RESUMEN

Gremlin 1 (GREM1) is an antagonist of bone morphogenetic protein (BMP). GREM1 is expressed in the stromal cells of various carcinomas and promotes tumor progression by suppressing BMP signaling. We designed this study to establish an evaluation strategy for GREM1 expression, focusing on the tumor stroma, and to examine its clinicopathological significance in gastric cancer (GC) progression. We employed RNA in situ hybridization (ISH) to evaluate the prognostic value of GREM1 expression in a cohort of 104 surgically resected GC cases and assessed ISH scores according to previous reports. GREM1 expression was observed in tumor stromal cells, including fibroblasts. We defined GREM1-positive cells as those expressing ISH score ≥ 3 and quantified the number of GREM1-positive cells using image analysis software. We examined the relationship between the number of GREM1-positive cells in the tumor stroma and clinicopathological features. The number of GREM1-positive cells per tumor stroma ranged from 0 to 714.7 cells/mm2 (median, 1.65 cells/mm2). We divided the 104 GC cases into GREM1-High and GREM1-Low expression groups based on the abovementioned median value. GREM1-High expression group was significantly associated with a more advanced pT grade, pN grade, lymphatic invasion, and venous invasion. Kaplan-Meier analysis showed significantly poorer survival in the GREM1-High expression group than in the GREM1-Low expression group. These results indicated that GREM1 expression in GC is localized in tumor stromal cells, and that high GREM1 expression in the tumor stroma could be a poor prognostic factor.

RESUMEN

OBJECTIVE: To investigate the biological regulatory function of Gremlin1 (GREM1) and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein eta (YWHAH) in dental pulp stem cells (DPSCs), and determine the underlying molecular mechanism involved. METHODS: Alkaline phosphatase (ALP) activity, alizarin red staining, scratch migration assays and in vitro and in vivo osteo-/dentinogenic marker detection of bone-like tissue generation in nude mice were used to assess osteo-/dentinogenic differentiation. Coimmunoprecipitation and polypeptide microarray assays were employed to detect the molecular mechanisms involved. RESULTS: The data revealed that knockdown of GREM1 promoted ALP activity, mineralisation in vitro and the expression of osteo-/dentinogenic differentiation markers and enhanced osteo-/ dentinogenesis of DPSCs in vivo. GREM1 bound to YWHAH in DPSCs, and the binding site was also identified. Knockdown of YWHAH suppressed the osteo-/dentinogenesis of DPSCs in vitro, and overexpression of YWHAH promoted the osteo-/dentinogenesis of DPSCs in vitro and in vivo. CONCLUSION: Taken together, the findings highlight the critical roles of GREM1-YWHAH in the osteo-/dentinogenesis of DPSCs.

Asunto(s)

RESUMEN

BACKGROUND: Gremlin1 is a multifunctional protein whose expression is demonstrated to be involved in a series of physiology and pathological processes. The association between Gremlin1 and apcial periodontitis (AP) has been established. M1-polarized macrophages are crucial immune cells that exacerbate the progression of apical periodontal inflammatory response, but the function of Gremlin1 during macrophages activation in periapical lesions is still unclear. This study attempts to explore the regulatory effects of Gremlin1 on macrophage polarization on apical periodontitis microenviroment. METHODS: Clinical specimens were used to determine the expression of Gremlin1 in periapical tissues by immunohistochemical (IHC) staining. Then, the disease models of periapical inflammation in rats were established, and adenovirus- associated virus (AAVs) was used to blockade Gremlin1 expression. Lentivirus carrying sh-Gremlin1 particles were used to transfect THP-1 induced M1-subtype macrophages. To assess the expression of associated molecules, Western blot, immunofluorescence staining were performed. RESULTS: Gremlin1 was significantly up-regulated in the periapical tissues of subjects with AP as identified by IHC staining, and positively correlated with levels of M1 macrophage-associated genes. Rats AP model with inhibition of Gremlin1 in periapical lesions exhibited limited infiltration of macrophages and decreased expression of M1 macrophage-related genes in periapical lesions. Furthermore, Gremlin1 blockade substantially decreased the Notch1/Hes1 signaling pathway activation level. The in vitro experiments confirmed the above results. CONCLUSION: Taken together, current study illustrated that the Gremlin1 suppression in periapical lesions inhibited M1 macrophage polarization through Notch1/Hes1 axis. Moreover, Gremlin1 may act as a potential candidate in the treatment of AP.

RESUMEN

A relevant role of osteopontin (OPN) and gremlin 1 (Grem1) in regulating cardiac tissue remodeling and formation of heart failure (HF) are documented, with the changes of OPN and Grem1 levels in blood plasma due to acute ischemia, ischemic heart disease-induced advanced HF or dilatative cardiomyopathy being the primary focus in most of these studies. However, knowledge on the early OPN and Grem1 proteins expression changes within cardiomyocytes during remodeling due to chronic ischemia remains insufficient. The aim of this study was to determine the OPN and Grem1 proteins expression changes in human cardiomyocytes at different stages of ischemic HF. A semi-quantitative immunohistochemical analysis was performed in 105 myocardial tissue samples obtained from the left cardiac ventricles. Increased OPN immunostaining intensity was already detected in the stage A HF group, compared to the control group (p < 0.001), and continued to increase in the stage B HF (p < 0.001), achieving the peak of immunostaining in the stages C/D HF group (p < 0.001). Similar data of Grem1 immunostaining intensity changes in cardiomyocytes were documented. Significantly positive correlations were detected between OPN, Grem1 expression in cardiomyocytes and their diameter as well as the length, in addition to positive correlation between OPN and Grem1 expression changes within cardiomyocytes. These novel findings suggest that OPN and Grem1 contribute significantly to reorganization of cellular geometry from the earliest stage of cardiomyocyte remodeling, providing new insights into the ischemic HF pathogenesis.

Asunto(s)

RESUMEN

Introduction: Investigating how circular RNAs (circRNAs) function during tumorigenesis may help uncover novel diagnostic markers for cancer treatment. The oncogenic role of circ_001621 has been verified in osteosarcoma, but its role in lung cancer has yet to be reported. This research is the first to investigate the circ_001621 expression and regulatory mechanism in lung cancer. Material and methods: RT-qPCR was performed to assess the circ_001621 expression levels in lung cancer cells and tissues. The influence of circ_001621 on the viability, invasive ability, and apoptosis of lung cancer cells was investigated through CCK-8, transwell, and caspase-3 activity experiments, respectively. A xenograft nude mouse model was designed to evaluate how circ_001621 functions in vivo. The RIP and luciferase reporter experiments confirmed the binding among circRNA, miRNA, and mRNA. Results: Circ_001621 was dramatically upregulated in lung cancer tissues and cells. Silencing circ_001621 in lung cancer cells reduced their viability and invasive ability but stimulated apoptosis. The nude mice experiment demonstrated that circ_001621 downregulation considerably stunted tumor growth in vivo. Additionally, circ_001621 could sponge miR-199a-3p. The inhibitor of miR-199a-3p improved the viability and invasion of cells while inhibiting apoptosis. Moreover, it offset the impact of circ_001621 on lung cancer cells. MiR-199a-3p was observed to target GREM1, and the downregulation of GREM1 could counteract miR-199a-3p-induced effects on lung cancer cells. Conclusions: The circ_001621/miR-199a-3p/GREM1 axis exhibits an association with the development of lung cancer, suggesting its potential as a future therapeutic target for the disease.

RESUMEN

Ocular angiogenic diseases, such as proliferative diabetic retinopathy (PDR), are often characterized by pathological new vessels and fibrosis formation. Anti-vascular endothelial growth factor (VEGF) therapy, despite of its efficiency to inhibit new vessels, has limitations, including drug resistance and retinal fibrosis. Here, we identified that Gremlin1, a novel angiogenesis and fibrosis inducer, was secreted from Müller glial cells, and its expression increased in the vitreous fluid from patients with PDR. Mechanistically, Gremlin1 triggered angiogenesis by promoting endothelial-mesenchymal transition via the EGFR/RhoA/ROCK pathway. In addition, Gremlin1 activated microglia to present profibrotic and fibrogenic properties. Further, anti-Gremlin1 antibody inhibited ocular angiogenesis and microglia fibrosis in mouse models. Collectively, Gremlin1 could be a potential therapeutic target in the treatment of ocular angiogenic diseases.

Asunto(s)

RESUMEN

Ephrin B3, a member of Eph/ephrin family, contributes to embryogenesis and carcinogenesis, but few studies have suggested whether this ligand has regulatory effect on colitis. This study was to determine whether ephrin B3 played a role in colitis and colonic carcinogenesis. Dextran sodium sulfate (DSS)-induced colitis and azoxymethane (AOM)/DSS-induced colitis-associated carcinogenesis model was established in Efnb3-deficient (Efnb3-/-) mice. Label-free quantitative proteomics were performed to identify the Efnb3-regulated proteins. Our results showed that Efnb3 knock out reduced the symptoms of DSS-induced colitis, such as disease activity index (DAI), inflammatory factors release, and dysfunction of the intestinal barrier. Quantitative proteomics revealed that Efnb3 regulated 95 proteins which clustered in the platelet degranulation, response to elevated platelet cytosolic Ca2+, MAPK signaling for integrins such as ITGB4. Furthermore, ephrin B3 inactived ITGB4/AKT signal pathway and then promoted epithelial barrier dysfunction. Simultaneously, ephrin B3 promoted Gremlin-1/NF-κB signal pathway and thereby increased inflammatory factors release. In addition, the higher level of Efnb3 in colon cancer patients is correlated with worse survival. Efnb3-/- mice exhibited susceptibility to AOM/DSS-induced colorectal cancer. Our finding discovered that Efnb3 played an important role in the development of colitis and colitis-associated colorectal cancer. Efnb3 deficiency improved the intestinal barrier by ITGB4 and suppressed inflammation via Gremlin-1/NF-κB signal pathway, which may provide a novel therapeutic strategy for the treatment of colitis and colitis-associated colorectal cancer.

Asunto(s)

RESUMEN

Gremlin-1, a high-affinity antagonist of bone morphogenetic proteins (BMP)-2, -4, and -7, is implicated in tumor initiation and progression. Increased gremlin-1 expression, and therefore suppressed BMP signaling, correlates with poor prognosis in a range of cancer types. A lack of published work using therapeutic modalities has precluded the testing of the hypothesis that blocking the gremlin-1/BMP interaction will provide benefits to patients. To address this shortfall, we developed ginisortamab (UCB6114), a first-in-class clinical anti-human gremlin-1 antibody, currently in clinical development for the treatment of cancer, along with its murine analog antibody Ab7326 mouse immunoglobulin G1 (mIgG1). Surface plasmon resonance assays revealed that ginisortamab and Ab7326 mIgG1 had similar affinities for human and mouse gremlin-1, with mean equilibrium dissociation constants of 87 pM and 61 pM, respectively. The gremlin-1/Ab7326 antigen-binding fragment (Fab) crystal structure revealed a gremlin-1 dimer with a Fab molecule bound to each monomer that blocked BMP binding. In cell culture experiments, ginisortamab fully blocked the activity of recombinant human gremlin-1, and restored BMP signaling pathways in human colorectal cancer (CRC) cell lines. Furthermore, in a human CRC - fibroblast co-culture system where gremlin-1 is produced by the fibroblasts, ginisortamab restored BMP signaling in both the CRC cells and fibroblasts, demonstrating its activity in a relevant human tumor microenvironment model. The safety and efficacy of ginisortamab are currently being evaluated in a Phase 1/2 clinical trial in patients with advanced solid tumors (NCT04393298).

Asunto(s)

RESUMEN

BACKGROUND: In the current study, we aimed to assess the levels of Gremlin 1, an adipokine with a rich repertoire of metabolic effects, in association with the glycemic and lipid parameters after sleeve gastrectomy. MATERIAL AND METHODS: This study was conducted on 31 males with obesity aged 25 to 50 years who underwent sleeve gastrectomy. Plasma Gremlin 1 levels were evaluated using enzyme-linked immunosorbent assay (ELISA) at baseline and 6-12 months after the operation, along with body mass index, insulin, glucose, and lipid profile. RESULTS: Plasma Gremlin 1 levels were elevated (148.19±17.43 vs. 193.29±19.82 ng/mL, p < 0.05) after sleeve gastrectomy. This was accompanied by a decrease in body mass index (from 51.47±1.71 to 39.23±1.56 kg/m2, p < 0.05). Insulin and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) also exhibited a significant decrease (19.69±1.81 vs. 8.98±1.09 mIU/L and 6.52±0.98 vs. 2.57±0.036 p < 0.05, respectively) in the postoperative period. Total cholesterol levels were significantly increased after surgery (4.29±0.16 to 5.10±0.16, p < 0.05). Pearson correlation analysis showed that Gremlin 1 was positively correlated with insulin before surgery, but there was no significant correlation after surgery. CONCLUSION: The circulating Gremlin 1 levels were elevated postoperatively among our participants. The improvement in insulin sensitivity appears to be independent of the reported antagonistic effects of Gremlin 1.

RESUMEN

BACKGROUND: Gremlin-1 (GREM1) and Gremlin-2 (GREM2) are bone morphogenetic protein antagonists that play important roles in organogenesis, tissue differentiation, and tissue homeostasis. Although GREM1 has been reported to be involved in promoting various cancers, little has been reported about effects of GREM2 on cancer. Recently, it has been reported that GREM2 can inhibit adipogenesis in adipose-derived stromal/stem cells. However, as an inhibitor of adipogenesis, the role of GREM2 in cancer progression is not well understood yet. METHODS: Pre-adipocyte 3T3-L1 cells overexpressing mock or Grem2 were established using a lentiviral transduction system and differentiated into adipocytes-mock and adipocytes-Grem2, respectively. To investigate the effect of adipocyte-Grem2 on breast cancer cells, we analyzed the proliferative and invasion abilities of spheroids using a 3D co-culture system of breast cancer cells and adipocytes or conditioned medium (CM) of adipocytes. An orthotopic breast cancer mouse model was used to examine the role of adipocytes-Grem2 in breast cancer progression. RESULTS: Grem2 overexpression suppressed adipogenesis of 3T3-L1 cells. Proliferative and invasion abilities of spheroids formed by co-culturing MTV/TM-011 breast cancer cells and adipocytes-Grem2 were significantly reduced compared to those of spheroids formed by co-culturing MTV/TM-011 cells and adipocytes-mock. Compared to adipocytes-mock, adipocytes-Grem2 showed decreased mRNA expression of several adipokines, notably IL-6. The concentration of IL-6 in the CM of these cells was also decreased. Proliferative and invasive abilities of breast cancer cells reduced by adipocytes-Grem2 were restored by IL-6 treatment. Expression levels of vimentin, slug, and twist1 in breast cancer cells were decreased by treatment with CM of adipocytes-Grem2 but increased by IL-6 treatment. In orthotopic breast cancer mouse model, mice injected with both MTV/TM-011 cells and adipocytes-Grem2 showed smaller primary tumors and lower lung metastasis than controls. However, IL-6 administration increased both the size of primary tumor and the number of metastatic lung lesions, which were reduced by adipocytes-Grem2. CONCLUSIONS: Our study suggests that GREM2 overexpression in adipocytes can inhibit adipogenesis, reduce the expression and secretion of several adipokines, including IL-6, and ultimately inhibit breast cancer progression.

Asunto(s)

RESUMEN

GREM1 is a secreted protein that antagonizes bone morphogenetic proteins (BMPs) and participates in critical biological processes, including embryonic development, organogenesis and tissue differentiation. Gremlin 1 (GREM1) is also an inhibitor of TGF-ß and a ligand for vascular endothelial growth factor receptor 2. In addition, GREM1 can induce cells, participate in the process of epithelial-mesenchymal transition, and then participate in tumor development. GREM1 has a variety of biological functions and can participate in the malignant progression of a variety of tumors through the BMP signaling pathway. GREM1 also can inhibit TGF-ß in some tumors, thereby inhibiting tumors, and its involvement in tumor development varies in different types of cancer. The present review examines the role and function of GREM1 in tumors. GREM1 is expressed in a variety of tumor types. GREM1 expression can affect the epithelial-mesenchymal transformation of tumor cells. GREM1 has been studied in breast and colon cancer, and its potential role is to promote cancer. However, in pancreatic cancer, which was found to act differently from other cancer types, overexpression of GREM1 inhibits tumor metastasis. The present review suggests that GREM1 can be a diagnostic and prognostic indicator. In future studies, the study of GREM1 based on single-cell sequencing technology will further clarify its role and function in tumors.

RESUMEN

Background: Anterior cruciate ligament (ACL) injury is recognized as a risk factor for osteoarthritis (OA) progression. Herein, the function of TAF15 in ACL injury-induced OA was investigated. Methods: OA cell model and OA mouse model were established by interleukin-1 beta (IL-1ß) stimulation and ACL transection administration, respectively. The pathological changes were analyzed by histopathology. The mRNA and protein expressions were assessed using qRT-PCR, Western blot and IHC. Chondrocyte viability and apoptosis were examined by CCK8 assay and TUNEL staining, respectively. The interactions between TAF15, BRD4 and GREM1 were analyzed by RIP or ChIP assay. Results: TAF15 expression was markedly elevated in OA, and its knockdown suppressed IL-1ß-induced chondrocyte apoptosis and ECM degradation in vivo and cartilage pathological changes in vitro. TAF15 promoted BRD4 mRNA stability, and TAF15 silencing's repression on chondrocyte apoptosis and ECM degradation induced by IL-1ß was abrogated following BRD4 overexpression. BRD4 promoted GREM1 expression by directly binding with GREM1. In addition, the GREM1/NF-κB pathway functioned as the downstream pathway of BRD4 in promoting OA progression. Conclusion: TAF15 upregulation facilitated chondrocyte apoptosis and ECM degradation during OA development by acting on the BRD4/GREM1/NF-κB axis, which provided a theoretical basis for the development of novel therapies for OA.

RESUMEN

Pro-proliferative, M2-like polarization of macrophages is a critical step in the development of fibrosis and remodeling in chronic lung diseases such as pulmonary fibrosis and pulmonary hypertension. Macrophages in healthy and diseased lungs express gremlin 1 (Grem1), a secreted glycoprotein that acts in both paracrine and autocrine manners to modulate cellular function. Increased Grem1 expression plays a central role in pulmonary fibrosis and remodeling, however, the role of Grem1 in M2-like polarization of macrophages has not previously been explored. The results reported here show that recombinant Grem1 potentiated M2-like polarization of mouse macrophages and bone marrow-derived macrophages (BMDMs) in response to the Th2 cytokines IL4 and IL13. Genetic depletion of Grem1 in BMDMs inhibited M2 polarization while exogenous gremlin 1 could partially rescue this effect. Taken together, these findings reveal that gremlin 1 is required for M2-like polarization of macrophages.NEW & NOTEWORTHY We show here that gremlin 1 potentiated M2 polarization of mouse bone marrow-derived macrophages (BMDMs) in response to the Th2 cytokines IL4 and IL13. Genetic depletion of Grem1 in BMDMs inhibited M2 polarization while exogenous gremlin 1 partially rescued this effect. Taken together, these findings reveal a previously unknown requirement for gremlin 1 in M2 polarization of macrophages and suggest a novel cellular mechanism promoting fibrosis and remodeling in lung diseases.

Asunto(s)

RESUMEN

INTRODUCTION: Gremlin-1 is a peptide that functions as an antagonist to bone morphogenic proteins and is overexpressed in obesity and type 2 diabetes mellitus. Gremlin-1 has not yet been investigated in pregnancy, pregnancy-related insulin resistance or gestational diabetes mellitus (GDM). PATIENTS AND METHODS: Gremlin-1 levels were measured throughout the pregnancy of 58 women at high risk for GDM at the Medical University of Vienna. Furthermore, an oral glucose tolerance test, fasting insulin, fasting glucose, sex hormones, blood lipids, liver and renal parameters, and markers of bone development were evaluated at two points during pregnancy (< 20 weeks of gestation (GW), GW 24-28) and 12-14 weeks postpartum. RESULTS: Gremlin-1 levels decreased from < 20 GW (mean = 9.2 pg/ml, SD = 8.4 pg/ml) to GW 24-28 (mean = 6.7 pg/ml, SD = 5.7 pg/ml, p = 0.033) and increased again postpartum, albeit not significantly (mean = 10.7 pg/ml, SD = 13.1 pg/ml, p = 0.339). During pregnancy, Gremlin-1 levels correlated negatively with osteocalcin and procollagen type I aminoterminal propeptide (P1NP), markers of bone health. Concerning glucose metabolism, Gremlin-1 levels were inversely related to the Insulinogenic Index at GW < 20. However, Gremlin-1 levels were not significantly different between women with normal glucose tolerance and GDM during pregnancy. Postpartum, Gremlin-1 was associated with the fatty liver index, osteocalcin levels, diastolic blood pressure and weight. CONCLUSION: Gremlin-1 levels decreased significantly during pregnancy. The biomarker is not related to GDM status, but correlates negatively with the Insulinogenic Index, an index related to beta cell function. Trial Registry Number ACTRN12616000924459.

Asunto(s)

RESUMEN

BACKGROUND: Long intergenic non-protein-coding RNA 173 (LINC00173) executes vital functions in various cancers. Nevertheless, its role and expression in nasopharyngeal carcinoma (NPC) have yet to be investigated. Here, we investigated its effects on the malignancy characteristics of NPC and elucidated the potential molecular mechanism of LINC00173 in NPC progression. METHODS: Quantitative real-time reverse transcription-PCR (qRT-PCR) and immunoblotting were conducted to estimate the LINC00173, microRNA-765 (miR-765), and Gremlin 1 (GREM1) expressions in NPC cells and tissues. Cell counting kit-8 (CCK8), colony formation, and wound healing experiments were done to evaluate the proliferation, growth, and migration of NPC cells, respectively. The tumorous growth of NPC cells in vivo was assessed through the xenograft tumor experiment. Furthermore, the interactions among miR-765, LINC00173, and GREM1 were investigated through bioinformatics analyses, luciferase reporter and RNA immunoprecipitation chip assays. RESULTS: An upregulated LINC00173 expression was found in NPC cell lines and tissues. The functional experiments uncovered that its downregulation repressed NPC cell proliferation, growth, and migration. In addition, LINC00173 knockdown hampered the NPC cells' tumorous growth in vivo. These effects could partially be reversed by downregulating miR-765. GREM1 is a downstream target of miR-765. GREM1 knockdown could repress the proliferation, growth, and migration of NPC cells. Nonetheless, these anti-tumor effects could be abolished by miR-765 downregulation. Mechanistically, LINC00173 increased the expression of GREM1 by binding with miR-765. CONCLUSIONS: LINC00173 functions as an oncogenic factor by binding with miR-765 to promote the progression of NPC via GREM1 upregulation. This study provides a novel insight into the molecular mechanisms involved in NPC progression.

Asunto(s)

RESUMEN

The role and mechanism of Gremlin-1 in osteoarthritis (OA) were expected to be probed in this study. Firstly, an in vitro OA model was constructed by stimulating human chondrocyte cell line CHON-001 with IL-1ß. Next, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) were utilized for assessing the effect of IL-1ß with different concentrations (5, 10, and 20 ng/mL) on the activity and Gremlin-1 messenger RNA of CHON-001 cells, respectively. Besides, the influence of knocking down/over-expressing Gremlin-1 on the inflammatory factors (IL-6, TNF-α, IL-18 and PGE2), oxidative stress-related substances (malondialdehyde [MDA]; superoxide dismutase [SOD]; lactate dehydrogenase [LDH]), extracellular matrix (ECM) degradation-related proteins, and mitogen-activated protein kinase (MAPK) pathway proteins in IL-1ß-stimulated CHON-001 cells were tested by enzyme-linked immunosorbent assay, related kits, qRT-PCR, and western blot, respectively. IL-1ß inhibited CHON-001 cell proliferation and upregulated Gremlin-1 expression in a concentration-dependent manner. Overexpression of Gremlin-1 increased the IL-6, TNF-α, IL-18, PGE2, and MDA levels, enhanced the LDH activity, and decreased the SOD activity in IL-1ß-induced CHON-001 cells; while the effect of Gremlin-1 knockdown on the above factors was in contrast with that of the overexpression. Furthermore, overexpression of Gremlin-1 upregulated protein expression of matrix metalloproteinase (MMP)-3, MMP-13, and ADAMTS4 while downregulated protein expression of collagen III, aggrecan, and SOX-9 in IL-1ß-stimulated CHON-001 cells. Besides, overexpression of Gremlin-1 increased the p-p38/p38 value while decreased the p-JNK/JNK value in L-1ß-stimulated CHON-001 cells; however, knockdown of Gremlin-1 reversed the above results. Gremlin-1 may promote IL-1ß-stimulated CHON-001 cell inflammation and ECM degradation by activating the MAPK signaling pathway.

Asunto(s)

RESUMEN

Background: Coal worker's pneumoconiosis (CWP) is a chronic occupational disease mainly caused by coal dust inhalation in miners. This study aimed to investigate the clinical value of Osteopontin (OPN), KL-6, Syndecan-4 and Gremlin-1 as serum biomarkers in CWP. Patients and Methods: We integrated reported lung tissues transcriptome data in pneumoconiosis patients with silica-exposed alveolar macrophage microarray data to identify four CWP-associated serum biomarkers. The serum concentrations of Osteopontin, Krebs von den Lungen-6 (KL-6), Syndecan-4 and Gremlin-1 were measured in 100 healthy controls (HCs), 100 dust-exposed workers (DEWs) and 200 patients of CWP. Receiver operating characteristic (ROC) curve analysis was used to determine the sensitivity, specificity, cut-off value and area under the curve (AUC) value of biomarkers. Results: The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups. Among all participants, multivariable analysis revealed that these four biomarkers were negatively correlated with the pulmonary function parameters (all p<0.05). Compared with HCs, patients with higher OPN, KL-6, Syndecan-4 and Gremlin-1 had higher risk for CWP. The combination of OPN, KL-6, and Syndecan-4 can improve the diagnostic sensitivity and specificity of CWP patients differentiated from HCs or DEWs. Conclusion: OPN, KL-6 and Syndecan-4 are novel biomarkers that can be used for CWP auxiliary diagnosis. The combination of three biomarkers can improve the diagnostic values of CWP.

RESUMEN

Atrial fibrillation (AF) is the most common chronic arrhythmia presenting a heavy disease burden. We report a new approach for generating cardiomyocytes (CMs) resembling atrial cells from human-induced pluripotent stem cells (hiPSCs) using a combination of Gremlin 2 and retinoic acid treatment. More than 40% of myocytes showed rod-shaped morphology, expression of CM proteins (including ryanodine receptor 2, α-actinin-2 and F-actin) and striated appearance, all of which were broadly similar to the characteristics of adult atrial myocytes (AMs). Isolated myocytes were electrically quiescent until stimulated to fire action potentials with an AM profile and an amplitude of approximately 100 mV, arising from a resting potential of approximately -70 mV. Single-cell RNA sequence analysis showed a high level of expression of several atrial-specific transcripts including NPPA, MYL7, HOXA3, SLN, KCNJ4, KCNJ5 and KCNA5. Amplitudes of calcium transients recorded from spontaneously beating cultures were increased by the stimulation of α-adrenoceptors (activated by phenylephrine and blocked by prazosin) or ß-adrenoceptors (activated by isoproterenol and blocked by CGP20712A). Our new approach provides human AMs with mature characteristics from hiPSCs which will facilitate drug discovery by enabling the study of human atrial cell signalling pathways and AF. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.

Asunto(s)

RESUMEN

Leptin regulates energy balance via leptin receptors expressed in central and peripheral tissues, but little is known about leptin-sensitive kidney genes and the role of the tubular leptin receptor (Lepr) in response to a high-fat diet (HFD). Quantitative RT-PCR analysis of Lepr splice variants A, B, and C revealed a ratio of ∼100:10:1 in the mouse kidney cortex and medulla, with medullary levels being ∼10 times higher. Leptin replacement in ob/ob mice for 6 days reduced hyperphagia, hyperglycemia, and albuminuria, associated with normalization of kidney mRNA expression of molecular markers of glycolysis, gluconeogenesis, amino acid synthesis, and megalin. Normalization of leptin for 7 h in ob/ob mice did not normalize hyperglycemia or albuminuria. Tubular knockdown of Lepr [Pax8-Lepr knockout (KO)] and in situ hybridization revealed a minor fraction of Lepr mRNA in tubular cells compared with endothelial cells. Nevertheless, Pax8-Lepr KO mice had lower kidney weight. Moreover, while HFD-induced hyperleptinemia, increases in kidney weight and glomerular filtration rate, and a modest blood pressure lowering effect were similar compared with controls, they showed a blunted rise in albuminuria. Use of Pax8-Lepr KO and leptin replacement in ob/ob mice identified acetoacetyl-CoA synthetase and gremlin 1 as tubular Lepr-sensitive genes that are increased and reduced by leptin, respectively. In conclusion, leptin deficiency may increase albuminuria via systemic metabolic effects that impinge on kidney megalin expression, whereas hyperleptinemia may induce albuminuria by direct tubular Lepr effects. Implications of Lepr variants and the novel tubular Lepr/acetoacetyl-CoA synthetase/gremlin 1 axis remain to be determined.NEW & NOTEWORTHY This study provides new insights into kidney gene expression of leptin receptor splice variants, leptin-sensitive kidney gene expression, and the role of the leptin receptor in renal tubular cells for the response to diet-induced hyperleptinemia and obesity including albuminuria.

Asunto(s)

RESUMEN

Gremlin-1 (GR1) is a novel adipokine that is highly expressed in human adipocytes and has been shown to inhibit the BMP2/4-TGFb signaling pathway. It has an effect on insulin sensitivity. Elevated levels of Gremlin have been shown to lead to insulin resistance in skeletal muscle, adipocytes, and hepatocytes. In this study, we investigated the effect of GR1 on hepatic lipid metabolism under hyperlipidemic conditions and explored the molecular mechanisms associated with GR1 by in vitro and in vivo studies. We found that palmitate increased GR1 expression in visceral adipocytes. Recombinant GR1 increased lipid accumulation, lipogenesis, and ER stress markers in cultured primary hepatocytes. Treatment with GR1 increased EGFR expression and mTOR phosphorylation and reduced autophagy markers. EGFR or rapamycin siRNA reduced the effects of GR1 on lipogenic lipid deposition and ER stress in cultured hepatocytes. Administration of GR1 via the tail vein induced lipogenic proteins and ER stress while suppressing autophagy in the livers of experimental mice. Suppression of GR1 by in vivo transfection reduced the effects of a high-fat diet on hepatic lipid metabolism, ER stress, and autophagy in mice. These results suggest that the adipokine GR1 promotes hepatic ER stress due to the impairment of autophagy, ultimately causing hepatic steatosis in the obese state. The current study demonstrated that targeting GR1 may be a potential therapeutic approach for treating metabolic diseases, including metabolic-associated fatty liver disease (MAFLD).

Asunto(s)