Interleukin-19 Research Articles

Effects of Interleukin-19 overexpression in the medial prefrontal cortex on anxiety-related behaviors, BDNF expression and p38/JNK/ERK pathways

Anxiety is a prevalent mental illness known for its high incidence, comorbidity, and tendency to recur, posing significant societal and individual burdens. Studies have highlighted Interleukin-19 (IL-19) as having potential relevance in neuropsychiatric disorders. Our previous research revealed that IL-19 overexpression in colonies exacerbated anxiety-related behaviors induced by dextran sodium sulfate/stress. However, the precise role and molecular mechanisms of IL-19 in anxiety regulation remain uncertain. In this study, we initiated an acute restraint stress (ARS)-induced anxious mouse model and identified heightened expression of IL-19 and IL-20Rα in the medial prefrontal cortex (mPFC) of ARS mice. Notably, IL-19 and IL-20Rα were predominantly present in the excitatory pyramidal neurons of the mPFC under both basal and ARS conditions. Utilizing the adeno-associated virus (AAV) strategy, we demonstrated that IL-19 overexpression in the mPFC induced anxiety-related behaviors and elevated stress susceptibility. Additionally, we observed decreased protein levels of brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95) in the mPFC of IL-19 overexpression mice, accompanied by reduced phosphorylation of in the p38, JNK, and Erk signaling pathways. These findings emphasize the role of IL-19 in modulating anxiety-related behaviors within the mPFC and suggest its potential as a pathological gene and therapeutic target for anxiety.

Abstract LB323: Deciphering the immunomodulatory role of IL-19 in glioblastoma-promoting ecosystem: Insights into glioblastoma stem cell-tumor-associated macrophage symbiosis

Abstract Glioblastoma multiforme (GBM) stands out as a highly aggressive and resistant brain tumor, characterized by profound immunosuppression and chemoresistance, resulting in a dismal 5% survival rate at the five-year mark. Glioblastoma Stem Cells (GSCs) drive the progression of GBM, orchestrating tumor initiation, growth, and therapeutic resistance. The symbiotic interplay between GSCs and tumor-associated macrophages (TAMs) within hypoxic and perivascular niches is pivotal for sustaining tumorigenesis and immunosuppression. In this study, Interleukin-19 (IL-19), a member of the IL-10 family, was identified among the top five immune-related genes strongly associated with poor survival in patients with GBM from TCGA and Taiwan GBM cohorts. However, the function of IL-19 in glioblastoma is completely unknown. Genomic screening identified IL-19 as a predicted immunosuppressive cytokine in the peritumoral region, associated with poor survival in GBM patients. Blocking IL-19 inhibits both temozolomide (TMZ)-sensitive and TMZ-resistant tumor progression. Molecular studies revealed that IL-19 promotes TMZ-resistant GBM cell migration and invasion through a novel IL-19/β-catenin/WISP1 signaling. Single-cell transcriptome analysis showed that blocking IL-19 promotes T cell activation, upregulates the effector function of T cell subsets, and reprograms TAM subsets toward weakened pro-tumoral phenotypes with lower Arginase 1 expression. Silencing IL-19 significantly disrupts self-renewal GSC activity through a novel IL-19/S100A4/WISP1 signaling. Additionally, we identified that TAM-derived IL-19 positively regulates GSC self-renewal through the paracrine IL-19/WISP1 axis. Our study demonstrates IL-19 as a linchpin in the complex GSC-TAM symbiosis, leading to GSC maintenance and immunosuppression, providing critical insights into the immune landscape orchestrated by GSC-TAM symbiosis Citation Format: Gilbert Aaron Lee, Cheng-Yu Chen. Deciphering the immunomodulatory role of IL-19 in glioblastoma-promoting ecosystem: Insights into glioblastoma stem cell-tumor-associated macrophage symbiosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB323.

Interleukin-19 in Bone Marrow Contributes to Bone Loss Via Suppressing Osteogenic Differentiation Potential of BMSCs in Old Mice.

Cellular senescence is an important process related to the pathogenic mechanism of different disorders, especially bone loss. During senescence, bone marrow stromal cells (BMSCs) lose their self-renewal and functional differentiation abilities. Therefore, finding signals opposing the osteogenic differentiation of BMSCs within bone marrow microenvironment is the important for elucidating these above-mentioned mechanisms. Inflammatory cytokines affect bone physiology and remodeling. However, the function of interleukin-19 (IL-19) in skeletal system remains unclear. The mouse model of IL-19 knockout was established through embryonic stem cell injection for analyzing how IL-19 affected bone formation. Micro-CT examinations were performed to evaluate bone microstructures. We performed a three-point bending test to measure bone stiffness and the ultimate force. Antibody arrays were performed to detect interleukin family members in bone marrow aspirates. BMSCs were cultured and induced for osteogenic differentiation. According to our findings, there was increased IL-19 accumulation within bone marrow in old mice relative to that in their young counterparts, resulting in bone loss via the inhibition of BMSCs osteogenic differentiation. Among Wnt/β-catenin pathway members, IL-19 strongly upregulated sFRP1 via STAT3 phosphorylation. The inhibition of STAT3 and sFRP1 abolished IL-19's inhibition against the BMSCs osteogenic differentiation. To sum up, IL-19 inhibited BMSCs osteogenic differentiation in old mice. Our findings shed novel lights on pathogenic mechanism underlying age-related bone loss and laid a foundation for further research on identifying novel targets to treat senile osteoporosis.

Deciphering the Receptor-Mediated Signaling Pathways of Interleukin-19 and Interleukin-20.

Interleukin-19 (IL-19) and Interleukin-20 (IL-20) are inflammatory cytokines belonging to the IL-10 family with immunoregulatory properties. Emerging evidence highlights the importance of association of these cytokines with both immunological and inflammatory disorders, including chronic inflammation, cardiac dysfunction, and cancer. IL-19 and IL-20 bind to the heterodimeric receptor complex and induce multiple downstream signaling cascades by activating the signal transducer and activator of transcription 3 (STAT3), Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), AKT serine/threonine kinase 1 (AKT1), and NFKB inhibitor alpha (NFKBIA), leading to proinflammatory and anti-inflammatory reactions in cancer, inflammation, tumor microenvironment, and infectious diseases. Considering the significant role of these cytokines, we integrated its cellular signaling network by combining multiomics molecular events associated with 56 molecules of induced by IL-19 and 156 molecules of by IL-20. The reactions of these signaling events are classified into enzyme catalysis/post-translational modifications, activation/inhibition events, molecular associations, gene regulations at the mRNA and protein level, and the protein translocation events. We believe that this signaling pathway map would serve as a knowledge base, that aid researchers and clinicians to understand and explore the intricate mechanisms and identify novel signaling components and therapeutic targets for diseases associated with dysregulated IL-19 and IL-20 signaling.

PSTPIP2 ameliorates aristolochic acid nephropathy by suppressing interleukin-19-mediated neutrophil extracellular trap formation.

Aristolochic acid nephropathy (AAN) is a progressive kidney disease caused by herbal medicines. Proline-serine-threonine phosphatase-interacting protein 2 (PSTPIP2) and neutrophil extracellular traps (NETs) play important roles in kidney injury and immune defense, respectively, but the mechanism underlying AAN regulation by PSTPIP2 and NETs remains unclear. We found that renal tubular epithelial cell (RTEC) apoptosis, neutrophil infiltration, inflammatory factor, and NET production were increased in a mouse model of AAN, while PSTPIP2 expression was low. Conditional knock-in of Pstpip2 in mouse kidneys inhibited cell apoptosis, reduced neutrophil infiltration, suppressed the production of inflammatory factors and NETs, and ameliorated renal dysfunction. Conversely, downregulation of Pstpip2 expression promoted kidney injury. In vivo, the use of Ly6G-neutralizing antibody to remove neutrophils and peptidyl arginine deiminase 4 (PAD4) inhibitors to prevent NET formation reduced apoptosis, alleviating kidney injury. In vitro, damaged RTECs released interleukin-19 (IL-19) via the PSTPIP2/nuclear factor (NF)-κB pathway and induced NET formation via the IL-20Rβ receptor. Concurrently, NETs promoted apoptosis of damaged RTECs. PSTPIP2 affected NET formation by regulating IL-19 expression via inhibition of NF-κB pathway activation in RTECs, inhibiting RTEC apoptosis, and reducing kidney damage. Our findings indicated that neutrophils and NETs play a key role in AAN and therapeutic targeting of PSTPIP2/NF-κB/IL-19/IL-20Rβ might extend novel strategies to minimize Aristolochic acid I-mediated acute kidney injury and apoptosis.

Serum Interleukin-19 Levels in Acne Vulgaris Patients of Varying Clinical Severity in Erbil City.

Background Acne vulgaris (AV) is a common multifactorial disorder affecting the pilosebaceous units. Research has shown that inflammation plays a crucial role in the pathogenesis of AV, including both inflammatory and non-inflammatory acne. Several studies have linked proinflammatory cytokines to AV; however, only a few have explored the correlation between interleukin-19 (IL-19) and AV. Our aim is to estimate the level of IL-19 in patients with AV compared to matched controls and to investigate the role of IL-19 in the pathogenesis of acne. Materials and methods This prospective cross-sectional case and control study includes 80 patients and 40 matched controls. Patients were divided into mild (20), moderate (40), and severe (20) groups based on their global acne score severity index. Detailed history and complete general and dermatological examinations were taken from each patient. Furthermore, 5 ml of blood was taken from all participants to assess the level of IL-19. Results IL-19 levels were significantly higher in patients with AV compared to matched controls. Furthermore, IL-19 concentrations were found to be proportional to the severity of acne, with the highest levels detected in patients with severe AV (p-value <0.005). Conclusion IL-19 levels in AV were significantly higher than in matched control. The difference was proportional to its severity. This might indicate IL-19 as an inflammatory marker and could potentially be related to AV.

Abstract 13070: Interleukin-19 Regulates Lymphatic Permeability and Induces Prox1-Dependent Lymphangiogenesis

Introduction: Increased lymphangiogenesis is associated with atherosclerosis, but whether it is disease-causative or a compensatory attempt to attenuate disease is currently unresolved. Recent studies suggest lymphatic permeability plays a role in reverse cholesterol transport (RCT) as a possible mechanism for attenuating atherosclerosis. We previously reported that that Interleukin-19 (IL-19), an immunomodulatory cytokine, is unique by inducing angiogenesis while reducing atherosclerosis. The purpose of this study was to test the hypothesis that IL-19 could be atheroprotective by inducing functional lymphangiogenesis and promoting lymphatic flux. Methods &amp; Results: RNA sequencing of IL-19-treated human Lymphatic Endothelial Cells (hLEC) identified induction of chemokines, pro-lymphangiogenic, and permeability-associated genes. Prox1, the master regulator of lymphatic formation, was increased by six-fold, validated by qPCR and western blot. Cellular assays further demonstrated IL-19-associated lymphangiogenesis through hLEC proliferation, migration, and tube formation, each mitigated by Prox1 siRNA knockdown. Angpt2, a regulator of permeability through VE-cadherin, is also upregulated by IL-19 and mitigated by Prox1 siRNA knockdown. Electric Cell-substrate Impedance Sensing (ECIS) showed that IL-19 mitigates oxLDL-associated decreases in permeability, suggestive of preventing lymphatic barrier malfunction during atherosclerosis. Preliminary in vivo lymphatic permeability assays suggest injection of rmIL-19 improves lymphatic function in conditional lymphatic-specific Prox1 heterozygous mice. Conversely, similar experiments show that Il19 / LDLR double knockout mice, which are known to have exacerbated atherosclerosis, also have significantly decreased lymphatic permeability compared to LDLR -/- mice after 16-weeks of high fat diet. Conclusion: These data suggest that IL-19 is a previously unrecognized regulator of lymphatic function as it increases lymphangiogenesis and permeability, with the potential to improve RCT. Together, these effects may regulate atherosclerosis, and influence our understanding of the association between the lymphatic system and atherosclerosis.

Interleukin-19 promotes bone resorption by suppressing osteoprotegerin expression in BMSCs in a lipopolysaccharide-induced bone loss mouse model

AimsOsteoporosis is characterized by decreased trabecular bone volume, and microarchitectural deterioration in the medullary cavity. Interleukin-19 (IL-19), a member of the IL-10 family, is an anti-inflammatory cytokine produced primarily by macrophages. The aim of our study was to investigate the effect of IL-19 on osteoporosis.MethodsBlood and femoral bone marrow suspension IL-19 levels were first measured in the lipopolysaccharide (LPS)-induced bone loss model. Small interfering RNA (siRNA) was applied to knock down IL-19 for further validation. Thereafter, osteoclast production was stimulated with IL-19 in combination with mouse macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). The effect of IL-19 was subsequently evaluated using tartrate-resistant acid phosphatase (TRAP) staining and quantitative real-time polymerase chain reaction (RT-qPCR). The effect of IL-19 on osteoprotegerin (OPG) was then assessed using in vitro recombinant IL-19 treatment of primary osteoblasts and MLO-Y4 osteoblast cell line. Finally, transient transfection experiments and chromatin immunoprecipitation (ChIP) experiments were used to examine the exact mechanism of action.ResultsIn the LPS-induced bone loss mouse model, the levels of IL-19 in peripheral blood serum and femoral bone marrow suspension were significantly increased. The in vivo results indicated that global IL-19 deletion had no significant effect on RANKL content in the serum and bone marrow, but could increase the content of OPG in serum and femoral bone marrow, suggesting that IL-19 inhibits OPG expression in bone marrow mesenchymal stem cells (BMSCs) and thus increases bone resorption.ConclusionIL-19 promotes bone resorption by suppressing OPG expression in BMSCs in a LPS-induced bone loss mouse model, which highlights the potential benefits and side effects of IL-19 for future clinical applications.Cite this article: Bone Joint Res 2023;12(11):691–701.

Elucidation of interleukin-19 as a therapeutic target for breast cancer by computational analysis and experimental validation

Interleukin 19 (IL-19) is a cytokine produced by monocytes and belongs to the family of IL-10. The IL-19 protein stimulates fibronectin (FN) expression and assembly, metastasis, and cell division in breast cancer (BC) cells. IL-19, which is connected to breast pathogenesis and has an autocrine action in BC cells, is a key predictor of prognosis for many tumour forms, including breast cancer. Augmented IL-19 expression has been related to poorer clinical outcomes for patients with BC and directly enhances proliferation and migration while also serving as a microenvironment for tumour formation. The main aim of our study was to examine the expression profile, functional role, and prognostic significance of interleukin-19 in BC pathogenesis and also to find out the molecular mechanism of IL-19 in BC. In this work, we used the various computational approach and tools, to evaluate the expression profile and prognostic implication of IL-19 in BC and discover the role of IL-19 in BC pathogenesis. IL-19 was shown to be highly upregulated in BC as compared to other interleukins. Also, its levels were highly overexpressed in liminal BC patients, mostly in 3rd stage groups under the age group of 21–40 years. IL-19 levels were increased in BC and elevated expression of IL-19 was examined to have worse overall survival (OS). The KEGG analysis andgene ontology of IL-19 depict that IL-19 is significantly augmented in cytokine activity and receptor-ligand activity and also in the JAK-STAT signaling pathway. Moreover, IL-19 showed a high correlation with IL20RA, as later is involved with the JAK-STAT signaling pathway. The in-vivo and in-vitro studies have also reflected that upregulation of IL-19 enhances tumor development and affects clinical outcomes in BC patients through several pathways including the JAK TAT signalling pathway. Overall, our study indicates that IL-19 increases tumour growth and that inhibiting it in addition to standard treatments will greatly improve BC patient’s therapeutic responses.

Abstract 712: IL-19 Is A Lymphokine That Induces Prox1-dependent Lymphangiogenesis And Permeability

Introduction: Atherosclerosis is a vascular inflammatory disease associated with lymphangiogenesis, but whether lymphangiogenesis contributes to disease progression or is simply a compensatory attempt at disease resolution is currently unresolved. Recent studies are revealing a role for lymphatic vessels in reverse cholesterol transport (RCT), which could attenuate atherosclerosis. We have previously reported that Interleukin-19 (IL-19), an anti-inflammatory cytokine, uniquely attenuates atherosclerotic plaque progression while also being pro-angiogenic. This drives our hypothesis that one mechanism whereby IL-19 is atheroprotective is by promoting functional lymphangiogenesis and lymphatic flux. Methods &amp; Results: IL-19 can significantly induce human dermal lymphatic endothelial cell (hdLEC) proliferation, migration, and tube formation, to the same degree as VEGFC, a potent inducer of lymphangiogenesis. RNA sequencing analysis indicates that IL-19 induces an angiogenic transcriptional program through Prox1, a master regulator of lymphangiogenesis. Knockdown of Prox1 led to a significant decrease in IL-19-associated proliferation and migration. IL-19 also increased expression of Angpt2, an endothelial cell protein that induces permeability through regulation of tight junctions, through a Prox1-dependent mechanism. Electric Cell-substrate Impedance Sensing assays showed that IL-19 treatment increased hdLEC permeability and mitigated oxLDL-associated decreased permeability, suggestive of maintaining lymphatic barrier function during atherosclerosis. IL-19 treatment also increased dil-HDL transport across an hdLEC barrier. Preliminary in vivo data suggests injection of rmIL-19 in Il19 -/- mice increases lymphatic permeability and flux through increased lymphatic uptake of Evans blue dye. Conclusion: These data suggest that IL-19 increases lymphangiogenesis, permeability, and may increase RCT to plausibly decrease atherosclerosis. These results can influence our understanding of the association between the lymphatic system and atherosclerosis.

Translational perspective on bone-derived cytokines in inter-organ communications

Translational perspective on bone-derived cytokines in inter-organ communications

1,25-Dihydroxyvitamin D3 Negatively Regulates the Inflammatory Response to Porcine Epidemic Diarrhea Virus Infection by Inhibiting NF-κB and JAK/STAT Signaling Pathway in IPEC-J2 Porcine Epithelial Cells.

Porcine epidemic diarrhea virus (PEDV) infection causes watery diarrhea and vomiting in piglets. The pathogenesis of PEDV infection is related to intestinal inflammation. It is known that 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has potent anti-inflammatory activity, but it is unknown whether 1,25(OH)2D3 can inhibit the PEDV-induced inflammatory response and the underlying mechanism. We used transcriptome analysis, gene and protein expression, RNA interference and overexpression, and other techniques to study the anti-inflammatory effects of 1,25(OH)2D3 on PEDV infection in IPEC-J2 cells. The results showed that interleukin 19 (IL-19) and C-C motif chemokine ligand 20 (CCL20) gene expression were enhanced with the increase in PEDV infection time in IPEC-J2 cells. Interestingly, 1,25(OH)2D3 supplementation obviously inhibited IL-19 and CCL20 expression induced by PEDV. Meanwhile, we also found that 1,25(OH)2D3 reduced p-NF-κB, p-STAT1, and p-STAT3 protein levels induced by PEDV at 24 h post-infection. IκBα and SOCS3, NF-κB, and STAT inhibitor respectively, were increased by 1,25(OH)2D3 supplementation upon PEDV infection. In addition, 1,25(OH)2D3 supplementation inhibited ISG15 and MxA expression induced by PEDV. Although 1,25(OH)2D3 suppressed the JAK/STAT signal pathway and antiviral gene expression, it had no significant effects on PEDV replication and IFN-α-induced antiviral effects. In addition, when the vitamin D receptor (VDR) was silenced by siRNA, the anti-inflammatory effect of 1,25(OH)2D3 was inhibited. Meanwhile, the overexpression of VDR significantly downregulated IL-19 and CCL20 expression induced by PEDV infection. Together, our results provide powerful evidence that 1,25(OH)2D3 could alleviate PEDV-induced inflammation by regulating the NF-κB and JAK/STAT signaling pathways through VDR. These results suggest that vitamin D could contribute to inhibiting intestinal inflammation and alleviating intestinal damage in PEDV-infected piglets, which offers new approaches for the development of nutritional strategies to prevent PEDV infection in piglets.

IL‐19 Regulates Atherosclerotic Plaque Progression via Lymphangiogenesis

IntroductionCardiovascular diseases are the leading cause of deaths globally, representing approximately 31% of deaths per year, 85% of which are due to myocardial infarction (MI) or stroke. This does not account for the millions of patients suffering daily with current therapies that are not efficacious in treating the root cause of MI and stroke, atherosclerosis, by reducing inflammation or increasing reverse cholesterol transport (RCT). Atherosclerosis is a vascular inflammatory disease characterized by the formation of fatty plaques which can rupture, leading vessel occlusion. Lymphangiogenesis is the process whereby lymphatic vessels are generated, but its role in atherogenesis is currently under‐characterized and controversial. It has been suggested that lymphangiogenesis is either protective by promoting plaque regression through RCT or it is deleterious by promoting plaque instability through white blood cell trafficking. Our lab has previously reported that Interleukin‐19 (IL‐19), an anti‐inflammatory cytokine, uniquely attenuates atherosclerotic plaque progression while also being pro‐angiogenic. This drives our hypothesis that one mechanism whereby IL‐19 is atheroprotective is by driving lymphangiogenesis, allowing attenuation of plaque progression.Methods &amp; ResultsSeveral approaches were performed to test the hypothesis that IL‐19 is lymphangiogenic. IL‐19 can significantly induce primary human lymphatic endothelial cell (LEC) proliferation, migration, and tube formation, all angiogenic assays, to the same degree as VEGF‐C, a known mediator of lymphangiogenesis. RNA sequencing (RNAseq) analysis indicates that IL‐19 induces chemokine expression as well as an angiogenic transcriptional program in LECs. Notably it induces expression of Prox1, a master transcription factor of lymphangiogenesis, 6.2‐fold. The increases of chemokine and transcription factor expression from RNAseq were verified through qPCR analysis. To further analyze the translational effects of IL‐19, we utilized an LDL Receptor Knockout (LDLR‐/‐) mouse model fed a high fat diet for 16‐weeks with daily injections of either recombinant mouse IL‐19 or saline. Preliminary results suggest an increase in lymphatic vessel presence associated with the known decrease IL‐19 causes in atherosclerotic plaque progression.Conclusion &amp; SummaryThese data suggest that IL‐19 increases lymphatic vessel formation, potentially allowing RCT to take place to decrease plaque burden in atherosclerosis. Further studies will confirm IL‐19’s mechanistic pathway in LECs. We will also determine RCT and inflammatory cell trafficking by intravital microscopy. These results have the potential to shift our understanding toward a positive view of the association between the lymphatic system and atherosclerosis.

Abstract 497: IL-19 Induces Lymphangiogenesis Through A Prox1-dependent Mechanism

Introduction: The role of lymphangiogenesis in atherogenesis is currently under-characterized and controversial. It has been suggested that lymphangiogenesis is either protective by promoting plaque regression through reverse cholesterol transport (RCT) or deleterious by promoting plaque instability through white blood cell trafficking. We have previously reported that Interleukin-19 (IL-19), an anti-inflammatory cytokine, uniquely attenuates atherosclerotic plaque progression while also being pro-angiogenic. This drives our hypothesis that one mechanism whereby IL-19 is atheroprotective is by promoting lymphangiogenesis. Methods &amp; Results: IL-19 can significantly induce primary human lymphatic endothelial cell (LEC) proliferation, migration, and tube formation, all angiogenic assays, to the same degree as VEGF-C, a known mediator of lymphangiogenesis. RNA sequencing (RNAseq) analysis indicates that IL-19 induces expression of chemokines as well as several angiogenic transcription factors in LECs. Notably, it induces expression of Prox1, a master transcription factor of lymphangiogenesis, 6.2-fold. The increases seen in chemokine and transcription factor expression from RNAseq were verified through qPCR analysis. Subsequent Prox1 siRNA knockdown prevented IL-19 associated LEC proliferation and migration. We then utilized an LDL Receptor Knockout mouse model fed a high fat diet for 16-weeks with daily injections of either recombinant mouse IL-19 or saline. Preliminary results suggest an increase in lymphatic vessel presence is associated with the known decrease IL-19 causes in atherosclerotic plaque progression. Transendothelial resistance assays were performed to determine IL-19's effect on lymphatic cell permeability. Preliminary data suggests that IL-19 alters LEC resistance, indicative of permeability and possibly RCT. We will also continue to evaluate RCT and inflammatory cell trafficking via intravital microscopy. Conclusion: These data suggest that IL-19 increases lymphatic vessel formation, likely through a Prox1-dependent mechanism. These results have the potential to shift our understanding toward a positive view of lymphangiogenesis and attenuation of atherosclerosis.

Effect of Microbiota in the Development of Breast Cancer.

Breast cancer is the most frequent cancer among women and causes the greatest number of cancer-related death among women all over the world. It approximately accounts for 15% of all cancer death. The human microbiota is the term applied to the aggregate of microbes that live in different habitats of living organisms 'bodies, including the gut, skin, vagina, and mouth, as well as nose, conjunctiva, pharynx, and urethra, among others. Increasing evidence is pointing to the role of the microbiome in the occurrence and development of a variety of cancers. Intestinal microbiome imbalance is related to the occurrence of gastrointestinal tumors, such as esophageal, gastric, colorectal, and gallbladder cancer. The present study aimed to identify the role of microbiota in the development of breast cancer. The women with breast cancer (n=130) in this study were in the age range of 25-75 years. The study was conducted in Kirkuk city of Iraq from September 10, 2019, to March 15, 2020. The control group included 20 women diagnosed with benign breast lesions in the age range 25-75 years, who matched the women in the patient group. Blood samples and breast tissue samples were taken from patients with breast cancer and benign breast lesions. Blood samples were examined through immunological methods, enzyme-linked immunosorbent assay (ELISA) was adopted for the detection of interleukin-19 (IL-19). Breast tissue samples were taken from breast cancer and benign breast lesions patients to isolate and identify bacteria. Based on the obtained results, only 6 out of 30 (20%) cultured breast tissue samples from women with breast cancer showed bacterial growth. In total, 4 (67%) and 2(33%) of these 6 positive cultures were Escherichia coli was and Staphylococcus aureus, respectively, and this relation was statistically significant. However, no bacterial growth was observed on the cultured breast tissue samples taken from women with benign breast lesions. Moreover, the difference between women with a positive and negative result of bacterial culture and stages of breast cancer was statistically non-significant. It is worth mentioning that 50 % of women with breast cancer and bacterial growth were within the age range of 40-49 year. The present study revealed that the difference between women with breast cancer and those with benign breast lesions was statistically highly significant according to the place of residence. In addition, the mean level of IL-19 among women with breast cancer was lower than that in women with benign breast lesions, and this relation was statistically highly significant.

Interleukin 19 suppresses RANKL-induced osteoclastogenesis via the inhibition of NF-κB and p38MAPK activation and c-Fos expression in RAW264.7 cells

Interleukin 19 (IL-19) is a member of the IL-10 family of cytokines and is known as an inhibitory cytokine. IL-10, also an inhibitory cytokine, suppresses the receptor activator of nuclear factor κB (NF-κB) ligand (RANKL)-induced osteoclast differentiation. However, the effects of IL-19 on osteoclast differentiation are not currently well-understood. In this study, we examined whether IL-19 suppresses osteoclast differentiation in the mouse macrophage-like cell line RAW264.7. We found that IL-19 inhibited RANKL-induced osteoclast differentiation. In addition, IL-19 suppressed RANKL-induced NF-κB and p38 mitogen-activated protein kinase (p38MAPK) activation and c-Fos expression. Moreover, RANKL inhibited IL-19 mRNA expression and secretion in RAW264.7 cells, and the inhibition of the IL-19 function promoted osteoclast differentiation. These results indicate that IL-19 suppressed osteoclast differentiation via the inhibition of NF-κB and p38MAPK activation and c-Fos expression. Furthermore, IL-19 may maintain the osteoclast precursor state, such as monocytes and macrophages. These findings may be useful in the development of osteoclast inhibitors, thereby improving treatments for osteoclast activation-related diseases, such as osteoporosis.

Association of BCL2 polymorphisms and the IL19 single nucleotide polymorphism rs2243188 with systemic lupus erythematosus.

ObjectiveAbnormal B cell lymphoma-2 (Bcl-2) and interleukin-19 (IL-19) expression is closely related to systemic lupus erythematosus (SLE) pathogenesis. We aimed to determine whether BCL2 polymorphisms and a single nucleotide polymorphism (SNP) of IL19 are significantly associated with SLE susceptibility and if this is affected by synergism between IL19 and BCL2 genotypes.MethodsThis observational cohort study randomly enrolled 150 patients with SLE and 150 healthy controls. Major BCL2 and IL19 allele and genotype distributions were examined in the two groups. The IL19 SNP rs2243188 was determined using the TaqMan-MGB probe method. The synergistic effect between BCL2 and IL19 and clinical symptoms of SLE was also analyzed.ResultsThe distribution of major BCL2 genotypes and common BCL2 alleles, especially for genotypes 191, 193, and 197, differed significantly between patients and controls. A significant difference in the dominant genetic model was also observed between groups, but not in the recessive model. The risk of disease in individuals who carried both 195-bp BCL2 and 138-bp IL19 susceptibility alleles was higher than in those carrying either allele alone.ConclusionsThis preliminary study suggested that BCL2 polymorphisms and the IL19 SNP rs2243188 are closely related to the pathogenesis of SLE.

Ablation of interleukin-19 improves motor function in a mouse model of amyotrophic lateral sclerosis

Neuroinflammation by activated microglia and astrocytes plays a critical role in progression of amyotrophic lateral sclerosis (ALS). Interleukin-19 (IL-19) is a negative-feedback regulator that limits pro-inflammatory responses of microglia in an autocrine and paracrine manner, but it remains unclear how IL-19 contributes to ALS pathogenesis. We investigated the role of IL-19 in ALS using transgenic mice carrying human superoxide dismutase 1 with the G93A mutation (SOD1G93A Tg mice). We generated IL-19–deficient SOD1G93A Tg (IL-19−/−/SOD1G93A Tg) mice by crossing SOD1G93A Tg mice with IL-19−/− mice, and then evaluated disease progression, motor function, survival rate, and pathological and biochemical alternations in the resultant mice. In addition, we assessed the effect of IL-19 on glial cells using primary microglia and astrocyte cultures from the embryonic brains of SOD1G93A Tg mice and IL-19−/−/SOD1G93A Tg mice. Expression of IL-19 in primary microglia and lumbar spinal cord was higher in SOD1G93A Tg mice than in wild-type mice. Unexpectedly, IL-19−/−/SOD1G93A Tg mice exhibited significant improvement of motor function. Ablation of IL-19 in SOD1G93A Tg mice increased expression of both neurotoxic and neuroprotective factors, including tumor necrosis factor-α (TNF-α), IL-1β, glial cell line–derived neurotrophic factor (GDNF), and transforming growth factor β1, in lumbar spinal cord. Primary microglia and astrocytes from IL-19−/−/SOD1G93A Tg mice expressed higher levels of TNF-α, resulting in release of GDNF from astrocytes. Inhibition of IL-19 signaling may alleviate ALS symptoms.

Interleukin-19 Abrogates Experimental Autoimmune Encephalomyelitis by Attenuating Antigen-Presenting Cell Activation.

Interleukin-19 (IL-19) acts as a negative-feedback regulator to limit proinflammatory response of macrophages and microglia in autocrine/paracrine manners in various inflammatory diseases. Multiple sclerosis (MS) is a major neuroinflammatory disease in the central nervous system (CNS), but it remains uncertain how IL-19 contributes to MS pathogenesis. Here, we demonstrate that IL-19 deficiency aggravates experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by promoting IL-17-producing helper T cell (Th17 cell) infiltration into the CNS. In addition, IL-19-deficient splenic macrophages expressed elevated levels of major histocompatibility complex (MHC) class II, co-stimulatory molecules, and Th17 cell differentiation-associated cytokines such as IL-1β, IL-6, IL-23, TGF-β1, and TNF-α. These observations indicated that IL-19 plays a critical role in suppression of MS pathogenesis by inhibiting macrophage antigen presentation, Th17 cell expansion, and subsequent inflammatory responses. Furthermore, treatment with IL-19 significantly abrogated EAE. Our data suggest that IL-19 could provide significant therapeutic benefits in patients with MS.

Osteocytes regulate neutrophil development through IL-19: a potent cytokine for neutropenia treatment

Osteocytes are the most abundant (90% to 95%) cells in bone and have emerged as an important regulator of hematopoiesis, but their role in neutrophil development and the underlying mechanisms remain unclear. Interleukin 19 (IL-19) produced predominantly by osteocytes stimulated granulopoiesis and neutrophil formation, which stimulated IL-19 receptor (IL-20Rβ)/Stat3 signaling in neutrophil progenitors to promote their expansion and neutrophil formation. Mice with constitutive activation of mechanistic target of rapamycin complex (mTORC1) signaling in osteocytes (Dmp1-Cre) exhibited a dramatic increase in IL-19 production and promyelocyte/myelocytic expansion, whereas mTORC1 inactivation in osteocytes reduced IL-19 production and neutrophil numbers in mice. We showed that IL-19 administration stimulated neutrophil development, whereas neutralizing endogenous IL-19 or depletion of its receptor inhibited the process. Importantly, low-dose IL-19 reversed chemotherapy, irradiation, or chloramphenicol-induced neutropenia in mice more efficiently than granulocyte colony-stimulating factor. This evidence indicated that IL-19 was an essential regulator of neutrophil development and a potent cytokine for neutropenia treatment.