Group II metabotropic glutamate receptor activation attenuates acid-sensing ion channel currents in rat primary sensory neurons.

Acid-sensing ion channels (ASICs) play an important role in pain associated with tissue acidification. Peripheral inhibitory group II metabotropic glutamate receptors (mGluRs) have analgesic effects in a variety of pain conditions. Whether there is a link between ASICs and mGluRs in pain processes is still unclear. Herein, we show that the group II mGluR agonist LY354740 inhibited acid-evoked ASIC currents and action potentials in rat dorsal root ganglia neurons. LY354740 reduced the maximum current response to protons, but it did not change the sensitivity of ASICs to protons. LY354740 inhibited ASIC currents by activating group II mGluRs. We found that the inhibitory effect of LY354740 was blocked by intracellular application of the Gi/o protein inhibitor pertussis toxin and the cAMP analogue 8-Br-cAMP and mimicked by the protein kinase A (PKA) inhibitor H-89. LY354740 also inhibited ASIC3 currents in CHO cells coexpressing mGluR2 and ASIC3 but not in cells expressing ASIC3 alone. In addition, intraplantar injection of LY354740 dose-dependently alleviated acid-induced nociceptive behavior in rats through local group II mGluRs. Together, these results suggested that activation of peripheral group II mGluRs inhibited the functional activity of ASICs through a mechanism that depended on Gi/o proteins and the intracellular cAMP/PKA signaling pathway in rat dorsal root ganglia neurons. We propose that peripheral group II mGluRs are an important therapeutic target for ASIC-mediated pain.

Microbial agents obtained from tomato straw composting effectively promote tomato straw compost maturation and improve compost quality.

Appropriate management of agricultural organic waste (AOW) presents a significant obstacle in the endeavor to attain sustainable agricultural development. The proper management of AOW is a necessity for sustainable agricultural development. This can be done skillfully by incorporating microbial agents in the composting procedure. In this study, we isolated relevant bacteria strains from tomato straw AOW, which demonstrated efficient degradation of lignocellulose without any antagonistic effects in them. These strains were then combined to create a composite microbial agent called Zyco Shield (ZS). The performance of ZS was compared with a commercially effective microorganism (EM) and a control CK. The results indicate that the ZS treatment significantly prolonged the elevated temperature phase of the tomato straw pile, showing considerable degradation of lignocellulosic material. This substantial degradation did not happen in the EM and CK treatments. Moreover, there was a temperature rise of 4-6 â„ƒ in 2 days of thermophilic phase, which was not the case in the EM and CK treatments. Furthermore, the inoculation of ZS substantially enhanced the degradation of organic waste derived from tomato straw. This method increased the nutrient content of the resulting compost and elevated the enzymatic activity of lignocellulose-degrading enzymes, while reducing the urease enzyme activity within the pile. The concentrations of NH4+-N and NO3--N showed increases of (2.13% and 47.51%), (14.81% and 32.17%) respectively, which is again very different from the results of the EM and CK treatments. To some extent, the alterations observed in the microbial community and the abundance of functional microorganisms provide indirect evidence supporting the fact that the addition of ZS microbial agent facilitates the composting process of tomato straw. Moreover, we confirmed the degradation process of tomato straw through X-ray diffraction, Fourier infrared spectroscopy, and by scanning electron microscopy to analyze the role of ZS microbial inoculum composting. Consequently, reinoculation compost strains improves agricultural waste composting efficiency and enhances product quality.

Lipid mediator resolvin D2 inhibits ATP currents in rat primary sensory neurons.

Resolvin D2 (RvD2), an endogenous lipid mediator derived from docosahexaenoic acid, has been demonstrated to have analgesic effects. However, little is known about the mechanism underlying RvD2 in pain relief. Herein, we demonstrate that RvD2 targeted the P2X3 receptor as an analgesic. The electrophysiological activity of P2X3 receptors was suppressed by RvD2 in rat dorsal root ganglia (DRG) neurons. RvD2 pre-application dose-dependently decreased α,ß-methylene-ATP (α,ß-meATP)-induced inward currents. RvD2 remarkably decreased the maximum response to α,ß-meATP, without influencing the affinity of P2X3 receptors. RvD2 also voltage-independently suppressed ATP currents. An antagonist of the G protein receptor 18 (GPR18), O-1918, prevented the RvD2-induced suppression of ATP currents. Additionally, intracellular dialysis of the Gαi/o -protein antagonist pertussis toxin (PTX), the PKA antagonist H89, or the cAMP analog 8-Br-cAMP also blocked the RvD2-induced suppression. Furthermore, α,ß-meATP-triggered depolarization of membrane potential along with the action potential bursts in DRG neurons were inhibited by RvD2. Lastly, RvD2 attenuated spontaneous nociceptive behaviors as well as mechanical allodynia produced by α,ß-meATP in rats via the activation of the peripheral GPR18. These findings indicated that RvD2 inhibited P2X3 receptors in rat primary sensory neurons through GPR18, PTX-sensitive Gαi/o -proteins, and intracellular cAMP/PKA signaling, revealing a novel mechanism that underlies its analgesic effects by targeting P2X3 receptors.

Potentiation of ASIC currents by lysophosphatidic acid in rat dorsal root ganglion neurons.

Lysophosphatidic acid (LPA) is a phospholipid which has been implicated in pain. Acid-sensing ion channels (ASICs) are important players in pain associated with tissue acidification. However, it is still unclear whether there is a link between LPA signaling and ASICs in pain processes. Herein, we show that a functional interaction between them in rat dorsal root ganglia (DRG) neurons. Pre-application of LPA enhanced ASIC-mediated and acid-evoked inward currents in a concentration-dependent manner. LPA shifted the concentration-response curve for protons upwards, with an increase of 41.79 ± 4.71% in the maximal current response of ASICs to protons in the presence of LPA. Potentiation of ASIC currents by LPA was blocked by the LPA1 receptor antagonist Ki16198, but not by the LPA2 receptor antagonist H2L5185303. The LPA-induced potentiation was also prevented by intracellular application of either G protein inhibitor or protein kinase C (PKC) inhibitor, but not by Rho inhibitor. LPA also enhanced ASIC3 currents in CHO cells co-expressing ASIC3 and LPA1 receptors, but not in cells expressing ASIC3 alone. Moreover, LPA increased the amplitude of the depolarization and the number of spikes induced by acid stimuli. Finally, LPA exacerbated acid-induced nociceptive behaviors in rats. These results suggested that LPA enhanced ASIC-mediated electrophysiological activity and nociception via a LPA1 receptor and its downstream PKC rather than Rho signaling pathway, which provided a novel peripheral mechanism underlying the sensitization of pain.

Resveratrol inhibits the activity of acid-sensing ion channels in male rat dorsal root ganglion neurons.

Resveratrol can relieve pain under various pain conditions. One of the mechanisms of resveratrol analgesia is the regulation of ion channels. Acid-sensing ion channels (ASICs) are expressed predominantly in nociceptive sensory neurons to detect changes in extracellular pH. ASICs are important players in pain associated with tissue acidification. However, it is still unclear whether ASICs are resveratrol targets. Electrophysiological recordings showed that resveratrol decreased acid-induced and ASIC-mediated currents in male rat dorsal root ganglion (DRG) neurons in a concentration-dependent manner. Resveratrol downwardly shifted the concentration-response curve for protons, suggesting that it inhibited ASICs not by changing the pH0.5 , but by suppressing the proton-induced maximum response. It also suppressed acid-triggered action potentials in the rat DRG neurons. Finally, intraplantar pretreatment with resveratrol relieved acid-induced nociceptive responses in male rats in a dose-dependent manner. These results indicated that resveratrol inhibited ASIC-mediated electrophysiological activity and nociception, suggesting a novel peripheral mechanism underlying its analgesic effect.

Pre-service teachers' perceptions of technological pedagogical content knowledge in mainland China: A survey of teachers of Chinese as a second language.

There is an urgent need to address the critical demand for qualified Chinese language teachers against the background of China's seeking greater Sino-foreign cultural and educational cooperation. The literature on integrating technological pedagogical content knowledge (TPACK) in language teaching has been increasing in the last few years. However, most of these studies focus on English language teachers. The objective of this study was to examine pre-service teachers' understanding of TPACK for teaching Chinese as a second language (TCSL). This study investigated the TPACK factor structure of 286 pre-service TCSL teachers via exploratory factor analysis, which yielded a six-factor structure. The results revealed that the teachers could not distinguish the boundaries between technological pedagogical knowledge (TPK) and technological content knowledge (TCK); and TPK and synthesized TPACK. Further, confirmatory factor analysis using structural equation modeling substantiated the validity and reliability of the adapted 32-item TCSL-TPACK survey instrument. The study also found that the teachers were slightly satisfied with their overall TPACK but were least confident of their technological knowledge (TK), and the more experienced teachers exhibited higher confidence in all six factors. These findings not only remind educators and policymakers of the need to revise current teacher training programs but also persuade TCSL student teachers to explore methods that can help integrate technology into lesson designs.

LncRNA MSC-AS1 facilitates lung adenocarcinoma through sponging miR-33b-5p to up-regulate GPAM.

Many reports have indicated that long non-coding RNAs (lncRNAs) are closely associated with the occurrence and development of various cancers. Musculin antisense RNA 1 (MSC-AS1) is a an lncRNA known to act as an oncogene in several types of human cancers; however, its specific function in lung adenocarcinoma (LUAD) is still unclear. For this study, we designed and conducted experiments to clarify the function of the lncRNA MSC-AS1 in LUAD and its underlying mechanisms. We found that the expression of MSC-AS1 was significantly higher in LUAD tissues and cells than that in normal ones. Through loss-of function assays, we confirmed that the proliferation of LUAD cells was significantly restrained by down-regulation of MSC-AS1 and the rate of cell apoptosis was accelerated. The results from our mechanistic experiments showed that MSC-AS1 interacts with microRNA-33b-5p (miR-33b-5p). Moreover, glycerol-3-phosphate acyltransferase, mitochondrial (GPAM) was found to be a direct target gene of miR-33b-5p, and it has similar functions to MSC-AS1. Further, inhibition of miR-33b-5p or overexpression GPAM reversed the inhibitory effects of MSC-AS1 silencing on LUAD cell growth. In short, MSC-AS1 facilitates LUAD progression through sponging miR-33b-5p to up-regulate GPAM.

TNF-α acutely enhances acid-sensing ion channel currents in rat dorsal root ganglion neurons via a p38 MAPK pathway.

BACKGROUND: Tumor necrosis factor-α (TNF-α) is a pro-inflammatory cytokine involved in pain processing and hypersensitivity. It regulates not only the expression of a variety of inflammatory mediators but also the functional activity of some ion channels. Acid-sensing ion channels (ASICs), as key sensors for extracellular protons, are expressed in nociceptive sensory neurons and contribute to pain signaling caused by tissue acidosis. It is still unclear whether TNF-α has an effect on functional activity of ASICs. Herein, we reported that a brief exposure of TNF-α acutely sensitized ASICs in rat dorsal root ganglion (DRG) neurons. METHODS: Electrophysiological experiments on rat DRG neurons were performed in vitro and acetic acid induced nociceptive behavior quantified in vitro. RESULTS: A brief (5min) application of TNF-α rapidly enhanced ASIC-mediated currents in rat DRG neurons. TNF-α (0.1-10 ng/ml) dose-dependently increased the proton-evoked ASIC currents with an EC50 value of 0.12 ± 0.01 nM. TNF-α shifted the concentration-response curve of proton upwards with a maximal current response increase of 42.34 ± 7.89%. In current-clamp recording, an acute application of TNF-α also significantly increased acid-evoked firing in rat DRG neurons. The rapid enhancement of ASIC-mediated electrophysiological activity by TNF-α was prevented by p38 mitogen-activated protein kinase (MAPK) inhibitor SB202190, but not by non-selective cyclooxygenase inhibitor indomethacin, suggesting that p38 MAPK is necessary for this enhancement. Behaviorally, TNF-α exacerbated acid-induced nociceptive behaviors in rats via activation of local p38 MAPK pathway. CONCLUSIONS: These results suggest that TNF-α rapidly enhanced ASIC-mediated functional activity via a p38 MAPK pathway, which revealed a novel peripheral mechanism underlying TNF-α involvement in rapid hyperalgesia by sensitizing ASICs in primary sensory neurons.

Comparison of intravascular ultrasound-guided with angiography-guided double kissing crush stenting for patients with complex coronary bifurcation lesions: Rationale and design of a prospective, randomized, and multicenter DKCRUSH VIII trial.

BACKGROUND: Double kissing (DK) crush approach for patients with coronary bifurcation lesions, particularly localized at distal left main or lesions with increased complexity, is associated with significant reduction in clinical events when compared with provisional stenting. Recently, randomized clinical trial has demonstrated the net clinical benefits by intravascular ultrasound (IVUS)-guided implantation of drug-eluting stent in all-comers. However, the improvement in clinical outcome after DK crush treatment guided by IVUS over angiography guidance for patients with complex bifurcation lesions have never been studied in a randomized fashion. TRIAL DESIGN: DKCRUSH VIII study is a prospective, multicenter, randomized controlled trial designed to assess superiority of IVUS-guided vs angiography-guided DK crush stenting in patients with complex bifurcation lesions according to DEFINITION criteria. A total of 556 patients with complex bifurcation lesions will be randomly (1:1 of ratio) assigned to IVUS-guided or angiography-guided DK crush stenting group. The primary end point is the rate of 12-month target vessel failure, including cardiac death, target vessel myocardial infarction, or clinically driven target vessel revascularization. The secondary end points consist of the individual component of primary end point, all-cause death, myocardial infarction, and in-stent restenosis. The safety end point is the incidence of definite or probable stent thrombosis. An angiographic follow-up will be performed for all patients at 13 months and clinical follow-up will be continued annually until 3 years after the index procedure. CONCLUSIONS: DKCRUSH VIII trial is the first study designed to evaluate the differences in efficacy and safety between IVUS-guided and angiography-guided DK crush stenting in patients with complex true bifurcation lesions. This study will also provide IVUS-derived criteria to define optimal DK crush stenting for bifurcation lesions at higher complexity.

Association of long-term inhalation of caffeine-sodium benzoate with coronary heart disease in men.

OBJECTIVE: A possible correlation between caffeine and coronary heart disease (CHD) is controversial. The objective of this study was to explore the effect of long-term inhalation of caffeine-sodium benzoate (CSB) on the development of CHD in men, the severity of coronary artery lesions and the possible contributing effects of smoking. MATERIALS: A retrospective analysis was performed on 2,001 consecutive men who underwent selective coronary angiography. These men were assigned to a CSB inhalation group (CSB; 1 - 6 times/d, 274 - 1,644 mg/d, > 10 years; n = 326) or a non-inhalation group (non-CSB; n = 1,675). METHODS: The two groups were compared for the prevalence, onset age, and risk factors of CHD. The men were also stratified as CSB-only, smoking-only, combined CSB+ smoking, and the control (non-CSB+non-smoking). The prevalence, onset age, risk factors of CHD, and severity of coronary artery lesions and major adverse cardiovascular events (MACE) were compared among these groups. RESULTS: The prevalence of CHD in the CSB group was higher compared with the non-CSB group (91.72 vs. 86.09%, p < 0.01). In the CSB+smoking group, the percentages of men with CHD (93.11%) or > 70% stenosis of the coronary artery lesion (64.92%) were significantly higher than that of the smoking-only group (88.19 and 54.29%, respectively) or control (83.20 and 52.90%), while the percentage with stenosis involving the anterior descending branch was lower (62.30 vs. 72.29% and 74.17%, p < 0.01). CONCLUSION: Men who inhaled CSB long-term had a higher rate of CHD compared with those who did not take CSB. The combination of CSB inhalation and smoking appears to increase synergistically the risk and severity of CHD.

CD169-positive macrophages dominate antitumor immunity by crosspresenting dead cell-associated antigens.

The generation of tumor-directed cytotoxic T lymphocytes is considered crucial for the induction of antitumor immunity. To activate these CD8(+) T cells, antigen-presenting cells (APCs) must initially acquire tumor cell-associated antigens. The major source of tumor antigens is dead tumor cells, but little is known about how APCs in draining lymph nodes acquire and crosspresent these antigens. Here we show that CD169(+) macrophages phagocytose dead tumor cells transported via lymphatic flow and subsequently crosspresent tumor antigens to CD8(+) T cells. Subcutaneous immunization with irradiated tumor cells protects mice from syngenic tumor. However, tumor antigen-specific CD8(+) T cell activation and subsequent antitumor immunity are severely impaired in mice depleted with CD169(+) macrophages. Neither migratory dendritic cells (DCs) nor lymph node-resident conventional DCs are essential for the crosspresentation of tumor antigens. Thus, we have identified CD169(+) macrophages as lymph node-resident APCs dominating early activation of tumor antigen-specific CD8(+) T cells.

Hepatic steatosis is associated with abnormal hepatic enzymes, visceral adiposity, altered myocardial glucose uptake measured by 18F-FDG PET/CT.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a multisystem disease that affects the liver and a variety of extra-hepatic organ systems. This study aimed to investigate the relationship between hepatic steatosis and glucose metabolism in liver and extra-hepatic tissues and organs. METHODS: The whole body 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) images of 191 asymptomatic tumor screening patients were retrospectively analyzed. Patients with the ratio of spleen/liver CT densities > 1.1 were defined to have NAFLD, and their clinical symptoms, laboratory markers, FDG uptake in a variety of tissues and organs including heart, mediastinal blood pool, liver, spleen, pancreas, and skeletal muscle, as well as abdominal adipose tissue volumes including visceral adipose tissue (VAT) volume and subcutaneous adipose tissue (SAT) volume were compared with those of the non-NAFLD patients and used to analyze the independent correlation factors of NAFLD. RESULTS: Among the 191 patients, 33 (17.3%) were NAFLD, and 158 (82.7%) were non-NAFLD. There was no significant correlation between the mean standardized uptake value (SUVmean) and CT density of liver as well as the ratio of spleen/liver CT densities. Hepatic steatosis, but not FDG intake, was more significant in NAFLD patients with abnormal liver function than those with normal liver function. Compared with the non-NAFLD patients, NAFLD patients had significantly reduced myocardial glucose metabolism, but significantly increased mediastinal blood pool, spleen SUVmean and abdominal adipose tissue volumes (including VAT and SAT volumes) (P < 0.05). Multivariate regression analysis showed that elevated serum ALT, increased abdominal VAT volume, and decreased myocardial FDG uptake were independent correlation factors for NAFLD. Further studies showed that hepatic steatosis and myocardial FDG uptake were mildly linearly correlated (r = 0.366 with hepatic CT density and - 0.236 with the ratio of spleen/liver CT densities, P < 0.05). CONCLUSIONS: NAFLD is a systemic disease that can lead to the change of glucose metabolism in some extra-hepatic tissues and organs, especially the myocardium.

Endothelin-1 enhances acid-sensing ion channel currents in rat primary sensory neurons.

Endothelin-1 (ET-1), an endogenous vasoactive peptide, has been found to play an important role in peripheral pain signaling. Acid-sensing ion channels (ASICs) are key sensors for extracellular protons and contribute to pain caused by tissue acidosis. It remains unclear whether an interaction exists between ET-1 and ASICs in primary sensory neurons. In this study, we reported that ET-1 enhanced the activity of ASICs in rat dorsal root ganglia (DRG) neurons. In whole-cell voltage-clamp recording, ASIC currents were evoked by brief local application of pH 6.0 external solution in the presence of TRPV1 channel blocker AMG9810. Pre-application with ET-1 (1-100 nM) dose-dependently increased the proton-evoked ASIC currents with an EC50 value of 7.42 ± 0.21 nM. Pre-application with ET-1 (30 nM) shifted the concentration-response curve of proton upwards with a maximal current response increase of 61.11% ± 4.33%. We showed that ET-1 enhanced ASIC currents through endothelin-A receptor (ETAR), but not endothelin-B receptor (ETBR) in both DRG neurons and CHO cells co-expressing ASIC3 and ETAR. ET-1 enhancement was inhibited by blockade of G-protein or protein kinase C signaling. In current-clamp recording, pre-application with ET-1 (30 nM) significantly increased acid-evoked firing in rat DRG neurons. Finally, we showed that pharmacological blockade of ASICs by amiloride or APETx2 significantly alleviated ET-1-induced flinching and mechanical hyperalgesia in rats. These results suggest that ET-1 sensitizes ASICs in primary sensory neurons via ETAR and PKC signaling pathway, which may contribute to peripheral ET-1-induced nociceptive behavior in rats.

Monitoring and Management of Home-Quarantined Patients With COVID-19 Using a WeChat-Based Telemedicine System: Retrospective Cohort Study.

BACKGROUND: Most patients with coronavirus disease (COVID-19) who show mild symptoms are sent home by physicians to recover. However, the condition of some of these patients becomes severe or critical as the disease progresses. OBJECTIVE: The aim of this study was to evaluate a telemedicine model that was developed to address the challenges of treating patients with progressive COVID-19 who are home-quarantined and shortages in the medical workforce. METHODS: A telemedicine system was developed to continuously monitor the progression of home-quarantined patients with COVID-19. The system was built based on a popular social media smartphone app called WeChat; the app was used to establish two-way communication between a multidisciplinary team consisting of 7 medical workers and 188 home-quarantined individuals (including 74 confirmed patients with COVID-19). The system helped patients self-assess their conditions and update the multidisciplinary team through a telemedicine form stored on a cloud service, based on which the multidisciplinary team made treatment decisions. We evaluated this telemedicine system via a single-center retrospective study conducted at Tongji Hospital in Wuhan, China, in January 2020. RESULTS: Among 188 individuals using the telemedicine system, 114 (60.6%) were not infected with COVID-19 and were dismissed. Of the 74 confirmed patients with COVID-19, 26 (35%) recovered during the study period and voluntarily stopped using the system. The remaining 48/76 confirmed patients with COVID-19 (63%) used the system until the end of the study, including 6 patients whose conditions progressed to severe or critical. These 6 patients were admitted to hospital and were stabilized (one received extracorporeal membrane oxygenation support for 17 days). All 74 patients with COVID-19 eventually recovered. Through a comparison of the monitored symptoms between hospitalized and nonhospitalized patients, we found prolonged persistence and deterioration of fever, dyspnea, lack of strength, and muscle soreness to be diagnostic of need for hospitalization. CONCLUSIONS: By continuously monitoring the changes in several key symptoms, the telemedicine system reduces the risks of delayed hospitalization due to disease progression for patients with COVID-19 quarantined at home. The system uses a set of scales for quarantine management assessment that enables patients to self-assess their conditions. The results are useful for medical staff to identify disease progression and, hence, make appropriate and timely treatment decisions. The system requires few staff to manage a large cohort of patients. In addition, the system can solicit help from recovered but self-quarantined medical workers to alleviate shortages in the medical workforce and free healthy medical workers to fight COVID-19 on the front line. Thus, it optimizes the usage of local medical resources and prevents cross-infections among medical workers and patients.

The oncolytic virus H101 combined with GNAQ siRNA-mediated knockdown reduces uveal melanoma cell viability.

BACKGROUND: Uveal melanoma (UM) is a severe human malignancy with a high mortality rate, as well as high metastasis and recurrence potential. The active mutation of G protein subunit alpha q (GNAQ) or G protein subunit alpha 11 (GNA11) is a major trigger for UM. Oncolytic adenovirus H101 (H101) is the first oncolytic virus approved for clinical applications in cancer therapy by the China Food and Drug Administration. We investigated whether combining H101 with the downregulation of GNAQ expression would act synergistically in UM therapy. METHODS: Three UM cell lines OMM2.3 and 92.1, harboring GNAQ mutation, and OCM1, harboring B-Raf proto-oncogene mutation, were chosen for our research. The cellular toxicity of adenoviral infection and the cell growth rate were measured with a Cell Counting Kit-8. Western blot analysis was used to detect GNAQ, p-MEK1/2, YAP, and p-YAP expression. The apoptosis and cell-cycle distribution of cells were evaluated with annexin-V and propidium iodide staining. RESULTS: Our results revealed that OMM2.3 and 92.1 cells were more sensitive to H101 infection than OCM1 cells. GNAQ expression was markedly reduced by small interfering RNA, siGNAQ. Combined treatment of siGNAQ and H101 inhibited the proliferation and activated the apoptosis of OMM2.3 and 92.1 cells by blocking the phosphorylation of MEK1/2 and increasing the phosphorylation of YAP. CONCLUSIONS: In summary, a therapy combining H101 and siGNAQ is feasible, with potential utility as a novel targeted molecular therapy for UM, especially those carrying a GNAQ mutation.

TGF-ß1 enhances the activity of acid-sensing ion channel in rat primary sensory neurons.

Transforming growth factor-ß1 (TGF-ß1) is an important member of multifunctional growth factor superfamily. It has been implicated in pain signaling, but little is known about the underlying mechanisms. Herein, we report that TGF-ß1 can exert a sustained enhancing effect on the functional activity of acid-sensing ion channels (ASICs) in rat dorsal root ganglia (DRG) neurons. Pre-application of TGF-ß1 increased the amplitude of proton-gated currents in a dose-dependent manner. Enhancement of ASIC currents lasted for more than 30 min although TGF-ß1 was treated once only. This sustained enhancement by TGF-ß1 could be blocked by extracellular treatment of selective TGF-ß receptor I antagonist SD-208, and abolished by blockade of intracellular several non-Smad-signaling pathways. TGF-ß1 also sustainedly enhanced proton-evoked spikes in rat DRG neurons. Moreover, peripheral pre-treatment with TGF-ß1 dose-dependently exacerbated nociceptive behaviors evoked by intraplantar injection of acetic acid through TGF-ß receptor I in rats. These results suggested that TGF-ß1 potentiated ASIC-mediated electrophysiological activity and nociceptive behaviors, which revealed a novel mechanism underlying TGF-ß1 implicated in peripheral pain signaling by sensitizing ASICs.

The association between diabetes mellitus and reduction in myocardial glucose uptake: a population-based 18F-FDG PET/CT study.

BACKGROUND: In diabetes, dysregulated substrate utilization and energy metabolism of myocardium can lead to heart failure. To examine the dynamic changes of myocardium, most of the previous studies conducted dynamic myocardial PET imaging following euglycemic-hyperinsulinemic clamp, which involves complicated procedures. In comparison, the whole-body 18F-FDG PET/CT scan is a simple and widely used method. Therefore, we hope to use this method to observe abnormal myocardial glucose metabolism in diabetes and determine the influencing factors. METHODS: We retrospectively analyzed PET/CT images of 191 subjects from our medical examination center. The levels of FDG uptake in myocardium were visually divided into 4 grades (Grade 0-3, from low to high). The differences in clinical and metabolic parameters among diabetes mellitus (DM), impaired fasting glucose (IFG), and normal fasting glucose (NFG) groups were analyzed, as well as their associations with myocardial FDG uptake. RESULTS: Compared with NFG and IFG groups, DM group had more cardiovascular-related risk factors. The degree of myocardial FDG uptake was significantly decreased in DM group; when myocardial FDG uptake ≤ Grade 1, the sensitivity of DM prediction was 84.0%, and the specificity was 58.4%. Univariate analysis showed that the myocardial FDG uptake was weakly and negatively correlated with multiple metabolic-related parameters (r = - 0.173~ - 0.365, P < 0.05). Multivariate logistic regression analysis showed that gender (male), HOMA-IR and nonalcoholic fatty liver disease (NAFLD) were independent risk factors for poor myocardial FDG uptake. CONCLUSIONS: Diabetes is associated with decreased myocardial glucose metabolism, which is mediated by multiple metabolic abnormalities.

Sensitization of ASIC3 by proteinase-activated receptor 2 signaling contributes to acidosis-induced nociception.

BACKGROUND: Tissue acidosis and inflammatory mediators play critical roles in pain. Pro-inflammatory agents trypsin and tryptase cleave and activate proteinase-activated receptor 2 (PAR2) expressed on sensory nerves, which is involved in peripheral mechanisms of inflammation and pain. Extracellular acidosis activates acid-sensing ion channel 3 (ASIC3) to trigger pain sensation. Here, we show that a functional interaction of PAR2 and ASIC3 could contribute to acidosis-induced nociception. METHODS: Electrophysiological experiments were performed on both rat DRG neurons and Chinese hamster ovary (CHO) cells expressing ASIC3 and PAR2. Nociceptive behavior was induced by acetic acid in rats. RESULTS: PAR2-AP, PAR2-activating peptide, concentration-dependently increased the ASIC3 currents in CHO cells transfected with ASIC3 and PAR2. The proton concentration-response relationship was not changed, but that the maximal response increased 58.7 ± 3.8% after pretreatment of PAR2-AP. PAR2 mediated the potentiation of ASIC3 currents via an intracellular cascade. PAR2-AP potentiation of ASIC3 currents disappeared after inhibition of intracellular G protein, PLC, PKC, or PKA signaling. Moreover, PAR2 activation increased proton-evoked currents and spikes mediated by ASIC3 in rat dorsal root ganglion neurons. Finally, peripheral administration of PAR2-AP dose-dependently exacerbated acidosis-induced nocifensive behaviors in rats. CONCLUSIONS: These results indicated that PAR2 signaling sensitized ASIC3, which may contribute to acidosis-induced nociception. These represent a novel peripheral mechanism underlying PAR2 involvement in hyperalgesia by sensitizing ASIC3 in primary sensory neurons.

Critical role of CCL22/CCR4 axis in the maintenance of immune homeostasis during apoptotic cell clearance by splenic CD8α(+) CD103(+) dendritic cells.

Macrophages and dendritic cells (DCs) in murine spleen are essential for the maintenance of immune homeostasis by elimination of blood-borne foreign particles and organisms. It has been reported that splenic DCs, especially CD8α(+) CD103(+) DCs, are responsible for tolerance to apoptosis-associated antigens. However, the molecular mechanism by which these DCs maintain immune homeostasis by blood-borne apoptotic cell clearance remains elusive. Here, we found that the CCL22/CCR4 axis played a critical role in the maintenance of immune homeostasis during apoptotic cell clearance by splenic CD8α(+) CD103(+) DCs. The present results revealed that systemic administration of apoptotic cells rapidly induced a large number of CCL22 and CCR4(+) regulatory T (Treg) cells in the spleen of C57BL/6J mice. Further study demonstrated that CD8α(+) CD103(+) DCs dominantly produce much higher CCL22 than CD8α(+) CD103(-) DCs. Moreover, the transient deletion of CD8α(+) CD103(+) DCs caused a decrease in CCL22 levels together with CCR4(+) Treg cell percentage. Subsequently, the levels of some pro-inflammatory cytokines, such as interleukin-17 and interferon-γ in the spleen with the absence of CD8α(+) CD103(+) DCs increased in response to the administration of apoptotic cells. Hence, intravenous injection of apoptotic cells induced a subsequent increase in CCL22 expression and CCR4(+) Treg cells, which contribute to the maintenance of immune homeostasis at least partially by splenic CD8α(+) CD103(+) DCs.

Pseudogene integrator complex subunit 6 pseudogene 1 (INTS6P1) as a novel plasma-based biomarker for hepatocellular carcinoma screening.

In this study, we aimed to determine whether the pseudogene integrator complex subunit 6 pseudogene 1 (INTS6P1) in plasma could be used as a novel approach to screen for and detect hepatocellular carcinoma (HCC). We explored the clinical role of INTS6P1: First, the expression level of INTS6P1 was measured in a cohort of 33 HCC tissue samples and adjacent normal liver tissue, next, the INTS6P1 expression was detected in the culture medium and tumor cells in a cellular experiment, and last, the diagnostic performance of INTS6P1 was examined in an independent cohort of 100 people. The expression level of INTS6P1 was remarkably downregulated in the HCC tissues compared with that in the normal liver tissues (p = 0.0066). In plasma, the INTS6P1 levels were significantly decreased in HCC patients compared with non-HCC patients (p < 0.01). Additionally, we inferred that INTS6P1 might be a prospective biomarker for screening HCC patients in which the serum-AFP levels were lower than 20 ng/ml by the area under the curve-receiver operating characteristic (AUC-ROC) analysis (p < 0.05). Pseudogene INTS6P1 could be used as a novel HCC plasma-based biomarker and might improve the accuracy of HCC screening.