TRPM2 deficiency in mice protects against atherosclerosis by inhibiting TRPM2-CD36 inflammatory axis in macrophages

Atherosclerosis is the major cause of ischemic heart disease and stroke, the leading causes of mortality worldwide. The central pathological features of atherosclerosis include macrophage infiltration and foam cell formation. However, the detailed mechanisms regulating these two processes remain unclear. Here we show that oxidative stress-activated Ca²⁺-permeable transient receptor potential melastatin 2 (TRPM2) plays a critical role in atherogenesis. Both global and macrophage-specific Trpm2 deletion protect Apoe^−/− mice against atherosclerosis. Trpm2 deficiency reduces oxidized low-density lipoprotein (oxLDL) uptake by macrophages, thereby minimizing macrophage infiltration, foam cell formation and inflammatory responses. Activation of the oxLDL receptor CD36 induces TRPM2 activity, and vice versa. In cultured macrophages, TRPM2 is activated by CD36 ligands oxLDL and thrombospondin-1 (TSP1), and deleting Trpm2 or inhibiting TRPM2 activity suppresses the activation of CD36 signaling cascade induced by oxLDL and TSP1. Our findings establish the TRPM2-CD36 axis as a molecular mechanism underlying atherogenesis, and suggest TRPM2 as a potential therapeutic target for atherosclerosis.

Use of real-time artificial intelligence in detection of abnormal image patterns in standard sonographic reference planes in screening for fetal intracranial malformations

OBJECTIVES

To develop and validate an artificial intelligence system, the Prenatal ultrasound diagnosis Artificial Intelligence Conduct System (PAICS), to detect different patterns of fetal intracranial abnormality in standard sonographic reference planes for screening for congenital central nervous system (CNS) malformations.

METHODS

Neurosonographic images from normal fetuses and fetuses with CNS malformations at 18-40 gestational weeks were retrieved from the databases of two tertiary hospitals in China and assigned randomly (ratio, 8:1:1) to training, fine-tuning and internal validation datasets to develop and evaluate the PAICS. The system was built based on a real-time convolutional neural network (CNN) algorithm, You Only Look Once, version 3 (YOLOv3). An image dataset from a third tertiary hospital was used to further validate, externally, the performance of the PAICS and to compare its performance with that of sonologists with different levels of expertise. Furthermore, a prospective video dataset was employed to evaluate the performance of the PAICS in a real-time scan scenario. The diagnostic accuracy, sensitivity, specificity and area under the receiver-operating-characteristics curve (AUC) were calculated to assess the performance of the PAICS and to compare this with the performance of sonologists with different levels of experience.

RESULTS

In total, 43 890 images from 16 297 pregnancies and 169 videos from 166 pregnancies were used to develop and validate the PAICS. The system achieved excellent performance in identifying 10 types of intracranial image pattern, with macro- and microaverage AUCs, respectively, of 0.933 (95% CI, 0.798-1.000) and 0.977 (95% CI, 0.970-0.985) for the internal validation image dataset, 0.902 (95% CI, 0.816-0.989) and 0.898 (95% CI, 0.885-0.911) for the external validation image dataset and 0.969 (95% CI, 0.886-1.000) and 0.981 (95% CI, 0.974-0.988) in the real-time scan setting. The performance of the PAICS was comparable to that of expert sonologists in terms of macro- and microaverage accuracy (P = 0.863 and P = 0.775, respectively), sensitivity (P = 0.883, P = 0.846) and AUC (P = 0.891, P = 0.788), but required significantly less time (0.025 s per image for PAICS vs 4.4 s for experts, P < 0.001).

CONCLUSIONS

Both in the image dataset and in the real-time scan setting, the PAICS achieved excellent diagnostic performance for various fetal CNS abnormalities. Its performance was comparable to that of experts, but it required less time. A CNN algorithm can be trained to detect fetal CNS abnormalities. The PAICS has the potential to be an effective and efficient tool in screening for fetal CNS malformations in clinical practice. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

A Systemic Review of the Integral Role of TRPM2 in Ischemic Stroke: From Upstream Risk Factors to Ultimate Neuronal Death

Ischemic stroke causes a heavy health burden worldwide, with over 10 million new cases every year. Despite the high prevalence and mortality rate of ischemic stroke, the underlying molecular mechanisms for the common etiological factors of ischemic stroke and ischemic stroke itself remain unclear, which results in insufficient preventive strategies and ineffective treatments for this devastating disease. In this review, we demonstrate that transient receptor potential cation channel, subfamily M, member 2 (TRPM2), a non-selective ion channel activated by oxidative stress, is actively involved in all the important steps in the etiology and pathology of ischemic stroke. TRPM2 could be a promising target in screening more effective prophylactic strategies and therapeutic medications for ischemic stroke.

Effects of Low-Temperature Construction Additives (LCAs) on the Performance of Asphalt Mixtures

Green production of asphalt materials is very important to promote energy savings and emission reduction during the construction and maintenance of asphalt pavement. A low-temperature construction additive (LCA) made from the waste plastic and waste rubber is proposed, which belongs to a class of environmentally friendly additives for asphalt mixtures. Marshall stability was tested to evaluate the mechanical performance of LCA-modified asphalt mixtures (LCA-AMs). In order to determine the best preparation parameters of LCA-AMs, the influence of the content and LCA addition method on the strength of LCA-AMs was studied. In addition, the impact of epoxy resin (ER) on the mixtures' performances was evaluated. The results show that the LCA can significantly reduce the formation temperature of asphalt mixtures, and the resulting asphalt mixtures have good workability in a lower temperature range (90-110 °C). The ER should be added to the LCA-AMs after 4 h of curing. All the volumetric properties satisfy the technical requirements. The low-temperature crack resistance and fatigue resistance of LCA-AMs were obviously improved with appropriate dosages of ER, which can effectively improve the mechanical performance of the asphalt mixtures. The ER can significantly increase the rutting resistance and water sensitivity of LCA-AMs, therefore making it feasible to improve the mixture performance by the enhancement provided by a low dosage of ER.

Neurotoxic 18-kDa apolipoprotein E fragment production contributes to anesthetic sevoflurane-induced tau phosphorylation and neuroinflammation in vitro

Anesthesia may induce neuronal tau phosphorylation and neurotoxicity in the developing brain. Apolipoprotein E (ApoE) may play a protective role in neuronal activity and injury repair, whereas its 18-kDa fragments are reported to induce neurodegeneration and neuroinflammation in Alzheimer's disease patients. We aimed to test the hypothesis that differences in 18-kDa ApoE fragment levels, but not full-length ApoE, in primary neurons contribute to differences in tau phosphorylation and neuroinflammation with or without sevoflurane administration. Neurons extracted from wild-type (WT), ApoE knockout (ApoE-KO), and ApoE ε3-and ε2-targeted replacement (ApoE ε3, ApoE ε2) mice were divided into control and sevoflurane groups. Neurons in the sevoflurane group were treated with 21% O₂, 5% CO₂, and 4.1% sevoflurane, whereas those in the control group were treated with 21% O₂ and 5% CO₂ only on day 5 of neuronal culture. ApoE mRNA, full-length ApoE, 18-kDa ApoE fragments, Tau-PS202/PT205 (AT8), Tau-PSer396/404 (PHF1), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 and IL-1β levels were measured. The data showed that sevoflurane-induced AT8 and PHF1 increases, and TNF-α, IL-6, and IL-1β increases in WT or ApoE ε3 neurons (both expressing full-length and 18-kDa fragmented ApoE) could be mitigated in ApoE ε2 (only expressing full-length ApoE), but not in ApoE-KO neurons, indicating that differences in 18-kDa ApoE fragments, but not full-length ApoE, in primary mouse neurons contributed to differences in tau phosphorylation and neuroinflammation with or without 4.1% sevoflurane administration.

Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV

We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×10^{9} protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∼10  GV and ∼20  GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.

CNNM proteins selectively bind to the TRPM7 channel to stimulate divalent cation entry into cells

Magnesium is essential for cellular life, but how it is homeostatically controlled still remains poorly understood. Here, we report that members of CNNM family, which have been controversially implicated in both cellular Mg²⁺ influx and efflux, selectively bind to the TRPM7 channel to stimulate divalent cation entry into cells. Coexpression of CNNMs with the channel markedly increased uptake of divalent cations, which is prevented by an inactivating mutation to the channel’s pore. Knockout (KO) of TRPM7 in cells or application of the TRPM7 channel inhibitor NS8593 also interfered with CNNM-stimulated divalent cation uptake. Conversely, KO of CNNM3 and CNNM4 in HEK-293 cells significantly reduced TRPM7-mediated divalent cation entry, without affecting TRPM7 protein expression or its cell surface levels. Furthermore, we found that cellular overexpression of phosphatases of regenerating liver (PRLs), known CNNMs binding partners, stimulated TRPM7-dependent divalent cation entry and that CNNMs were required for this activity. Whole-cell electrophysiological recordings demonstrated that deletion of CNNM3 and CNNM4 from HEK-293 cells interfered with heterologously expressed and native TRPM7 channel function. We conclude that CNNMs employ the TRPM7 channel to mediate divalent cation influx and that CNNMs also possess separate TRPM7-independent Mg²⁺ efflux activities that contribute to CNNMs’ control of cellular Mg²⁺ homeostasis.

Magnesium is essential for cellular life, but how is it homeostatically controlled? This study shows that proteins of the CNNM family bind to the TRPM7 channel to stimulate divalent cation entry into cells, independent of their function in regulating magnesium ion efflux.

Research progress on the regulation mechanism of probiotics on the microecological flora of infected intestines in livestock and poultry

The animal intestine is a complex ecosystem composed of host cells, gut microbiota and available nutrients. Gut microbiota can prevent the occurrence of intestinal diseases in animals by regulating the homeostasis of the intestinal environment. The intestinal microbiota is a complex and stable microbial community, and the homeostasis of the intestinal environment is closely related to the invasion of intestinal pathogens, which plays an important role in protecting the host from pathogen infections. Probiotics are strains of microorganisms that are beneficial to health, and their potential has recently led to a significant increase in studies on the regulation of intestinal flora. Various potential mechanisms of action have been proposed on probiotics, especially mediating the regulation mechanism of the intestinal flora on the host, mainly including competitive inhibition of pathogens, stimulation of the host's adaptive immune system and regulation of the intestinal flora. The advent of high-throughput sequencing technology has given us a clearer understanding and has facilitated the development of research methods to investigate the intestinal microecological flora. This review will focus on the regulation of probiotics on the microbial flora of intestinal infections in livestock and poultry and will depict future research directions.

ToxR modulates biofilm formation in fish pathogen Vibrio harveyi

Vibrio harveyi is a common aquaculture pathogen causing diseases in a variety of aquatic animals. toxR, a conserved virulence-associated gene in vibrios, is identified in V. harveyi 345, a pathogenic strain isolated from diseased fish. In this study, to gain insight into function of ToxR in V. harveyi, an in-frame deletion of the toxR gene was constructed to reveal the role of ToxR in the physiology and virulence of V. harveyi. The statistical analysis showed no significant differences in the growth ability, motility, extracellular protease secretion, antibiotic susceptibility, virulence by intraperitoneal injection and the ability of V. harveyi to colonize the spleen and liver tissues of the pearl gentian grouper between the wild-type (WT) and the toxR mutant. However, the deletion of toxR increased the biofilm formation. The structure of the V. harveyi biofilm was further analysed by using scanning electron microscopy (SEM) and confocal laser scanning microscopy, and the results showed that deletion of toxR increased the number and density of V. harveyi biofilm. Since biofilm production is flagella, exopolysaccharide (EPS) and lipopolysaccharide dependent, 16 of V. harveyi biofilm-related genes were selected for further analysis. Based on quantitative real-time reverse transcription-PCR, the expression levels of these genes, including genes flrB, motY and mshA, flaE, flrA and gmhD, were significantly up-regulated in the ΔtoxR⁺ strain as compared with the WT⁺ and C-ΔtoxR strains during the early and mid-exponential, while epsG, flaA, flaE, flgD, flgE, flrB, flrC, lpxB, motY, mshA and scrG genes were inhibited because of deletion of the toxR gene in the stationary growth phase. Our results indicate that ToxR plays an important role in controlling the biofilm in V. harveyi.

Establishing reference intervals for islet autoantibodies in Han Chinese type 1 diabetes

Currently, islet autoantibodies (IAbs) constitute the most reliable marker for detecting the autoimmune process of type 1 diabetes (T1D). However, there are no appropriate reference intervals (RIs) to interpret the results of IAbs in China. In this study, we aimed to establish the RIs of four common IAbs based on the Han Chinese population and evaluate their clinical diagnostic values in patients with T1D. We collected 177 blood samples from healthy volunteers to detect the levels of IAbs directed against insulin (IAA), glutamic acid decarboxylase-65 (GADA), insulinoma antigen 2 (IA-2A), and zinc transporter-8 (ZnT8A) using a chemiluminescence immunoassay. RIs were calculated using nonparametric 95th percentile intervals in accordance with the Clinical and Laboratory Standards Institute guidelines, and their clinical diagnostic values were evaluated by detecting the levels of IAbs of 140 blood samples from patients with T1D in a clinical setting. We defined 138 individuals as the apparently healthy population from the 177 healthy volunteers based on the exclusion criteria. No association between the levels of the four IAbs and gender (p > .05) and age (p > .05) were found in the apparently healthy population. The combined RIs for GADA, IA-2A, ZnT8A, and IAA were 0-1.78 IU/mL, 0-3.91 IU/mL, 0-2.36 AU/mL, and 0-0.58 COI, respectively. Overall, the diagnostic efficiency for the four IAbs, especially for GADA and IAA, were improved by using the RIs established in this study. The RIs for IAbs established in this study will be a valuable tool for disease diagnosis and the therapeutic management of T1D in a clinical setting.

An Effective Biclustering-Based Framework for Identifying Cell Subpopulations From scRNA-seq Data

The advent of single-cell RNA sequencing (scRNA-seq) techniques opens up new opportunities for studying the cell-specific changes in the transcriptomic data. An important research problem related with scRNA-seq data analysis is to identify cell subpopulations with distinct functions. However, the expression profiles of individual cells are usually measured over tens of thousands of genes, and it remains a difficult problem to effectively cluster the cells based on the high-dimensional profiles. An additional challenge of performing the analysis is that, the scRNA-seq data are often noisy and sometimes extremely sparse due to technical limitations and sampling deficiencies. In this paper, we propose a biclustering-based framework called DivBiclust that effectively identifies the cell subpopulations based on the high-dimensional noisy scRNA-seq data. Compared with nine state-of-the-art methods, DivBiclust excels in identifying cell subpopulations with high accuracy as evidenced by our experiments on ten real scRNA-seq datasets with different size and diverse dropout rates. The supplemental materials of DivBiclust, including the source codes, data, and a supplementary document, are available at https://www.github.com/Qiong-Fang/DivBiclust.

Study on a new manner of the magnetization switching actuated by a unidirectional pulse current

A new writing scheme with a unidirectional pulse current is proposed for spin transfer torque (STT) based magnetic random-access memory (MRAM). To investigate the feasibility of the writing scheme, bilayered nano-pillars composed of a soft layer with small in-plane shape anisotropy and a hard layer with either large perpendicular anisotropy (PMA) or in-plane anisotropy (IMA) are designed and their switching behaviors are studied. It is found that in either type of bilayered nano-pillars, with the aid of the attached hard layer, the magnetization of the soft layer can be switched back and forth under a unidirectional pulse current. In an IMA/IMA nano-pillar, the magnetization of the free layer (FL) can achieve excellent alignment, which is in contrast to the IMA/PMA nano-pillar. By optimizing the dimensions and magnetic parameters of the IMA/IMA nano-pillar, a decently low switching current density (4.3 × 10¹¹A m^-2) and ultrashort switching time (<1 ns) can be reached. Based on these results, the unidirectional writing scheme is practical if an IMA/IMA bilayer is used to replace the FL in a magnetic tunnel junction. Considering that a unidirectional writing scheme can enable the application of materials with high spin polarization such as half metals, and avoid the injection of writing current into junction using a special design, it may be very promising for STT-MRAM.

Erratum: Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen [Phys. Rev. Lett. 127, 021101 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.127.021101.

Development and validation of a three-immune-related gene signature prognostic risk model in papillary thyroid carcinoma

PURPOSE

Increasing evidence indicates that there is a correlation between papillary thyroid carcinoma (PTC) prognosis and the immune signature. Our goal was to construct a new prognostic tool based on immune genes to achieve more accurate prognosis predictions and earlier diagnoses of PTC.

METHODS

The 493 PTCs samples and 58 tumor-adjacent normal tissues were obtained from The Cancer Genome Atlas database (TCGA). Immune genes were obtained from the ImmPort database. First, this cohort was randomly divided into training cohort and testing cohort. Second, the differentially expressed (DE) immune genes from the training set were used to construct the prognostic model. Then, the testing and entire data cohorts were used to validate the model, and the data were analyzed to determine the correlation of the clinical prognostic model with immune cell infiltration and expression profiles of human leukocyte antigen (HLA) genes. Finally, an analysis of the gene ontology (GO) annotation was performed.

RESULTS

A total of 189 upregulated and 128 downregulated DE immune genes were identified. We developed and validated a three-immune gene model for PTC that includes Hsp70, NOX5, and FGF23. This model was demonstrated to be an independent prognostic variable. In addition, the overall immune activity of the high-risk group was higher than that of the low-risk group.

CONCLUSIONS

We developed and validated a three-immune gene model for PTC that includes HSPA1A, NOX5, and FGF23. This model can be used as a validated tool to predict outcomes in PTC.

Dental Pulp Stem Cell Polarization: Effects of Biophysical Factors

Dental pulp stem cells (DPSCs) have the potential to polarize, differentiate, and form tubular dentin under certain conditions. However, the factors that initiate and regulate DPSC polarization and its underlying mechanism remain unclear. Identification of the factors that control DPSC polarization is a prerequisite for tubular dentin regeneration. We recently developed a unique bioinspired 3-dimensional platform that is capable of deciphering the factors that initiate and modulate cell polarization. The bioinspired platform has a simple background and confines a single cell on each microisland of the platform; therefore, it is an effective tool to study DPSC polarization at the single-cell level. In this work, we explored the effects of biophysical factors (surface topography, microisland area, geometry, tubular size, and gravity) on single DPSC polarization. Our results demonstrated that nanofibrous architecture, microisland area, tubular size, and gravity participated in regulating DPSC polarization by influencing the formation of the DPSC process and relocation of the Golgi apparatus. Among these factors, nanofibrous architecture, tubular size, and appropriate microisland area were indispensable for initiating DPSC polarization, whereas gravity served as an auxiliary factor to the process of DPSC polarization. Meanwhile, microisland geometry had a limited effect on DPSC polarization. Collectively, this work provides information on DPSC polarization and paves the way for the development of new biomaterials for tubular dentin regeneration.

Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen

We report the properties of sodium (Na) and aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV based on 0.46 million sodium and 0.51 million aluminum nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We found that Na and Al, together with nitrogen (N), belong to a distinct cosmic ray group. In this group, we observe that, similar to the N flux, both the Na flux and Al flux are well described by the sums of a primary cosmic ray component (proportional to the silicon flux) and a secondary cosmic ray component (proportional to the fluorine flux). The fraction of the primary component increases with rigidity for the N, Na, and Al fluxes and becomes dominant at the highest rigidities. The Na/Si and Al/Si abundance ratios at the source, 0.036±0.003 for Na/Si and 0.103±0.004 for Al/Si, are determined independent of cosmic ray propagation.

Substantial involvement of TRPM7 inhibition in the therapeutic effect of Ophiocordyceps sinensis on pulmonary hypertension

Ophiocordyceps sinensis (OCS), an entomopathogenic fungus, is known to exert antiproliferative and antitissue remodeling effects. Vascular remodeling and vasoconstriction play critical roles in the development of pulmonary hypertension (PH). The therapeutic potential of OCS for PH was investigated using rodent PH models, and cultured pulmonary artery endothelial and smooth muscle cells (PAECs and PASMCs), with a focus on the involvement of TRPM7. OCS ameliorated the development of PH, right ventricular hypertrophy and dysfunction in the monocrotaline-induced PH rats. The genetic knockout of TRPM7 attenuated the development of PH in mice with monocrotaline pyrrole-induced PH. TRPM7 was associated with medial hypertrophy and the plexiform lesions in rats and humans with PH. OCS suppressed proliferation of PASMCs derived from the PH patients. Ethanol extracts of OCS inhibited TRPM7-like current, TGF-β2-induced endothelial-mesenchymal transition, IL-6-induced STAT3 phosphorylation, and PDGF-induced Akt phosphorylation in PAECs or PASMCs. These inhibitory effects were recapitulated by either siRNA-mediated TRPM7 knockdown or treatment with TRPM7 antagonist FTY-720. OCS and FTY-720 induced vasorelaxation in the isolated normal human pulmonary artery. As a result, the present study proposes the therapeutic potential of OCS for the treatment of PH. The inhibition of TRPM7 is suggested to underlie the therapeutic effect of OCS.

Cigarette Smoke Exposure Inhibits Osteoclast Apoptosis via the mtROS Pathway

It is widely known that smoking is a risk factor for bone loss and plays a key role in osteopenia. Despite this well-known association, the mechanisms by which smoking affects bone have not been definitively established. Since smoking increases bone loss and potentially affects bone resorption in response to mechanical force, we investigated the impact of cigarette smoke on osteoclast numbers and underlying mechanisms in a mouse model of orthodontic tooth movement (OTM). The experimental group was exposed to once-daily cigarette smoke while the control group was not, and tooth movement distance and osteoclast numbers were assessed. In addition, the effect of cigarette smoke extract (CSE) on osteoclast precursor proliferation and osteoclast apoptosis was assessed in vitro. We found that cigarette smoke exposure enhanced bone remodeling stimulated by mechanical force and increased osteoclast numbers in vivo. Also, CSE increased the number of osteoclasts by inhibiting osteoclast apoptosis via the mitochondrial reactive oxygen species/cytochrome C/caspase 3 pathway in vitro. Moreover, exposure of mice to cigarette smoke affected bone marrow cells, leading to increased formation of osteoclasts in vitro. This study identifies a previously unknown mechanism of how smoking has a detrimental impact on bone.

[Mechanism of hepatocyte mitochondrial NDUFA13 deficiency-induced liver fibrogenesis: the role of abnormal hepatic stellate cell activation]

OBJECTIVE

To investigate the role of hepatocyte mitochondrial NDUFA13 loss in the liver fibrogenesis in mice and explore the possible mechanisms.

OBJECTIVE

We used liver-specific NDUFA13 heterozygous knockout mouse models (NDUFA13^fl/-; Alb-Cre) established previously by intercrossing NDUFA13^fl/fl and Alb-Cre mice, with their littermate control NDUFA13^fl/fl mice as the control (n=8). The mice were euthanized at the age of 4 weeks and 2 years, and the liver tissues were collected for HE and Masson staining to observe the pathological changes and fibrosis phenotypes. Western blotting was performed to detect the expression of NDUFA13 protein in the liver tissues, and the infiltration of F4/80⁺ macrophages and the expressions of TGF-β1, TNF-α and IL-1β were analyzed by immunofluorescence assay. The expression levels of α-SMA, matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteases 1 (TIMP-1), collagen-Ⅰ and collagen-Ⅲ were assayed by immunohistochemistry.

OBJECTIVE

HE and Masson staining showed obvious inflammatory infiltration but no significant fibrosis in the liver tissues of 4-week-old NDUFA13^fl/- mice, but severe liver damage with massive fibrosis was observed in 2-year-old NDUFA13^fl/- mice. NDUFA13 expression in 2-year-old NDUFA13^fl/- mice markedly decreased compared with that in the control NDUFA13^fl/fl mice as shown by Western blotting (P < 0.05). Immunohistochemistry showed obvious infiltration of F4/80⁺ macrophages in the liver tissue with a large amount of TGF-β1 production (P < 0.05) and TNF-α and IL-1β secretions in NDUFA13^fl/- mice (P < 0.05). NDUFA13 knockout obviously promoted α-SMA expression (P < 0.05) and collagen-Ⅰ and collagen-Ⅲ deposition (P < 0.05) while significantly decreased MMP-9 and increased TIMP-1 expression in the liver (P < 0.05).

OBJECTIVE

Hepatocytes-specific NDUFA13 deficiency can trigger spontaneous and chronic liver fibrosis phenotypes in mice probably in association with abnormal activation of hepatic stellate cells induced by macrophages and inflammatory factors.

[Exenatide promotes cholesterol efflux in pancreatic tissue of obese diabetic rats]

OBJECTIVE

To study the effect of exenatide on the expression of ABCA1 and cholesterol metabolism in the pancreas of obese diabetic rats.

OBJECTIVE

Twenty-four normal male SD rats and 18 obese diabetic rats (induced by high-fat feeding and STZ injection) were both divided equally into 2 groups for injections of saline or exenatide. After treatment for a week, the expression of ABCA1, cholesterol metabolism, and islet function of the rats were examined using real-time PCR, Western blotting, oil red O staining, cholesterol content determination, and HE staining.

OBJECTIVE

The expressions of ABCA1 at both mRNA and protein levels in pancreatic tissue were significantly lower in obese diabetic rats than in normal SD rats. The obese diabetic rats showed obvious lipid deposition and increased cholesterol content in the pancreatic tissue with significantly reduced islet volume and structural changes (P < 0.05); exenatide treatment of the diabetic rats significantly up-regulated ABCA1 expression, reduced lipid deposition and cholesterol content in pancreatic tissue, and increased number and volume of the islets, which presented with more orderly alignment (P < 0.05).

OBJECTIVE

Obese diabetic rats have lowered ABCA1 expression, cholesterol efflux block, and cholesterol accumulation in the pancreatic tissue. Exenatide can up-regulate ABCA1 expression and promote cholesterol efflux to reduce cholesterol content in the pancreatic tissue and improve islet function in obese diabetic rats.

The genetic polymorphisms of XPR1 and SCL34A3 are associated with Fanconi syndrome in Chinese patients of tumor-induced osteomalacia

PURPOSE

Tumor-induced osteomalacia (TIO) is an acquired form of hypophosphatemia caused by tumors with excess production of fibroblast growth factor 23 (FGF23). Some reports showed that TIO patients had renal Fanconi syndrome (FS) with unidentified mechanism. In this study, we investigated the association between genetic polymorphisms of phosphate transporters in renal proximal tubules and TIO with FS.

METHODS

We recruited 30 TIO patients with FS (TIO-FS) as well as 30 TIO patients (TIO-nonFS) without any urine abnormalities matched by age and gender. We collected clinical manifestations and conducted targeted sequencing of SLC34A1, SLC34A3 and XPR1 genes and the association analysis between variants in TIO with FS and phenotypes.

RESULTS

TIO-FS group had lower levels of serum phosphate (0.44 ± 0.12 vs. 0.51 ± 0.07 mmol/L, p < 0.05) than TIO-nonFS group. Among the 16 SNPs in SLC34A1, SLC34A3 and XPR1 genes, GG/GC genotypes of rs148196667 in XPR1 and AA/TA genotypes of rs35535797 in SLC34A3 were associated with a reduced susceptibility to have FS. The G allele of rs148196667 in XPR1 decreased the risk of FS. The GGAA haplotype in SLC34A3 and GCT haplotype in XPR1 were associated with a decreased risk for FS.

CONCLUSIONS

The polymorphisms of XPR1 and SCL34A3 are associated with TIO patients with Fanconi syndrome. It provides novel insight to the relationship of phosphate transportation and general functions of renal proximal tubules.

MiR-129-5p inhibits proliferation of gastric cancer cells through targeted inhibition on HMGB1 expression

OBJECTIVE

The aim of this study was to investigate the effects of micro ribonucleic acid (miR)-129-5p on the proliferation and apoptosis of gastric cancer cells via targeted repression on the expression of high mobility group protein B1 (HMGB1).

PATIENTS AND METHODS

Expression levels of miR-129-5p and HMGB1 in gastric cancer tissues (n=25) and adjacent normal tissues were measured via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The regulatory effect of miR-129-5p on the proliferation of gastric cancer MGC-803 and SGC7901 cells was determined through Cell Counting Kit-8 (CCK-8) assay. Flow cytometry was employed to analyze the apoptosis rate of gastric cancer cells. To further discover the mechanism of miR-129-5p in regulating malignant behaviors of gastric cancer cells, the miRDB database was employed to predict the binding targets of miR-129-5p. Finally, binding sites of HMGB1 3'-untranslated region (3'-UTR) to miR-129-5p were discovered. Subsequently, HMGB1 wild-type or mutant 3'-UTR Luciferase reporter vectors were constructed, and transfected to MGC-803 and SGC7901 cells together with miR-129-5p or negative control miRNA. Next, Western blotting was adopted to measure the protein expression level of HMGB1 in MGC-803 and SGC7901 cells transfected with miR-129-5p or negative control miRNA, so as to investigate whether miR-129-5p affected HMGB1 protein expression. Additionally, to determine whether HMGB1 mediated the regulatory effect of miR-129-5p on the proliferation of gastric cancer cells, MGC-803 and SGC7901 cells were transfected with pcDNA-HMGB1 or pcDNA-vector, respectively. The expression level of HMGB1 was measured via RT-qPCR, and cell proliferation was determined by CCK-8 assay.

RESULTS

The expression level of miR-129-5p in gastric cancer tissues was significantly lower than that in adjacent normal tissues (p<0.001). Meanwhile, the level of miR-129-5p was overtly lower in gastric cancer MGC-803 and SGC7901 cell lines than that in normal gastric mucosal epithelial GES-1 cells (p<0.001). These results indicated that miR-129-5p was lowly expressed in gastric cancer tissues and cell lines. Subsequent results demonstrated that the expression of HMGB1 increased remarkably in gastric cancer tissues compared with normal adjacent tissues (p<0.05). The proliferation ability of MGC-803 (p<0.001) and SGC7901 (p<0.01) cells with over-expressed miR-129-5p was remarkably weakened. Overexpression of miR-129-5p distinctly promoted the apoptosis rate of gastric cancer MGC-803 (p<0.01) and SGC7901 (p<0.001) cells. Moreover, miR-129-5p up-regulation significantly reduced the Luciferase activity of wild-type HMGB1 (p<0.001). However, no significant effect was observed on that of mutant HMGB1. The results suggested that overexpression of miR-129-5p significantly down-regulated the level of HMGB1 in gastric cancer cells. In addition, the messenger RNA (mRNA) level of HMGB1 in cells transfected with miR-129-5p also decreased significantly (p<0.001). HMGB1 overexpression overtly reversed the inhibitory effect of miR-129-5p on the proliferation of gastric cancer cells (p<0.05). All these results demonstrated that the miR-129-5p/HMGB1 axis played a key role in regulating the growth of gastric cancer cells.

CONCLUSIONS

MiR-129-5p suppresses the progression of gastric cancer through targeted inhibition on the expression of HMGB1.

The significance of Hashimoto's thyroiditis for postoperative complications of thyroid surgery: a systematic review and meta-analysis

INTRODUCTION

Hashimoto's thyroiditis (HT) is one of the most common immune-mediated diseases. It makes thyroid surgery more complicated and difficult because there may be adhesions between the thyroid gland and surrounding structures. However, it is still controversial whether HT patients carry a high risk for postoperative complications of thyroid surgery. The purpose of this study was to investigate the significance of HT for the postoperative complications of thyroid surgery.

METHODS

A search for studies assessing the postoperative complication risks of HT patients compared with that of patients with benign nodules (BNs) was performed in PubMed, EMBASE and Web of Science. Nine studies (20,118 cases, 1,582 cases of HT and 18,536 cases of BN) were identified, and the data from the relevant outcomes were extracted and analysed.

RESULTS

There were no significant differences between the HT group and BN group in recurrent laryngeal nerve palsy (RLNP) and permanent hypoparathyroidism (PHP). The rate of transient hypocalcaemia (THC) was significantly higher in the HT group (16.85%) than in the BN group (13.20%).

CONCLUSIONS

The meta-analysis showed that HT only increased the risk of the postoperative complication THC compared to BN. Understanding the significance of HT in postoperative hypoparathyroidism after thyroid surgery would help clinicians perform sufficient preoperative (and postoperative) assessments and to optimise surgical planning.

[The 486th case: chronic diarrhea and orthostatic hypotension]

A 57-year-old man was admitted to hospital with diarrhea for 10 months and dizziness for 4 months. The patient had 1-2 liters watery stool per day, without pyogenic blood or abnormality in gastroenteroscopy examination. The level of hemoglobin and albumin was generally normal, and fasting test was positive. At the same time, he was accompanied with hyperalgesia of lower limbs and orthostatic hypotension. After the discussion of multiple disciplinary teams, the patient was diagnosed with amyloidosis by sural nerve biopsy, myocardial MRI, and the assays of urine immunoelectrophoresis and serum free light chain. Light chain amyloidosis was confirmed after excluded the diagnosis of familial amyloidosis. The patient was improved after courses of chemotherapy with melphalan and dexamethasone.

Upregulation of transient receptor potential melastatin 4 (TRPM4) in ventricular fibroblasts from heart failure patients

The transient receptor potential melastatin 4 (TRPM4) is a Ca2+-activated nonselective monovalent cation channel belonging to the TRP channel superfamily. TRPM4 is widely expressed in various tissues and most abundantly expressed in the heart. TRPM4 plays a critical role in cardiac conduction. Patients carrying a gain-of-function or loss-of-function mutation of TRPM4 display impaired cardiac conduction. Knockout or over-expression of TRPM4 in mice recapitulates conduction defects in patients. Moreover, recent studies have indicated that TRPM4 plays a role in hypertrophy and heart failure. Whereas the role of TRPM4 mediated by cardiac myocytes has been well investigated, little is known about TRPM4 and its role in cardiac fibroblasts. Here we show that in human left ventricular fibroblasts, TRPM4 exhibits typical Ca2+-activation characteristics, linear current-voltage (I-V) relation, and monovalent permeability. TRPM4 currents recorded in fibroblasts from heart failure patients (HF) are more than 2-fold bigger than those from control individuals (CTL). The enhanced functional TRPM4 in HF is not resulted from changed channel properties, as TRPM4 currents from both HF and CTL fibroblasts demonstrate similar sensitivity to intracellular calcium activation and extracellular 9-phenanthrol (9-phen) blockade. Consistent with enhanced TRPM4 activity, the protein level of TRPM4 is about 2-fold higher in HF than that of CTL hearts. Moreover, TRPM4 current in CTL fibroblasts is increased after 24 hours of TGFβ1 treatment, implying that TRPM4 in vivo may be upregulated by fibrogenesis promotor TGFβ1. The upregulated TRPM4 in HF fibroblasts suggests that TRPM4 may play a role in cardiac fibrogenesis under various pathological conditions.

Quasifree Neutron Knockout Reaction Reveals a Small s-Orbital Component in the Borromean Nucleus ^{17}B

A kinematically complete quasifree (p,pn) experiment in inverse kinematics was performed to study the structure of the Borromean nucleus ^{17}B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for 1s_{1/2} and 0d_{5/2} orbitals, and a surprisingly small percentage of 9(2)% was determined for 1s_{1/2}. Our finding of such a small 1s_{1/2} component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in ^{17}B. The present work gives the smallest s- or p-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of s or p orbitals is not a prerequisite for the occurrence of a neutron halo.

Strong Superexchange in a d^{9-δ} Nickelate Revealed by Resonant Inelastic X-Ray Scattering

The discovery of superconductivity in a d^{9-δ} nickelate has inspired disparate theoretical perspectives regarding the essential physics of this class of materials. A key issue is the magnitude of the magnetic superexchange, which relates to whether cuprate-like high-temperature nickelate superconductivity could be realized. We address this question using Ni L-edge and O K-edge spectroscopy of the reduced d^{9-1/3} trilayer nickelates R_{4}Ni_{3}O_{8} (where R=La, Pr) and associated theoretical modeling. A magnon energy scale of ∼80  meV resulting from a nearest-neighbor magnetic exchange of J=69(4)  meV is observed, proving that d^{9-δ} nickelates can host a large superexchange. This value, along with that of the Ni-O hybridization estimated from our O K-edge data, implies that trilayer nickelates represent an intermediate case between the infinite-layer nickelates and the cuprates. Layered nickelates thus provide a route to testing the relevance of superexchange to nickelate superconductivity.

Properties of Heavy Secondary Fluorine Cosmic Rays: Results from the Alpha Magnetic Spectrometer

Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity R range 2.15 GV to 2.9 TV based on 0.29 million events collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The fluorine spectrum deviates from a single power law above 200 GV. The heavier secondary-to-primary F/Si flux ratio rigidity dependence is distinctly different from the lighter B/O (or B/C) rigidity dependence. In particular, above 10 GV, the F/Si/B/O ratio can be described by a power law R^{δ} with δ=0.052±0.007. This shows that the propagation properties of heavy cosmic rays, from F to Si, are different from those of light cosmic rays, from He to O, and that the secondary cosmic rays have two classes.

The interplay between spatial and heliconical orientational order in twist-bend nematic materials

The helical pitch formed by organic molecules, such as the α-helix of proteins, usually requires hydrogen bonding between chiral units and long-range positional order. It was recently found that certain liquid crystal oligomers can have a twist-bend nematic (NTB) phase with nanoscale heliconical structure without hydrogen bonding, molecular chirality or positional order. To understand the nature of this unique structure, here we present hard and resonant tender X-ray scattering studies of two novel sulfur containing dimer materials. We simultaneously measure the temperature dependences of the helical pitch and the correlation length of both the helical and positional order. In addition to an unexpected strong variation of the pitch with the length of the spacer connecting the monomer units, we find that at the transition to the NTB phase the positional correlation length drops. The helical structure was found not only in the NTB phase but observed even in the upper range of a smectic phase that forms just below the NTB state. The coexistence of smectic layering and the heliconical order indicates a layered (SmATB) phase wherein the rigid units of the dimers are tilted with respect to the smectic layer normal in order to accommodate the bent conformation of the dimers and the tilt direction rotates along the heliconical axis.

Properties of Iron Primary Cosmic Rays: Results from the Alpha Magnetic Spectrometer

We report the observation of new properties of primary iron (Fe) cosmic rays in the rigidity range 2.65 GV to 3.0 TV with 0.62×10^{6} iron nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. Above 80.5 GV the rigidity dependence of the cosmic ray Fe flux is identical to the rigidity dependence of the primary cosmic ray He, C, and O fluxes, with the Fe/O flux ratio being constant at 0.155±0.006. This shows that unexpectedly Fe and He, C, and O belong to the same class of primary cosmic rays which is different from the primary cosmic rays Ne, Mg, and Si class.