Irisin inhibits neutrophil extracellular traps formation and protects against acute pancreatitis in mice.

INTRODUCTION: Irisin is a newly discovered myokine which links exercise to inflammation and inflammation-related diseases through macrophage regulation. However, the effect of irisin on the activity of inflammation related immune cells (such as neutrophils) has not been clearly described. OBJECTIVES: The objective of our study was to explore the effect of irisin on the neutrophil extracellular traps (NETs) formation. METHODS: Phorbol-12-myristate-13-acetate (PMA) was used to construct a classic neutrophil inflammation model that was used to observe the formation of NETs in vitro. We studied the effect of irisin on NETs formation and its regulation mechanism. Subsequently, acute pancreatitis (AP) was used to verify the protective effect of irisin in vivo, which was an acute aseptic inflammatory response disease model closely related to NETs. RESULTS: Our study found that addition of irisin significantly reduced the formation of NETs via regulation of the P38/MAPK pathway through integrin αVß5, which might be the one of key pathways in NETs formation, and which could theoretically offset the immunoregulatory effect of irisin. Systemic treatment with irisin reduced the severity of tissue damage common in the disease and inhibited the formation of NETs in pancreatic necrotic tissue of two classical AP mouse models. CONCLUSION: The findings confirmed for the first time that irisin could inhibit NETs formation and protect mice from pancreatic injury, which further elucidated the protective effect of exercise on acute inflammatory injury.

Prediction of the severity of acute pancreatitis using machine learning models.

BACKGROUND: Acute pancreatitis (AP) is the most common pancreatic disease. Predicting the severity of AP is critical for making preventive decisions. However, the performance of existing scoring systems in predicting AP severity was not satisfactory. The purpose of this study was to develop predictive models for the severity of AP using machine learning (ML) algorithms and explore the important predictors that affected the prediction results. METHODS: The data of 441 patients in the Department of Gastroenterology in our hospital were analyzed retrospectively. The demographic data, blood routine and blood biochemical indexes, and the CTSI score were collected to develop five different ML predictive models to predict the severity of AP. The performance of the models was evaluated by the area under the receiver operating characteristic curve (AUC). The important predictors were determined by ranking the feature importance of the predictive factors. RESULTS: Compared to other ML models, the extreme gradient boosting model (XGBoost) showed better performance in predicting severe AP, with an AUC of 0.906, an accuracy of 0.902, a sensitivity of 0.700, a specificity of 0.961, and a F1 score of 0.764. Further analysis showed that the CTSI score, ALB, LDH, and NEUT were the important predictors of the severity of AP. CONCLUSION: The results showed that the XGBoost algorithm can accurately predict the severity of AP, which can provide an assistance for the clinicians to identify severe AP at an early stage.

Effects of Mycobacterium vaccae vaccine in a mouse model of tuberculosis: protective action and differentially expressed genes.

BACKGROUND: Tuberculosis is a leading cause of death worldwide. BCG is an effective vaccine, but not widely used in many parts of the world due to a variety of issues. Mycobacterium vaccae (M. vaccae) is another vaccine used in human subjects to prevent tuberculosis. In the current study, we investigated the potential mechanisms of M. vaccae vaccination by determining differentially expressed genes in mice infected with M. tuberculosis before and after M. vaccae vaccination. METHODS: Three days after exposure to M. tuberculosis H37Rv strain (5 × 105 CFU), adult BALB/c mice randomly received either M. vaccae vaccine (22.5 µg) or vehicle via intramuscular injection (n = 8). Booster immunization was conducted 14 and 28 days after the primary immunization. Differentially expressed genes were identified by microarray followed by standard bioinformatics analysis. RESULTS: M. vaccae vaccination provided protection against M. tuberculosis infection (most prominent in the lungs). We identified 2326 upregulated and 2221 downregulated genes in vaccinated mice. These changes could be mapped to a total of 123 signaling pathways (68 upregulated and 55 downregulated). Further analysis pinpointed to the MyD88-dependent TLR signaling pathway and PI3K-Akt signaling pathway as most likely to be functional. CONCLUSIONS: M. vaccae vaccine provided good protection in mice against M. tuberculosis infection, via a highly complex set of molecular changes. Our findings may provide clue to guide development of more effective vaccine against tuberculosis.

Mannose-binding lectin 2 gene polymorphisms and their association with tuberculosis in a Chinese population.

BACKGROUND: Immune- and inflammation-related genes (IIRGs) play an important role in the pathogenesis of tuberculosis (TB). However, the relationship between IIRG polymorphisms and TB risk remains unknown. In this study, the gene polymorphisms and their association with tuberculosis were determined in a Chinese population. METHODS: We performed a case-control study involving 1016 patients with TB and 507 healthy controls of Han Chinese origin. Sixty-four single-nucleotide polymorphisms (SNPs) belonging to 18 IIRGs were genotyped by the PCR-MassArray assay, and the obtained data was analyzed with χ2-test, Bonferroni correction, and unconditional logistic regression analysis. RESULTS: We observed significant differences in the allele frequency of LTA rs2229094*C (P = 0.015), MBL2 rs2099902*C (P = 0.001), MBL2 rs930507*G (P = 0.004), MBL2 rs10824793*G (P = 0.004), and IL12RB1 rs2305740*G (P = 0.040) between the TB and healthy groups. Increased TB risk was identified in the rs930507 G/G genotype (Padjusted = 0.027) under a codominant genetic model as well as in the rs2099902 (C/T + C/C) vs T/T genotype (Padjusted = 0.020), rs930507 (C/G + G/G) vs C/C genotype (Padjusted = 0.027), and rs10824793 (G/A + G/G) vs A/A genotype (Padjusted = 0.017) under a dominant genetic model after Bonferroni correction in the analysis of the overall TB group rather than the TB subgroups. Furthermore, the rs10824793_rs7916582*GT and rs10824793_rs7916582*GC haplotypes were significantly associated with increased TB risk (P = 0.001, odds ratio [OR] = 1.421, 95% confidence interval [CI]: 1.152-1.753; and P = 0.018, OR = 1.364, 95% CI: 1.055-1.765, respectively). Moreover, the rs10824793_rs7916582*AT/AT or rs10824793_rs7916582*GT/GT diplotype showed a protective (P = 0.003, OR = 0.530, 95% CI: 0.349-0.805) or harmful (P = 0.009, OR = 1.396, 95% CI: 1.087-1.793) effect against the development of TB. CONCLUSIONS: This study indicated that MBL2 polymorphisms, haplotypes, and diplotypes were associated with TB susceptibility in the Han Chinese population. Additionally, larger sample size studies are needed to further confirm these findings in the future.

Metabolites from Two Dominant Thermophilic Fungal Species Thermomyces lanuginosus and Scytalidium thermophilum.

Thermomyces lanuginosus and Scytalidium thermophilum are among the most ubiquitous thermophilic fungi in compost and soil. Chemical study on these two prevalent strains collected from Yunnan led to isolation of 23 metabolites, including one new metabolite, therlanubutanolide, and 15 known compounds, isolated from the YGP culture broth of Thermomyces lanuginosus and 7 known compounds isolated from Scytalidium thermophilum, respectively. Therlanubutanolide shared the quite similar features of the same carbon skeleton and saturation as natural hexadecanoic acids. This was the first reported discovery of such a lactone as natural occurring metabolite. All the compounds were reported for the first time from thermophilic fungi. Among them, N-[(2S,3R,4E,8E)-1,3-dihydroxy-9-methyloctadeca-4,8-dien-2-yl]acetamide was for the first time reported to be a naturally occurring metabolite and its NMR data was first provided in this study. A type of PKS-derived metabolites, three 3,4-dihydronaphthalen-1(2H)-ones, which were widely found in plant pathogenic fungi as phytotoxins and reported to have antimicrobial activity, were obtained from both dominant thermophilic fungi. The frequent occurrence of such PKS phytotoxins in these two thermophilic fungi might suggest particular ecological interest.

Cytokine and soluble adhesion molecule profiles and biomarkers for treatment monitoring in Re-treated smear-positive patients with pulmonary tuberculosis.

Relapse of pulmonary tuberculosis (PTB) is associated with a failure of the host immune system to control the invading Mycobacterium tuberculosis. Severe immunodeficiency or immune disorders may be the main reason for TB recurrence. This study aimed to quantify serum inflammatory cytokine and soluble adhesion molecule levels in Re-treated smear-positive PTB patients before and after re-anti-TB drug therapy. Serum samples were collected from 30 healthy controls and 215 Treated active PTB patients at baseline and 2, 4, and 6 months post-re-treatment. Levels of 18 serum cytokines and soluble adhesion molecules were measured by a high-throughput Cytometric Bead Array. At baseline, IL-1, IL-2, IL-12P70, and soluble CD62E levels were significantly higher in PTB patients than those in the healthy controls (p < 0.05); IL-4, IL-5, IL-7, IL-8, IL-10, IL-17, IL-21, soluble CD54, MIG, and TGF-ß levels in PTB patients were significantly lower than those in the healthy controls (p < 0.05), of which TGF-ß, IL-7, IL-8, IL-10, soluble CD54, and MIG were most notably (p < 0.0005). After re-treatment, IFN-γ, IL-2, IL-7, and soluble CD54 levels and IL-2/IL-10 and IFN-γ/IL-10 ratios showed an upward trend during the re-treatment period. They were more sensitive than other cytokines and adhesion molecules and could be effective as serum indicators for re-treatment response. The immune response was imbalance in treated smear-positive PTB patients: Th1 response was elevated, but Th2 and Th17 responses were reduced. Systematic and comprehensive understanding of the cytokine and soluble adhesion molecule profiles provides a theoretical basis for immuno-diagnosis, immunotherapy, and immuno-monitoring of Re-treated PTB patients.

Potential novel markers to discriminate between active and latent tuberculosis infection in Chinese individuals.

Latent tuberculosis infection (LTBI) constitutes the main reservoir for reactivation tuberculosis. The finding of potential biomarkers for differentiating between TB and LTBI is very necessary. In this study, the immunological characteristics and potential diagnostic utility of Rv2029c, Rv2628 and Rv1813c proteins were assessed. These three proteins stimulated PBMCs from ELISPOT-positive LTBI subjects produced higher levels of IFN-γ in comparison with TB patients and ELISPOT-negative healthy subjects (p<0.05). BCG vaccination and non-TB respiratory disease had little influence on the immunological responses of Rv2029c and Rv2628 proteins (p>0.05). The LTBI diagnostic performance of Rv2029c was higher than Rv2628 and Rv1813c by ROC evaluation. But Rv2628 had much higher specificity than Rv2029c in active TB patients and uninfected healthy subjects. The IgG level against Rv1813c was higher in the TB group than in LTBI and uninfected healthy subjects (p<0.05). These results suggest that T cell response to Rv2628 and antibody against Rv1813c might be applicable as biomarkers to distinguish TB from LTBI and uninfected individuals.

Immune responses to latent tuberculosis antigen Rv2659c in Chinese populations.

BACKGROUND: The latency-associated antigen Rv2659c is a starvation-related protein of Mycobacterium tuberculosis (M. tuberculosis). It has potential use in tuberculosis (TB) control, but its immunological characteristics in Chinese populations are unclear. METHODS: In this study, immunological characteristics and potential diagnostic use of recombinant Rv2659c protein were assessed. Interferon-γ (IFN-γ) production from peripheral blood mononuclear cells (PBMC) was assayed by enzyme-linked immunospot (ELISPOT) in TB patients (80 cases), individuals who were purified protein derivative (PPD)-positive after Bacillus Calmette-Guérin (BCG) vaccination (27 cases), nontuberculous respiratory disease patients (30 cases), individuals who were identified by standard techniques as having latent TB infection (LTBI) (37 cases), and uninfected healthy individuals (75 cases). Serum immunoglobulin G (IgG) levels were assayed by enzyme-linked immunosorbent assay (ELISA) in TB patients (43 cases), LTBI individuals (36 cases) and uninfected healthy individuals (66 cases). RESULTS: When stimulated by rRv2659c, PBMC from LTBI individuals gave ELISPOT counts that were significantly higher than those from TB patients, BCG vaccinated individuals, non-TB respiratory disease patients and uninfected healthy individuals (p < 0.05). The rRv2659c stimulation gave detectable IFN-γ production in a higher proportion of persons with LTBI compared with TB patients and uninfected healthy individuals. BCG vaccination and non-TB respiratory disease had little influence on the PBMC response to rRv2659c. The levels of serum IgG specific for rRv2659c were not significantly different between LTBI individuals and TB patients (p > 0.05). CONCLUSION: These results suggest that rRv2659c has potential for the diagnosis of LTBI. This is the first clinical report of human immune recognition of Rv2659c in Chinese populations.

Thermolides, potent nematocidal PKS-NRPS hybrid metabolites from thermophilic fungus Talaromyces thermophilus.

Macrocyclic PKS-NRPS hybrid metabolites represent a unique family of natural products mainly from bacteria with broad and outstanding biological activities. However, their distribution in fungi has rarely been reported, and little has been reported regarding their nematocidal activity. Here we describe an unprecedented class of PKS-NRPS hybrid metabolites possessing a 13-membered lactam-bearing macrolactone, thermolides A-F (1-6) from a thermophilic fungus Talaromyces thermophilus. We showed that 1 and 2 displayed potent inhibitory activity against three notorious nematodes with LC(50) values of 0.5-1 µg/mL, as active as commercial avermectins. This work provided a new class of promising lead compounds for nematocide discovery.

[The relationship between carboxylesterase 1 gene polymorphisms and susceptibility to antituberculosis drug-induced hepatotoxicity].

OBJECTIVE: To study the relationship between the genetic polymorphisms of carboxylesterase 1 gene (CES1) and the susceptibility to antituberculosis drug-induced hepatotoxicity (ATBDIH). METHODS: Genetic polymorphisms of CES1 in 473 tuberculosis patients with or without hepatotoxicity (200:273) after antituberculosis chemotherapy were analyzed by PCR-MassArray. RESULTS: In 4 tags of CES1 single nucleotide polymorphism (SNP), the frequency of the rs1968753 allele had statistical difference between the hepatotoxicity group and the no-hepatotoxicity group(P = 0.0236). The characteristics of anti-hepatotoxicity had been shown relationship with rs8192950 (P = 0.044, OR = 0.649, 95%CI = 0.426 - 0.989, AC/AA) and rs1968753 (P = 0.048, OR = 0.556, 95%CI = 0.311 - 0.995, GG/AA). The diplotypes with 'CGC' haplotype exhibited significant protection against hepatotoxicity at one copy (P = 0.048, OR = 0.654, 95%CI = 0.430 - 0.996). CONCLUSIONS: The genetic polymorphisms of CES1 might have significant association with ATBDIH. SNP rs8192950 AC genotype and rs1968753 GG genotype might be the candidates for risk prediction of ATBDIH.

NAT2 and CYP2E1 polymorphisms associated with antituberculosis drug-induced hepatotoxicity in Chinese patients.

1. The present study investigated the relationship between antituberculosis (anti-TB) drug-induced hepatotoxicity and genetic polymorphisms of two important drug-metabolizing enzymes involved in the metabolism of isoniazid, namely N-acetyltransferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1). 2. A polymerase chain reaction direct sequencing approach was used to detect genetic polymorphisms of the NAT2 and CYP2E1 genes in tuberculosis (TB) patients with (n = 101) or without (n = 107) anti-TB drug-induced hepatotoxicity. Associations between various genetic polymorphisms and anti-TB drug-induced hepatotoxicity were then determined. 3. Patients with NAT2 (282TT , 590AA and 857GA) alleles had an increased susceptibility to anti-TB drug-induced hepatotoxicity. The slow acetylator NAT2 genotypes (especially NAT2*6A/7B and NAT2*6A/6A) were risk factors for hepatotoxicity (odds ratio (OR) 9.57 (P < 0.001) for NAT2*6A/7B; OR 5.24 (P = 0.02) for NAT2*6A/6A). 4. The CYP2E1 genotype per se was not significantly associated with the development of anti-TB drug-induced hepatotoxicity. However, the combination of the CYP2E1 C1/C1 genotype with a slow acetylator NAT2 genotype increased the risk of anti-TB drug-induced hepatotoxicity (OR 5.33; P = 0.003) compared with the combination of a rapid acetylator NAT2 genotype with either a C1/C2 or C2/C2 genotype. 5. Thus, slow acetylators with the NAT2*6A/7B and NAT2*6A/6A genotypes combined with the C1/C1 CYP2E1 genotype may be involved in the pathogenesis of anti-TB drug-induced hepatotoxicity. 6. The present findings may be explained, in part, by changes in the metabolism of the anti-TB drug isoniazid induced via NAT2 and CYP2E1, a metabolic process known to produce hepatotoxic intermediates.

[The associations of polymorphism of N-acetyltransferase 2 gene is associated with antituberculosis drug-induced hepatotoxicity in tuberculosis patients].

OBJECTIVE: To study the possible relationship between polymorphic N-acetyltransferase 2 (NAT2) acetylator status and antituberculosis drug-induced hepatotoxicity and to elucidate the molecular mechanism of antituberculosis drug-induced hepatotoxicity. METHODS: Blood samples from 101 tuberculosis cases with antituberculosis drug-induced hepatotoxicity and from 107 tuberculosis without antituberculosis drug-induced hepatotoxicity were collected for a case-control study. DNA of the subjects was extracted and amplified by polymerase chain reaction (PCR). The single nucleotide polymorphisms of NAT2 were determined by direct PCR sequencing. The genotype frequencies were compared between cases and controls by χ(2) test, using SPSS 12.0 software, and the association between the disease and genotypes was analyzed. RESULTS: Among the 101 patients with antituberculosis drug-induced liver injury, 36 patients (35.6%) were found with 282 T/T, 12 (11.9%) with 590 A/A, and 48 (47.5%) with 857 G/A or A/A. However, among the 107 controls, 9 patients (8.4%) were found with 282 T/T, 3 (2.8%) with 590 A/A, and 33 (33.8%) with 857 G/A or A/A. The patients with 282 T/T, 590 A/A, or 857 G/A or A/A genotype had a higher risk of antituberculosis drug-induced hepatotoxicity than those with 282 C/C or C/T, 590 G/G or G/A, or 857 G/G, and the OR values were 6.03 (95%CI: 2.88 - 12.62; χ(2) = 22.73, P < 0.05), 4.67 (95%CI: 1.42 - 15.44; χ(2) = 6.40, P < 0.05) and 2.03 (95%CI: 1.16 - 3.57; χ(2) = 6.08, P < 0.05) respectively. There were 40 patients with slow acetylator (39.6%) in cases with hepatotoxicity and 13 with slow acetylator (12.2%) in controls without hepatotoxicity. Patients with slow acetylator genotype (OR = 4.74, 95% CI = 2.42 - 9.28; χ(2) = 20.62, P < 0.05) had a significantly higher risk of antituberculosis drug-induced hepatotoxicity than those with rapid or intermediate acetylator genotypes. Among the cases, 19.8% (20/101) were found with NAT2(*)6A/7B, and 11.9% (12/101) with NAT2(*)6A/6A, whereas among the controls, 2.8% (3/107) were found with NAT2(*)6A/7B, and 2.8% (3/107) with NAT2(*)6A/6A respectively, the patients with NAT2(*)6A/7B and NAT2(*)6A/6A had a much higher risk of antituberculosis drug-induced hepatotoxicity, and the OR values were 8.40 (95%CI: 2.85 - 24.73; χ(2) = 14.90, P < 0.05) and 4.67 (95%CI: 1.42 - 15.44; χ(2) = 6.40, P < 0.05) respectively. CONCLUSION: Perhaps, the slow acetylation genotypes of NAT2 were the main risk factors of developing antituberculosis drug-induced hepatotoxicity.

Detection of streptomycin resistance in Mycobacterium tuberculosis clinical isolates using four molecular methods in China.

To evaluate the relationship between mutations in rpsL or rrs genes and streptomycin (SM) resistance, we compared four molecular methods for their clinical value in the detection of SM resistance. Genotypic analysis of SM resistance in 167 M. tuberculosis clinical strains isolated from Chinese patients was performed by direct DNA sequencing, SSCP, RFLP, and reverse dot-blot hybridization (RDBH) assays. Of the 98 SM-resistant isolates, 78 (79.6%) had missense mutations in codon 43 or 88 of rpsL resulting in a Lys to Arg substitution, 6 (6.1%) had mutations of the rrs gene at positions 513 A to C or T or 516 C to T, and 14 (14.3%) had the wild-type sequence. None of the 69 SM-susceptible isolates examined had alterations in rpsL or rrs. The results of the SSCP, RFLP, and RDBH analyses for these mutations and wild-type sequences were completely consistent with DNA sequencing data. Five distinct single-nucleotide substitutions in codon 43 or 88 of rpsL gene or in position 513 or 516 of rrs gene were correctly identified in 84 of 98 (85.7%) phenotypically SM-resistant isolates by RDBH assay. Molecular analyses of the rpsL and rrs genes are useful for rapid prediction of SM resistance in most clinical strains of M. tuberculosis. Reverse dot-blot hybridization assay is a rapid, simple, and reliable method for the detection of drug resistance.

[Rapid detection of rpoB mutations in Mycobacterium tuberculosis by gene array].

OBJECTIVE: To develop a new method, gene array, which can be used for rapid detection of rpoB mutations in Mycobacterium tuberculosis. METHODS: Probes were designed according to the sequence of Mycobacterium tuberculosis rpoB gene and the gene array was developed. The DNA fragment which contained hot mutation sites of rpoB gene was amplified with biotin-labelled primers by PCR, and then hybridized with gene array. Mycobacterium tuberculosis strain H(37)Rv DNA was used as the control. The rpoB genes in Mycobacterium tuberculosis clinical isolates were also analyzed by polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) and PCR-DNA sequencing. RESULTS: We analyzed the rpoB genes of 111 Mycobacterium tuberculosis clinical isolates by PCR-SSCP. Of 70 rifampicin-resistant Mycobacterium tuberculosis isolates, 63 isolates had different SSCP profiles from that of the standard strain H(37)Rv. No difference from the standard strain was found in 41 rifampicin-susceptible and 7 rifampicin-resistant isolates. We also analyzed their rpoB genes by gene array. Of 111 Mycobacterium tuberculosis clinical isolates, the results of gene array in 41 drug-sensitive strains were similar to that in Mycobacterium tuberculosis H(37)Rv. 90% (63/70) rifampicin-resistant strains had rpoB gene mutation. 53% (37/70) rifampicin-resistant strains had serine substitution at codon 531. 21% (15/70) strains had histidine substitution at codon 526. 16% (11/70) strains had amino acids substitution in other position. The results of gene array corresponded with that of PCR-SSCP and DNA sequencing. CONCLUSION: Gene array might become a rapid, simple, and accurate method for detecting rpoB mutations in most of the rifampicin-resistant Mycobacterium tuberculosis.