A retrospective study of cumulative absolute reduction in axial length after photobiomodulation therapy

BACKGROUND

To assess the age and timeline distribution of ocular axial length shortening among myopic children treated with photobiomodulation therapy in the real world situations.

METHODS

Retrospective study of photobiomodulation therapy in Chinese children aged 4 to 13 years old where axial length measurements were recorded and assessed to determine effectiveness at two age groups (4 ∼ 8 years old group and 9 ∼ 13 years old group). Data was collected from myopic children who received photobiomodulation therapy for 6 ∼ 12 months. Effectiveness of myopia control was defined as any follow-up axial length ≤ baseline axial length, confirming a reduction in axial length. Independent t-test was used to compare the effectiveness of the younger group and the older group with SPSS 22.0.

RESULTS

342 myopic children were included with mean age 8.64 ± 2.20 years and baseline mean axial length of 24.41 ± 1.17 mm. There were 85.40%, 46.30%, 71.20% and 58.30% children with axial length shortening recorded at follow-up for 1 month, 3 months, 6 months and 12 months, respectively. With respect to the axial length shortened eyes, the mean axial length difference (standard deviation) was - 0.039 (0.11) mm, -0.032 (0.11) mm, -0.037 (0.12) mm, -0.028 (0.57) mm at 1, 3, 6, and 12-month follow-up, respectively. Greater AL shortening was observed among the older group who had longer baseline axial lengths than the younger group (P < 0.001).

CONCLUSIONS

Overall myopia control effectiveness using photobiomodulation therapy was shown to be age and time related, with the maximum absolute reduction in axial elongation being cumulative.

Insulin resistance and osteocalcin associate with the incidence and severity of postoperative delirium in elderly patients undergoing joint replacement

AIM

While insulin sensitivity plays an important role in maintaining glucose metabolic homeostasis and cognitive function, its impact on postoperative delirium (POD) remains unclear. This study aimed to investigate the association between POD and indicators of insulin sensitivity, including insulin resistance and osteocalcin.

METHODS

A total of 120 elderly patients undergoing joint replacement were recruited and divided into delirium and non-delirium groups. Plasma and cerebrospinal fluid (CSF) samples were collected for the analysis of biomarkers, including insulin, uncarboxylated osteocalcin (ucOC), total osteocalcin (tOC), and glucose. Insulin resistance was assessed through the homeostatic model assessment of insulin resistance (HOMA-IR).

MAIN RESULTS

Out of the total, 28 patients (23.3%) experienced POD within 5 days after surgery. Patients with delirium exhibited higher levels of preoperative HOMA-IR and ucOC in CSF and plasma, and of tOC in CSF (P = 0.028, P < 0.001, P = 0.005, P = 0.019). After adjusting for variables, including age, Mini-Mental State Examination score, surgical site and preoperative fracture, only preoperative ucOC in CSF and HOMA-IR were significantly linked to the incidence of delirium (OR = 5.940, P = 0.008; OR = 1.208, P = 0.046, respectively), both of which also correlated with the severity of delirium (P = 0.007, P < 0.001). Receiver operating curve analysis indicated that preoperative HOMA-IR and ucOC in CSF might partly predict POD (area under the curve [AUC] = 0.697, 95% confidence interval [CI] = 0.501-0.775, AUC = 0.745, 95% CI = 0.659-0.860).

CONCLUSIONS

We observed that preoperative elevated HOMA-IR and ucOC in CSF were associated with the incidence and severity of POD. While these preliminary results need confirmation, they suggest a potential involvement of insulin resistance and osteocalcin in the pathological mechanism of POD. Geriatr Gerontol Int 2024; 24: 421-429.

The effects of long-term lactate and high-intensity interval training (HIIT) on brain neuroplasticity of aged mice

Extensive research has confirmed numerous advantages of exercise for promoting brain health. More recent studies have proposed the potential benefits of lactate, the by-product of exercise, in various aspects of brain function and disorders. However, there remains a gap in understanding the effects of lactate dosage and its impact on aged rodents. The present study first examined the long-term effects of three different doses of lactate intervention (2000 mg/kg, 1000 mg/kg, and 500 mg/kg) and high-intensity interval training (HIIT) on aging mice (20-22 months) as the 1st experiment. Subsequently, in the 2nd experiment, we investigated the long-term effects of 500 mg/kg lactate intervention and HIIT on brain neuroplasticity in aged mice (25-27 months). The results of the 1st experiment demonstrated that both HIIT and different doses of lactate intervention (500 mg/kg and 2000 mg/kg) positively impacted the neuroplasticity biomarker VEGF in the hippocampus of aging mice. Subsequently, the 2nd experiment revealed that long-term HIIT significantly improved the performance of mice in open-field, novel object recognition, and passive avoidance tests. However, lactate intervention did not significantly affect these behavioral tests. Moreover, compared to the control group, both HIIT and lactate intervention positively influenced the angiogenesis signaling pathway (p/t-AKT/ENOS/VEGF), mitochondrial biomarker (SDHA), and metabolic protein (p/t-CREB, p/t-HSL, and LDH) in the hippocampus of aged mice. Notably, only lactate intervention significantly elevated the BDNF (PGC-1α, SIRT1, and BDNF) signaling pathway and metabolic content (lactate and pyruvate). In the end, long-term HIIT and lactate intervention failed to change the protein expression of p/t-MTOR, iNOS, nNOS, HIF-1α, SYNAPSIN, SIRT3, NAMPT, CS, FNDC5 and Pan Lactic aid-Lysine in the hippocampus of aged mice. In summary, the present study proved that long-term HIIT and lactate treatment have positive effects on the brain functions of aged mice, suggesting the potential usage of lactate as a therapeutic strategy in neurodegenerative diseases in the elderly population.

High temperature stress induced oxidative stress, gut inflammation and disordered metabolome and microbiome in tsinling lenok trout

Tsinling lenok trout (Brachymystax lenok tsinlingensis Li) is a species of cold-water salmon that faces serious challenges due to global warming. High temperature stress has been found to damage the gut integrity of cold-water fish, impacting their growth and immunity. However, limited research exists on the causal relationship between gut microbial disturbance and metabolic dysfunction in cold-water fish induced by high temperature stress. To address this gap, we conducted a study to investigate the effects of high temperature stress (24 °C) on the gut tissue structure, antioxidant capacity, gut microorganisms, and metabolome reactions of tsinling lenok trout. Our analysis using 16 S rDNA gene sequencing revealed significant changes in the gut microbial composition and metabolic profile. Specifically, the abundance of Firmicutes and Gemmatimonadetes decreased significantly with increasing temperature, while the abundance of Bacteroidetes increased significantly. Metabolic analysis revealed a significant decrease in the abundance of glutathione, which is synthesized from glutamate and glycine, under high temperature stress. Additionally, there was a notable reduction in the levels of adenosine, inosine, xanthine, guanosine, and deoxyguanosine, which are essential for DNA/RNA synthesis. Conversely, there was a significant increase in the abundance of D-glucose 6 P. Furthermore, high temperature stress adversely affects intestinal structure and barrier function. Our findings provide valuable insights into the mechanism of high temperature stress in cold-water fish and serve as a foundation for future research aimed at mitigating the decline in production performance caused by such stress.

Single Cell Analysis of Macrophage Heterogeneity and NK-Cell Exhaustion in Lewis Lung Cancer Xenograft Tumor

PURPOSE/OBJECTIVE(S)

Stereotactic body radiation therapy (SBRT) has attracted much attention because of its ability to stimulate anti-tumor immune response. However, the mechanism of SBRT reprogramming the tumor microenvironment remains to be elucidated.

MATERIALS/METHODS

Using Lewis lung carcinoma (LLC) xenograft mice model treated with SBRT (8Gy x 3F), multiplex assay was performed to measure serum chemokine levels, and single-cell RNA sequencing was performed to assess tumor microenvironment. The differential expression genes of each cell subcluster were identified by the "Find-All markers" function with default parameters provided by Seurat. Intercellular communication analysis was explored by using CellPhone DB package.

RESULTS

The majority of serum chemokines involved macrophage recruitment, including CCL3, CCL4, CCL8, and CCL20, were highly secreted at 7 days after SBRT. Single-cell RNA sequencing of 108,741 cells were contained from 6 mouse Lewis lung carcinoma samples (n = 3 tumors for SBRT, n = 3 tumors pooled for SHAM). Besides Lewis cancer cells, myeloid cells were 57.61% ,70.82% in Sham-irradiation (SHAM) and SBRT while NT and T cells were 20.50%, 7.81% in SHAM and SBRT, respectively. When compared with SHAM group, upregulation of Ccl3, Ccl4, Ccl8 chemokine genes were observed in cancer cells of SBRT group. Differential expression genes analysis showed high expression level of Ccl8 (Log2FC 2.54, p<0.01) in cluster of Mrc1+macrophage. The SBRT group consisted of more Ccl8+Mrc1+macrophages (proportion 36.28% for SBRT, 27.44% for SHAM) and exhausted NK cells (proportion 22.56% for SBRT, 13.70% for SHAM). More importantly, intercellular communication analysis revealed a potential communication network between Ccl8+Mrc1+macrophages and exhausted NK cells.

CONCLUSION

Our results provide a potential therapeutic strategy by disrupting Ccl8+ Mrc1+macrophages and NK-cell interaction to facilitate the stimulation of the anti-tumor immune response by SBRT.

High-Flux Neutron Generator Based on Laser-Driven Collisionless Shock Acceleration

A novel compact high-flux neutron generator with a pitcher-catcher configuration based on laser-driven collisionless shock acceleration (CSA) is proposed and experimentally verified. Different from those that previously relied on target normal sheath acceleration (TNSA), CSA in nature favors not only acceleration of deuterons (instead of hydrogen contaminants) but also increasing of the number of deuterons in the high-energy range, therefore having great advantages for production of high-flux neutron source. The proof-of-principle experiment has observed a typical CSA plateau feature from 2 to 6 MeV in deuteron energy spectrum and measured a forward neutron flux with yield 6.6×10^{7}  n/sr from the LiF catcher target, an order of magnitude higher than the compared TNSA case, where the laser intensity is 10^{19}  W/cm^{2}. Self-consistent simulations have reproduced the experimental results and predicted that a high-flux forward neutron source with yield up to 5×10^{10}  n/sr can be obtained when laser intensity increases to 10^{21}  W/cm^{2} under the same laser energy.

RNNCon: Contribution Coverage Testing for Stacked Recurrent Neural Networks

Recurrent Neural Networks (RNNs) are applied in safety-critical fields such as autonomous driving, aircraft collision detection, and smart credit. They are highly susceptible to input perturbations, but little research on RNN-oriented testing techniques has been conducted, leaving a threat to a large number of sequential application domains. To address these gaps, improve the test adequacy of RNNs, find more defects, and improve the performance of RNNs models and their robustness to input perturbations. We aim to propose a test coverage metric for the underlying structure of RNNs, which is used to guide the generation of test inputs to test RNNs. Although coverage metrics have been proposed for RNNs, such as the hidden state coverage in RNN-Test, they ignore the fact that the underlying structure of RNNs is still a fully connected neural network but with an additional "delayer" that records the network state at the time of data input. We use the contributions, i.e., the combination of the outputs of neurons and the weights they emit, as the minimum computational unit of RNNs to explore the finer-grained logical structure inside the recurrent cells. Compared to existing coverage metrics, our research covers the decision mechanism of RNNs in more detail and is more likely to generate more adversarial samples and discover more flaws in the model. In this paper, we redefine the contribution coverage metric applicable to Stacked LSTMs and Stacked GRUs by considering the joint effect of neurons and weights in the underlying structure of the neural network. We propose a new coverage metric, RNNCon, which can be used to guide the generation of adversarial test inputs. And we design and implement a test framework prototype RNNCon-Test. 2 datasets, 4 LSTM models, and 4 GRU models are used to verify the effectiveness of RNNCon-Test. Compared to the current state-of-the-art study RNN-Test, RNNCon can cover a deeper decision logic of RNNs. RNNCon-Test is not only effective in identifying defects in Deep Learning (DL) systems but also in improving the performance of the model if the adversarial inputs generated by RNNCon-Test are filtered and added to the training set to retrain the model. In the case where the accuracy of the model is already high, RNNCon-Test is still able to improve the accuracy of the model by up to 0.45%.

Small molecule-mediated rapid maturation of human induced pluripotent stem cell derived cardiomyocytes

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Gravitation Program “Materials Driven Regeneration” by the Netherlands Organization for Scientific Research (RegmedXB #024.003.013) and the Marie Skłodowska-Curie Actions (Grant agreement RESCUE #801540). The EU-funded project BRAV3 (H2020, ID:874827)

Background

Human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) do not display all hallmarks of mature human primary cardiomyocytes: the ability to use fatty acids as an energy source, high mitochondrial mass, increased nuclei polyploidism, synchronized electrical conduction, and forceful contractions. Instead, their phenotype is similar to immature cardiomyocytes in the late fetal stage. This immaturity represents a bottleneck to their application in 1) disease modeling – as most cardiac (genetic) diseases have a middle-age onset – and 2) clinical use, where integration and functional coupling are key. So far, the mainly used methods to enhance iPSC-CM maturation include prolonged time-in-culture, 3D culture, cyclic mechanical stretch, and electrical stimulation with specialized media. However, these protocols are laborious, costly, and not easily scalable.

Methods

In this study, we developed a simple, low cost, and rapid protocol using two peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A/PGC-1α) activating small molecules: Asiatic Acid (AA) and GW501516 (GW) to promote cardiomyocyte maturity by inducing a metabolic switch to fatty acid utilization and increased mitochondrial biogenesis.

Results

Monolayers of iPSC-CMs were incubated with AA and GW every other day for 10 days resulting in increased expression of fatty acid-metabolism-related genes (5 and 10-fold increase in CPT1B gene expression, respectively), mitochondria biogenesis (protein expression of ATP5A) and fusion (50 and 100-fold increase in OPA1 gene expression, respectively). In addition, AA treated iPSC-CMs responded in the seahorse mitochondria stress test more rapidly to an artificial increase in mitochondrial activity and showed a higher flexibility in substrate utilization in the seahorse stress test. A more mature electrophysiological functionality was shown by increased ion channel gene expression (KCNA4, SCN5A, GJA1, CACNA1C, and SCN1B) and enhanced synchronous contraction in treated samples. Moreover, maturation was further shown by increased sarcomeric gene expression (5 and 7-fold increase in TNNI3 in AA and GW respectively) and nuclear polyploidism (&gt;4N fold 2.16 and 1.48-fold increase in AA and GW respectively).

Conclusions

Collectively, these findings show that AA and GW trigger a metabolic switch and induce extensive maturation of iPSC-CMs, providing a rapid and cost-effective method to obtain iPSC-CMs that more closely resemble their adult counterparts.

E2F7/8 is involved in cardiomyocyte polyploidy but does not affect myocardial reperfusion injury recovery

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): CSC fellowship

Background

Polyploidy cells consist of more than two complete sets of homologous chromosomes. Although a characteristic feature of cardiomyocytes and observed in all mammalian species, its molecular mechanism and biological functions are still unknown. Cardiomyocytes polyploidy in rodents occurs mainly through incomplete cytokinesis and increases with age. Studies have demonstrated that E2F7/8 transcription factors are key regulators of polyploidy in the liver and pancreas, however, it remains unclear if E2F7/8 control the generation of polyploidy cardiomyocytes and what the functional consequence is post-myocardial infarction (MI).

Methods

By using a tamoxifen inducible Cre/LoxP approach in new-born mice, we deleted E2F7/8 transcription factors ubiquitously and evaluated the biological significance of postnatal E2F7/8 loss. Mice underwent myocardial ischemia reperfusion injury (IRI) and heart function was assessed by 4D-echocardiography. Cardiomyocyte nucleus polyploidy was measured by FACS and microscope.

Results

Deficiency of E2F7/8 significantly suppress cardiomyocyte mononucleated and multinucleated polyploidy, as well as dramatically decreased hepatocytes polyploidy. E2F7/8 defect also led to a decrease in cardiac stress related marker lever such as ANP, BNP, MMP2, β-MHC/α-MHC and an increase in CD31 expression level. Surprisingly, E2F7/8 deletion did not have impact on cardiac function and dimensions post-IRI.

Conclusion

In summary, we identified that E2F7/8 activity is involved in the cellular polyploidy in the heart but did not affect myocardial function after myocardial injury.

Myocardial tissue slices for modeling of the human PLN p.Arg14del associated cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NWO - The Dutch Research Council

Background

Current in vivo preclinical models lack the predictability of the clinical efficacy resulting in a high dropout rate of therapeutic candidates. Advanced human-based models are required to bridge this gap and indicate the potential of novel therapeutic approaches[1].  Myocardial tissue slices are an in vitro model that recapitulates the native multicellular architecture of the heart. This allows for modeling cellular processes in a macroscopic context entailing great promise. The most common cardiomyopathy-related mutation in the Netherlands is the loss of arginine at position 14 (p.Arg14del) in the phospholamban protein (PLN). PLN is a critical regulator of calcium cycling and contractility in the heart. The p.Arg14del mutation results in a super inhibition of SERCA2a and thus aberrant calcium handling and reduced contractile force. Mice models harbouring the PLN p.Arg14del do not completely recapitulate the human manifestation mainly due to the difference between species; heart rate, Calcium-cycling and ion properties, and different myosin heavy chain isoforms, showing the unmet need for a human-based model[2,3].

Methods & Results

300 µm thick viable myocardial tissue were sectioned from a PLN p.Arg14del patient’s left ventricle. Although the myocardial tissue slices were kept alive for eight days in static culture, these conditions initiated cell death and dedifferentiation. The tissue slices show the greatest resemblance to the intact architecture of the in vivo human heart, it is the most relevant model for viral transduction in the human heart, and proof-of-principle of this is performed. Myocardial tissue slices of a PLN p.Arg14del patient retain the structural phenotype shown by the fibrofatty deposition. Similarly, functional patient characteristics, aberrant calcium handling, and reduced contractile force are preserved.

Conclusion

Myocardial tissue slices recapitulate the (patho)physiology of the heart, as shown here with the PLN p.Arg14del case. However, the static culture conditions induce remodeling of the heart and thus only allow for acute measures in the native heart. To prolong the period that the slices recapitulate the native heart, culture conditions should mimic the environment of the heart. The tissue slices allow for a currently unmet need to modulate the complex architecture of the human heart with e.g. novel delivery tools or therapeutic interventions. All in all, myocardial tissue slices are a promising model that can give novel insights into the physiology of the human heart, and therapeutic intervention on induced or genetic cardiomyopathies.

From force chains to nonclassical nonlinear dynamics in cemented granular materials

In this letter, we present evidence for a mechanism responsible for the nonclassical nonlinear dynamics observed in many cemented granular materials that are generally classified as mesoscopic nonlinear elastic materials. We demonstrate numerically that force chains are created within the complex grain-pore network of these materials when subjected to dynamic loading. The interface properties between grains along with the sharp and localized increase of the stress occurring at the grain-grain contacts leads to a reversible decrease of the elastic properties at macroscopic scale and peculiar effects on the propagation of elastic waves when grain boundary properties are appropriately considered. These effects are observed for relatively small amplitudes of the elastic waves, i.e., within tens of microstrain, and relatively large wavelengths, i.e., orders of magnitude larger than the material constituents. The mechanics are investigated numerically using the hybrid finite-discrete-element method and match those observed experimentally using nonlinear resonant ultrasound spectroscopy.

MicroRNA-214-3p Ameliorates LPS-Induced Cardiomyocyte Injury by Inhibiting Cathepsin B

Myocardial injury is a common complication of sepsis. MicroRNA (miRNA) miR-214-3p is protective against myocardial injury caused by sepsis, but its mechanism in lipopolysaccharide (LPS)- induced cardiomyocyte injury is still unclear. An AC16 cell injury model was induced by LPS treatment. Cell Counting Kit-8 and flow cytometry assay showed decreased cell viability and increased apoptosis in LPS-treated AC16 cells. The levels of caspase- 3, Bax, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), myosin 6 (Myh6), myosin 7 (Myh7), reactive oxygen species (ROS), and malondialdehyde (MDA) were increased in LPS-treated AC16 cells, but the levels of Bcl-2 and superoxide dismutase (SOD) were decreased. MiR-214-3p was down-regulated and cathepsin B (CTSB) was upregulated in LPS-treated AC16 cells. At the same time, miR-214-3p could target CTSB and reduce its expression. We also found that a miR-214-3p mimic or CTSB silencing could significantly reduce LPSinduced apoptosis, decrease ROS, MDA, caspase-3, and Bax and increase SOD and Bcl-2. CTSB silencing could significantly reduce ANP, BNP, Myh6, and Myh7 in LPS-treated AC16 cells. The effects of CTSB silencing were reversed by a miR-214-3p inhibitor. In summary, miR-214-3p could inhibit LPSinduced myocardial injury by targeting CTSB, which provides a new idea for myocardial damage caused by sepsis.

Preparation and properties of caffeic-chitosan grafting fish bone collagen peptide

In this study, a novel peptide grafted chitosan (CACS-FBP) with high peptide content, excellent moisture-absorption and moisture-retention abilities was prepared. Caffeic acid (CA) was used to modify chitosan, the highly water-soluble intermediate further reacted with fish bone collagen peptide to obtain the final product, and the synthesis of CACS-FBP was confirmed by the Fourier transform infrared spectroscopy (FT-IR), NMR, and UV-vis. The single-factor experiments indicated that the degree of substitution (DS) of CACS-FBP depended on the reaction temperature, reaction time, the mass ratio of fish bone collagen peptide to CACS (mFBP/mCACS) and the mass ratio of MTGase to CACS (mMTGase/mCACS). In addition, the antioxidant assay indicated that CACS-FBP had an excellent antioxidant capacity, and the CACS-FBP showed no cytotoxicity toward L929 mouse fibroblasts, all the results mean that the prepared peptide-containing chitosan derivative has potential application in pharmaceutical and biomedical fields.

Onset of inverse magnetic energy transfer in collisionless turbulent plasmas

Inverse magnetic energy transfer from small to large scales is a key physical process for the origin of large-scale strong magnetic fields in the universe. However, so far, from the magnetohydrodynamic perspective, the onset of inverse transfer is still not fully understood, especially the underlying dynamics. Here, we use both two-dimensional and three-dimensional particle-in-cell simulations to show the self-consistent dynamics of inverse transfer in collisionless decaying turbulent plasmas. Using the space filtering technique in theory and numerical analyses, we identify magnetic reconnection as the onset and fundamental drive for inverse transfer, where, specifically, the subscale electromotive force driven by magnetic reconnection do work on the large-scale magnetic field, resulting in energy transfer from small to large scales. The mechanism is also verified by the strong correlations in locations and characteristic scales between inverse transfer and magnetic reconnection.

Downregulated long noncoding RNA LUCAT1 inhibited proliferation and promoted apoptosis of cardiomyocyte via miR-612/HOXA13 pathway in chronic heart failure

OBJECTIVE

Long non-coding RNAs (lncRNAs) have been reported to play important roles in numerous kinds of cardiovascular disease, including chronic heart failure (CHF). In this study, we mainly focused on investigating the potential roles of lncRNA LUCAT1 patients with CHF.

PATIENTS AND METHODS

RT-PCR was used to detect the expressions of LUCAT1 and miR-612 in serum samples of CHF patients (n=60) and healthy volunteers. Relationships between the expressions of LUCAT1 and miR-612, LUCAT1 and overall survival (OS) were analyzed using the Kaplan-Meier method. Si-LUCAT1 and miR-612 mimic were constructed and respectively transfected into AC16 cells to explore the functions of LUCAT1 and miR-612. Cell proliferation abilities were detected by CCK-8 assay AC16 cells. Cell apoptotic rates were measured by flow cytometry (FACS) analysis. Western blot (WB) was performed to detect the protein levels of HOXA13, Bcl-2, Bax, Bad and Cleaved Caspase3. In addition, luciferase gene reporter assay was used to prove the relationships between LUCAT1 and miR-612, miR-612 and HOXA13.

RESULTS

Firstly, we found that LUCAT1 was decreased for 1.7 folds in CHF patients, which was correlated with poor prognosis patients. LUCAT1 repression inhibited cell proliferation and promoted cell apoptosis in human cardiomyocyte cell line AC16 cells. Furthermore, we found that miR-612 was increased for 2.0 folds in CHF patients, which was negatively interacted with LUCAT1 expression. Luciferase gene reporter assay demonstrated that LUCAT1 could directly bind with miR-612 in AC16 cells. Moreover, miR-612 overexpression also inhibited cell proliferation and promoted cell apoptosis in AC16 cells. Luciferase reporter assay indicated that miR-612 could directly target at HOXA13 in AC16 cells, which was associated with cell proliferation and apoptosis. Finally, miR-612 inhibitor was transfected into AC16 cells with si-LUCAT1. The results showed that the inhibited cell proliferation and promoted cell apoptosis were reversed, which confirmed that LUCAT1 repression inhibited cell proliferation and promoted apoptosis via miR-612/HOXA13 axis in CHF patients.

CONCLUSIONS

According to the above results, our study revealed that LUCAT1 was decreased in CHF patients, which was correlated with poor prognosis of CHF patients. Furthermore, the downregulation of LUCAT1 inhibited cell proliferation and promoted cell apoptosis via targeting miR-612/HOXA13 axis. Our results elucidated a potential mechanism underlying cardiomyocyte apoptosis, which might be used as a promising prognostic marker and a potential target for CHF patients.

Structure and thermal properties of beeswax-based oleogels with different types of vegetable oil

Beeswax-based oleogels with different types of vegetable oil, including camellia oil (CO), soybean oil (SO), sunflower oil (SFO), or flaxseed oil (FO), were prepared and their structure and thermal properties were evaluated. The critical concentration of oleogel obtained from each of CO, SO, and SFO at 25 °C was 3% (w/w), and that from FO was 4%. Thermal measurements revealed similar thermodynamic curves for oleogels in different lipid phases. X-Ray diffraction showed orthorhombic perpendicular subcell packing and characteristic peaks of the β’ form. Furthermore, a morphology analysis of the crystals showed that they were needle shaped. Fourier transform-infrared spectra revealed that beeswax-based oleogels were formed via non-covalent bonds and may be stabilized with physical entanglements. The oleogels showed oil type-dependent oxidative abilities, but they were all stable and showed no obvious changes in peroxide value during 90 days of storage at 5 °C.

Oscillatory surface deformation of paramagnetic rare-earth solutions driven by an inhomogeneous magnetic field

The deformation of the free surface of a paramagnetic liquid subjected to a nonuniform magnetic field is studied. A transient deformation of the surface caused by the interplay of gravity, magnetic field, and surface tension is observed when a permanent magnet is moved vertically downward to the free surface of the liquid. Different concentrations of rare-earth-metal salt (DyCl_{3}) are used and different magnet velocities are studied. The deformation of the interface is followed optically by means of a microscope and recorded with a high-speed camera. The experimental results are compared and discussed with complementary numerical simulations. Detailed results are given for the static shape of the deformed surface and the temporal evolution of the surface deformation below the center of the magnet. The frequency of the surface oscillations is found to depend on the concentration of the salt and is compared with analytical findings. Finally, a potential application of the effects observed is presented.

Improvement of gibberellin production by a newly isolated Fusarium fujikuroi mutant

AIMS

To obtain and investigate the potential mechanism for GA₃ production in Fusarium fujikuroi GA-251, a high GA₃ producer.

METHODS AND RESULTS

Fusarium fujikuroi IMI 58289 was bred with Cobalt-60 (⁶⁰ Co) radiation and lithium chloride treatment. The best mutant strain GA-251 was obtained for the subsequent optimization of fermentation conditions. The yield of GA₃ by GA-251 was 2100 mg l^-1 , while the wild-type strain was 100 mg l^-1 , which is a 21-fold increase in the yield. To elucidate the mechanism of high GA₃ yield of GA-251, the genome was sequenced and compared with wild-type strain IMI 58289. The results showed 2295 single nucleotide polymorphisms, 1242 small indels and 30 structural variants. These mutations were analysed and enriched in the MAPK signalling pathway, the mRNA surveillance pathway and endocytosis. The potential reasons for the improved GA₃ biosynthesis were investigated.

CONCLUSIONS

The potential mechanism of high GA₃ yield was attributed to endocytosis pathway and histone modification proteins family.

SIGNIFICANCE AND IMPACT OF THE STUDY

A mutant strain GA-251 in this work that could potentially be utilized in the industrial yield of GA₃ . The comparative genome analysis would shed light onto the mechanism of yield improvement and be a theoretical guide for further metabolic engineering.

Computed tomography versus ultrasound/fine needle aspiration biopsy in differential diagnosis of thyroid nodules: a retrospective analysis

Introduction

Ultrasound sonography provides a quick method for determining which nodule to sample for fine needle aspiration biopsy in thyroid nodules. On the other hand, the computed tomography examination is not restricted by echo attenuation and distinguishes between benign and malignant nodules.

Objective

To compare computed tomography examinations against ultrasound/fine needle aspiration biopsy in the differential diagnosis of thyroid nodules.

Methods

Data regarding computed tomography examinations, sonographic finding following fine needle aspiration biopsy, and tumor histology of 953 nodules from 698 patients who underwent thyroidectomy were collected and analyzed. The beneficial score for detection of the malignant tumor for each adopted modality was evaluated.

Results

Ultrasound images did not show a well-circumscribed solid mass in 89 nodules, and ultimately did not detect nodules in fine needle aspiration biopsies (false positive non-malignant nodules). Ultrasound images showed parenchymatous disease (false positive malignant nodules) in several nodules. Computed tomography examinations demonstrated higher difficulty in detection of malignant nodules of 1.0–2.0 cm size than ultrasound examination following fine needle aspiration biopsies; compared to tumor histological data, computed tomography examinations had a sensitivity of 0.879.

Conclusion

Computed tomography examinations are a more reliable method for differential diagnosis of thyroid nodules than ultrasound examinations followed by fine needle aspiration biopsy.

Level of Evidence

III.

Candidate genes mediated by estrogen-related receptor γ in pancreatic β cells

Recent studies have established the importance of estrogen-related receptor γ (ERRγ) as a required participant for insulin secretion in pancreatic β cells. Key downstream genes of ERRγ remain unclear in the pancreatic β cell. To understand the molecular role of ERRγ and elucidate potential key candidate genes involved in pancreatic β cells, the eukaryotic expression plasmid containing mouse ERRγ was constructed and transfected into NIT-1 pancreatic β cells. Overexpression of ERRγ was confirmed by quantitative real-time reverse-transcription polymerase chain reaction and Western blot analyses. RNA-seq was conducted to get the gene expression profiling between the overexpression group cells and control cells. Differentially expressed genes (DEGs) were identified by edgR and subsequently analyzed by gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. We found that overexpression of ERRγ in pancreatic β cells enables regulation of the expression of certain genes involved in cell apoptosis and mitochondrial function, such as TFPT, Bcl7c, Dap, Thoc6, Ube2d3, ATP5H, MPV17, and NDUFA6. GO analysis revealed that the DEGs were mainly enriched in apoptotic process, cytoplasm, and protein binding. KEGG pathway analysis demonstrated that downregulated DEGs were mainly enriched in protein processing in endoplasmic reticulum, estrogen signaling pathway, and metabolic pathways. This study helps to further understand and reposition the molecular mechanisms of ERRγ in β cells.

Simulation of crack induced nonlinear elasticity using the combined finite-discrete element method

Numerical simulation of nonlinear elastic wave propagation in solids with cracks is indispensable for decoding the complicated mechanisms associated with the nonlinear ultrasonic techniques in Non-Destructive Testing (NDT). Here, we introduce a two-dimensional implementation of the combined finite-discrete element method (FDEM), which merges the finite element method (FEM) and the discrete element method (DEM), to explicitly simulate the crack induced nonlinear elasticity in solids with both horizontal and inclined cracks. In the FDEM model, the solid is discretized into finite elements to capture the wave propagation in the bulk material, and the finite elements along the two sides of the crack also behave as discrete elements to track the normal and tangential interactions between crack surfaces. The simulation results show that for cracked models, nonlinear elasticity is generated only when the excitation amplitude is large enough to trigger the contact between crack surfaces, and the nonlinear behavior is very sensitive to the crack surface contact. The simulations reveal the influence of normal and tangential contact on the nonlinear elasticity generation. Moreover, the results demonstrate the capabilities of FDEM for decoding the causality of nonlinear elasticity in cracked solid and its potential to assist in Non-Destructive Testing (NDT).

The Therapeutic Implications of Tea Polyphenols Against Dopamine (DA) Neuron Degeneration in Parkinson's Disease (PD)

: Accumulative evidence indicated that the pathologically accumulated metal ions (iron species and Mn³⁺) and abnormally up-regulated monoamine oxidase B (MAOB) activity induced oxidation of endogenous dopamine (DA) can lead to mitochondria impairment, lysosome dysfunction, proteasome inhibition, and selective DA neuron vulnerability, which is implicated in the pathogenesis of Parkinson's disease (PD). The DA oxidation can generate deleterious reactive oxygen species (ROS) and highly reactive DA quinones (DAQ) to induce DA-related toxicity, which can be alleviated by DA oxidation suppressors, ROS scavengers, DAQ quenchers, and MAOB inhibitors. On the other hand, the nuclear factor erythroid 2-related factor 2 (Nrf2)-Keap1 and Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) anti-oxidative and proliferative signaling pathways play roles in anti-oxidative cell defense and mitochondria biogenesis, which is implicated in DA neuron protections. Therefore, agents with capabilities to suppress DA-related toxicity including inhibition of DA oxidation, scavenge of ROS, detoxification of DAQ, inhibition of MAOB, and modulations of anti-oxidative signaling pathways can be protective to DA neurons. Accumulative evidence shows that tea or coffee consumptions and smoking are related to deceased PD prevalence with unknown mechanisms. In this study, we investigate the protective capabilities of tea polyphenols and other PD relevant agents to inhibit DA-related toxicity and protect against environmental or genetic factors induced DA neuron degeneration in vitro and in vivo. We find that tea polyphenols can significantly suppress DA-related toxicity to protect DA neurons. The tea polyphenols can protect DA neurons via inhibition of DA oxidation, conjugation with DAQ, scavenge of ROS, inhibition of MAOB, and modulations of Nrf2-Keap1 and PGC-1α anti-oxidative signaling pathways. The tea polyphenols with more phenolic hydroxyl groups and ring structures have stronger protective functions. The protective capabilities of tea polyphenols is further strengthened by evidence that phenolic hydroxyl groups can directly conjugate with DAQ. However, GSH and other sulfhydyl groups containing agents have weaker capabilities to abrogate DA oxidation, detoxify ROS and DAQ and inhibit MAOB; whereas nicotine (NICO) and caffeine (CAF) can only modulate Nrf2-Keap1 and PGC-1α pathways to protect DA neurons weakly. The tea polyphenols are identified to protect against overexpression of mutant A30P α-synuclein (α-syn) induced DA neuron degeneration and PD-like symptoms in transgenic Drosophila. Based on achievements from current studies, the excellent and versatile protective capabilities of tea polyphenols are highlighted, which will contribute and benefit to future anti-PD therapy.

Directed elimination of senescent cells attenuates development of osteoarthritis by inhibition of c-IAP and XIAP

Aging drives the accumulation of senescent cells (SnCs) by secreting factors that cause the senescence-associated secretory phenotype (SASP), including stem cells in the bone marrow, which contribute to aging-related bone degradation. Osteoarthritis (OA) is a serious chronic injury disease, and increasing age is a major risk factor. The accumulation of SnCs may accelerate the development of OA, and the accumulation of SnCs may benefit from its resistance to apoptotic stimuli. Therefore, local elimination of SnCs could be a promising treatment for OA. Apoptosis inhibitor protein (IAP) is an important antiapoptotic protein in vivo. AT-406 is a small molecule inhibitor of the IAP genes and also regulates the transcription of several genes. Here, we show that SnCs upregulate the antiapoptotic proteins c-IAP1, c-IAP2 and XIAP.The combined inhibition of c-IAP1, c-IAP2 and XIAP using siRNA or AT-406 specifically induce the apoptosis of SnCs.In addition, XIAP and STX17 bind to each other to regulate the fusion of autophagosomes and lysosomes in SnCs, which in turn, affects the fate of SnCs. It is worth noting that the clearance of SnCs attenuated the secretion of SASP and created a proregenerative environment. Most importantly, local clearance of SnCs significantly attenuated the progression of osteoarthritis in rats without significant toxic effects. Thus, local elimination of SnCs may be a potential treatment for OA. This is the first report of inhibition of IAPs for clearing SnCs and suggests that eradication of SnCs may be a new strategy for the treatment of age-related diseases.

Erythromycin combined with corticosteroid reduced inflammation and modified trauma-induced tracheal stenosis in a rabbit model

Background:

Patients with endotracheal intubation or tracheostomy are subject to benign tracheal stenosis (TS), for which current therapies are unsatisfactory. We conducted a preliminary investigation of drugs and drug combinations for the prevention and treatment of TS in a rabbit model.

Methods:

Fifty-four rabbits were apportioned into nine groups according to treatment: sham-operated control; untreated TS model; amikacin; budesonide; erythromycin; penicillin; amikacin + budesonide; erythromycin + budesonide; and penicillin + budesonide. TS was induced by abrasion during surgery. The drugs were applied for 7 days before and 10 days after the surgery. Rabbits were killed on the eleventh day. Tracheal specimens were processed for determining alterations in the thicknesses of tracheal epithelium and lamina propria via hematoxylin and eosin. The tracheal mRNA (assessed by real-time quantitative polymerase chain reaction) expressions of the following fibrotic-related factors were determined: transforming growth factor-β1 (TGF- β1), collagen type I (COL1A1), collagen type III (COL3A1), and interleukin-17 (IL-17). The protein levels of TGF-β1, COL1A1, and COL3A1 were determined through immunohistochemistry and integrated optical densities.

Results:

Compared with all other groups, the untreated TS model had significantly thicker tracheal epithelium and lamina propria, and higher mRNA and protein levels of all targeted fibrotic factors. The mRNA and protein levels of the targeted fibrotic factors in all the drug-treated groups were lower than those of the untreated TS model, and differences were most significant in the erythromycin + budesonide group.

Conclusions:

Erythromycin combined with budesonide may reduce inflammation and modify fibrosis progression in TS after tracheal injury.

Epigallocatechin-3-gallate(EGCG) suppresses melanoma cell growth and metastasis by targeting TRAF6 activity

TRAF6 (TNF Receptor-Associated Factor 6) is an E3 ubiquitin ligase that contains a Ring domain, induces K63-linked polyubiquitination, and plays a critical role in signaling transduction. Our previous results demonstrated that TRAF6 is overexpressed in melanoma and that TRAF6 knockdown dramatically attenuates tumor cell growth and metastasis. In this study, we found that EGCG can directly bind to TRAF6, and a computational model of the interaction between EGCG and TRAF6 revealed that EGCG probably interacts with TRAF6 at the residues of Gln54, Gly55, Asp57 ILe72, Cys73 and Lys96. Among these amino acids, mutation of Gln54, Asp57, ILe72 in TRAF6 could destroy EGCG bound to TRAF6, furthermore, our results demonstrated that EGCG significantly attenuates interaction between TRAF6 and UBC13(E2) and suppresses TRAF6 E3 ubiquitin ligase activity in vivo and in vitro. Additionally, the phosphorylation of IκBα, p-TAK1 expression are decreased and the nuclear translocation of p65 and p50 is blocked by treatment with EGCG, leading to inactivation of the NF-κB pathway. Moreover, EGCG significantly inhibits cell growth as well as the migration and invasion of melanoma cells. Taken together, these findings show that EGCG is a novel E3 ubiquitin ligase inhibitor that could be used to target TRAF6 for chemotherapy or the prevention of melanoma.

Are the warning icons more attentional?

The rapid growth of attention to visual warnings is a representation of the adaptive behavior of humans. However, the ways warning icons attract attention in the cognition context has yet to be clarified. This research aims to investigate cognitive mechanism of warning icons under various perceptual loads. The results of Experiment A, whose average attentional capture effect of the warning icons (69 ms) was significantly higher than that of the ordinary icons (35 ms), show that compared with ordinary icons, warning icons are prioritized in processing under both high and low perceptual loads. Besides, the attention capturing abilities of non-target warning icons are the same under high and low perceptual loads. To isolate the effects of salient visual features and semantics, warning icons in Experiment B are replaced with transposed icons with saliency but no semantics. The attentional capture effect of warning icons is found to be significantly smaller under high load than under low load, so the effect in Experiment A can be attributed to the semantics of warning icons. In Experiment C the icons of negative and neutral semantics without salient frames are used as interfering stimuli, and the RT to the negative icons (823 ms) was longer than both the RT to the neutral icons (780 ms) and to the no interference icons (743 ms) (P < 0.001), which show that negative icons have stronger attention capturing ability than neutral icons. This research verifies that the semantics of icons is vital, and icons with salient visual features and negative semantics can enhance attentional capture effect.

[Preparation processes of 3% yttria-stabilized tetragonal zirconia polycrystalline ceramic composite powders coated with nano-sized Al₂O₃-boron nitride]

OBJECTIVE

In this work, we aim to determine the optimum pH value for the preparation of 3% yttria-stabilized tetragonal zirconia polycrystalline (3Y-TZP)/3%Al₂O₃ and optimum calcination temperature of Al₂O₃ precursor and amorphous boron nitride (BN) for Al₂O₃-BN coating 3Y-TZP powders.

METHODS

The 3Y-TZP/3%Al₂O₃ composite powders were prepared through the heterogeneous precipitation method under different pH values (6.5, 7.5, 8.5, and 9.5) and analyzed through transmission electron microscopy (TEM) to determine the optimum coating morphology. Al₂O₃ precursor, which was prepared under the optimum pH value, was calcined at different temperatures (800, 1 000, 1 200, and 1 400 ℃). The amorphous BN coating 3Y-TZP/3%Al₂O₃ powder was prepared via in situ reaction with boric acid and urea (calcined with N₂ at 850 ℃ for 5 and 3 h and 800 ℃ for 5 and 3 h). TEM, energy dispersive spectrometry (EDS), and X-ray diffraction (XRD) were performed to characterize the results.

RESULTS

The optimum coating morphology was obtained at 8.5 pH. When the Al₂O₃ precursor was calcined at 1 200 ℃ and coated with BN (calcined with N₂ at 800 ℃ for 5 h), the Al-B-O compound was less, and t-ZrO₂ was more represented.

CONCLUSIONS

The optimum pH value for 3Y-TZP/3%Al₂O₃ composite preparation is 8.5. For the preparation of Al₂O₃-BN coating 3Y-TZP powders, the optimum calcination temperature of the Al₂O₃ precursor and amorphous BN are 1 200 and 800 ℃, respectively.

Metabolomics of Diabetic Retinopathy

PURPOSE OF REVIEW

Metabolomics is the study of dysregulated metabolites in biological materials. We reviewed the use of the technique to elucidate the genetic and environmental factors that contribute to the development of diabetic retinopathy.

RECENT FINDINGS

With regard to metabolomic studies of diabetic retinopathy, the field remains in its infancy with few studies published to date and little replication of results. Vitreous and serum samples are the main tissues examined, and dysregulation in pathways such as the pentose phosphate pathway, arginine to proline pathway, polyol pathway, and ascorbic acidic pathways have been reported. Few studies have examined the metabolomic underpinnings of diabetic retinopathy. Further research is required to replicate findings to date and determine longitudinal associations with disease.

Aspartate β-hydroxylase disrupts mitochondrial DNA stability and function in hepatocellular carcinoma

The mechanism of aberrant mitochondrial genome and function in hepatocellular carcinoma (HCC) remains largely unknown. Our previous study demonstrated an increased expression of aspartate β-hydroxylase (ASPH) in HCC tissues, which was associated with tumor invasiveness and a worse prognosis. Currently, we unexpectedly observed the presence of ASPH in purified mitochondrial protein fraction. In addition, immunostaining of both exogenously and endogenously expressed ASPH showed a colocalization with mitochondrial biomarkers. This study aimed to investigate whether the mitochondrial ASPH is involved in mitochondrial malfunction in HCC. Our results showed that ASPH overexpression in HCC tissues was correlated with decreased copy numbers of displacement loop (D-loop) and NADH dehydrogenase subunit 1 (ND-1) and enhanced D-loop mutation, suggesting the disrupted mitochondrial DNA (mtDNA) stability. The reduced mtDNA copy numbers were associated with aggressive clinicopathological features of HCC. The loss of mtDNA integrity induced by enforced expression of ASPH was accompanied with mitochondrial dysfunction, which was characterized by the aberrant mitochondrial membrane potential, decreased ATP generation and enhanced reactive oxygen species. In contrast, knocking down ASPH by siRNA in HCC cell lines showed the opposite impact on mtDNA integrity and function. Mass spectrometry and co-immunoprecipitation further identified that ASPH interacted with histone H2A member X (H2AX). ASPH overexpression diminished the interaction between H2AX and mitochondrial transcription factor A (mtTFA), an important DNA-binding protein for mtDNA replication, which then reduced the binding of mtTFA to D-loop region. Collectively, our results demonstrate that ASPH overexpression disrupts the mtDNA integrity through H2AX-mtTFA signal, thereby affecting mitochondrial functions in HCC.

Preparation and evaluation of cefquinome-loaded gelatin microspheres and the pharmacokinetics in pigs

Cefquinome (CEF) is widely used for veterinary clinical applications because of its broad spectrum and high efficiency. However, frequent administrations are required due to its short elimination half-life. In this study, cefquinome sulfate gelatin microspheres (CEF-GMS) were prepared as a sustained-release formulation using emulsion chemical cross-linking technique. Physical properties, stability, sustained-release property in vitro, and pharmacokinetics in pigs were assessed. The morphology of CEF-GMS showed a good sphericity with porous structure on the surface, and the mean diameter was 8.80 ± 0.78 μm, with 90.60 ± 3.98% of the total in the range of 5-20 μm. There were no significant changes of all estimated indexes in the stability tests. In vitro drug release study showed that the release of CEF from CEF-GMS was much slower than that from crude CEF in a release medium. Pharmacokinetic characteristics were evaluated following intramuscular administration of CEF-GMS or Cefquinome sulfate injection (CEF-Inj) in pigs at a dosage of 4 mg CEF/kg body weight. The plasma drug concentration-time data of CEF-GMS and CEF-Inj were both best fitted by two-compartment models with first-order absorption, and the elimination half-life of CEF-GMS was almost 10 times that of CEF-Inj. Overall, CEF-GMS might be used as a sustained-release formulation of CEF for veterinary clinical applications.

Patients with HBV-related acute-on-chronic liver failure have increased concentrations of extracellular histones aggravating cellular damage and systemic inflammation

Acute-on-chronic liver failure (ACLF) is the most common type of liver failure and associated with grave consequences. Systemic inflammation has been linked to its pathogenesis and outcome, but the identifiable triggers are absent. Recently, extracellular histones, especially H4, have been recognized as important mediators of cell damage in various inflammatory conditions. This study aimed to investigate whether extracellular histones have clinical implications in patients with hepatitis B virus (HBV)-related ACLF. One hundred and twelve patients with HBV-related ACLF, 90 patients with chronic hepatitis B, 88 patients with HBV-related liver cirrhosis and 40 healthy volunteers were entered into this study. Plasma histone H4 levels, cytokine profile and clinical data were obtained. Besides, patient's sera were incubated overnight with human L02 hepatocytes or monocytic U937 cells in the presence or absence of antihistone H4 antibody, and cellular damage and cytokine production were evaluated. We found that plasma histone H4 levels were greatly increased in patients with ACLF as compared with chronic hepatitis B, liver cirrhosis and healthy control subjects and were significantly associated with disease severity, systemic inflammation and outcome. Notably, ACLF patients' sera incubation decreased cultured L02 cell integrity and induced profound cytokine production in the supernatant of U937 cells. Antihistone H4 antibody treatment abrogated these adverse effects, thus confirming a cause-effect relationship between extracellular histones and organ injury/dysfunction. The data support the hypothesis that the increased extracellular histone levels in ACLF patients may aggravate disease severity by inducing cellular injury and systemic inflammation. Histone-targeted therapies may have potentially interventional value in clinical practice.

Construction and identification of a model for HJURP gene defect expression in human embryo villus cells

OBJECTIVES

To construct a lentiviral vector for RNA interference (RNAi) of the HJURP gene and to identify the silencing efficiency in the human embryo villus cells and to provide a human embryo villus cells multiplication and chromosome segregation.

MATERIALS AND METHODS

In accordance with the study, three specific sequences of siRNA targeting HJURP gene were designed, synthesized, then the complementary DNA containing both sense and antisense oligonucleotides of the targeting sequences were annealed and inserted into the lentiviral vector.The correct clonings were confirmed by PCR and sequencing. The most effective recombinant lentivirus vector was screened, and the recombinant plasmids with the lentivirus packaging mixes were co-transfected into 293T cells to obtain packaged lentivirus particles. Then viral titer was determined. The silencing efficiency of target gene in human embryo villus cells was detected by Real-Time PCR.

RESULTS

DNA sequencing showed that the shRNA sequence was successfully inserted into the lentivirus vector. The recombinant lentiviral vector was successfully transfected into 293T cells. The recombinant lentivirus had a titer of 108 PFU/ml. After silencing HJURP gene in human embryo villus cells, the expression level of HJURP mRNA decreased significantly and the RNAi efficiency was greater than 70%.

CONCLUSION

A lentiviral shRNA expression vector targeting the HJURP gene was successfully constructed and may effectively silence the target gene at a cellular level, which provides a experimental model for the influence of HJURP gene expressing inhibition on human embryo villus cells multiplication and chromosome segregation.

Understanding hydraulic fracturing: a multi-scale problem

Despite the impact that hydraulic fracturing has had on the energy sector, the physical mechanisms that control its efficiency and environmental impacts remain poorly understood in part because the length scales involved range from nanometres to kilometres. We characterize flow and transport in shale formations across and between these scales using integrated computational, theoretical and experimental efforts/methods. At the field scale, we use discrete fracture network modelling to simulate production of a hydraulically fractured well from a fracture network that is based on the site characterization of a shale gas reservoir. At the core scale, we use triaxial fracture experiments and a finite-discrete element model to study dynamic fracture/crack propagation in low permeability shale. We use lattice Boltzmann pore-scale simulations and microfluidic experiments in both synthetic and shale rock micromodels to study pore-scale flow and transport phenomena, including multi-phase flow and fluids mixing. A mechanistic description and integration of these multiple scales is required for accurate predictions of production and the eventual optimization of hydrocarbon extraction from unconventional reservoirs. Finally, we discuss the potential of CO2 as an alternative working fluid, both in fracturing and re-stimulating activities, beyond its environmental advantages.This article is part of the themed issue 'Energy and the subsurface'.

Effects of taurochenodeoxycholic acid on Ca2+/CaM signalling mediated by the TGR5 signalling pathway

Taurochenodeoxycholic acid (TCDCA), a natural bioactive substance in animal bile, has anti-inflammatory and immunoregulatory effects. This study evaluates the effects of TCDCA on calcium/calmodulin (Ca2+/CaM) signalling mediated by G Protein Coupled Bile Acid Receptor 1 (TGR5) to provide preliminary information on the mechanism of TCDCA in immune regulation and also to benefit future research. After treatment of NR8383 and high TGR5 expression cell (TGR5-NR8383) with TCDCA (10-6 mol/L, 10-5 mol/L, and 10-4 mol/L) for 1 h, we measured TGR5 and CaM gene and protein levels by quantitative reverse transcription-polymerase chain reaction (qPCR) and western blotting, respectively. The inositol triphosphate (IP3) concentration was measured by Enzyme-linked Immunosorbent Assay (ELISA), and the Ca2+ concentration was measured by calcium fluorescent probe (Fluo-3 AM). The present study showed that the expression levels of IP3, Ca2+, and CaM in NR8383 cells were increased by TCDCA at concentrations ranging from 10-6 mol/L to 10-4 mol/L. TCDCA (10-4 mol/L) increased both the gene and protein expression of IP3and CaM through TGR5. TCDCA (10-4 mol/L or 10-5 mol/L) also increased the Ca2+ concentration via the TGR5 receptor. Our data suggest TCDCA activates Ca2+/CaM signalling via the TGR5 signalling pathway.