Uric acid metabolism promotes apoptosis against Bombyx mori nucleopolyhedrovirus in silkworm, Bombyx mori.

The white epidermis of silkworms is due to the accumulation of uric acid crystals. Abnormal silkworm uric acid metabolism decreases uric acid production, leading to a transparent or translucent phenotype. The oily silkworm op50 is a mutant strain with a highly transparent epidermis derived from the p50 strain. It shows more susceptibility to Bombyx mori nucleopolyhedrovirus (BmNPV) infection than the wild type; however, the underlying mechanism is unknown. This study analysed the changes in 34 metabolites in p50 and op50 at different times following BmNPV infection based on comparative metabolomics. The differential metabolites were mainly clustered in six metabolic pathways. Of these, the uric acid pathway was identified as critical for resistance in silkworms, as feeding with inosine significantly enhanced larval resistance compared to other metabolites and modulated other metabolic pathways. Additionally, the increased level of resistance to BmNPV in inosine-fed silkworms was associated with the regulation of apoptosis, which is mediated by the reactive oxygen species produced during uric acid synthesis. Furthermore, feeding the industrial strain Jingsong (JS) with inosine significantly increased the level of larval resistance to BmNPV, indicating its potential application in controlling the virus in sericulture. These results lay the foundation for clarifying the resistance mechanism of silkworms to BmNPV and provide new strategies and methods for the biological control of pests.

Transcriptomic analysis of the fat body of resistant and susceptible silkworm strains, Bombyx mori (Lepidoptera), after oral treatment with fenpropathrin.

The widespread use of pyrethroid pesticides has brought serious economic losses in sericulture, but there is still no viable solution. The key to solving the problem is to improve silkworm resistance to pesticides, which depends on understanding the resistance mechanism of silkworms to pesticides. This study aimed to use transcriptomes to understand the underlying mechanism of silkworm resistance to fenpropathrin, which will provide a theoretical molecular reference for breeding pesticide-resistant silkworm varieties. In this study, the fat bodies of two strains with differential resistance after 12 h of fenpropathrin feeding were analyzed using RNA-Seq. After feeding fenpropathrin, 760 differentially expressed genes (DEGs) were obtained in the p50(r) strain and 671 DEGs in the 8y strain. The DEGs involved in resistance to fenpropathrin were further identified by comparing the two strains, including 207 upregulated DEGs in p50(r) and 175 downregulated DEGs in 8y. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that these fenpropathrin-related DEGs are mainly enriched in the metabolism and transporter pathways. Moreover, 28 DEGs involved in the metabolic pathway and 18 in the transporter pathway were identified. Furthermore, organic cation transporter protein 6 (BmOCT6), a transporter pathway member, was crucial in enhancing the tolerance of BmN cells to fenpropathrin. Finally, the knockdown of the expression of the homologs of BmOCT6 in Glyphodes pyloalis (G. pyloalis) significantly decreased the resistant level of larvae to fenpropathrin. The findings showed that the metabolism and transporter pathways are associated with resistance to fenpropathrin in silkworm, and OCT6 is an effective and potential target not only for silkworm breeding but also for pest biocontrol.

Identification of optimal reference genes in Bombyx mori (Lepidoptera) for normalization of stress-responsive genes after challenge with pesticides.

Pesticides are frequently used to control pests in agriculture due to their ease of use and effectiveness, but their use causes serious economic losses to sericulture when their production overlaps with agriculture. However, no suitable internal reference genes (RGs) have been reported in the study of silkworms in response to pesticides. In this study, a standard curve was established to detect the expression levels of seven RGs in different tissues of different silkworm strains after feeding with pesticides using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), including BmGAPDH, BmActin3, BmTBP, BmRPL3, Bm28sRNA, Bmα-tubulin, and BmUBC, and the stability of them was evaluated by using NormFinder, geNorm, Delta CT, BestKeeper, and RefFinder. The results showed that BmGAPDH and Bmα-tubulin were relatively stable in the midgut after feeding with fenvalerate, BmGAPDH and Bmactin3 were relatively stable in the fat body, and Bmα-tubulin and Bmactin3 were relatively stable in the hemolymph, indicating that Bmactin3 was the most suitable RG when evaluating fenvalerate, followed by BmGAPDH and Bmα-tubulin. Besides, BmGAPDH and Bmactin3 were relatively stable in the midgut after treatment with DDVP, BmGAPDH and Bmα-tubulin were relatively stable in the fat body, and BmGAPDH and Bmα-tubulin were relatively stable in the hemolymph, indicating that Bmα-tubulin was the most stable RG when evaluating DDVP, followed by BmGAPDH and Bmactin3. Of note, BmGAPDH was shared by the two pesticides. The results will be valuable for RG selection in studying the pesticide response mechanism of silkworms and other lepidopteran insects.

The validation of the role of several genes related to Bombyx mori nucleopolyhedrovirus infection in vivo.

Bombyx mori nucleopolyhedrovirus (BmNPV) is one of primary silkworm pathogens and causes a serious damage of cocoon losses every year. Recent years, many works have been done to clarify the silkworm anti-BmNPV mechanism, and a significant progress has been made in screening and studying of genes and proteins related to BmNPV infection, but several of them lacked the proofs in vivo. In this study, to further validate the function of seven newly reported genes in vivo, including BmAtlatin-n, Bmferritin-heavy chain (BmFerHCH), Bmthymosin (BmTHY), Bmseroin1, Bmseroin2, Bmnuclear hormone receptors 96 (BmNHR96), and BmE3 ubiquitin-protein ligase SINA-like 10 (BmSINAL10), the response of them in the midgut, fat body, and hemolymph of differentially resistant strains (resistant strain YeA and susceptible strain YeB) at 48 h following BmNPV infection were analyzed. The results showed that the relative stable or upregulated expression level of BmAtlatin-n, BmTHY, Bmseroin1, and Bmseroin2 in YeA resistant strain following BmNPV infection further indicated their antiviral role in vivo, compared with susceptible YeB strain. Moreover, the significant downregulation of BmFerHCH, BmNHR96, and BmSINAL10 in both strains following BmNPV infection revealed their role in benefiting virus infection, as well as the upregulation of BmFerHCH in YeB midgut and BmSINAL10 in YeB hemolymph. These data could be used to complementary the proofs of the function of these genes in response to BmNPV infection.

Bmcas-1 plays an important role in response against BmNPV infection in vitro.

Apoptosis, as one kind of innate immune system, is involved in host response against pathogens innovation. Caspases play a vital role in the execution stage of host cell apoptosis. It has been reported that Bmcaspase-1 (Bmcas-1) has a close relationship with Bombyx mori nucleopolyhedrovirus (BmNPV) infection for its differentially expressed patterns after viral infection. However, its underlying response mechanism is still unclear. The significant differential expression of Bmcas-1 in different tissues of differentially resistant strains revealed its vital role in BmNPV infection. To further validate its role in BmNPV infection, budded virus (BV)-eGFP was analyzed after knockdown and overexpression of Bmcas-1 by small interfering RNA and the pIZT-mCherry vector, respectively. The reproduction of BV-eGFP obviously increased at 72 h after knockdown of Bmcas-1, and decreased after overexpression in BmN cells. Moreover, the conserved functional domain of Cas-1 among different species and the closed evolutionary relationship of Cas-1 in Lepidoptera hinted that Bmcas-1 might be associated with apoptosis, and this was also validated by the apoptosis inducer, Silvestrol, and the inhibitor, Z-DEVD-FMK. Therefore, Bmcas-1 plays an essential antiviral role by activating apoptosis, and this result lays a fundament for clarifying the molecular mechanism of silkworm in response against BmNPV infection and breeding of resistant strains.

[Research Progress of circRNA and Its Significance in Forensic Science].

RNA has received more attention in the field of forensic medicine and the development of the new biological markers based on RNA shows great significance in the analysis of complex cases. circular RNA (circRNA) is a kind of non-coding RNA which is widely reported recently. Although the regulatory mechanisms of generation and expression are not fully clear, the existing research indicates that circRNA has important biological functions. CircRNA has a cell-type-specific expression with great stability and a high expression level, which makes it meaningful in forensic applications potentially. In this paper, the research progress, the generation and regulation of circRNA as well as its biological characteristics and functions are summarized, which will provide references for related studies and forensic applications.

[Analysis of 59 Anaphylactic Death Cases].

OBJECTIVE: To analyze the cases of anaphylactic death cases and explore the standards of judicial expertise of anaphylactic death for providing evidence for judicial expertise. METHODS: Fifty-nine cases death due to allergic reaction in Shanghai were collected. And details of medical history, clinical manifestation of anaphylactic reaction and postmortem examination findings were reviewed for all cases. RESULTS: In the 59 cases, there were 58 cases died from drug allergy, including 77.6% of them were antibiotics. The rates of treating in standard hospital and illegal clinic were 37.3% and 61.0%, respectively. The allergic symptoms were dyspnea and facial cyanosis. The time from contacting allergens to death ranged from 1 min to 3 d. The concentration of total serum IgE ranged from 50 to 576.92 IU/mL. The results of clinical manifestation and pathological anatomy had obviously changes. CONCLUSION: Based on the exclusion of all other cause of death and synthetically analysis of details of cases, medical history, clinical manifestation and anatomy, the conclusion of anaphylactic death can reached. The details of cases including clinical history, exposure to allergens, and clinical manifestation play an important role in diagnosis of anaphylactic death.

[Progress in Association between Genetic Correlation and Human Violent Behavior].

Human violent behavior is a complex behavior which is influenced by genetic and environmental factors. There is a trend in investigating the mechanism of violent behavior by using the genetic methods. This article reviews several candidate genes and advances in epigenetics which are associated with violent behavior. The prospects and significance of violent behavior research from the view of gene polymorphism and epigenetics are also discussed.

JMJD2A contributes to breast cancer progression through transcriptional repression of the tumor suppressor ARHI.

INTRODUCTION: Breast cancer is a worldwide health problem and the leading cause of cancer death among females. We previously identified Jumonji domain containing 2A (JMJD2A) as a critical mediator of breast cancer proliferation, migration and invasion. We now report that JMJD2A could promote breast cancer progression through transcriptional repression of the tumor suppressor aplasia Ras homolog member I (ARHI). METHODS: Immunohistochemistry was performed to examine protein expressions in 155 cases of breast cancer and 30 non-neoplastic tissues. Spearman correlation analysis was used to analyze the correlation between JMJD2A expression and clinical parameters as well as several tumor regulators in 155 cases of breast cancer. Gene and protein expressions were monitored by quantitative polymerase chain reaction (qPCR) and Western blot. Results from knockdown of JMJD2A, overexpression of JMJD2A, Co-immunoprecipitation (Co-IP) assay, dual luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) elucidated molecular mechanisms of JMJD2A action in breast cancer progression. Furthermore, the effects of ARHI overexpression on JMJD2A-mediated tumor progression were investigated in vitro and in vivo. For in vitro experiments, cell proliferation, wound-healing, migration and invasion were monitored by cell counting, scratch and Boyden Chamber assays. For in vivo experiments, control cells and cells stably expressing JMJD2A alone or together with ARHI were inoculated into mammary fat pads of mice. Tumor volume, tumor weight and metastatic nodules were measured by caliper, electronic balance and nodule counting, respectively. RESULTS: JMJD2A was highly expressed in human breast cancers and positively correlated with tumor progression. Knockdown of JMJD2A increased ARHI expression whereas overexpression of JMJD2A decreased ARHI expression at both protein and mRNA levels. Furthermore, E2Fs and histone deacetylases were involved in the transcriptional repression of ARHI expression by JMJD2A. And the aggressive behavior of JMJD2A in breast cancers could be reversed by re-expression of ARHI in vitro and in vivo. CONCLUSION: We demonstrated a cancer-promoting effect of JMJD2A and defined a novel molecular pathway contributing to JMJD2A-mediated breast cancer progression.

Epitome of China's unnatural deaths: a historically retrospective study of forensic autopsy cases in Shanghai Public Security Bureau from 1990 to 1999.

The unnatural death investigation in China seems vague to the world. Shanghai is one of the largest city located in Yangtze River Delta in the East China. This study is committed to lift the veil of unnatural death investigation and describe the epitome of China's unnatural deaths. Based on the 7302 forensic report archives from 1990 to 1999 in Shanghai Public Security Bureau, statistics were carried out in 5 areas according to the manner of death. In 3502 accidental deaths, there was a rapid increase during the 1990s, and 71.6% were involved in traffic accidents whose major cause of death was head and neck injuries. The first 3 causes of death in nontraffic accidents (994) were head and neck injuries (42.8%), poisoning (11.8%), and drowning (9.0%). In 2456 homicides, sharp force injury (36.7%), blunt force injury (35.8%), and manual strangulation (12.9%) were the first 3 causes of death. In 563 suicides, drug/chemical intoxication (40.1%), hanging (23.4%), and injuries because of fall from height (11.4%) were the 3 leading causes of death, especially pesticides ingestion. The causes of natural deaths were diseases mainly in circulatory system (23.1%), central nervous system (12.8%), and respiratory system (6.4%). However, the cause of death remained undetermined in 500 victims. Childhood fatalities were different. The victims of accidents and homicides were nearly equal, and the main cause of homicide was manual strangulation. Besides, 1997 was the landmark year when drug abuse began to emerge in Shanghai.

[Allele-specific PCR and its application in forensic science].

Allele-specific polymerase chain reaction (AS-PCR) is a technique based on allele-specific primers, which can be used to analyze single nucleotide polymorphism (SNP) effectively including the transition, transversion and insertion/deletion polymorphism and has been exploited in the study of diseases research, molecular diagnosis, and forensic biological evidence. The article systematically reviews the principle, the detection methods, improvement of AS-PCR, and its research updates in the fields of autosome, Y chromosome and mitochondrial SNP, as well as its application in forensic science.

[Expression of EIIIA+ fibronectin in incised wound of rat's skin].

OBJECTIVE: To explore the relationship between the expression of EIIIA+ fibronectin in incised wound of rat's skin and injury time. METHODS: The wounding model was established by cutting the dorsal skin of 48 adult SD rats. The rats were sacrificed at the pre-set injury time as immediately, 0.5 h, 1 h, 2 h, 3 h, 4 h, 6 h, and 8 h. The skin samples were taken at the margin of wound. The expression of the EIIIA? fibronectin was detected by immunohistochemistry and Western blotting and the relationship be- tween its expression and injury time was observed. Results The expression of EIIIA+ fibronectin was not observed immediately. The basal cell of skin began to show positive expression 0.5 h after injury. With the extension of injury time, positive staining became stronger. The value of relative optical density was gradually increased with prolonged injury time by the Western blotting analysis. CONCLUSION: The expression of EIIIA+ fibronectin could be used for estimation of injury time in the early stage of skin injury.

Expression of JMJD2A in infiltrating duct carcinoma was markedly higher than fibroadenoma, and associated with expression of ARHI, p53 and ER in infiltrating duct carcinoma.

Jumonji Domain Containing 2A (JMJD2A) may be a cancer-associated gene involved in human breast cancer. With a view to investigating expression of JMJD2A in human breast cancer and benign lesion tissues as well as relationship between JMJD2A and tumor related proteins, histological and immunohistochemical analysis, Western blot and quantitative real-time PCR in infiltrating duct carcinoma and fibroadenoma for JMJD2A and immunohistochemical analysis and quantitative real-time PCR in infiltrating duct carcinoma for tumor related proteins (ARHI, p53, ER, PR and CerbB-2) were performed. Histological examination validated the clinical diagnosis. The JMJD2A positive rate of infiltrating duct carcinoma was significantly higher than fibroadenoma by immunohistochemical analysis. The mean optical density of JMJD2A in infiltrating duct carcinoma was higher than fibroadenoma by western blot. JMJD2A mRNA level in infiltrating duct carcinoma was higher than fibroadenoma by quantitative real-time PCR. Spearman correlation analysis revealed that the expression of JMJD2A was associated with ARHI, p53 and ER from immunohistochemical results respectively. Pearson correlation analysis revealed that the expression of JMJD2A was associated with ARHI, p53 and ER from quantitative real-time PCR results respectively. Expression of JMJD2A in infiltrating duct carcinoma was higher, and associated with ARHI, p53 and ER. The results may take JMJD2A as a potential diagnostic and therapeutic target in human breast cancer.

[The role and significance of microRNA in human cardiovascular disease and forensic science].

microRNA (miRNA or miR) is a small single stranded non-coding RNA (21-25nt) that regulates gene expression in almost creatures. Currently, plenty of researches on how miRNA affects human cardiovascular disease have been reported. This review highlights recent findings about the role of miRNA in heart tissue and circulation correlated with human cardiovascular disease and explores the application of miRNA in sudden cardiac death in forensic science.

Electroretinogram and histopathologic changes of the retina after methanol intoxication.

In order to study the functional and structural alterations of the retina in SD rat model after methanol intoxication, 35 rats were divided randomly into five groups administrated with saline, 3-day high dose, 7-day high dose, 3-day low dose and 7-day low dose methanol separately. The retinal function of each group was assessed by flash electroretinogram (F-ERG) 3 and 7 days after methanol poisoning. The microstructure and ultrastructure of the retina were observed at the same time. The high-dose methanol intoxication induced irreversible retinal functional and structural damages 3 days after poisoning, which included prolonged latency and reduced amplitude of the Max-reaction of F-ERG. These injuries were aggravated 7 days after poisoning. Meanwhile, the latency and amplitude of the Cone-reaction of F-ERG were also affected 3 days after poisoning, but there were no further worsening tendency 7 days after poisoning. The retinal histological analysis showed cellular edema, heteromorphy and disarrangement, tissular loosen of the inner nuclear layer and photoreceptors layer. The mitochondrial damage began at the photoreceptors layer and developed further into the inner nuclear layer. The low-dose methanol intoxication only caused transient damage of the retina. Our results showed that the function and structure of the photoreceptor and inner nuclear layer were the primary target of methanol intoxication and that the rod cells were more sensitive to methanol intoxication than the cone cells. The mitochondrial damage developed from outer layer to inner layer of the retina.

[Genotyping and parental related methylation of SNRPN gene rs220030].

OBJECTIVE: To establish two methods by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing for genotyping rs220030 (a SNP in the promoter region of small nuclear ribonucleoprotein polypeptide N, SNRPN). To establish an analytical technique for detecting CpG methylation status by pyrosequencing and to further investigate the feasibility of applying rs220030 to the determination of parental origin allele. METHODS: The rs220030 of 97 blood samples from individuals of Shanghai Han population were genotyped by DGGE, meanwhile the rs220030 of 25 blood samples of them were genotyped by pyrosequencing to compare the two methods in genotyping SNP. Pyrosequencing united bisulfite conversion method was applied to detect CpG methylation status of region upstream rs220030 of two random blood genealogical samples and investigate whether the methylation status was parental related. RESULTS: The rs220030 genotyping results of 97 blood samples detected by DGGE were 20 C homozygote, 29 T homozygote, and 48 C/T heterozygote. Twenty-five blood samples genotyped by pyrosequencing showed the same result with DGGE. The CpG methylation status of region upstream rs220030 of the child was similar to the mother. CONCLUSION: Compared with DGGE, pyrosequencing is more accurate, convenient, and suitable for large samples and high throughput SNP genotyping. Pyrosequencing united bisulfite conversion can be used to detect CpG methylation status precisely. It is feasible to apply rs220030 to parental origin allele determination.

[Myocardial expression of Spry1 and MAPK proteins of viral myocarditis].

OBJECTIVE: To discuss the myocardial expression of Spry1 and MAPK proteins of viral myocarditis (VMC), to reveal its mechanism of sudden death, and to provide guides for forensic identification of sudden cardiac death. METHODS: Thirty Balb/c male mice were randomly divided into VMC group and control group, inoculated intraperitoneally with Coxsackievirus B3 and Eagel's solution, respectively. After the mice were sacrificed, the cardiac tissues of the mice were taken to proceed regular pathological examination. The changes of Spry1 protein, Spry1 mRNA and MAPK protein were detected by immunohistochemistry, Western blotting and real-time PCR. RESULTS: Under light microscope, the pathologic changes included myocardial interstitial edema, inflammatory cells infiltration, myocardial necrosis, and focal and patchy necrosis of myocardial fiber in VMC group. The expression of Spry1 protein in VMC group was lower than that in control group (P < 0.05). There was slightly decreased expression of Spry1 of the mRNA level in VMC group (P > 0.05). But the MAPK protein expression in VMC group was higher than that in control group (P < 0.05). CONCLUSION: The pathway of MAPK/ERK involving Spry1 protein accelerates the expression of collagen, which may contribute to arrhythmia, heart failure and even sudden cardiac death.

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.

MicroRNA- 1 represses Cx43 expression in viral myocarditis.

MicroRNAs (miRNAs) are increasingly reported to have important roles in diverse biological and pathological processes. Changes in abundance of muscle-specific microRNA, miR-1, have been implicated in cardiac disease, including arrhythmia and heart failure. However, the specific molecular targets and cellular mechanisms involved in the miR-1 function in the heart are only beginning to emerge. In this study, we investigated miR-1 expression and its potential role in the mouse model of viral myocarditis (VMC). The expression levels of miR-1 and its target gene Connexin 43 (Cx43) were measured by real-time PCR and western blotting, respectively. The miR-1 expression levels were significantly increased in cardiac myocytes from VMC mice in comparison with control samples (relative expression: 10 ± 2.5 vs. 31 ± 7.6, P < 0.05). Among the target genes of miR-1, the expression Cx43 protein was significantly reduced in such mice while there was no significant difference in the its mRNA levels. Our results revealed an inverse correlation between miR-1 levels and Cx43 protein expression in VMC samples. Using a bioinformatics-based approach, we found two identical potential binding sites were found in mouse miR-1 and Cx43 3'- untranslated region, this confirms a possible regulatory role of miR-1. In cultured, miRNA transfected myocardial cells, we show overexpression of miR-1 accompanied by a decrease in Cx43 protein's expression. There was only a slight (not statistically significant) drop in Cx43 mRNA levels. Our results indicate that miR-1 is involved in VMC via post-transcriptional repression of Cx43, and might constitute potentially valuable data for the development of a new approach in the treatment of this disease.

[Genetic polymorphisms of the dinucleotide STR locus D6S261].

OBJECTIVE: To investigate the application of dinucleotide STR locus in paternity testing. METHODS: Dinucleotide STR locus D6S261 was selected and the paternity testing blood samples were amplified using 200 random blood samples, 16 family samples and 193 paternity test samples. Data of the PCR products were collected by 3130XL Genetic Analyzer and the genetic parameters of population were calculated by PowerStats v12. RESULTS: Fifteen alleles and 50 genotypes were found and H, DP, PE and PIC were 0.850, 0.953, 0.695, and 0.820, respectively. The typing results of both family samples and paternity test samples were accord with the law of inheritance, which no mutation was discovered. CONCLUSION: The genetic polymorphisms of D6S261 show good characteristics with low mutation rate and high stability. It can be an effective method to solve the indetermination caused by mutation in paternity testing if the stutter bands can be decreased.