Study on a Highly Thermostable Dy3+-Activated Borophosphate Phosphor.

Constructing a phosphor with multifunctional applications is an imperative challenge. Especially, highly thermostable luminescence of phosphor is indispensable for stable white-light-emitting diodes (LEDs). Nevertheless, good thermal quenching resistance behavior is unfavorable for a fluorescence intensity ratio (FIR)-based optical temperature sensor. Herein, a highly thermostable Ba3(ZnB5O10)PO4 (BZBP)-based phosphor is successfully achieved via replacing Ba2+ with Dy3+, demonstrating simultaneously promising lighting and thermometry utilizations. Under the excitation of 350 nm, the title phosphor only loses 12% of the initial intensity when the temperature is up to 473 K, ensuring sufficient luminescence thermostability for white-LED lighting. The white-LED device fabricated using the title phosphor emits high-quality white light with a high color rendering index (Ra = 93) and low correlated color temperature (CCT = 3996 K). Meanwhile, the yellow and blue emission intensities demonstrate a downtrend difference with rising temperature. Temperature sensing properties are assessed through FIR technology. The maximal relative sensitivity reaches as high as 0.0379 K-1 at 298 K. These results reveal that the title phosphor has a great potential for indoor lighting and thermometry applications.

Cationic proteins from eosinophils bind bone morphogenetic protein receptors promoting vascular calcification and atherogenesis.

AIMS: Blood eosinophil count and eosinophil cationic protein (ECP) concentration are risk factors of cardiovascular diseases. This study tested whether and how eosinophils and ECP contribute to vascular calcification and atherogenesis. METHODS AND RESULTS: Immunostaining revealed eosinophil accumulation in human and mouse atherosclerotic lesions. Eosinophil deficiency in ΔdblGATA mice slowed atherogenesis with increased lesion smooth muscle cell (SMC) content and reduced calcification. This protection in ΔdblGATA mice was muted when mice received donor eosinophils from wild-type (WT), Il4-/-, and Il13-/- mice or mouse eosinophil-associated-ribonuclease-1 (mEar1), a murine homologue of ECP. Eosinophils or mEar1 but not interleukin (IL) 4 or IL13 increased the calcification of SMC from WT mice but not those from Runt-related transcription factor-2 (Runx2) knockout mice. Immunoblot analyses showed that eosinophils and mEar1 activated Smad-1/5/8 but did not affect Smad-2/3 activation or expression of bone morphogenetic protein receptors (BMPR-1A/1B/2) or transforming growth factor (TGF)-ß receptors (TGFBR1/2) in SMC from WT and Runx2 knockout mice. Immunoprecipitation showed that mEar1 formed immune complexes with BMPR-1A/1B but not TGFBR1/2. Immunofluorescence double-staining, ligand binding, and Scatchard plot analysis demonstrated that mEar1 bound to BMPR-1A and BMPR-1B with similar affinity. Likewise, human ECP and eosinophil-derived neurotoxin (EDN) also bound to BMPR-1A/1B on human vascular SMC and promoted SMC osteogenic differentiation. In a cohort of 5864 men from the Danish Cardiovascular Screening trial and its subpopulation of 394 participants, blood eosinophil counts and ECP levels correlated with the calcification scores of different arterial segments from coronary arteries to iliac arteries. CONCLUSION: Eosinophils release cationic proteins that can promote SMC calcification and atherogenesis using the BMPR-1A/1B-Smad-1/5/8-Runx2 signalling pathway.

Eosinophils protect pressure overload- and ß-adrenoreceptor agonist-induced cardiac hypertrophy.

AIMS: Blood eosinophil (EOS) counts and EOS cationic protein (ECP) levels associate positively with major cardiovascular disease (CVD) risk factors and prevalence. This study investigates the role of EOS in cardiac hypertrophy. METHODS AND RESULTS: A retrospective cross-section study of 644 consecutive inpatients with hypertension examined the association between blood EOS counts and cardiac hypertrophy. Pressure overload- and ß-adrenoreceptor agonist isoproterenol-induced cardiac hypertrophy was produced in EOS-deficient ΔdblGATA mice. This study revealed positive correlations between blood EOS counts and left ventricular (LV) mass and mass index in humans. ΔdblGATA mice showed exacerbated cardiac hypertrophy and dysfunction, with increased LV wall thickness, reduced LV internal diameter, and increased myocardial cell size, death, and fibrosis. Repopulation of EOS from wild-type (WT) mice, but not those from IL4-deficient mice ameliorated cardiac hypertrophy and cardiac dysfunctions. In ΔdblGATA and WT mice, administration of ECP mEar1 improved cardiac hypertrophy and function. Mechanistic studies demonstrated that EOS expression of IL4, IL13, and mEar1 was essential to control mouse cardiomyocyte hypertrophy and death and cardiac fibroblast TGF-ß signalling and fibrotic protein synthesis. The use of human cardiac cells yielded the same results. Human ECP, EOS-derived neurotoxin, human EOS, or murine recombinant mEar1 reduced human cardiomyocyte death and hypertrophy and human cardiac fibroblast TGF-ß signalling. CONCLUSION: Although blood EOS counts correlated positively with LV mass or LV mass index in humans, this study established a cardioprotective role for EOS IL4 and cationic proteins in cardiac hypertrophy and tested a therapeutic possibility of ECPs in this human CVD.

Differential IL18 signaling via IL18 receptor and Na-Cl co-transporter discriminating thermogenesis and glucose metabolism regulation.

White adipose tissue (WAT) plays a role in storing energy, while brown adipose tissue (BAT) is instrumental in the re-distribution of stored energy when dietary sources are unavailable. Interleukin-18 (IL18) is a cytokine playing a role in T-cell polarization, but also for regulating energy homeostasis via the dimeric IL18 receptor (IL18r) and Na-Cl co-transporter (NCC) on adipocytes. Here we show that IL18 signaling in metabolism is regulated at the level of receptor utilization, with preferential role for NCC in brown adipose tissue (BAT) and dominantly via IL18r in WAT. In Il18r-/-Ncc-/- mice, high-fat diet (HFD) causes more prominent body weight gain and insulin resistance than in wild-type mice. The WAT insulin resistance phenotype of the double-knockout mice is recapitulated in HFD-fed Il18r-/- mice, whereas decreased thermogenesis in BAT upon HFD is dependent on NCC deletion. BAT-selective depletion of either NCC or IL18 reduces thermogenesis and increases BAT and WAT inflammation. IL18r deletion in WAT reduces insulin signaling and increases WAT inflammation. In summary, our study contributes to the mechanistic understanding of IL18 regulation of energy metabolism and shows clearly discernible roles for its two receptors in brown and white adipose tissues.

Microbial dysbiosis and childhood asthma development: Integrated role of the airway and gut microbiome, environmental exposures, and host metabolic and immune response.

Asthma is a chronic and heterogeneous respiratory disease with many risk factors that typically originate during early childhood. A complex interplay between environmental factors and genetic predisposition is considered to shape the lung and gut microbiome in early life. The growing literature has identified that changes in the relative abundance of microbes (microbial dysbiosis) and reduced microbial diversity, as triggers of the airway-gut axis crosstalk dysregulation, are associated with asthma development. There are several mechanisms underlying microbial dysbiosis to childhood asthma development pathways. For example, a bacterial infection in the airway of infants can lead to the activation and/or dysregulation of inflammatory pathways that contribute to bronchoconstriction and bronchial hyperresponsiveness. In addition, gut microbial dysbiosis in infancy can affect immune development and differentiation, resulting in a suboptimal balance between innate and adaptive immunity. This evolving dysregulation of secretion of pro-inflammatory mediators has been associated with persistent airway inflammation and subsequent asthma development. In this review, we examine current evidence around associations between the airway and gut microbial dysbiosis with childhood asthma development. More specifically, this review focuses on discussing the integrated roles of environmental exposures, host metabolic and immune responses, airway and gut microbial dysbiosis in driving childhood asthma development.

IL18 signaling causes islet ß cell development and insulin secretion via different receptors on acinar and ß cells.

Diabetic patients show elevated plasma IL18 concentrations. IL18 has two receptors: the IL18 receptor (IL18r) and the Na-Cl co-transporter (NCC). Here, we report that IL18 is expressed on islet α cells, NCC on ß cells, and IL18r on acinar cells in human and mouse pancreases. The deficiency of these receptors reduces islet size, ß cell proliferation, and insulin secretion but increases ß cell apoptosis and exocrine macrophage accumulation after diet-induced glucose intolerance or streptozotocin-induced hyperglycemia. Together with the glucagon-like peptide-1 (GLP1), IL18 uses the NCC and GLP1 receptors on ß cells to trigger ß cell development and insulin secretion. IL18 also uses the IL18r on acinar cells to block hyperglycemic pancreas macrophage expansion. The ß cell-selective depletion of the NCC or acinar-cell-selective IL18r depletion reduces glucose tolerance and insulin sensitivity with impaired ß cell proliferation, enhanced ß cell apoptosis and macrophage expansion, and inflammation in mouse hyperglycemic pancreas. IL18 uses NCC, GLP1r, and IL18r to maintain islet ß cell function and homeostasis.

Eosinophils Protect Mice From Angiotensin-II Perfusion-Induced Abdominal Aortic Aneurysm.

RATIONALE: Blood eosinophil count and ECP (eosinophil cationic protein) associate with human cardiovascular diseases. Yet, whether eosinophils play a role in cardiovascular disease remains untested. The current study detected eosinophil accumulation in human and murine abdominal aortic aneurysm (AAA) lesions, suggesting eosinophil participation in this aortic disease. OBJECTIVE: To test whether and how eosinophils affect AAA growth. METHODS AND RESULTS: Population-based randomized clinically controlled screening trials revealed higher blood eosinophil count in 579 male patients with AAA than in 5063 non-AAA control (0.236±0.182 versus 0.211±0.154, 109/L, P<0.001). Univariate (odds ratio, 1.381, P<0.001) and multivariate (odds ratio, 1.237, P=0.031) logistic regression analyses indicated that increased blood eosinophil count in patients with AAA served as an independent risk factor of human AAA. Immunostaining and immunoblot analyses detected eosinophil accumulation and eosinophil cationic protein expression in human and murine AAA lesions. Results showed that eosinophil deficiency exacerbated AAA growth with increased lesion inflammatory cell contents, matrix-degrading protease activity, angiogenesis, cell proliferation and apoptosis, and smooth muscle cell loss using angiotensin-II perfusion-induced AAA in Apoe-/- and eosinophil-deficient Apoe-/-ΔdblGATA mice. Eosinophil deficiency increased lesion chemokine expression, muted lesion expression of IL (interleukin) 4 and eosinophil-associated-ribonuclease-1 (mEar1 [mouse EOS-associated-ribonuclease-1], human ECP homolog), and slanted M1 macrophage polarization. In cultured macrophages and monocytes, eosinophil-derived IL4 and mEar1 polarized M2 macrophages, suppressed CD11b+Ly6Chi monocytes, and increased CD11b+Ly6Clo monocytes. mEar1 treatment or adoptive transfer of eosinophil from wild-type and Il13-/- mice, but not eosinophil from Il4-/- mice, blocked AAA growth in Apoe-/-ΔdblGATA mice. Immunofluorescent staining and immunoblot analyses demonstrated a role for eosinophil IL4 and mEar1 in blocking NF-κB (nuclear factor-κB) activation in macrophages, smooth muscle cells, and endothelial cells. CONCLUSIONS: Eosinophils play a protective role in AAA by releasing IL4 and cationic proteins such as mEar1 to regulate macrophage and monocyte polarization and to block NF-κB activation in aortic inflammatory and vascular cells.

Eosinophils improve cardiac function after myocardial infarction.

Clinical studies reveal changes in blood eosinophil counts and eosinophil cationic proteins that may serve as risk factors for human coronary heart diseases. Here we report an increase of blood or heart eosinophil counts in humans and mice after myocardial infarction (MI), mostly in the infarct region. Genetic or inducible depletion of eosinophils exacerbates cardiac dysfunction, cell death, and fibrosis post-MI, with concurrent acute increase of heart and chronic increase of splenic neutrophils and monocytes. Mechanistic studies reveal roles of eosinophil IL4 and cationic protein mEar1 in blocking H2O2- and hypoxia-induced mouse and human cardiomyocyte death, TGF-ß-induced cardiac fibroblast Smad2/3 activation, and TNF-α-induced neutrophil adhesion on the heart endothelial cell monolayer. In vitro-cultured eosinophils from WT mice or recombinant mEar1 protein, but not eosinophils from IL4-deficient mice, effectively correct exacerbated cardiac dysfunctions in eosinophil-deficient ∆dblGATA mice. This study establishes a cardioprotective role of eosinophils in post-MI hearts.

Reduced Nhe1 (Na+-H+ Exchanger-1) Function Protects ApoE-Deficient Mice From Ang II (Angiotensin II)-Induced Abdominal Aortic Aneurysms.

IgE-mediated activation of Nhe1 (Na+-H+ exchanger-1) induces aortic cell extracellular acidification and promotes cell apoptosis. A pH-sensitive probe pHrodo identified acidic regions at positions of macrophage accumulation, IgE expression, and cell apoptosis in human and mouse abdominal aortic aneurysm (AAA) lesions. Ang II (angiotensin II)-induced AAA in Nhe1-insufficient Apoe-/-Nhe1+/- mice and Apoe-/-Nhe1+/+ littermates tested Nhe1 activity in experimental AAA, because Nhe1-/- mice develop ataxia and epileptic-like seizures and die early. Nhe1 insufficiency reduced AAA incidence and size, lesion macrophage and T-cell accumulation, collagen deposition, elastin fragmentation, cell apoptosis, smooth muscle cell loss, and MMP (matrix metalloproteinase) activity. Nhe1 insufficiency also reduced blood pressure and the plasma apoptosis marker TCTP (translationally controlled tumor protein) but did not affect plasma IgE. While pHrodo localized the acidic regions to macrophage clusters, IgE expression, and cell apoptosis in AAA lesions from Apoe-/-Nhe1+/+ mice, such acidic areas were much smaller in lesions from Apoe-/-Nhe1+/- mice. Nhe1-FcεR1 colocalization in macrophages from AAA lesions support a role of IgE-mediated Nhe1 activation. Gelatin zymography, immunoblot, and real-time polymerase chain reaction analyses demonstrated that Nhe1 insufficiency reduced the MMP activity, cysteinyl cathepsin expression, IgE-induced apoptosis, and NF-κB activation in macrophages and blocked IgE-induced adhesion molecule expression in endothelial cells. A near-infrared fluorescent probe (LS662) together with fluorescence reflectance imaging of intact aortas showed reduced acidity in AAA lesions from Nhe-1-insufficient mice. This study revealed extracellular acidity at regions rich in macrophages, IgE expression, and cell apoptosis in human and mouse AAA lesions and established a direct role of Nhe1 in AAA pathogenesis.

Adipocytes promote interleukin-18 binding to its receptors during abdominal aortic aneurysm formation in mice.

AIMS: Obesity is a risk factor of abdominal aortic aneurysm (AAA). Inflammatory cytokine interleukin-18 (IL18) has two receptors: IL18 receptor (IL18r) and Na-Cl co-transporter (NCC). In human and mouse AAA lesions, IL18 colocalizes to its receptors at regions rich in adipocytes, suggesting a role of adipocytes in promoting IL18 actions in AAA development. METHODS AND RESULTS: We localized both IL18r and NCC in human and mouse AAA lesions. Murine AAA development required both receptors. In mouse AAA lesions, IL18 binding to these receptors increased at regions enriched in adipocytes or adjacent to perivascular adipose tissue. 3T3-L1 adipocytes enhanced IL18 binding to macrophages, aortic smooth muscle cells (SMCs), and endothelial cells by inducing the expression of both IL18 receptors on these cells. Adipocytes also enhanced IL18r and IL18 expression from T cells and macrophages, AAA-pertinent protease expression from macrophages, and SMC apoptosis. Perivascular implantation of adipose tissue from either diet-induced obese mice or lean mice but not that from leptin-deficient ob/ob mice exacerbated AAA development in recipient mice. Further experiments established an essential role of adipocyte leptin and fatty acid-binding protein 4 (FABP4) in promoting IL18 binding to macrophages and possibly other inflammatory and vascular cells by inducing their expression of IL18, IL18r, and NCC. CONCLUSION: Interleukin-18 uses both IL18r and NCC to promote AAA formation. Lesion adipocyte and perivascular adipose tissue contribute to AAA pathogenesis by releasing leptin and FABP4 that induce IL18, IL18r, and NCC expression and promote IL18 actions.

Shared genetic and experimental links between obesity-related traits and asthma subtypes in UK Biobank.

BACKGROUND: Clinical and epidemiologic studies have shown that obesity is associated with asthma and that these associations differ by asthma subtype. Little is known about the shared genetic components between obesity and asthma. OBJECTIVE: We sought to identify shared genetic associations between obesity-related traits and asthma subtypes in adults. METHODS: A cross-trait genome-wide association study (GWAS) was performed using 457,822 subjects of European ancestry from the UK Biobank. Experimental evidence to support the role of genes significantly associated with both obesity-related traits and asthma through a GWAS was sought by using results from obese versus lean mouse RNA sequencing and RT-PCR experiments. RESULTS: We found a substantial positive genetic correlation between body mass index and later-onset asthma defined by asthma age of onset at 16 years or greater (Rg = 0.25, P = 9.56 × 10-22). Mendelian randomization analysis provided strong evidence in support of body mass index causally increasing asthma risk. Cross-trait meta-analysis identified 34 shared loci among 3 obesity-related traits and 2 asthma subtypes. GWAS functional analyses identified potential causal relationships between the shared loci and Genotype-Tissue Expression (GTEx) quantitative trait loci and shared immune- and cell differentiation-related pathways between obesity and asthma. Finally, RNA sequencing data from lungs of obese versus control mice found that 2 genes (acyl-coenzyme A oxidase-like [ACOXL] and myosin light chain 6 [MYL6]) from the cross-trait meta-analysis were differentially expressed, and these findings were validated by using RT-PCR in an independent set of mice. CONCLUSIONS: Our work identified shared genetic components between obesity-related traits and specific asthma subtypes, reinforcing the hypothesis that obesity causally increases the risk of asthma and identifying molecular pathways that might underlie both obesity and asthma.

Calcium-activated chloride channel regulator 1 (CLCA1): More than a regulator of chloride transport and mucus production.

CLCA1 is a member of the CLCA (calcium-activated chloride channel regulator) family and plays an essential role in goblet cell mucus production from the respiratory tract epithelium. CLCA1 also regulates Ca2+-dependent Cl- transport that involves the channel protein transmembrane protein 16A (TMEM16A) and its accessary molecules. CLCA1 modulates epithelial cell chloride current and participates in the pathogenesis of mucus hypersecretory-associated respiratory and gastrointestinal diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, pneumonia, colon colitis, cystic fibrosis intestinal mucous disease, ulcerative colitis, and gastrointestinal parasitic infection. Most studies have been focused on the expression regulation of CLCA1 in human specimens. Limited studies used the CLCA1-deficient mice and CLCA1 blocking agents and yielded inconsistent conclusions regarding its role in these diseases. CLCA1 not only regulates mucin expression, but also participates in innate immune responses by binding to yet unidentified molecules on inflammatory cells for cytokine and chemokine production. CLCA1 also targets lymphatic endothelial cells and cancer cells by regulating lymphatic cell proliferation and lymphatic sinus growth in the lymphatic organs and controlling cancer cell differentiation, proliferation, and apoptosis, all which depend on the location of the lymphatic vessels, the type of cancers, the presence of Th2 cytokines, and possibly the availability and type of CLCA1-binding proteins. Here we summarize available studies related to these different activities of CLCA1 to assist our understanding of how this secreted modifier of calcium-activated chloride channels (CaCCs) affects mucus production and innate immunity during the pathogenesis of respiratory, gastrointestinal, and malignant diseases.

Shared genetics of asthma and mental health disorders: a large-scale genome-wide cross-trait analysis.

Epidemiological studies demonstrate an association between asthma and mental health disorders, although little is known about the shared genetics and causality of this association. Thus, we aimed to investigate shared genetics and the causal link between asthma and mental health disorders.We conducted a large-scale genome-wide cross-trait association study to investigate genetic overlap between asthma from the UK Biobank and eight mental health disorders from the Psychiatric Genomics Consortium: attention deficit hyperactivity disorder (ADHD), anxiety disorder (ANX), autism spectrum disorder, bipolar disorder, eating disorder, major depressive disorder (MDD), post-traumatic stress disorder and schizophrenia (sample size 9537-394 283).In the single-trait genome-wide association analysis, we replicated 130 previously reported loci and discovered 31 novel independent loci that are associated with asthma. We identified that ADHD, ANX and MDD have a strong genetic correlation with asthma at the genome-wide level. Cross-trait meta-analysis identified seven loci jointly associated with asthma and ADHD, one locus with asthma and ANX, and 10 loci with asthma and MDD. Functional analysis revealed that the identified variants regulated gene expression in major tissues belonging to the exocrine/endocrine, digestive, respiratory and haemic/immune systems. Mendelian randomisation analyses suggested that ADHD and MDD (including 6.7% sample overlap with asthma) might increase the risk of asthma.This large-scale genome-wide cross-trait analysis identified shared genetics and potential causal links between asthma and three mental health disorders (ADHD, ANX and MDD). Such shared genetics implicate potential new biological functions that are in common among them.

Na+-H+ exchanger 1 determines atherosclerotic lesion acidification and promotes atherogenesis.

The pH in atherosclerotic lesions varies between individuals. IgE activates macrophage Na+-H+ exchanger (Nhe1) and induces extracellular acidification and cell apoptosis. Here, we show that the pH-sensitive pHrodo probe localizes the acidic regions in atherosclerotic lesions to macrophages, IgE, and cell apoptosis. In Apoe-/- mice, Nhe1-deficiency or anti-IgE antibody reduces atherosclerosis and blocks lesion acidification. Reduced atherosclerosis in Apoe-/- mice receiving bone marrow from Nhe1- or IgE receptor FcεR1-deficient mice, blunted foam cell formation and signaling in IgE-activated macrophages from Nhe1-deficient mice, immunocomplex formation of Nhe1 and FcεR1 in IgE-activated macrophages, and Nhe1-FcεR1 colocalization in atherosclerotic lesion macrophages support a role of IgE-mediated macrophage Nhe1 activation in atherosclerosis. Intravenous administration of a near-infrared fluorescent pH-sensitive probe LS662, followed by coregistered fluorescent molecular tomography-computed tomography imaging, identifies acidic regions in atherosclerotic lesions in live mice, ushering a non-invasive and radiation-free imaging approach to monitor atherosclerotic lesions in live subjects.

Genetic overlap of chronic obstructive pulmonary disease and cardiovascular disease-related traits: a large-scale genome-wide cross-trait analysis.

BACKGROUND: A growing number of studies clearly demonstrate a substantial association between chronic obstructive pulmonary disease (COPD) and cardiovascular diseases (CVD), although little is known about the shared genetics that contribute to this association. METHODS: We conducted a large-scale cross-trait genome-wide association study to investigate genetic overlap between COPD (Ncase = 12,550, Ncontrol = 46,368) from the International COPD Genetics Consortium and four primary cardiac traits: resting heart rate (RHR) (N = 458,969), high blood pressure (HBP) (Ncase = 144,793, Ncontrol = 313,761), coronary artery disease (CAD)(Ncase = 60,801, Ncontrol = 123,504), and stroke (Ncase = 40,585, Ncontrol = 406,111) from UK Biobank, CARDIoGRAMplusC4D Consortium, and International Stroke Genetics Consortium data. RESULTS: RHR and HBP had modest genetic correlation, and CAD had borderline evidence with COPD at a genome-wide level. We found evidence of local genetic correlation with particular regions of the genome. Cross-trait meta-analysis of COPD identified 21 loci jointly associated with RHR, 22 loci with HBP, and 3 loci with CAD. Functional analysis revealed that shared genes were enriched in smoking-related pathways and in cardiovascular, nervous, and immune system tissues. An examination of smoking-related genetic variants identified SNPs located in 15q25.1 region associated with cigarettes per day, with effects on RHR and CAD. A Mendelian randomization analysis showed a significant positive causal effect of COPD on RHR (causal estimate = 0.1374, P = 0.008). CONCLUSION: In a set of large-scale GWAS, we identify evidence of shared genetics between COPD and cardiac traits.

Deficiency of mouse mast cell protease 4 mitigates cardiac dysfunctions in mice after myocardium infarction.

Mouse mast cell protease-4 (mMCP4) is a chymase that has been implicated in cardiovascular diseases, including myocardial infarction (MI). This study tested a direct role of mMCP4 in mouse post-MI cardiac dysfunction and myocardial remodeling. Immunoblot and immunofluorescent double staining demonstrated mMCP4 expression in cardiomyocytes from the infarct zone from mouse heart at 28 day post-MI. At this time point, mMCP4-deficient Mcpt4-/- mice showed no difference in survival from wild-type (WT) control mice, yet demonstrated smaller infarct size, improved cardiac functions, reduced macrophage content but increased T-cell accumulation in the infarct region compared with those of WT littermates. mMCP4-deficiency also reduced cardiomyocyte apoptosis and expression of TGF-ß1, p-Smad2, and p-Smad3 in the infarct region, but did not affect collagen deposition or α-smooth muscle actin expression in the same area. Gelatin gel zymography and immunoblot analysis revealed reduced activities of matrix metalloproteinases and expression of cysteinyl cathepsins in the myocardium, macrophages, and T cells from Mcpt4-/- mice. Immunoblot analysis also found reduced p-Smad2 and p-Smad3 in the myocardium from Mcpt4-/- mice, yet fibroblasts from Mcpt4-/- mice showed comparable levels of p-Smad2 and p-Smad3 to those of WT fibroblasts. Flow cytometry, immunoblot analysis, and immunofluorescent staining demonstrated that mMCP4-deficiency reduced the expression of proapoptotic cathepsins in cardiomyocytes and protected cardiomyocytes from H2O2-induced apoptosis. This study established a role of mMCP4 in mouse post-MI dysfunction by regulating myocardial protease expression and cardiomyocyte death without significant impact on myocardial fibrosis or survival post-MI in mice.

Cathepsin K-deficiency impairs mouse cardiac function after myocardial infarction.

BACKGROUND: Extracellular matrix metabolism and cardiac cell death participate centrally in myocardial infarction (MI). This study tested the roles of collagenolytic cathepsin K (CatK) in post-MI left ventricular remodeling. METHODS AND RESULTS: Patients with acute MI had higher plasma CatK levels (20.49 ±â€¯7.07 pmol/L, n = 26) than those in subjects with stable angina pectoris (8.34 ±â€¯1.66 pmol/L, n = 28, P = .01) or those without coronary heart disease (6.63 ±â€¯0.84 pmol/L, n = 93, P = .01). CatK protein expression increases in mouse hearts at 7 and 28 days post-MI. Immunofluorescent staining localized CatK expression in cardiomyocytes, endothelial cells, fibroblasts, macrophages, and CD4+ T cells in infarcted mouse hearts at 7 days post-MI. To probe the direct participation of CatK in MI, we produced experimental MI in CatK-deficient mice (Ctsk-/-) and their wild-type (Ctsk+/+) littermates. CatK-deficiency yielded worsened cardiac function at 7 and 28 days post-MI, compared to Ctsk+/+ littermates (fractional shortening percentage: 5.01 ±â€¯0.68 vs. 8.62 ±â€¯1.04, P < .01, 7 days post-MI; 4.32 ±â€¯0.52 vs. 7.60 ±â€¯0.82, P < .01, 28 days post-MI). At 7 days post-MI, hearts from Ctsk-/- mice contained less CatK-specific type-I collagen fragments (10.37 ±â€¯1.91 vs. 4.60 ±â€¯0.49 ng/mg tissue extract, P = .003) and more fibrosis (1.67 ±â€¯0.93 vs. 0.69 ±â€¯0.20 type-III collagen positive area percentage, P = .01; 14.25 ±â€¯4.12 vs. 6.59 ±â€¯0.79 α-smooth muscle actin-positive area percentage, P = .016; and 0.82 ±â€¯0.06 vs. 0.31 ±â€¯0.08 CD90-positive area percentage, P = .008) than those of Ctsk+/+ mice. Immunostaining demonstrated that CatK-deficiency yielded elevated cardiac cell death but reduced cardiac cell proliferation. In vitro studies supported a role of CatK in cardiomyocyte survival. CONCLUSION: Plasma CatK levels are increased in MI patients. Heart CatK expression is also elevated post-MI, but CatK-deficiency impairs post-MI cardiac function in mice by increasing myocardial fibrosis and cardiomyocyte death.

Plasma Cystatin B Association With Abdominal Aortic Aneurysms and Need for Later Surgical Repair: A Sub-study of the VIVA Trial.

OBJECTIVE/BACKGROUND: The development of an abdominal aortic aneurysm (AAA) involves extensive extracellular matrix remodelling, leading to aortic wall weakening. This process is mediated by proteases, including cysteinyl cathepsins. Cystatins are their endogenous inhibitors. This study tested whether plasma cystatin B levels in patients with AAA differed from those of healthy controls. METHODS: Plasma samples from patients with AAA and age matched controls were selected from the Viborg Vascular (VIVA) screening trial for AAA. Enzyme linked immunosorbent assay determined plasma cystatin B. T-test, logistic regression, Pearson's correlation and Cox regression tested whether plasma cystatin B correlates with AAA size and growth rate, or serves as a marker for AAA. RESULTS: Plasma cystatin B levels were significantly higher in patients with AAA than in controls (p < 0.001). Logistic regression analysis showed that cystatin B tertile at baseline was associated with the presence of AAA before (odds ratio [OR] 1.656; p < 0.001) and after adjustment for peripheral arterial disease (PAD), chronic obstructive pulmonary disease (COPD), and previous ischaemic events (OR 1.526; p < 0.001). A t-test showed a significant association between cystatin B and PAD at screening, hospital diagnosis of COPD, previous atherosclerotic events, and use of low dose aspirin. Pearson's correlation test showed positive and significant associations between cystatin B and AAA size (r = 0.15; p < 0.001). Cox regression test showed that plasma cystatin B tertile at baseline was associated with later AAA surgical repair before (hazard ratio [HR] 1.387; p < 0.001) and after adjustment for PAD, COPD, previous ischaemic event, and maximum infrarenal aortic diameter (HR 1.523; p < 0.001). CONCLUSION: In contrast to prior studies that showed that cystatin C is negatively associated with AAA development, this study demonstrated a positive association between cystatin B and AAA size and associations between cystatin B tertile at baseline and AAA presence and need for later surgical repair. It is possible that these two cystatins inhibit cathepsin activity and participate in AAA with different mechanisms.

Cysteine protease cathepsins in cardiovascular disease: from basic research to clinical trials.

Cysteine protease cathepsins have traditionally been considered as lysosome-restricted proteases that mediate proteolysis of unwanted proteins. However, studies from the past decade demonstrate that these proteases are localized not only in acidic compartments (endosomes and lysosomes), where they participate in intracellular protein degradation, but also in the extracellular milieu, plasma membrane, cytosol, nucleus, and nuclear membrane, where they mediate extracellular matrix protein degradation, cell signalling, and protein processing and trafficking through the plasma and nuclear membranes and between intracellular organelles. Studies in experimental disease models and on cathepsin-selective inhibitors, as well as plasma and tissue biomarker data from animal models and humans, have verified the participation of cysteinyl cathepsins in the pathogenesis of many cardiovascular diseases, including atherosclerosis, myocardial infarction, cardiac hypertrophy, cardiomyopathy, abdominal aortic aneurysms, and hypertension. Clinical trials of cathepsin inhibitors in chronic inflammatory diseases suggest the utility of these inhibitors for the treatment of cardiovascular diseases and associated complications. Moreover, development of cell transfer technologies that enable ex vivo cell treatment with cathepsin inhibitors might limit the unwanted systemic effects of cathepsin inhibition and provide new avenues for targeting cysteinyl cathepsins. In this Review, we summarize the available evidence implicating cysteinyl cathepsins in the pathogenesis of cardiovascular diseases, discuss their potential as biomarkers of disease progression, and explore the potential of cathepsin inhibitors for the treatment of cardiovascular diseases.

Interleukin-18, matrix metalloproteinase-22 and -29 are independent risk factors of human coronary heart disease.

BACKGROUND: Coronary heart disease (CHD) is characterized by arterial wall inflammation and matrix degradation. Matrix metalloproteinase (MMP)-22 and -29 and pro-inflammatory cytokine interleukin-18 (IL18) are present in human hearts. IL18 may regulate MMP-22 and -29 expression, which may correlate with CHD progression. METHODS AND RESULTS: Immunoblot analysis showed that IL18 induced MMP-22 expression in human aortic smooth muscle cells. The Mann Whitney test from a prospective study of 194 CHD patients and 68 non-CHD controls demonstrated higher plasma levels of IL18, MMP-22 and -29 in CHD patients than in the controls. A logistic regression test suggested that plasma IL18 (odds ratio (OR)=1.131, P=0.007), MMP-22 (OR=1.213, P=0.040), and MMP-29 (OR=1.198, P=0.033) were independent risk factors of CHD. Pearson's correlation test showed that IL18 (coefficient (r)=0.214, P=0.045; r=0.246, P=0.031) and MMP-22 (r=0.273, P=0.006; r=0.286, P=0.012) were associated with the Gensini score before and after adjusting for potential confounding factors. The multivariate Pearson's correlation test showed that plasma MMP-22 levels correlated positively with high-sensitive-C-reactive protein (hs-CRP) (r=0.167, P=0.023), and MMP-29 levels correlated negatively with triglyceride (r=-0.169, P=0.018). Spearman's correlation test indicated that plasma IL18 levels associated positively with plasma MMP-22 (r=0.845, P<0.001) and MMP-29 (r=0.548, P<0.001). CONCLUSIONS: Our observations suggest that IL18, MMP-22 and -29 serve as biomarkers and independent risk factors of CHD. Increased systemic IL18 in CHD patients may contribute to elevated plasma MMP-22 and -29 levels in these patients.