New Role for Interleukin-13 Receptor α1 in Myocardial Homeostasis and Heart Failure.

BACKGROUND: The immune system plays a pivotal role in myocardial homeostasis and response to injury. Interleukins-4 and -13 are anti-inflammatory type-2 cytokines, signaling via the common interleukin-13 receptor α1 chain and the type-2 interleukin-4 receptor. The role of interleukin-13 receptor α1 in the heart is unknown. METHODS AND RESULTS: We analyzed myocardial samples from human donors (n=136) and patients with end-stage heart failure (n=177). We found that the interleukin-13 receptor α1 is present in the myocardium and, together with the complementary type-2 interleukin-4 receptor chain Il4ra, is significantly downregulated in the hearts of patients with heart failure. Next, we showed that Il13ra1-deficient mice develop severe myocardial dysfunction and dyssynchrony compared to wild-type mice (left ventricular ejection fraction 29.7±9.9 versus 45.0±8.0; P=0.004, left ventricular end-diastolic diameter 4.2±0.2 versus 3.92±0.3; P=0.03). A bioinformatic analysis of mouse hearts indicated that interleukin-13 receptor α1 regulates critical pathways in the heart other than the immune system, such as extracellular matrix (normalized enrichment score=1.90; false discovery rate q=0.005) and glucose metabolism (normalized enrichment score=-2.36; false discovery rate q=0). Deficiency of Il13ra1 was associated with reduced collagen deposition under normal and pressure-overload conditions. CONCLUSIONS: The results of our studies in humans and mice indicate, for the first time, a role of interleukin-13 receptor α1 in myocardial homeostasis and heart failure and suggests a new therapeutic target to treat heart disease.

MicroRNA-143 inhibits IL-13-induced dysregulation of the epidermal barrier-related proteins in skin keratinocytes via targeting to IL-13Rα1.

Atopic dermatitis is a chronic inflammatory skin disease characterized by the dysregulation of the epidermal barrier and the immune system. Interleukin (IL)-13, a key T helper 2 cytokine, has been shown to impair the epidermal barrier function via downregulating epidermal barrier proteins. MicroRNAs are small noncoding RNAs of approximately 22 nucleotides that act as negative regulators of gene expression at posttranscriptional levels. MicroRNA-143 is known to be a tumor suppressor in various tumors; however, its role in the regulation of allergic diseases including atopic dermatitis remains elusive. In this study, we investigated whether IL-13Rα1 was a microRNA-143 target to regulate the effects of IL-13 on epidermal barrier function. After the stimulation of IL-13 in human epidermal keratinocytes, the level of microRNA-143 was decreased. The luciferase activity of the vector containing 3'UTR of IL-13Rα1 was decreased in keratinocytes transfected with microRNA-143 mimic compared to those of the corresponding controls. The forced expression of microRNA-143 mimic blocked the IL-13-induced downregulation of filaggrin, loricrin, and involucrin in epidermal keratinocytes. Collectively, these data suggest that microRNA-143 suppresses IL-13 activity and inflammation through targeting of IL-13Rα1 in epidermal keratinocytes. MicroRNA-143 may serve as a potential preventive and therapeutic target in atopic dermatitis.

Distal airways are protected from goblet cell metaplasia by diminished expression of IL-13 signalling components.

BACKGROUND: Increased mucus production is a critical factor impairing lung function in patients suffering from bronchial asthma, the most common chronic inflammatory lung disease worldwide. OBJECTIVE: This study aimed at investigating whether goblet cell (GC) metaplasia and mucus production are differentially regulated in proximal and distal airways. METHODS: Female Balb/c mice were sensitized to ovalbumin (OVA) and challenged with an OVA-aerosol on two consecutive days for 1 week (acute) or 12 weeks (chronic). Real-time RT-PCR analysis was applied on microdissected airways. RESULTS: In acutely and chronically OVA-challenged mice, GC metaplasia and mucus production were observed in proximal but not in distal airways. In contrast, inflammation reflected by the infiltration of eosinophils and expression of the TH2-type cytokines IL-4 and IL-13 was increased in both proximal and distal airways. Abundance of IL-13Rα1 was lower in distal airways of healthy control mice. Under acute and chronic OVA-exposure, activation of IL-13Rα1-dependent signalling cascade, reflected by Spdef and Foxo3A transcription factors, was attenuated in distal compared to proximal airways. CONCLUSION AND CLINICAL RELEVANCE: These data indicate that distal airways might be less sensitive to IL-13-induced GC metaplasia and mucus production through lower expression of IL-13Rα1 and attenuated activation of downstream signalling. This might represent a protective strategy to prevent mucus plugging of distal airways and thus impaired ventilation of attached alveoli.

Recurrence and cancer-specific survival according to the expression of IL-4Rα and IL-13Rα1 in patients with oral cavity cancer.

BACKGROUND: Interleukin-4 (IL-4) and interleukin-13 (IL-13) are anti-inflammatory and immunomodulatory cytokines that play crucial roles in cancer progression. However, the clinical significance of the expression of these cytokines and their receptors (IL-4R) in oral cavity squamous cell carcinoma (OSCC) is unknown. Therefore, we evaluated the expression of IL-4R in OSCC specimens by immunohistochemistry (IHC) and analysed its relationship to recurrence and survival. METHODS: A total of 186 patients with OSCC were enrolled, and the expression of IL-4Rα and IL-13Rα1 on their primary tumour specimens was evaluated by IHC and correlated to clinicopathologic parameters, recurrence and survival. FINDINGS: High expression of IL-4Rα and IL-13Rα1 was observed in 60 (32.3%) and 165 (88.7%) patients, respectively. IL-4Rα expression was inversely correlated with parameters reflecting primary tumour burden, including tumour size, tumour stage and depth of invasion at the initial diagnosis (P < 0.05). High expression of IL-4Rα also correlated with a greater risk of recurrence (P = 0.002), but was unrelated to cancer-specific survival (CSS, P = 0.118). Conversely, high IL-13Rα1 expression correlated with reduced recurrence (P < 0.001) and increased CSS (P < 0.001) in OSCC patients. INTERPRETATIONS: High expression of IL-4Rα correlated with increased recurrence, while high IL-13Rα1 expression had an inverse relationship to recurrence and CSS in OSCC patients.

The effect to IL-3Ralpha, downstream PI3k/Akt signaling of all-trans retinoic acid and arsenic trioxide in NB4 cells.

All-trans retinoic acid (ATRA) and arsenic trioxide (As2O3) are the classic drugs used for induction therapy of acute promyelocytic leukemia (APL). IL-3Ralpha (CD123) is a specific marker of acute myeloid leukemia stem cells (AML-LSCs). The over-expression of IL-3Ralpha in patients with AML is related to high white blood cells counts, high percentages of blast cells, and poor prognosis. Moreover, in some studies, IL-3Ralpha has been considered a new detection marker of minimal residual disease in the bone marrow from patients with APL. In contrast to ATRA, As2O3 reduces both mRNA and protein expression of IL-3Ralpha and inhibits the activity of PI3K/Akt after 24 h, 48 h, and 72 h of exposure. Furthermore, NB4 cells adhered to the human stroma cell line HS-5 cells were used as an in vitro model of APL cells in the bone marrow microenvironment. Our results demonstrate that adhesion to HS-5 cells up-regulated IL-3Ralpha protein expression and activated the downstream PI3K/Akt signaling pathway in NB4 cells. Compared with ATRA, As2O3 more potently inhibits proliferation of NB4 cells adhered to stroma cells.

Cutting edge: IL-13Rα1 expression in dopaminergic neurons contributes to their oxidative stress-mediated loss following chronic peripheral treatment with lipopolysaccharide.

Inflammation and its mediators, including cytokines and reactive oxygen species, are thought to contribute to neurodegeneration. In the mouse brain, we found that IL-13Rα1 was expressed in the dopaminergic (DA) neurons of the substantia nigra pars compacta, which are preferentially lost in human Parkinson's disease. Mice deficient for Il13ra1 exhibited resistance to loss of DA neurons in a model of chronic peripheral inflammation using bacterial LPS. IL-13, as well as IL-4, potentiated the cytotoxic effects of t-butyl hydroperoxide and hydrogen peroxide on mouse DA MN9D cells. Collectively, our data indicate that expression of IL-13Rα1 on DA neurons can increase their susceptibility to oxidative stress-mediated damage, thereby contributing to their preferential loss. In humans, Il13ra1 lies on the X chromosome within the PARK12 locus of susceptibility to Parkinson's disease, suggesting that IL-13Rα1 may have a role in the pathogenesis of this neurodegenerative disease.

Inhibition of inflammatory mediators: role of statins in airway inflammation.

OBJECTIVE: To determine if statins induce anti-inflammatory effects in upper airway inflammation. Mediators of innate and adaptive immunity regulate airway inflammation. Release of these mediators involves enzymatic conversion of polyunsaturated fatty acids into biologically active mediators, which can be blocked by statins. Although upper airway inflammation and chronic sinusitis occur in millions of patients with asthma worldwide, the anti-inflammatory effects of statins in upper airway inflammation have not been previously studied. STUDY DESIGN: Laboratory research. SETTING: Tertiary referral center. SUBJECTS AND METHODS: Analysis of sinus tissues collected from patients with chronic rhinosinusitis revealed suppression of highly expressed inflammatory mediators in patients who were found to be on statins, suggesting that statins may induce anti-inflammatory effects. Therefore, the authors performed an in vitro study to determine if these anti-inflammatory effects were induced by statins. Cultured primary human airway epithelial cells were exposed to ambient air pollution particulates (PM) to trigger the inflammation, with and without statins, and the expression of inflammatory mediators was analyzed. RESULTS: The authors found that expression of CCL5, CCL11, and IL13RA was suppressed in patients on statins. In vitro exposure to PM enhanced the expression of these mediators, while pretreatment with statins completely blocked these effects. Furthermore, the effects of statins were blocked by inhibition of the statin pathway using isopentenyl-5-pyrophosphate. Statins did not have any significant effect on the viability of normal cells. CONCLUSION: Statins induce anti-inflammatory effects in human airway epithelial inflammation. Statins may play a role in the treatment and prevention of chronic rhinosinusitis and pulmonary exacerbation of obstructive airway diseases.

Human TH17 cells express a functional IL-13 receptor and IL-13 attenuates IL-17A production.

BACKGROUND: IL-13 is a central mediator of airway responsiveness and mucus expression in patients with allergic airway inflammation, and IL-13 is currently a therapeutic target for asthma. However, little is known about how IL-13 regulates human CD4(+) T-cell lineages because IL-13 receptor (IL-13R) α1, a subunit of IL-13R, has not previously been reported to exist on human T cells. OBJECTIVE: We sought to determine whether human CD4(+) T(H)17 cells express IL-13Rα1 and whether IL-13 regulates T(H)17 cytokine production. METHODS: Naive human CD4(+) cells were isolated from whole blood, activated with anti-CD3 and anti-CD28, and polarized to T(H)1, T(H)2, T(H)17, or induced regulatory T cells in the presence of IL-13 (0-10 ng/mL). Cell supernatants, total RNA, or total protein was examined 4 days after T(H)17 polarization. RESULTS: T(H)17 cells, but not T(H)0, T(H)1, T(H)2, or induced regulatory T cells, expressed IL-13Rα1. IL-13 attenuated IL-17A production, as well as expression of retinoic acid-related orphan receptor, runt-related transcription factor-1, and interferon regulatory factor 4 in T(H)17-polarized cells. IL-13 neither inhibited IFN-γ production from T(H)1 cells nor inhibited IL-4 production from T(H)2 cells. Furthermore, attenuation of IL-17A production only occurred when IL-13 was present within 24 hours of T-cell activation or at the time of restimulation. CONCLUSIONS: IL-13Rα1 is expressed on human CD4(+) T(H)17 cells, and IL-13 attenuates IL-17A production at polarization and restimulation. Although IL-13 is an attractive therapeutic target for decreasing symptoms associated with asthma, these results suggest that therapies inhibiting IL-13 production could have adverse side effects by increasing IL-17A production.

Regulation of IL-13 receptor alpha 1 expression and signaling on human tonsillar B-lymphocyte subsets.

BACKGROUND: T(H)2 cytokines play crucial roles in driving human B lymphocytes to produce IgE. However, it is unclear whether IL-4 and IL-13 have parallel or sequential roles in the development of B lymphocytes. OBJECTIVE: We investigated IL-13 receptor (IL-13R) expression and regulation in mature and immature human B cells. METHODS: Purified B cells were isolated from human tonsils. We evaluated IL-13Ralpha1 mRNA expression using real-time PCR and IL-13Ralpha1 and IL-4 receptor (IL-4R) alpha expression using flow cytometry and microscopy. Signal transduction was assessed on the basis of signal transducer and activator of transcription 6 phosphorylation. RESULTS: IL13Ralpha1 mRNA was induced after stimulation with anti-CD40 antibodies, anti-CD40 plus IL-4, or anti-IgM/IgG. Baseline surface IL13Ralpha1 levels were low in unstimulated B cells but increased significantly at 24 hours and were sustained for 5 to 14 days. In contrast, IL4R alpha was constitutively expressed on tonsillar B cells, and levels did not significantly vary after stimulation. B cells activated by CD40 ligation or B-cell receptor cross-linking, but not resting B cells, showed significant increases in signal transducer and activator of transcription 6 phosphorylation in response to IL-13. IL-13Ralpha1 expression was induced on mature and memory B cells, as well as on naive subsets. CONCLUSIONS: There is lower constitutive expression and signaling of IL13Ralpha1 in resting tonsillar B lymphocytes compared with that of IL4R alpha. IL-13 is induced on both immature and mature B lymphocytes. CLINICAL IMPLICATIONS: This implies different roles for IL-4 and IL-13 in B-cell development, which would allow for specific targeting of IL-13 in IgE-mediated diseases.

Mast cells express IL-13R alpha 1: IL-13 promotes human lung mast cell proliferation and Fc epsilon RI expression.

BACKGROUND: The Th2 cytokine interleukin (IL)-13 is implicated in the development of various allergic diseases including asthma. The IL-13 receptor, IL-13Ralpha1, is expressed on most leukocytes, except T-cells. Evidence to support IL-13Ralpha1 expression on mast cells is limited. METHODS: We investigated: (i) IL-13Ralpha1 expression by human lung mast cells (HLMC); (ii) the number of IL-13Ralpha1+ bronchial submucosal mast cells in subjects with asthma and normal controls and (iii) the effect of IL-13 priming on HLMC expression of high-affinity IgE receptor (FcepsilonRI), stem cell factor receptor (CD117), histamine release, proliferation, and survival. RESULTS: Human lung mast cell expressed IL-13Ralpha1 mRNA. IL-13Ralpha1 was highly expressed on the surface HLMC (82+/-9%). Bronchial submucosal mast cell IL-13Ralpha1 expression was higher in asthmatics (86+/-2%) than normal controls (78+/-2%; P=0.015). IL-13 priming for 30 min did not increase HLMC histamine release, in the presence or absence of SCF or in response to IgE/anti-IgE activation. IL-13 priming for 5 days upregulated HLMC FcepsilonRI expression (22% increase in fluorescent intensity; P=0.003), increased histamine release following IgE/anti-IgE activation by 56% (P=0.03) and increased proliferation by 50% (P=0.003) without affecting cell survival or CD117 expression. The IL-13 specific neutralizing antibody CAT-354 inhibited all IL-13 mediated effects. CONCLUSION: Human lung mast cell express IL-13Ralpha1 and activation by IL-13 for 5 days increased FcepsilonRI expression and proliferation. Histamine release was not affected by short-term priming with IL-13, but was upregulated by priming for 5 days suggesting that this effect was mediated by the increased FcepsilonRI expression. These data support the view that targeting IL-13 may be beneficial in the treatment of asthma.