expression of the inflammatory cytokines IL-8 and IL-1β in bronchial epithelial cells of patients with COPD and exert inflammatory effects. RELMβ may be a potential target for the treatment of COPD.

Hypoxia-Induced Mitogenic Factor: A Multifunctional Protein Involved in Health and Disease.

Hypoxia-induced mitogenic factor (HIMF), also known as resistin-like molecule α (RELMα) or found in inflammatory zone 1 (FIZZ1) is a member of the RELM protein family expressed in mice. It is involved in a plethora of physiological processes, including mitogenesis, angiogenesis, inflammation, and vasoconstriction. HIMF expression can be stimulated under pathological conditions and this plays a critical role in pulmonary, cardiovascular and metabolic disorders. The present review summarizes the molecular characteristics, and the physiological and pathological roles of HIMF in normal and diseased conditions. The potential clinical significance of these findings for human is also discussed.

Activation of Invariant Natural Killer T Cells by α-Galactosylceramide Attenuates the Development of Angiotensin II-Mediated Abdominal Aortic Aneurysm in Obese ob/ob Mice.

The infiltration and activation of macrophages as well as lymphocytes within the aorta contribute to the pathogenesis of abdominal aortic aneurysm (AAA). Invariant natural killer T (iNKT) cells are unique subset of T lymphocytes and have a crucial role in atherogenesis. However, it remains unclear whether iNKT cells also impact on the development of AAA. Ob/ob mice were administered angiotensin II (AngII, 1,000 ng/kg/min) or phosphate-buffered saline (PBS) by osmotic minipumps for 4 weeks and further divided into 2 groups; α-galactosylceramide (αGC; PBS-αGC; n = 5 and AngII-αGC; n = 12), which specifically activates iNKT cells, and PBS (PBS-PBS; n = 10, and AngII-PBS; n = 6). Maximal abdominal aortic diameter was comparable between PBS-PBS and PBS-αGC, and was significantly greater in AngII-PBS than in PBS-PBS. This increase was significantly attenuated in AngII-αGC without affecting blood pressure. αGC significantly enhanced iNKT cell infiltration compared to PBS-PBS. The ratio of F4/80-positive macrophages or CD3-positive T lymphocytes area to the lesion area was significantly higher in AngII-PBS than in PBS-PBS, and was significantly decreased in AngII-αGC. Gene expression of M2-macrophage specific markers, arginase-1 and resistin-like molecule alpha, was significantly greater in aortic tissues from AngII-αGC compared to AngII-PBS 1 week after AngII administration, and this increase was diminished at 4 weeks. Activation of iNKT cells by αGC can attenuate AngII-mediated AAA in ob/ob mice via inducing anti-inflammatory M2 polarized state. Activation of iNKT cells by the bioactive lipid αGC may be a novel therapeutic target against the development of AAA.

The Role of Hypoxia-Induced Mitogenic Factor in Organ-Specific Inflammation in the Lung and Liver: Key Concepts and Gaps in Knowledge Regarding Molecular Mechanisms of Acute or Immune-Mediated Liver Injury

Hypoxia-induced mitogenic factor (HIMF), which is also known as resistin-like molecule α (RELM-α), found in inflammatory zone 1 (FIZZ1), or resistin-like alpha (retlna), is a cysteine-rich secretory protein and cytokine. HIMF has been investigated in the lung as a mediator of pulmonary fibrosis, inflammation and as a marker for alternatively activated macrophages. Although these macrophages have been found to have a role in acute liver injury and acetaminophen toxicity, few studies have investigated the role of HIMF in acute or immune-mediated liver injury. The aim of this focused review is to analyze the literature and examine the effects of HIMF and its human homolog in organ-specific inflammation in the lung and liver. We followed the guidelines set by PRISMA in constructing this review. The relevant checklist items from PRISMA were included. Items related to meta-analysis were excluded because there were no randomized controlled clinical trials. We found that HIMF was increased in most models of acute liver injury and reduced damage from acetaminophen-induced liver injury. We also found strong evidence for HIMF as a marker for alternatively activated macrophages. Our overall risk of bias assessment of all studies included revealed that 80% of manuscripts demonstrated some concerns in the randomization process. We also demonstrated some concerns (54.1%) and high risk (45.9%) of bias in the selection of the reported results. The need for randomization and reduction of bias in the reported results was similarly detected in the studies that focused on HIMF and the liver. In conclusion, we propose that HIMF could be utilized as a marker for M2 macrophages in immune-mediated liver injury. However, we also detected the need for randomized clinical trials and additional experimental and human prospective studies in order to fully comprehend the role of HIMF in acute or immune-mediated liver injury.

Predictive and Prognostic Utility of the Serum Level of Resistin-Like Molecule Beta for Risk Stratification in Patients with Community-Acquired Pneumonia.

Despite progress in intensive care, the morbidity and mortality of patients with community-acquired pneumonia (CAP) remains high. Furthermore, the predictive and prognostic utility of resistin-like molecule beta (RELM-β) in patients with CAP is uncertain. This study investigated the role of RELM-β in patients with CAP and evaluated its correlation with disease severity and the risk of death. A prospective, multicenter study was conducted in 2017, and admission serum levels of RELM-β were detected using quantitative enzyme-linked immunosorbent assay. A total of 114 and 112 patients with severe CAP (SCAP) and non-severe CAP (NSCAP) were enrolled, respectively, with 15 healthy controls. Patients with SCAP, especially non-survivors, had significantly higher levels of serum RELM-β than patients with NSCAP. RELM-β levels positively correlated with severity scores and consistently predicted SCAP in patients with CAP (area under the curve = 0.794). Increased levels of RELM-β were closely related to the severity and prognosis of patients with CAP. The accuracy of 30-day mortality predictions of CURB-65 (confusion, urea, respiratory rate, blood pressure, and age ≥ 65 years) can be significantly improved when combined with RELM-β levels. The level of RELM-β can assist clinicians in risk stratification of patients with CAP in early stages.

Resistin-like molecule \u03b2 acts as a mitogenic factor in hypoxic pulmonary hypertension via the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK signaling pathways

BackgroundPulmonary arterial smooth muscle cell (PASMC) proliferation plays a crucial role in hypoxia-induced pulmonary hypertension (HPH). Previous studies have found that resistin-like molecule β (RELM-β) is upregulated de novo in response to hypoxia in cultured human PASMCs (hPASMCs). RELM-β has been reported to promote hPASMC proliferation and is involved in pulmonary vascular remodeling in patients with PAH. However, the expression pattern, effects, and mechanisms of action of RELM-β in HPH remain unclear.MethodsWe assessed the expression pattern, mitogenetic effect, and mechanism of action of RELM-β in a rat HPH model and in hPASMCs.ResultsOverexpression of RELM-β caused hemodynamic changes in a rat model of HPH similar to those induced by chronic hypoxia, including increased mean right ventricular systolic pressure (mRVSP), right ventricular hypertrophy index (RVHI) and thickening of small pulmonary arterioles. Knockdown of RELM-β partially blocked the increases in mRVSP, RVHI, and vascular remodeling induced by hypoxia. The phosphorylation levels of the PI3K, Akt, mTOR, PKC, and MAPK proteins were significantly up- or downregulated by RELM-β gene overexpression or silencing, respectively. Recombinant RELM-β protein increased the intracellular Ca2+ concentration in primary cultured hPASMCs and promoted hPASMC proliferation. The mitogenic effects of RELM-β on hPASMCs and the phosphorylation of PI3K, Akt, mTOR, PKC, and MAPK were suppressed by a Ca2+ inhibitor.ConclusionsOur findings suggest that RELM-β acts as a cytokine-like growth factor in the development of HPH and that the effects of RELM-β are likely to be mediated by the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK pathways.