MG53 protects against Coxsackievirus B3-induced acute viral myocarditis in mice by inhibiting NLRP3 inflammasome-mediated pyroptosis via the NF-κB signaling pathway.

Pyroptosis, a novel programmed cell death mediated by NOD-like receptor protein 3 (NLRP3) inflammasome, is a critical pathogenic process in acute viral myocarditis (AVMC). Mitsugumin 53 (MG53) is predominantly expressed in myocardial tissues and has been reported to exert cardioprotective effects through multiple pathways. Herein, we aimed to investigate the biological function of MG53 in AVMC and its underlying regulatory mechanism in pyroptosis. BALB/c mice and HL-1 cells were infected with Coxsackievirus B3 (CVB3) to establish animal and cellular models of AVMC. As inflammation progressed in the myocardium, we found a progressive decrease in myocardial MG53 expression, accompanied by a significant enhancement of cardiomyocyte pyroptosis. MG53 overexpression significantly alleviated myocardial inflammation, apoptosis, fibrosis, and mitochondrial damage, thereby improving cardiac dysfunction in AVMC mice. Moreover, MG53 overexpression inhibited NLRP3 inflammasome-mediated pyroptosis, reduced pro-inflammatory cytokines (IL-1ß/18) release, and suppressed NF-κB signaling pathway activation both in vivo and in vitro. Conversely, MG53 knockdown reduced cell viability, facilitated cell pyroptosis, and increased pro-inflammatory cytokines release in CVB3-infected HL-1 cells by promoting NF-κB activation. These effects were partially reversed by applying the NF-κB inhibitor BAY 11-7082. In conclusion, our results suggest that MG53 acts as a negative regulator of NLRP3 inflammasome-mediated pyroptosis in CVB3-induced AVMC, partially by inhibiting the NF-κB signaling pathway. MG53 is a promising candidate for clinical applications in AVMC treatment.

Analysis of long noncoding RNAs and messenger RNAs expression profiles in the hearts of mice with acute viral myocarditis.

Acute viral myocarditis (AVMC) is a common acute myocardial inflammation caused by viral infections, which can lead to severe cardiac dysfunction. Several long noncoding RNAs (lncRNAs) with aberrant expression have been identified in the pathogenesis of AVMC. However, the expression profiles and functions of lncRNAs in AVMC have not been fully elucidated. In the present study, we constructed AVMC mouse models by intraperitoneal injection of coxsackievirus B3 (CVB3) and performed RNA sequencing (RNA-seq) on heart tissues to investigate the differences in lncRNAs and messenger RNAs (mRNAs) expression profiles. Based on the cutoff criteria of adjusted p-values (padj) <0.05 and |log2FoldChange| >1, a total of 1122 differentially expressed lncRNAs (DElncRNAs) and 3186 differentially expressed mRNAs (DEmRNAs) were screened, including 734 upregulated and 388 downregulated lncRNAs, 1821 upregulated and 1365 downregulated mRNAs. RT-qPCR analysis validated that the expression patterns of 12 randomly selected genes (6 DElncRNAs and 6 DEmRNAs) were highly consistent with those in RNA-seq, proving the reliability of the RNA-seq data. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that differentially expressed genes were mainly involved in metabolic and immune-related processes. Furthermore, co-expression networks between DElncRNAs and DEmRNAs in cytokine-cytokine receptor interaction, MAPK signaling pathway, and PI3K-Akt signaling pathway were constructed to study the molecular interactions of these molecules. Our study, for the first time, reveals the expression profiles of lncRNAs and mRNAs associated with AVMC, which may shed light on the roles of lncRNAs in disease pathogenesis and aid in discovering new therapeutic targets.

LncGBP9 knockdown alleviates myocardial inflammation and apoptosis in mice with acute viral myocarditis via suppressing NF-κB signaling pathway.

BACKGROUND: Myocardial inflammation and apoptosis are key processes in coxsackievirus B3 (CVB3)-induced acute viral myocarditis (AVMC). Accumulating evidence reveals the essential roles of long noncoding RNAs (lncRNAs) in the pathogenesis of AVMC. Here, we aimed to evaluate the biological functions of a novel lncRNA guanylate-binding protein 9 (lncGBP9) in AVMC progression and further explore its underlying mechanisms. METHODS: Initially, mouse models of AVMC were constructed by CVB3 infection. The expression and localization of lncGBP9 in heart tissues were analyzed using RT-qPCR and FISH. Adeno-associated virus serotype 9 (AAV9)-mediated lncGBP9 knockdown was then employed to clarify its roles in survival, cardiac function, and myocardial inflammation and apoptosis. Moreover, the mRNA and protein levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß) were detected by RT-qPCR and ELISA, and the regulation of lncGBP9 knockdown on the NF-κB signaling pathway was investigated by Western blotting. Using an in vitro model of HL-1 cardiomyocytes exposed to CVB3 infection, the effects of lncGBP9 knockdown on cell viability, inflammation, and apoptosis were further evaluated in vitro. RESULTS: Increased lncGBP9 expression was detected in the heart tissues of AVMC mice and CVB3-infected HL-1 cells, and was mainly located in the cytoplasm. Knockdown of lncGBP9 remarkably alleviated the severity of AVMC in CVB3-infected mice, as verified by improved cardiac function, and reduced myocardial inflammation and apoptosis. Additionally, lncGBP9 knockdown suppressed the NF-κB signaling pathway and consequently reduced productions of pro-inflammatory cytokines in vivo. In vitro functional assays further confirmed that lncGBP9 knockdown promoted cell viability, inhibited cell apoptosis, and reduced pro-inflammatory cytokines release in CVB3-infected HL-1 cells through suppressing NF-κB activation. CONCLUSIONS: Collectively, lncGBP9 knockdown exerts anti-inflammatory and anti-apoptotic effects in CVB3-induced AVMC, which may be mediated in part via NF-κB signaling pathway. These findings highlight lncGBP9 as an attractive target for therapeutic interventions.

Knockdown of LncRNA MALAT1 Alleviates Coxsackievirus B3-Induced Acute Viral Myocarditis in Mice via Inhibiting Th17 Cells Differentiation.

Acute viral myocarditis (AVMC), most often caused by coxsackievirus B3 (CVB3) infection, is characterized by myocardial inflammation associated with high morbidity and mortality. A pathogenic role for T helper (Th) 17 cells in AVMC is well established. Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been shown to play a key role in various inflammatory diseases. However, the expression of MALAT1 and its impact on Th17 cells differentiation in AVMC remain unclear. In the present study, we found that MALAT1 was highly expressed in mice with AVMC, and the expression was correlated positively with cardiac pathological scores, cardiac IL-17 mRNA expression, and the percentages of splenic Th17 cells. We further demonstrated that MALAT1 knockdown could significantly alleviate the severity of disease and inhibit the differentiation of Th17 cells, accompanying the reduced mRNA expression of RORγt and productions of Th17-related pro-inflammatory cytokines in vivo. Additionally, in vitro analysis showed that MALAT1 knockdown suppressed naïve CD4+ T cells differentiation towards Th17 cells. In conclusion, our results suggest that MALAT1 knockdown alleviates CVB3-induced AVMC in mice, which may be partially attributable to the decline in Th17 cells responses. MALAT1 may serve as a novel therapeutic option in AVMC.

Novel biomarker panel for the diagnosis and prognosis assessment of sepsis based on machine learning.

Background: The authors investigated a panel of novel biomarkers for diagnosis and prognosis assessment of sepsis using machine learning (ML) methods. Methods: Hematological parameters, liver function indices and inflammatory marker levels of 332 subjects were retrospectively analyzed. Results: The authors constructed sepsis diagnosis models and identified the random forest (RF) model to be the most optimal. Compared with PCT (procalcitonin) and CRP (C-reactive protein), the RF model identified sepsis patients at an earlier stage. The sepsis group had a mortality rate of 36.3%, and the RF model had greater predictive ability for the 30-day mortality risk of sepsis patients. Conclusion: The RF model facilitated the identification of sepsis patients and showed greater accuracy in predicting the 30-day mortality risk of sepsis patients.

Neutralization of interleukin-38 exacerbates coxsackievirus B3-induced acute myocarditis in mice.

BACKGROUND: Interleukin (IL)-38, a novel member of the IL-1 family, has been reported to be involved in several diseases associated with viral infection. However, the expression and functional role of IL-38 in acute viral myocarditis (AVMC) have not been investigated. METHODS: Male BALB/c mice were treated with intraperitoneal (i.p.) injection of coxsackievirus B3 (CVB3) for establishing AVMC models. On day 7 post-injection, the expression of IL-38 and IL-36R (IL-36 receptor) were measured. Mice were then treated with i.p. injection of mouse Anti-IL-38 Antibodies (Abs) for neutralization of IL-38. The survival, bodyweight loss, cardiac function, and myocarditis severity of mice were recorded. The percentages of splenic Th1 and Th17 cells, the expression levels of Th1/Th17-related master transcription factors (T-bet and RORγt) and cytokines were determined by flow cytometry, RT-qPCR, and ELISA, respectively. Cardiac viral replication was further detected. RESULTS: The mRNA and protein expression levels of IL-38 in myocardium and serum, as well as cardiac IL-36R mRNA levels were significantly elevated in mice with AVMC. Increased IL-38 levels were negatively correlated with the severity of AVMC. Neutralization of IL-38 exacerbated CVB3-induced AVMC, as verified by the lower survival rate, impaired cardiac function, continuous bodyweight loss, and higher values of HW/BW and cardiac pathological scores. In addition, neutralization of IL-38 suppressed Th1 cells differentiation while promoted Th17 cells differentiation, accompanied by decreased T-bet mRNA expression and increased RORγt expression. Down-regulation of IFN-γ and up-regulation of IL-17, TNF-α, and IL-6 mRNA and protein expression levels in myocardium and serum were also observed in the IL-38 neutralization group. Furthermore, neutralization of IL-38 markedly promoted cardiac viral replication. CONCLUSIONS: Neutralization of IL-38 exacerbates CVB3-induced AVMC in mice, which may be attributable to the imbalance of Th1/Th17 cells and increased CVB3 replication. Thus, IL-38 can be considered as a potential therapeutic target for AVMC.

Performance of Lactate and CO2-Derived Parameters in Predicting Major Postoperative Complications After Cardiac Surgery With Cardiopulmonary Bypass: Protocol of a Diagnostic Accuracy Study.

Background: CO2-derived parameters are increasingly used to identify either low-flow status or anaerobic metabolism in shock resuscitation. However, the performance of CO2-derived parameters in cardiac surgical patients is poorly understood. This study aims to compare the performance of lactate and CO2-derived parameters in predicting major postoperative complications after cardiac surgery with cardiopulmonary bypass. Methods: This is a prospective, single-center, diagnostic accuracy study. All patients who receive elective cardiac surgery involving cardiopulmonary bypass will be screened for study eligibility. Blood samples will be taken for the calculation of CO2-derived parameters, including the venous-arterial difference in CO2 partial pressure (PCO2 gap), venous-arterial difference in CO2 content to arterial-venous O2 content ratio (Cv-aCO2/Ca-vO2), and venous-arterial difference in CO2 partial pressure to arterial-venous O2 content ratio (Pv-aCO2/Ca-vO2) at ICU admission, and 3, 6, and 12 h later. Baseline, perioperative data will be collected daily for 7 days; patients will be followed up for 28 days to collect outcome data. The primary endpoint is the occurrence of major postoperative complications. Receiver-operating characteristics (ROC) curve analysis will be carried out to assess the predictive performance of lactate and CO2-derived parameters. The performance of the ROC curves will be compared. Discussion: The performance of lactate and CO2-derived parameters in predicting major postoperative complications will be investigated in the non-sepsis population, which has not been extensively investigated. Our study will compare the two surrogates of respiratory quotient directly, which is an important strength. Trial Registration: ChiCTR, ChiCTR2000029365. Registered January 26th, 2020, http://www.chictr.org.cn/showproj.aspx?proj=48744.

[A clinical study of the evaluation of hemodynamic status in mechanically ventilated critically ill patients by continuous non-invasive arterial pressure monitor].

OBJECTIVE: To evaluate the difference and correlation between continuous non-invasive arterial pressure (CNAP) monitor and pulse indicated continuous cardiac output (PiCCO) monitor on determination of hemodynamic parameters in mechanically ventilated critically ill patients, and to assess the feasibility of non-invasive monitoring of hemodynamics with CNAP. METHODS: A prospective observation self-control study was conducted.The critically ill patients with mechanical ventilation who needed hemodynamics monitoring, and admitted to the fourth department of intensive care unit (ICU) of Fujian Provincial Hospital from June 2018 to March 2019 were enrolled. PiCCO catheter were inserted immediately after admission, the hemodynamic indexes were measured by thermodilution method, and mean arterial pressure (MAPPiCCO), cardiac index (CIPiCCO), pulse pressure variation rate (PPVPiCCO) and systemic vascular resistance index (SVRIPiCCO) were obtained at 0 hour and 24 hours respectively. Meanwhile, the above indexes (MAPCNAP, CICNAP, PPVCNAP and SVRICNAP) were measured with CNAP. All measurements were repeated thrice and average values were reported. The differences in above parameters between the two methods were evaluated. Pearson test was used for the correlation analysis and Bland-Altman analysis method was used for consistency test. RESULTS: Thirty-eight patients were enrolled into this study. One patient died within 24 hours was excluded, 2 patients were excluded due to withdrawing treatment within 24 hours, 2 patients were excluded because of atrial fibrillation, and 1 patient's data was lost due to technical problems. Thus, data from 32 patients were available for final analysis. There were 12 females and 20 males, aging 26-84 years old with the mean of (66.8±19.1) years old, body mass index (BMI) of (23.7±3.9) kg/m2, acute physiology and chronic health evaluation II (APACHE II) score of 19.5±5.3, sepsis-related organ failure assessment (SOFA) score of 9.7±4.1. There were no significant differences in CI or PPV between CNAP and PiCCO groups [CI (mL×s-1×m-2): 59.8±12.6 vs. 58.5±14.2, PPV: (14.7±6.8)% vs. (14.0±6.8)%, both P > 0.05]. MAP and SVRI measured by CNAP were significantly higher than those measured by PiCCO [MAP (mmHg, 1 mmHg = 0.133 kPa): 65.6±9.4 vs. 60.1±9.2, SVRI (kPa×s×L-1×m-2): 206.2±53.9 vs. 179.5±57.8, both P < 0.01]. The correlation analysis showed that MAP, CI, PPV and SVRI measured by the two methods were significantly positively correlated (r value was 0.624, 0.864, 0.835 and 0.655 respectively, all P < 0.05). Bland-Altman analysis showed that CNAP and PiCCO had a good consistency for the measurement of CI and PPV, the average differences were 1.2 mL×s-1×m-2 and 0.5% respectively, while the 95% confidence interval (95%CI) were -12.8-15.3 mL×s-1×m-2 and -7.1%-8.2% respectively. However, the consistency of MAP and SVRI measured by those two methods was poor, the average differences were 5.5 mmHg and 26.8 kPa×s×L-1×m-2 respectively, while the 95%CI was -10.4-21.3 mmHg and -64.5-118.0 kPa×s×L-1×m-2 respectively. CONCLUSIONS: CNAP was comparable with PiCCO when monitoring CI and PPV in mechanically ventilated critically ill patients; while the results of MAP and SVRI might be inaccurate, which should be interpreted correctly and carefully.

[Clinical research of target guided treatment of patients with severe heart failure under the guidance of pulse indicator continuous cardiac output].

OBJECTIVE: To investigate the value of pulse indicator continuous cardiac output (PiCCO) monitoring in the treatment management of patients with severe heart failure. METHODS: Sixty patients of severe heart failure admitted to intensive care unit (ICU) of Fujian Provincial Hospital from August 2017 to February 2019 were enrolled, and they were divided into control group and treatment group according to random number table method, with 30 in each group. The treatment group used bedside PiCCO to carry out minimally invasive hemodynamics monitoring, according to the monitoring data target guidance for vasoactive drugs and liquid management. The control group was based only on traditional electrocardiogram (ECG) monitoring and lung sound, urine volume of vasoactive drugs and liquid management. The changes of cardiac index (CI), global end diastolic volume index (GEDVI), extravascular lung water index (EVLWI), systemic vascular resistance index (SVRI), invasive mean arterial pressure (MAP) and central venous pressure (CVP) were observed before and 72 hours after treatment in the treatment group. The 7-day total effective rate, the length of ICU stay and 28-day mortality were compared between the two groups. RESULTS: Compared with before treatment, CI and MAP in the treatment group were significantly increased after treatment [CI (mL×s-1×m-2): 53.34±16.67 vs. 35.01±13.34, MAP (mmHg, 1 mmHg = 0.133 kPa): 72.6±10.6 vs. 62.5±10.3, both P < 0.05], GEDVI, EVLWI, SVRI, CVP were significantly decreased [GEDVI (mL/m2): 760.3±90.2 vs. 960.2±110.3, EVLWI (mL/kg): 6.5±1.3 vs. 12.5±6.2, SVRI (kPa×s×L-1×m-2): 297.3±35.1 vs. 434.1±58.8, CVP (mmHg): 10.1±2.6 vs. 12.2±3.4, all P < 0.05]. Compared with the control group, the 7-day total effective rate of the treatment group was significantly higher (90.0% vs. 80.0%), the length of ICU stay was significantly shorter (days: 8.2±4.5 vs. 10.3±2.5), and the 28-day mortality was significantly lower, with statistically significant difference (all P < 0.05). CONCLUSIONS: PiCCO monitoring is a goal-oriented treatment management for patients with severe heart failure, which is helpful to individualized accurate treatment, shorten the length of ICU stay and improve short-term prognosis.

[Interleukin-17 contributes to the macrophage secretion of interleukin-27 in a murine model of viral myocarditis].

OBJECTIVE: Interleukin-27 (IL-27) has been reported to reduce the levels of interleukin-17 (IL-17) and alleviate the severity of experimental autoimmune myocarditis. IL-17, an important tissue-protective cytokine in viral myocarditis (VMC), has been reported to increase synovial expression of IL-27 in rheumatoid arthritis. However, the influence of IL-17 on IL-27 expression in murine model of VMC remains unknown. METHODS: Wild-type (WT) and IL-17A-deficient (IL-17A(-/-)) mice on the BALB/c background were intraperitoneally (i.p) injected with coxsackievirus B3 (CVB3) for establishing VMC models. Cardiac tissue was obtained on day 7 after CVB3 injection. Myocardial histopathologic changes were observed by hematoxylin-eosin (HE) stained myocardial sections.Expression of IL-27 in heart and serum was measured by real-time reverse transcription-polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA), respectively. Furthermore, splenic lymphocytes and peritoneal macrophages were purified 1 week after injection from WT mice.Isolated lymphocytes were cultured in the presence of different concentrations (0 and 25 ng/ml) of recombinant IL-17 (rIL-17) for 24 h. Macrophages were cultured with different concentrations of rIL-17 (0 and 10 ng/ml) for 48 h.IL-27 mRNA expression of cultured cells was assayed by RT-PCR, and their protein level in the culture supernatant was measured by ELISA. RESULTS: Compared with WT mice, significantly less cardiac inflammation was evidenced in the heart of IL-17A-/- mice (0.9 ± 0.3 vs.1.9 ± 0.5) , relative cardiac IL-27 p28 mRNA expressions (1.11 ± 0.24 vs.3.1 ± 0.8) and serum IL-27 protein[(72 ± 18) pg/ml vs.(95 ± 25) pg/ml] were also significantly lower in IL-17A-/- mice (all P < 0.05).In the culture lymphocytes, the relative mRNA (1.02 ± 0.13 vs.1.32 ± 0.21) and protein [(49 ± 9) pg/ml vs.(52 ± 11) pg/ml]expressions of IL-27 p28 and were similar post treatment with 0 and 25 ng/ml rIL-17 (all P > 0.05). Compared with 0 ng/ml rIL-17 culture with macrophages, higher relative mRNA (8.5 ± 3.1 vs.2.2 ± 0.7) and protein [(368 ± 95) pg/ml vs.(150 ± 38) pg/ml] expressions of IL-27 p28 were detected in 10 ng/ml rIL-17 group (all P < 0.05). CONCLUSION: Our data indicates that cytokine IL-17 may contribute to the secretion of IL-27 in VMC mice.Furthermore, macrophages but not lymphocytes may be the important IL-27-producing immune cells and major target cells for IL-17. Thus,IL-27 and IL-17 might be actively involved in the pathogenesis of VMC.

Increased circulating T­helper 22 cells in patients with dilated cardiomyopathy.

Recently, the newly determined interleukin (IL)­22­producing T-helper (Th) 22 cell has been implicated to be involved in the pathogenesis of autoimmune diseases. However, its role in the pathogenesis of dilated cardiomyopathy (DCM) has yet to be elucidated. A total of 30 patients with DCM and 30 healthy controls were enrolled in the present study. The levels of Th22, Th17 and Th1 cells in the peripheral blood were analyzed by flow cytometry. Levels of plasma IL­22 and autoantibody adenine nucleotide translocator (ANT) were assessed using the ELISA. The key transcription factor of Th22, aryl hydrocarbon receptor (AHR), was assessed using quantitative polymerase chain reaction. Additionally, clinical data on the brain natriuretic peptide (BNP), C­reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were collected. In comparison with those in the control group, significantly elevated levels of Th22, Th17 and Th1 cells were detected in patients with DCM (all P<0.01). Similarly, elevated mRNA levels of peripheral AHR were detected in patients with DCM. The percentage of Th22 cells was higher in ANT­positive compared with ANT­negative patients with DCM. The levels of BNP and CRP, but not ESR, showed a significant positive correlation with those of Th22 cells. With regard to the concentrations of plasma IL­22, no statistical difference was found between patients with DCM and the healthy controls, nor did it demonstrate a statistical correlation with the percentage of Th22 cells. In conclusion, the present study showed that patients with DCM, particularly those of the ANT autoantibody positive subjects, exhibit elevated levels of peripheral Th22 cells, indicating that a Th22 immune response may be implicated in the pathogenesis of DCM.

MicroRNA-21 and -146b are involved in the pathogenesis of murine viral myocarditis by regulating TH-17 differentiation.

Viral myocarditis (VMC) is a common cardiovascular disease, and microRNAs (miRNAs) have been postulated to be involved in its pathology. Using microarrays, we observed that miRNA-21 and -146b were upregulated in a murine model of VMC. We also found that miRNA-451 was downregulated. In vivo silencing of miRNA-21 and -146b resulted in less-severe VMC. Overexpression of miRNA-451 did not ameliorate the severity of VMC. Further work revealed that inhibition of miRNA-21 and -146b decreased the expression levels of Th17 and RORγt . Overexpression of miRNA-451 had no effect on IL-17 and RORγt expression. Inhibition of miRNA-21 and -146b might ameliorate myocardium inflammation by mediating downregulation of RORγt expression, indicating that these miRNAs are involved in the pathogenesis of murine VMC.

Apolipoprotein E and its mimetic peptide suppress Th1 and Th17 responses in experimental autoimmune encephalomyelitis.

Apolipoprotein E (apoE) has been detected to possess anti-inflammatory properties that can contribute to protection against experimental autoimmune encephalomyelitis (EAE). However, its impact on Th1 and Th17 responses in EAE is unclear. In this study, we induced EAE in apoE-/- mice and wild-type mice. We observed that the absence of apoE resulted in the increased proportion of Th1 and Th17 cells in the spleens and brains, as well as up-regulated expressions of proinflammatory cytokines (IL-17, IFN-γ, TNF-α, IL-12, IL-1ß and IL-6) and transcription factors (RORγt and T-bet) in the CNS. ApoE-/- mice also showed the increased release of proinflammatory cytokines by macrophages in vitro. In addition, we used a mimetic peptide of apoE, which mimic the functions of apoE except for lipid transport. ApoE mimetic peptide could reverse the above negative effect in EAE. Thus, apoE can modulate Th1 and Th17 responses, likely through its inhibitory effect on the secretion of cytokines by macrophages. Our result also suggests that apoE mimetic peptide might be developed into a therapeutic agent for multiple sclerosis.

IL-22 exacerbates the severity of CVB3-induced acute viral myocarditis in IL-17A-deficient mice.

Interleukin (IL)-22 has either proinflammatory or tissue­protective properties, depending on the nature of the affected tissue and the local cytokine milieu, including the presence or absence of IL-17A co-expression. We have previously demonstrated that IL-22 has critical anti-inflammatory and antiviral roles in mice with coxsackievirus B3 (CVB3)­induced acute viral myocarditis (AVMC) in the presence of IL-17A. However, whether IL-17A determines the function of IL-22 in AVMC remains unknown. Therefore, the present study, in continuation of our previous investigations, aimed to determine whether IL-22 plays a distinctly different role in the absence of IL-17A in AVMC by using IL-17A-deficient mice. Results demonstrated that the neutralization of IL-22 in IL-17A­deficient mice alleviated the severity of myocarditis. This was demonstrated by the lower pathological scores of heart sections and ratios of heart weight/body weight (HW/BW), reduced production of activator of transcription 3 (STAT3) and proinflammatory cytokines TNF-α and IL-6, followed by increased viral replication and decreased levels of the antiviral cytokine IFN-γ. Furthermore, the correlation between cardiac CVB3 RNA and IL-22 mRNA or IFN-γ mRNA was negative. In conclusion, IL-22 exacerbated the severity of AVMC and restrained viral replication in the absence of IL-17A. Spleen lymphocytes cultured with recombinant IL-17 (rIL-17) increased the production of IL-22. Combined with our previous data, these results indicate that IL-17A is not involved in regulating the antiviral role, however, may mediate the tissue-protective versus pathogenic properties of IL-22 in CVB3-induced AVMC in mice.

Increased expressions of IL-22 and Th22 cells in the coxsackievirus B3-Induced mice acute viral myocarditis.

BACKGROUND: Recently, a new subset of T helper (Th) cell that predominantly secret cytokine interleukin-22 (IL-22) is identified, termed Th22 cells. The Th22 subset has been demonstrated to be involved in immunity and tissue inflammation. However, the existence of Th22 cells and role of IL-22 in acute viral myocarditis (AVMC) remain unknown. METHODS: BALB/c mice were intraperitoneally (i.p) infected with CVB3 for establishing AVMC models. Control mice were treated with phosphate-buffered saline (PBS) i.p. On day 14 post injection, frequencies of splenic Th22 cells were determined, productions of IL-22 and expressions of IL-22R (IL-22 receptor) were measured. To further investigate the effects of IL-22, AVMC mice treated with Anti-IL-22 neutralizing antibody were explored. The severity of AVMC were monitored; the frequencies of Th22 cells, the expressions of IL-22 and IL-22R were investigated; in addition to IFN-γ, inflammatory cytokines IL-17, TNF-α, IL-6 as well as IL-1ß, were evaluated. Cardiac viral replication were detected. RESULTS: Compared with control group, significant elevations of circulating Th22 cells and IL-22, cardiac protein and mRNA of IL-22, and IL-22R1 were demonstrated in AVMC group. Treatment of AVMC mice with Anti-IL-22 Ab exacerbated the severity of viral myocarditis, verified by lower survival rate, higher HW/BW ratios and cardiac pathological scores. Anti-IL-22 Ab decreased the frequencies of Th22 cells and the levels of IL-22, and increased the expressions of cardiac IL-22R1. Up-regulations of IL-17, IL-6 and TNF-α, down-regulations of IFN-γ proteins and gene expressions in the plasma and myocardium, were observed in Anti-IL-22 Ab group. Furthermore, neutralization of IL-22 significantly promoted cardiac viral replication. CONCLUSIONS: Our data indicate that the increased frequencies of IL-22-producing Th22 cells may play an important role in the pathogenesis of CVB3-induced mice AVMC, IL-22 may act as an myocardium-protective cytokine via the IL-22-IL-22R pathway, and suggest that targeting the Th22 cell and IL-22-IL-22R pathway could provide new therapeutic modalities for the treatment of CVB3-induced AVMC.

Isolation and characterization of 10 SSR markers of Momordica charantia (Cucurbitaceae).

PREMISE OF THE STUDY: Microsatellite markers were isolated and characterized from the genome of Momordica charantia (bitter melon) to be applied in studies of genetic diversity and population structure. METHODS AND RESULTS: Twenty-five microsatellite loci were isolated from the genome of bitter melon using the Fast Isolation by AFLP of Sequences COntaining Repeats (FIASCO) method. Ten loci were polymorphic, and the number of alleles per locus ranged from three to seven, with the observed heterozygosity ranging from 0.46 to 0.65. The markers also amplified successfully in the related species M. cochinchinensis and Cucurbita pepo. CONCLUSIONS: These markers will have potential utility for applications in genetic diversity evaluation, molecular fingerprinting, identification, comparative genomics analysis, and genetic mapping in Momordica species, as well as in C. pepo.