Fumarate mitigates disruption induced by fenpropathrin in the silkworm Bombyx mori (Lepidoptera): A metabolomics study

The silkworm Bombyx mori L. is a model organism of the order Lepidoptera. Understanding the mechanism of pesticide resistance in silkworms is valuable for Lepidopteran pest control. In this study, comparative metabolomics was used to analyze the metabolites of 2 silkworm strains with different pesticide resistance levels at 6, 12, and 24 h after feeding with fenpropathrin. Twenty-six of 27 metabolites showed significant differences after fenpropathrin treatment and were classified into 6 metabolic pathways: glycerophospholipid metabolism, sulfur metabolism, glycolysis, amino acid metabolism, the urea cycle, and the tricarboxylic acid (TCA) cycle. After analyzing the percentage changes in the metabolic pathways at the 3 time points, sulfur metabolism, glycolysis, and the TCA cycle showed significant responses to fenpropathrin. Confirmatory experiments were performed by feeding silkworms with key metabolites of the 3 pathways. The combination of iron(II) fumarate + folic acid (IF-FA) enhanced fenpropathrin resistance in silkworms 6.38 fold, indicating that the TCA cycle is the core pathway associated with resistance. Furthermore, the disruption of several energy-related metabolic pathways caused by fenpropathrin was shown to be recovered by IF-FA in vitro. Therefore, IF-FA may have a role in boosting silkworm pesticide resistance by modulating the equilibrium between the TCA cycle and its related metabolic pathways.

[Investigation on population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province]

OBJECTIVE

To investigate the population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province.

METHODS

Rodents were captured using the mouse trap method in pastures from Batang Township and Longbao Township of Yushu City, Qinghai Province on May, August and October, 2018. The body weight and snout-vent length of all captured rodents were measured, and the species was identified according to the rodent morphology. Genomic DNA was extracted from rodent liver specimens and lesion specimens, and the mitochondrial cox1 gene of Echinococcus was amplified using PCR assay for identification of parasite species. In addition, the tissue specimens positive for PCR assay were sampled for pathological examinations. The prevalence of Echinococcus infections was estimated in rodents, and a phylogenetic tree was created based on Echinococcus cox1 gene sequences.

RESULTS

A total of 285 small rodents were captured, including 143 Ochotona curzoniae (50.2%), 141 Lasiopodomys fuscus (49.5%), and 1 Neodon irene (0.3%), and there was a remarkable variation in habitat selection among these three rodent species. The number of L. fuscus correlated positively with vegetation coverage (r = 0.350, P = 0.264), with the greatest number seen in August, and the number of O. curzoniae negatively with vegetation coverage (r = -0.371, P = 0.235), with the highest number seen in August and the lowest number in May. The female/male ratios of O. curzoniae and voles were 1:0.96 and 0.82:1, respectively. The body weight (r = 0.519, P < 0.01) and snout-vent length (r = 0.578, P < 0.01) of O. curzoniae showed a tendency towards a rise with month, while the body weight (r = -0.401, P < 0.01) and snout-vent length (r = -0.570, P < 0.01) of voles presented a tendency towards a reduction with month. No Echinococcus infection was detected in voles, while 2.1% prevalence of E. shiquicus infection was seen in O. curzoniae. Phylogenetic analysis revealed consistent sequences of cox1 gene from E. shiquicus in Yushu City of Qinghai Province and Shiqu County, Ganzi Tibetan Autonomous Prefecture of Sichuan Province.

CONCLUSIONS

The small rodents around the human settlement in Yushu City of Qinghai Province mainly include O. curzoniae and L. fuscus, with the greatest numbers seen in May and August, respectively. Following the concerted efforts for echinococcosis control, the prevalence of Echinococcus infections is low in small rodents around the human settlement in Yushu City; however, there is still a risk of echinococcosis transmission.

Excessive mechanical stretch‑mediated osteoblasts promote the catabolism and apoptosis of chondrocytes via the Wnt/β‑catenin signaling pathway

Excessive biomechanical loading is considered an important cause of osteoarthritis. Although the mechanical responses of chondrocytes and osteoblasts have been investigated, their communication during mechanical loading and the underlying molecular mechanisms are not yet fully known. The present study investigated the effects of excessive mechanically stretched osteoblasts on the metabolism and apoptosis of chondrocytes, and also assessed the involvement of the Wnt/β‑catenin signaling pathway. In the present study, rat chondrocytes and osteoblasts were subjected to mechanical tensile strain, and an indirect chondrocyte‑osteoblast co‑culture model was established. Reverse transcription‑quantitative PCR and western blotting were performed to determine the expression levels of genes and proteins of interest. An ELISA was performed to investigate the levels of cytokines, including matrix metalloproteinase (MMP) 13, MMP 3, interleukin‑6 (IL‑6) and prostaglandin E2 (PG E2), released from osteoblasts. Flow cytometry was performed to detect the apoptosis of chondrocytes exposed to stretched osteoblast conditioned culture medium. The levels of MMP 13, IL‑6 and PG E2 increased significantly in the supernatants of stretched osteoblasts compared with the un‑stretched group. By contrast, the mRNA expression levels of Collagen 1a and alkaline phosphatase were significantly decreased in osteoblasts subjected to mechanical stretch compared with the un‑stretched group. The mRNA expression level of Collagen 2a was significantly decreased, whereas the expression levels of MMP 13 and a disintegrin and metalloproteinase with thrombospondin‑like motifs 5 were significantly increased in chondrocytes subjected to mechanical stretch compared with the un‑stretched group. In the co‑culture model, the results indicated that excessive mechanically stretched osteoblasts induced the catabolism and apoptosis of chondrocytes, which was partly inhibited by Wnt inhibitor XAV‑939. The results of the present study demonstrated that excessive mechanical stretch led to chondrocyte degradation and inhibited osteoblast osteogenic differentiation; furthermore, excessive mechanically stretched osteoblasts induced the catabolism and apoptosis of chondrocytes via the Wnt/β‑catenin signaling pathway.

P6424The association between long-term beta-blocker use and outcome in a contemporary large-scale cohort of patients with acute myocardial infarction

Background

Controversy exists regarding the use of beta-blockers (BBs) among patients with acute myocardial infarction (AMI) in contemporary reperfusion era. Previous studies predominantly focused on beta-blockers prescribed at discharge, and the effect of long-term adherence to beta-blocker on major adverse cardiovascular events (MACE) remains unclear.

Objective

To explore the association between long-term beta-blocker use patterns and MACE among contemporary AMI patients.

Methods

We enrolled 7860 patients with AMI, who were discharged alive and prescribed with BBs based on CAMI registry from January 2013 to September 2014. Patients were divided into two groups according to BBs use pattern: Always users group (n=4476) were defined as patients reporting BBs use at both 6- and 12-month follow-up; Inconsistent users group were defined as patients reporting at least once not using BBs at 6- or 12-month follow-up. Primary outcome was defined as MACE at 24-month follow-up, including all-cause death, non-fatal MI and repeat-revascularization. Multivariable cox proportional hazards regression model was used to assess the association between BBs and MACE.

Results

Baseline characteristics are shown in table 1. At 2-year follow-up, 518 patients in inconsistent users group (15.6%) and 548 patients in always users group (12.3%) had MACE. After multivariable adjustment, inconsistent use of BBs was associated with higher risk of MACE (HR: 1.323, 95% CI: 1.171–1.493, p<0.001).

Table 1 Baseline characteristics Variable Always user (N=4476) Inconsistent user (N=3384) P value Age (years) 60.6±12.0 61.2±12.2 <0.001 Male 3381 (75.7%) 2461 (74.3%) 0.084 Diabetes 892 (20.0%) 610 (18.4%) 0.003 Hypertension 2372 (53.2%) 1543 (46.6%) <0.001 Dyslipidemia 244 (5.5%) 126 (3.8%) <0.001 Prior myocardial infarction 351 (7.9%) 232 (7.0%) <0.001 Heart failure 88 (2.0%) 63 (1.9%) <0.001 Chronic obstructive pulmonary disease 66 (1.5%) 60 (1.8%) <0.001 Current smoker 2054 (46.1%) 1579 (47.8%) 0.179 Left ventricular ejection fraction (%) 53.7±11.48 54.0±10.9 <0.001 Major Adverse Cardiovascular Events 548 (12.3%) 518 (15.6%) <0.001

Conclusions

Our results showed consistent BBs use was associated with reduced risk of MACE among patients with AMI managed by contemporary treatment.

Acknowledgement/Funding

CAMS Innovation Fund for Medical Sciences (CIFMS) (2016-I2M-1-009)

[Efficacy and mechanism of local delivery of rapamycin and rapamycin-loaded poly(lactic-co-glycolic) acid nanoparticles on coronary restenosis of injury-stenosis model of minipigs]

OBJECTIVE

To determine whether intramural administration of rapamycin (RPM)-loaded polylactic-polyglycolic acid (PLGA) nanoparticles (NPs) can reduce intimal thickening and affect the mRNA expressions of matrix metalloproteinase (MMP)-2, tissue inhibitor of metalloproteinase (TIMP)-2 and p27(kipl) in a coronary injury-stenosis model of minipigs.

METHODS

Twenty eight minipigs were randomly separated into four groups: saline group (n=7), blank PLGA NPs group (5.0 mg/ml)(n=7), RPM group (1.0 mg/ml)(n=7), and RPM-PLGA NPs(5.0 mg/ml)group (n=7), respectively. Different treatments were intracoronary locally delivered via a Dispatch™ catheter for 10 minutes. Serial angiography was performed pre-and post-modeling 30 days and the percent stenosis degree was assessed. Hematoxylin-Eosin (HE) staining, Weigert's resorcin fuchsin staining and picric acid-sirius red staining were used for morphometric analysis. Immunohistochemistry was performed to assess the levels of proliferating cell nuclear antigen (PCNA), MMP-2, and TIMP-2 at early and late time points, respectively. The expression of p27(kip1) mRNA was detected by in situ hybridization staining.

RESULTS

Data from 21 minipigs had been collected at the end of the experiment with 6, 4, 5, and 6 from the former mentioned 4 groups, respectively. For the instant injury index, there was no significant difference among the four groups. The percent stenosis degree of RPM-PLGA NPs group was significantly lower than that of the other three groups respectively (all P< 0.05). The neointima area, net external elastic lamina area to external elastic laminal area ratio, and proliferative index of RPM-PLGA NPs group were significantly less than those of the other three groups, with all the P values less than 0.05. The mean value of integral optical density of p27(kip1)mRNA expression of RPM-PLGA group was 0.35 ± 0.06, higher than that of blank PLGA NPs group (0.12 ± 0.05, P< 0.01), saline group (0.16 ± 0.03, P< 0.05), and RPM group (0.15 ± 0.03, P< 0.05), respectively. The MMP-2/TIMP-2 ratio and the positive expression index of PCNA in RPM-PLGA group were lower than that of the other groups (P< 0.05).

CONCLUSIONS

Locally delivered rapamycin-loaded PLGA NPs significantly reduces MMP-2/TIMP-2 ratio and PCNA expression, increases p27(kip1) mRNA expression and significantly relieves percent stenosis degree and shows excellent acute procedural results in the minipig interventional coronary artery oversized balloon injury model. The results from minipig model further support that this approach could be a potential clinical procedure for vascular proliferative disease.

Serum cytokine modulation after Staphylococcus hyicus infection in BALB/c mice

Staphylococcal infection is a severe bacterial infection. Finding satisfactory predictable biological markers is essential for the treatment of this condition. In this study, we applied a 32-marker sandwich ELISA-based antibody array to evaluate cytokine changes in Staphylococcus hyicus-inoculated BALB/c mice at 24 and 48 h post infection. Among the cytokines detected, the expression levels of granulocyte colony stimulating factor (G-CSF), interleukin 6 (IL-6), macrophage inflammatory protein 2, and keratinocyte chemoattractant (KC) were increased to levels more than twice higher than those in the control group 24 h after infection, while the expression of interleukin 12p40p70 (IL-12p40p70) was decreased to less than half the level measured in the controls. The expression of G-CSF, IL-6, monocyte chemoattractant protei-5, chemokine ligand 11, and KC was upregulated 48 h post infection, whereas IL-12p40p70 expression was still significantly lower (P < 0.05). Among the detected cytokines, the expression levels of G-CSF, IL-6, and KC were constantly upregulated, while IL-12p40p70 was downregulated. This result was then validated by an ELISA assay analysis, which confirmed that G-CSF, IL-6, KC, and IL- 12p40p70 expression levels were specifically modulated after an S. hyicus bacterial infection, while granulocyte monocyte colony stimulation factor, IL-12, and IFNγ levels were significantly increased after a viral infection. Our study indicated the potential of cytokines G-CSF, IL-6, KC, and IL- 12p40p70 as markers for detecting S. hyicus infection. The results of this study may provide useful data for the appropriate use of medication following S. hyicus infection.

MCP-1 gene polymorphisms in North Chinese patients with pulmonary tuberculosis

Pulmonary tuberculosis (PTB) remains one of the most important infectious diseases worldwide. Several studies have suggested that genetic factors may affect the susceptibility to PTB, but the specific genes involved have not been fully characterized. The gene for monocyte chemoattractant protein 1 (MCP-1) has been linked to an increased risk of tuberculosis in some Mexican and Korean populations. To explore the role of the MCP-1 gene in the susceptibility to PTB in a North Chinese population, we evaluated the association between MCP-1 -2518A/G gene polymorphisms and the risk for tuberculosis. Polymerase chain reaction amplification of genomic DNA followed by restriction fragment length polymorphism analysis was used. There was a significant increase in the frequency of the GG genotype of MCP-1 -2518 in 136 patients with PTB compared to that in 152 healthy controls (P = 0.008, X(2) = 7.133, odds ratio = 1.96). Similarly, the frequencies of the A/G alleles in the 2 groups differed; the frequency of allele G was higher in patients with PTB (P = 0.011, X(2) = 6.428, odds ratio = 1.536). In conclusion, the -2518A/G polymorphism in the MCP-1 gene was found to be associated with an increased susceptibility to PTB in a North Chinese population.

Research progress in the radioprotective effect of superoxide dismutase

Irradiation from diverse sources is ubiquitous and closely associated with human activity. Radiation therapy (RT), an important component of the multiple radiation origins, contributes significantly to oncotherapy by killing tumor cells. On the other hand, RT can also cause some undesired normal tissue injuries that afflict numerous cancer patients. Although many promising radioprotective agents are emerging, few of them have entered the market successfully due to various limitations. At present, the most accepted hypothesis for the radiation-caused injury involves reactive oxygen species (ROS) generation. Superoxide dismutase (SOD), the unique enzyme responsible for the dismutation of superoxide radicals, is expected to occupy an indispensable position in the treatment of ROS-mediated tissue injuries originating from exposure to radiation. This review focuses on the mechanism of radioprotection by SOD at the tissue or organ level, cellular level, and molecular level, respectively, in order to provide references for further investigation of radiation injury and development of new radioprotectors.

Association of HLA-DRB alleles and pulmonary tuberculosis in North Chinese patients

Human leukocyte antigen (HLA) plays a central role in the regulation of the immune response. HLA class II molecules are essential for T cell-mediated adaptive immunity and present peptide antigens to CD4(+) T cells. Because of its important role in the immune response and its high degree of polymorphism, the HLA system is associated with many diseases. We examined the polymorphisms of HLA-DRB alleles and the sequences of the HLA-DRB promoter region in 97 unrelated patients with pulmonary tuberculosis and in 62 unrelated normal controls of the Han nationality from North China, using PCR with sequence-specific primers and PCR direct sequencing. We found that the frequency of HLA-DRB1*15 was significantly higher in the pulmonary tuberculosis group than in the healthy control group. The P value was 0.001, and the odds ratio was 3.793. The pulmonary tuberculosis group had the same HLA-DRB1 promoter region sequences as the control group. We concluded that the HLA-DRB1*15 allele is associated with pulmonary tuberculosis in the Han nationality from North China. The HLA-DRB1 promoter region sequences had no association with the development of pulmonary tuberculosis.

Relationship between genetic polymorphism of MCP-1 and non-small-cell lung cancer in the Han nationality of North China

Monocyte chemoattractant protein 1 (MCP-1) is an important chemokine that has a dose-dependent anti-tumoral effect. Polymorphism in the MCP-1 distal regulatory region (-2518A/G) can affect the level of MCP-1 expression. We examined the polymorphisms of 112 unrelated patients with non-small-cell lung cancer (NSCLC) and 82 unrelated healthy controls of Han nationality in North China using PCR-RFLP. We found that the distributions of AA, AG and GG genotypes of MCP-1-2518 were significantly different in NSCLC patients compared to controls (chi(2) = 10.106, P = 0.006). There was a significant increase in the frequency of the AA genotype (odds ratio (OR) = 3.138, chi(2) = 8.905, P = 0.003) and a significant decrease in the frequency of the GG genotype (OR = 0.516, chi(2) = 4.613, P = 0.032) in the NSCLC patients, compared to controls. The frequencies of AA, AG and GG genotypes did not differ in the NSCLC patients according to the number of pack-years smoked. Based on these results, we suggest that the MCP-1 -2518A/G polymorphism is associated with genetic susceptibility to NSCLC.

Analysis of HLA-A, HLA-B and HLA-DRB1 alleles in Chinese patients with lung cancer

The primary function of the human leukocyte antigen (HLA) system is to regulate the immune response. Because of its important role in the immune response and its high degree of polymorphism, the HLA system is associated with many diseases. We examined the polymorphisms of HLA-A, B and DRB1 alleles in 100 unrelated patients with lung carcinoma and in 438 unrelated normal controls of Han nationality from North China, using sequence-based typing and PCR with sequence-specific primers. We found that the frequencies of HLA-A*0201, A*2601, B*1518, B*3802, DRB1*0401, DRB1*0402, and DRB1*1201 were higher in the lung carcinoma group than in the normal control group. The P values were 0.035, 0.040, 0.001, 0.017, 0.014, 0.004, and 0.019, respectively, and the odds ratio values were 1.052, 3.513, 4.047, 3.054, 4.237, 19.397, and 2.128, respectively. The frequency of HLA-DRB1*1302 was lower in the lung carcinoma group than in the normal control group (P = 0.046, odds ratio = 0.168). We concluded that patients with lung cancer and healthy controls of Han nationality from North China differ in the frequencies of various HLA alleles.

The polymorphism of HLA antigens in the Chinese

Remarkable differences were observed in antigen frequencies (AF), gene frequencies (GF) and haplotype frequencies (HF) when 2441 healthy Chinese individuals representing nine different ethnic groups and living in 14 different geographic locations were examined for the genetic distribution of the various HLA Class I and II markers. A sizable number of individuals of each ethnic group within each of the three major categories of the Chinese population, namely, Hans, Mongols, and Southern minorities, have been studied here, providing useful population statistics for applications such as determination of probabilities of paternity, comparisons for HLA and disease associations, and anthropologic studies.