MicroRNA profile of silk gland reveals different silk yields of three silkworm strains

Silk proteins are synthesized and secreted by the silk gland. The differential gene expression in it leads to different silk yield among various silkworm strains. As crucial factors, microRNAs (miRNAs) regulate protein synthesis at post-transcriptional level in silk gland. MiRNAs expression level in the silk gland of three silkworm strains (Jingsong, Lan10 and Dazao) was analyzed and 33 differentially expressed miRNAs (DEMs) were discovered between JingSong (JS) and Lan10 (L10), 60 DEMs between JS and Dazao, 54 DEMs between L10 and Dazao respectively. The DEMs target genes were predicted combing with two different methods and their functions were annotated according to gene ontology. Our previous studies showed that a batch of genes related to silk yield were identified in JS and L10 strains by comparative transcriptome and quantitative trait loci (QTL) method. Thirteen DEMs whose target genes are related to protein biosynthesis processes were screened by combining with these researches. Twelve DEMs potentially regulate nineteen genes which exist in our QTL results. Six common DEMs potentially regulate the genes in both of previous results. Finally, five DEMs were selected to verify their expression levels between JS and L10 by qRT-PCR, which showed similar difference as the results of small RNA-sequencing. MiRNAs in the silk gland may directly affect silk protein biosynthesis in different silkworm strains. In current work, we identified a batch of DEMs which potentially regulate the genes related to silk yield. Further functionally study of these miRNAs will contribute to improve varieties and boost the silk yield. Our research provides a basis for studying these miRNAs and their functions in silk production.

Synergic interaction between amyloid precursor protein and neural cell adhesion molecule promotes neurite outgrowth

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases worldwide. The main features of AD are the pathological changes of density and distribution of intracellular neurofibrillary tangles (NFT) and extracellular amyloid plaques. The processing of amyloid beta precursor protein (APP) to β-amyloid peptide (Aβ) is one of the critical events in the pathogenesis of AD. In this study, we evaluated the role of the interaction of neural cell adhesion molecule (NCAM) and APP in neurite outgrowth using two different experimental systems: PC12E2 cells and hippocampal neurons that were isolated from wild type, APP knock-in and APP knock-out mice. PC12E2 cells or hippocampal neurons were co-cultured with NCAM-negative or NCAM-positive fibroblasts L929 cells. We found that APP promoted neurite outgrowth of PC12E2 cells and hippocampal neurons in either the presence or absence of NCAM. Secreted APP can rescue the neurite outgrowth in hippocampal neurons from APP knock-out mice. The interaction of APP and NCAM had synergic effect in promoting neurite outgrowth in both PC12E2 cells and hippocampal neurons. Our results suggested that the interaction of APP with NCAM played an important role in AD development and therefore could be a potential therapeutic target for AD treatment.

Effects of Ag Nanoparticles on Growth and Fat Body Proteins in Silkworms (Bombyx mori)

Ag nanoparticles (AgNPs), a widely used non-antibiotic, antibacterial material, have shown toxic and other potentially harmful effects in mammals. However, the deleterious effects of AgNPs on insects are still unknown. Here, we studied the effects of AgNPs on the model invertebrate organism Bombyx mori. After feeding silkworm larvae different concentrations of AgNPs, we evaluated the changes of B. mori body weights, survival rates, and proteomic differences. The results showed that low concentrations (<400 mg/L) of AgNPs promoted the growth and cocoon weights of B. mori. Although high concentrations (≥800 mg/L) of AgNPs also improved B. mori growth, they resulted in silkworm death. An analysis of fat body proteomic differences revealed 13 significant differences in fat body protein spots, nine of which exhibited significantly downregulated expression, while four showed significantly upregulated expression. Reverse transcription-polymerase chain reaction results showed that at an AgNP concentration of 1600 mg/L, the expression levels of seven proteins were similar to the transcription levels of their corresponding genes. Our results suggest that AgNPs lowered the resistance to oxidative stress, affected cell apoptosis, and induced cell necrosis by regulating related protein metabolism and metabolic pathways in B. mori.

Long Non-Coding RNAs in Hepatitis B Virus-Related Hepatocellular Carcinoma: Regulation, Functions, and Underlying Mechanisms

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer death in the world. Hepatitis B virus (HBV) and its X gene-encoded protein (HBx) play important roles in the progression of HCC. Although long non-coding RNAs (lncRNAs) cannot encode proteins, growing evidence indicates that they play essential roles in HCC progression, and contribute to cell proliferation, invasion and metastasis, autophagy, and apoptosis by targeting a large number of pivotal protein-coding genes, miRNAs, and signaling pathways. In this review, we briefly outline recent findings of differentially expressed lncRNAs in HBV-related HCC, with particular focus on several key lncRNAs, and discuss their regulation by HBV/HBx, their functions, and their underlying molecular mechanisms in the progression of HCC.

Caspase-1 from the silkworm, Bombyx mori, is involved in Bombyx mori nucleopolyhedrovirus infection

Caspase-1 is one of the effector caspases in mammals that plays a central role in apoptosis. However, the lepidopteran caspase-1, especially the Bombyx mori caspase-1 (Bm-caspase-1), has not been investigated in detail. In this study, Bm-caspase-1 was identified from an expressed sequence tag database in B. mori by BLAST search. The open reading frame of Bm-caspase-1 contained 879 nucleotides and encoded 293 amino acids with a predicted molecular mass of 33 kDa. Bm-caspase-1 contained two consensus amino acid motifs of caspase cleavage sites, DEGDA and TETDG. Caspase activity assays revealed significant proteolytic activity of the Ac-DEVD-pNA substrate. Bm-caspase-1 can be detected in all tissues and developmental stages by a semi quantitative polymerase chain reaction assay. More importantly, the expression level of Bm-caspase-1 is increased upon baculovirus infection and up-regulated in BmNPV-resistant silkworms. Taken together, these results indicate that Bm-caspase-1 plays an important role during baculovirus infection.

Long non-coding RNAs as biomarkers and therapeutic targets: Recent insights into hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer worldwide, and the survival rates of patients with HCC remains quite low after 5years. Long non-coding RNAs (LncRNAs) are a novel class of non-coding RNAs that are capable of regulating gene expression at various levels. Recent works have demonstrated that lncRNAs are often dysregulated in HCC, and the dysregulation of some of these lncRNAs are associated with the clinicopathological features of HCC. They regulate cell proliferation, apoptosis, autophagy, Epithelial-Mesenchymal Transition (EMT), invasion and metastasis of HCC by modulating gene expression and cancer-related signaling pathways, and thus contribute to the onset and progression of HCC. In this review, we provide a comprehensive survey of dysregulated lncRNAs in HCC, with particular focus on the functions and regulatory mechanisms of several essential and important lncRNAs, and discuss their potential clinical application as early diagnostic and/or prognostic biomarkers or therapeutic targets for HCC.

Silkworm: A Promising Model Organism in Life Science

As an important economic insect, silkworm Bombyx mori (L.) (Lepidoptera: Bombycidae) has numerous advantages in life science, such as low breeding cost, large progeny size, short generation time, and clear genetic background. Additionally, there are rich genetic resources associated with silkworms. The completion of the silkworm genome has further accelerated it to be a modern model organism in life science. Genomic studies showed that some silkworm genes are highly homologous to certain genes related to human hereditary disease and, therefore, are a candidate model for studying human disease. In this article, we provided a review of silkworm as an important model in various research areas, including human disease, screening of antimicrobial agents, environmental safety monitoring, and antitumor studies. In addition, the application potentiality of silkworm model in life sciences was discussed.

1-Deoxynojirimycin: Sources, Extraction, Analysis and Biological Functions

1-Deoxynojirimycin (DNJ), a natural polyhydroxylated piperidine alkaloid, is attracting growing attention due to its important biological functions. This paper introduces the discovery and origins of DNJ, its extraction, purification, and physiological functions in the treatment of diabetes. The mechanisms of DNJ in the inhibition of fat accumulation and tumor cell metastasis are also discussed. In addition, the prospects and challenges of DNJ for practical production are proposed. This work aims to provide technical advice on obtaining DNJ and a fuller understanding of its biological activities.

Association of angiotensin II receptor 1 and lectin-like oxidized low-density lipoprotein receptor-1 mediates the cardiac hypertrophy induced by oxidized low-density lipoprotein

To date the molecular mechanism of cardiac hypertrophy has not been completely elucidated. Since oxidized low-density lipoprotein (ox-LDL) is considered a risk marker for early ventricular remodeling, we speculated that ox-LDL may be related to cardiac hypertrophy. We observed the significantly upregulation of plasma ox-LDL and hypertrophic responses, such as cardiomyocyte size and specific gene expressions in Apo E^-/- mice fed with high fat diet, accompanied by the upregulation of AT1-R and lectin-like oxidized low-density protein receptor 1 (LOX-1). Ox-LDL treatment with neonatal rat cardiomyocyte for 24 h significantly induced similar hypertrophic responses and also upregulation of AT1-R and LOX-1. The analysis of co-immunoprecipitation and the bimolecular fluorescence complementation assay proved that LOX-1 and AT1-R could directly bind together in the presence of ox-LDL, suggesting a critical role of the association between LOX-1 and AT1-R in ox-LDL-induced cardiac hypertrophy. Furthermore, we found that the AT1-R blocker Losartan and LOX-1 neutralizing antibody through inhibiting AT1-R or LOX-1 could both decline ox-LDL-induced hypertrophic responses whereas angiotensin converting enzyme inhibitor Enalapril only partially inhibited the responses stimulated by ox-LDL. These findings suggested that ox-LDL could induce cardiac hypertrophy through the direct association of AT1-R and LOX-1.

Evidence for the role of BmNPV Bm65 protein in the repair of ultraviolet-induced DNA damage

It is unclear how, or to what extent, baculovirus DNA that has been damaged by ultraviolet (UV) light is repaired during infection and replication. In our previous study, expression of Bombyx mori nucleopolyhedrovirus (BmNPV) ORF Bm65, a homolog of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac79, correlated with decreased inactivation of virus by UV irradiation. In the current study, we accumulated more evidence pointing to a role for Bm65 in repair of UV-induced DNA damage. The localization of Bm65 was studied using enhanced green fluorescent protein (EGFP) fusion constructs expressed in BmN cells transfected with a Bm65 expression plasmid. The results indicate that Bm65-EGFP accumulates in the nucleus. A host cell reactivation assay showed that Bm65 significantly increased the expression of UV-damaged mCherry reporter gene. An assay measuring cyclobutane pyrimidine dimers (CPDs) in UV-irradiated BmN cells found that CPD quantity was decreased in cells transfected with a Bm65 expression plasmid. We also showed that after UVC treatment, the viability of Bm65-transfected cells was higher than that of egfp-transfected cells. These results suggest that Bm65 may be involved in the repair of baculovirus DNA that has been damaged by UV light.

Treatment of Diabetes Mellitus Using iPS Cells and Spice Polyphenols

Diabetes mellitus is a chronic disease that threatens human health. The disease is caused by a metabolic disorder of the endocrine system, and long-term illness can lead to tissue and organ damage to the cardiovascular, endocrine, nervous, and urinary systems. Currently, the disease prevalence is 11.4%, the treatment rate is 48.2%, and the mortality rate is 2.7% worldwide. Comprehensive and effective control of diabetes, as well as the use of insulin, requires further study to develop additional treatment options. Here, we reviewed the current reprogramming of somatic cells using specific factors to induced pluripotent stem (iPS) cells capable of repairing islet β cell damage in diabetes patients to treat patients with type 1 diabetes mellitus. We also discuss the shortcomings associated with clinical use of iPS cells. Additionally, certain polyphenols found in spices might improve glucose homeostasis and insulin resistance in diabetes patients, thereby constituting promising options for the treatment of type 2 diabetes.

Comparative transcriptomic analysis of Bombyx mori fat body tissue following dietary restriction

Dietary restriction (DR) refers to a reduction in food intake to induce undernutrition but not malnutrition, which extends the lifespan of multiple species. Although there are invertebrate aging models, such as the Caenorhabditis elegans and Drosophila melanogaster, aging studies in Lepidoptera are few in number and the underlying life-extending molecular mechanisms are not clear. Research on a broader range of animals is necessary to support generalizations on mechanisms of aging and rates of aging. The aim of this study was to further investigate genes and pathways associated with DR in Bombyx mori. Here, we used mRNA deep sequencing (RNA-seq) to further investigate genes and pathways associated with DR. The transcriptome profiles showed that most of the differentially expressed genes were upregulated following DR, and genes involved in amino acid and protein metabolism, RNA metabolism and translation, energy metabolism, nitrogen metabolism, and juvenile hormone pathway-related proteins were particularly affected. DR also affects the metabolism of uric acid and urea, which accumulated in silkworm following DR. We speculate that this may not be due to activation of uric acid biosynthesis, but rather by downregulating the degradation of uric acid and urea. These results may help us to understand the mechanisms by which DR prolong lifespan in insects and other animals.

Identification and Characterization of BmVta1, a Bombyx mori (Lepidoptera: Bombycidae) Homologue for Vta1 That is Up-Regulated in Development

Vps20-associated 1 (Vta1) positively regulates Vacuolar protein sorting 4 (Vps4) to disassemble endosomal sorting complex required for transport III (ESCRT-III) for repeated uses in multivesicular body (MVB) pathway, virus budding and other processes. Currently, these proteins have mainly been studied in yeast and mammalian cells, while identities of them in insects remain largely unknown. We previously identified BmVps4, a Vps4 homologue from Bombyx mori. Here, we report the identification of a homologue for Vta1, designated as BmVta1. The BmVta1 cDNA contains an open reading frame of 933 bp and encodes a protein of 311 amino acid residues. We cloned BmVta1, expressed it in Escherichia coli, and prepared mouse polyclonal antibodies. Like BmVps4, BmVta1 is well conserved as shown by sequence analysis. Both proteins are localized in cytoplasm as revealed by subcellular location analysis. Interestingly, as revealed by semi-quantitative reverse transcription polymerase chain reaction (sqRT-PCR), transcriptions of BmVta1 and BmVps4 are highly up-regulated during silkworm metamorphosis and embryogenesis but down-regulated during larva stages, and are of higher levels in head, silk gland and testis than in Malpighian tube, fat body and ganglion, indicating important and similar roles of them in silkworm development and in silkworm tissues and organs. However, compared to BmVps4, the transcription of BmVta1 changes less drastically during development and is of much higher levels in midgut, ovary and hemolymph, suggesting the existence of distinct requirements of them in silkworm development and in certain tissues and organs.

Serine protease Bm-SP142 was differentially expressed in resistant and susceptible Bombyx mori strains, involving in the defence response to viral infection

Bm-SP142 is a 35 kDa protease in the silkworm, but its exact functions remain unknown. In this study, sequence alignment revealed that the His-Asp-Ser catalytic triad is embedded in the TAAHC-DIAL-GDSGGP sequence motif, establishing Bm-SP142 as a serine protease. Soluble recombinant GST-BmSP142 was expressed and purified, and serine protease activity was confirmed in vitro. RT-qPCR results indicated that Bm-SP142 was mainly expressed in the middle part of the silkworm midgut, and Bm-SP142 transcripts were significantly up-regulated at 24 hours post infection (hpi) in BmBDV-resistant strains (798) inoculated with BmBDV and BmNPV-resistant strains (NB) inoculated with BmNPV, but not in BmBDV-susceptible strains (306). Surprisingly, transcripts were significantly down-regulated at 12 hpi in BmNPV-susceptible strains (HuaBa 35) inoculated with BmNPV, compared with healthy silkworms. Recombinant BmNPV treated with purified Bm-SP142 effectively impaired its ability to infect BmN cells, and Bm-SP142 decreases the efficiency of BmNPV and BmBDV propagation in silkworms. Furthermore, overexpression of Bm-SP142 in BmN cells inhibited viral propagation.

[Association of serum albumin level and clinical outcomes among heart failure patients receiving cardiac resynchronization therapy]

Objective: To assess the relationship between serum albumin level and clinical outcome in heart failure (HF) patients receiving cardiac resynchronization therapy (CRT). Methods: In this retrospective cohort study, 357 consecutive chronic heart failure patients receiving CRT between January 2010 and December 2015 were enrolled and divided into two groups based on pre-CRT serum albumin (albumin≥40 g/L, n=244; albumin<40 g/L, n=113). Clinical outcomes were defined as all-cause mortality (including heart transplantation) and rehospitalization due to worsening HF.Baseline characteristics were compared and all-cause mortality (including heart transplantation) and rehospitalization due to worsening heart failure (HF) were analyzed using Kaplan-Meier curves.Prognostic value of albumin level was evaluated in Cox proportional-hazards regression models. Results: Over a median follow-up time of 21 months, 45 patients (12.6%) died, 4 patients (1.1%) underwent heart transplantation and 100 patients (28.0%) were rehospitalized due to worsening HF. HF patients with pre-CRT albumin<40 g/L were related with worse NYHA function class, lower HDL-C level and ACEI/ARB use compared to HF patients with pre-CRT albumin≥40 g/L. Kaplan-Meier analyses evidenced lower survival rate in HF patients (log-rank test: P=0.000 4, χ(2)=12.60) and higher rehospitalization rate due to worsening HF (log-rank test: P=0.009, χ(2)=6.82) in HF patients with pre-CRT albumin<40 g/L.Multivariate Cox analyses indicated that serum pre-CRT albumin <40 g/L was an independent risk factor for all-cause mortality (HR=2.019, 95%CI 1.125-3.622, P=0.018) and HF rehospitalization (HR=1.517, 95%CI 1.014-2.270, P=0.043). Conclusion: Pre-CRT serum albumin level is associated with the severity of heart failure in CRT recipients.Patients with lower pre-CRT albumin level face increased risk of all-cause mortality and HF rehospitalization in chronic heart failure patients receiving cardiac resynchronization.

Adaptive laser shock micro-forming for MEMS device applications

Laser shock micro-forming is a non-thermal laser forming method that uses laser-induced shockwave to modify surface properties and to adjust shapes and geometry of work pieces. The magnitude and spatial distribution of the laser-induced shockwaves depend on the energy profiles of the laser beam focused on sample surfaces. In this paper, we present an adaptive optical technique to engineer spatial profiles of laser beams to control the shapes, sizes, and locations of the laser-induced shockwaves and the resulting forming features. Using a spatial light modulator, this adaptive laser beam forming tool was used to process free-standing MEMS structures in aluminum, which has led to highly uniform forming features. Shockwave simultaneously excited by multiple laser beams generated by the spatial light modulator and its effects on the micro-forming process were also studied. The results presented in this paper show that the adaptive optics laser beam forming is an effective and flexible method to generate shockwave with various shapes and sizes of wavefront and at multiple locations for laser processing at microscales.

Association between patient activity and long-term cardiac death in patients with implantable cardioverter-defibrillators and cardiac resynchronization therapy defibrillators

Background Patient activity (PA) has been demonstrated to predict all-cause mortality. However, the association between PA and cardiac death is unclear. Aims The aims of this study were to determine whether PA can predict cardiac death and what is the cut-off of PA to discriminate cardiac death, as well as the mechanism underlying the relationship between PA and survival in patients with home monitoring. Methods This study retrospectively analysed clinical and implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator device data in 845 patients. Data regarding PA and PP variability during the first 30-60 days of home monitoring were collected, and mean values were calculated. The primary endpoint was cardiac death, and the secondary endpoint was all-cause mortality. Results The mean PA percentage was 11 ± 5.8%. Based on receiver operating characteristic curve analysis, we determined that a PA cut-off value of 7.84% (113 min) can predict cardiac death. During a mean follow-up period of 31.1 ± 12.9 months (ranging from three to 60 months), PA ≤ 7.84% was associated with increased risks of cardiac death in an unadjusted analysis; after adjusting in a multivariate Cox model, the relationship remained significant between PA≤7.84% and cardiac death (hazard ratio = 3.644, 95% confidence interval = 2.424-5.477, p < 0.001). Moreover, a significant correlation was observed between PA and PP variability ( r = 0.601, p < 0.001). Conclusions A baseline PA ≤ 7.84% was associated with a higher risk of cardiac death in patients who have survived more than three months after implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator implantation. PA had a sizable effect on heart rate variability, reflecting autonomic function.

High incidence of ventricular arrhythmias in patients with left ventricular enlargement and moderate left ventricular dysfunction

BACKGROUND

Left ventricular ejection fraction (LVEF) ≤35% is the cutoff value used to identify patients at high risk of sudden cardiac death. However, whether patients who have moderate left ventricular dysfunction and left ventricular enlargement (LVE) have a high risk of ventricular arrhythmias (VAs) and cardiac death is unclear.

HYPOTHESIS

Patients with moderate left ventricular dysfunction and LVE may have a high risk of VAs.

METHODS

This study retrospectively analyzed the data of 853 patients who have an implantable cardioverter-defibrillator/cardiac resynchronization therapy cardioverter-defibrillator equipped with home monitoring. The patients were divided into 4 groups: group A, 35% < LVEF ≤ 45% and left ventricular end-diastolic dimension (LVEDD) ≥60 mm; group B, LVEF ≤35% and LVEDD <60 mm; group C, 35% < LVEF ≤ 45% and LVEDD <60 mm; and group D, LVEF ≤35% and LVEDD ≥60 mm.

RESULTS

During a mean follow-up period of 30 ± 13 months, 324 patients (38%) experienced VAs and 125 patients (14.7%) experienced cardiac death. Based on multivariate Cox regression modeling, group A had an increased risk of VAs (A vs B, hazard ratio [HR]: 1.563, 95% confidence interval [CI]: 1.029-2.375, P = 0.036; A vs C, HR: 1.661, 95% CI: 1.204-2.294, P = 0.002) and cardiac death (A vs B, HR: 1.845, 95% CI: 1.013-3.356; A vs C, HR: 2.041, 95% CI: 1.136-3.731, P = 0.021).

CONCLUSIONS

Patients with moderate left ventricular dysfunction and LVE have a high risk of VAs and cardiac death.