MAGP2 promotes osteogenic differentiation during fracture healing through its crosstalk with the ß-catenin pathway.

Osteogenic differentiation is important for fracture healing. Microfibrial-associated glycoprotein 2 (MAGP2) is found to function as a proangiogenic regulator in bone formation; however, its role in osteogenic differentiation during bone repair is not clear. Here, a mouse model of critical-sized femur fracture was constructed, and the adenovirus expressing MAGP2 was delivered into the fracture site. Mice with MAGP2 overexpression exhibited increased bone mineral density and bone volume fraction (BV/TV) at Day 14 postfracture. Within 7 days postfracture, overexpression of MAGP2 increased collagen I and II expression at the fracture callus, with increasing chondrogenesis. MAGP2 inhibited collagen II level but elevated collagen I by 14 days following fracture, accompanied by increased endochondral bone formation. In mouse osteoblast precursor MC3T3-E1 cells, MAGP2 treatment elevated the expression of osteoblastic factors (osterix, BGLAP and collagen I) and enhanced ALP activity and mineralization through activating ß-catenin signaling after osteogenic induction. Besides, MAGP2 could interact with lipoprotein receptor-related protein 5 (LRP5) and upregulated its expression. Promotion of osteogenic differentiation and ß-catenin activation mediated by MAGP2 was partially reversed by LRP5 knockdown. Interestingly, ß-catenin/transcription factor 4 (TCF4) increased MAGP2 expression probably by binding to MAGP2 promoter. These findings suggest that MAGP2 may interact with ß-catenin/TCF4 to enhance ß-catenin/TCF4's function and activate LRP5-activated ß-catenin signaling pathway, thus promoting osteogenic differentiation for fracture repair. mRNA sequencing identified the potential targets of MAGP2, providing novel insights into MAGP2 function and the directions for future research.

Integrated analysis reveals a novel 5-fluorouracil resistance-based prognostic signature with promising implications for predicting the efficacy of chemotherapy and immunotherapy in patients with colorectal cancer.

BACKGROUND: 5-Fluorouracil (5-FU) has been used as a standard first-line treatment for colorectal cancer (CRC) patients. Although 5-FU-based chemotherapy and immune checkpoint blockade (ICB) have achieved success in treating CRC, drug resistance and low response rates remain substantial limitations. Thus, it is necessary to construct a 5-FU resistance-related signature (5-FRSig) to predict patient prognosis and identify ideal patients for chemotherapy and immunotherapy. METHODS: Using bulk and single-cell RNA sequencing data, we established and validated a novel 5-FRSig model using stepwise regression and multiple CRC cohorts and evaluated its associations with the prognosis, clinical features, immune status, immunotherapy, neoadjuvant therapy, and drug sensitivity of CRC patients through various bioinformatics algorithms. Unsupervised consensus clustering was performed to categorize the 5-FU resistance-related molecular subtypes of CRC. The expression levels of 5-FRSig, immune checkpoints, and immunoregulators were determined using quantitative real-time polymerase chain reaction (RT‒qPCR). Potential small-molecule agents were identified via Connectivity Map (CMap) and molecular docking. RESULTS: The 5-FRSig and cluster were confirmed as independent prognostic factors in CRC, as patients in the low-risk group and Cluster 1 had a better prognosis. Notably, 5-FRSig was significantly associated with 5-FU sensitivity, chemotherapy response, immune cell infiltration, immunoreactivity phenotype, immunotherapy efficiency, and drug selection. We predicted 10 potential compounds that bind to the core targets of 5-FRSig with the highest affinity. CONCLUSION: We developed a valid 5-FRSig to predict the prognosis, chemotherapeutic response, and immune status of CRC patients, thus optimizing the therapeutic benefits of chemotherapy combined with immunotherapy, which can facilitate the development of personalized treatments and novel molecular targeted therapies for patients with CRC.

TRAF6 promotes spinal microglial M1 polarization to aggravate neuropathic pain by activating the c-JUN/NF-kB signaling pathway.

BACKGROUND: The neuropathic pain with complex networks of neuroinflammatory activation severely limits clinical therapeutic research. TNF receptor-associated factor 6 (TRAF6) is associated with multiple inflammatory diseases. However, there remains confusion about the effects and mechanisms of TRAF6 in neuropathic pain. METHODS: A chronic constriction injury (CCI) model was developed to simulate neuralgia in vivo. We overexpressed or knocked down TRAF6 in CCI mice, respectively. Activation of microglia by TRAF6, the inflammatory response, and disease progression were inspected using WB, qRT-PCR, immunofluorescence, flow cytometry, and ELISA assays. Moreover, the mechanism of M1/M2 polarization activation of microglia by TRAF6 was elaborated in BV-2 cells. RESULTS: TRAF6 was enhanced in the spinal neurons and microglia of the CCI mice model compared with the sham operation group.. Down-regulation of TRAF6 rescued the expression of Iba-1. In response to mechanical and thermal stimulation, PWT and PWL were improved after the knockdown of TRAF6. Decreased levels of pro-inflammatory factors were observed in TRAF6 knockdown groups. Meanwhile, increased microglial M1 markers induced by CCI were limited in mice with TRAF6 knockdown. In addition, TRAF6 overexpression has the precise opposite effect on CCI mice or microglia polarization. We also identifed that TRAF6 activated the c-JUN/NF-kB pathway signaling; the inhibitor of c-JUN/NF-kB could effectively alleviate the neuropathic pain induced by upregulated TRAF6 in the CCI mice model. CONCLUSION: In summary, this study indicated that TRAF6 was concerned with neuropathic pain, and targeting the TRAF6/c-JUN/NF-kB pathway may be a prospective target for treating neuropathic pain.

Integrated analysis of ceRNA-miRNA changes in paraquat-induced pulmonary epithelial-mesenchymal transition via high-throughput sequencing.

Recent studies have shown that epithelial-mesenchymal transition (EMT) plays an important role in paraquat (PQ)-induced tissue fibrosis, which is the main cause of death in patients with PQ poisoning. However, no effective treatment for pulmonary interstitial fibrosis caused by PQ poisoning exists. It is of great significance for us to find new therapeutic targets through bioinformatics in PQ-induced EMT. We conducted transcriptome sequencing to determine the expression profiles of 1210 messenger RNAs (mRNAs), 558 long noncoding RNAs, 28 microRNAs (miRNAs), including 18 known-miRNAs, 10 novel-miRNAs and 154 circular RNAs in the PQ-exposed EMT group mice. Using gene ontology and Kyoto Encyclopaedia of Genes and Genomes analyses, we identified the pathways associated with signal transduction, cancers, endocrine systems and immune systems were involved in PQ-induced EMT. Furthermore, we constructed long noncoding RNA-miRNA-mRNA interrelated networks and found that upregulated genes included Il22ra2, Mdm4, Slc35e2 and Angptl4, and downregulated genes included RGS2, Gabpb2, Acvr1, Prkd3, Sp100, Tlr12, Syt15 and Camk2d. Thirteen new potential competitive endogenous RNA targets were also identified for further treatment of PQ-induced pulmonary tissue fibrosis. Through further study of the pathway and networks, we may identify new molecular targets in PQ-induced pulmonary EMT.

Identification of Diagnostic Metabolic Signatures in Thyroid Tumors Using Mass Spectrometry Imaging.

"Gray zone" thyroid follicular tumors are difficult to diagnose, especially when distinguishing between benign follicular thyroid adenoma (FTA) and malignant carcinoma (FTC). Thus, proper classification of thyroid follicular diseases may improve clinical prognosis. In this study, the diagnostic performance of metabolite enzymes was evaluated using imaging mass spectrometry to distinguish FTA from FTC and determine the association between metabolite enzyme expression with thyroid follicular borderline tumor diagnosis. Air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFAIDESI-MSI) was used to build a classification model for thyroid follicular tumor characteristics among 24 samples. We analyzed metabolic enzyme marker expression in an independent validation set of 133 cases and further evaluated the potential biological behavior of 19 thyroid borderline lesions. Phospholipids and fatty acids (FAs) were more abundant in FTA than FTC (p < 0.001). The metabolic enzyme panel, which included FA synthase and Ca2+-independent PLA2, was further validated in follicular thyroid tumors. The marker combination showed optimal performance in the validation group (area under the ROC, sensitivity, and specificity: 73.6%, 82.1%, and 60.6%, respectively). The findings indicate that AFAIDESI-MSI, in combination with low metabolic enzyme expression, could play a role in the diagnosis of thyroid follicular borderline tumors for strict follow-up.

Quantifying the Effect of Public Activity Intervention Policies on COVID-19 Pandemic Containment Using Epidemiologic Data From 145 Countries.

OBJECTIVES: Most countries have adopted public activity intervention policies to control the coronavirus disease 2019 (COVID-19) pandemic. Nevertheless, empirical evidence of the effectiveness of different interventions on the containment of the epidemic was inconsistent. METHODS: We retrieved time-series intervention policy data for 145 countries from the Oxford COVID-19 Government Response Tracker from December 31, 2019, to July 1, 2020, which included 8 containment and closure policies. We investigated the association of timeliness, stringency, and duration of intervention with cumulative infections per million population on July 1, 2020. We introduced a novel counterfactual estimator to estimate the effects of these interventions on COVID-19 time-varying reproduction number (Rt). RESULTS: There is some evidence that earlier implementation, longer durations, and more strictness of intervention policies at the early but not middle stage were associated with reduced infections of COVID-19. The counterfactual model proved to have controlled for unobserved time-varying confounders and established a valid causal relationship between policy intervention and Rt reduction. The average intervention effect revealed that all interventions significantly decrease Rt after their implementation. Rt decreased by 30% (22%-41%) in 25 to 32 days after policy intervention. Among the 8 interventions, school closing, workplace closing, and public events cancellation demonstrated the strongest and most consistent evidence of associations. CONCLUSIONS: Our study provides more reliable evidence of the quantitative effects of policy interventions on the COVID-19 epidemic and suggested that stricter public activity interventions should be implemented at the early stage of the epidemic for improved containment.

Spatially resolved metabolomics to discover tumor-associated metabolic alterations.

Characterization of tumor metabolism with spatial information contributes to our understanding of complex cancer metabolic reprogramming, facilitating the discovery of potential metabolic vulnerabilities that might be targeted for tumor therapy. However, given the metabolic variability and flexibility of tumors, it is still challenging to characterize global metabolic alterations in heterogeneous cancer. Here, we propose a spatially resolved metabolomics approach to discover tumor-associated metabolites and metabolic enzymes directly in their native state. A variety of metabolites localized in different metabolic pathways were mapped by airflow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) in tissues from 256 esophageal cancer patients. In combination with in situ metabolomics analysis, this method provided clues into tumor-associated metabolic pathways, including proline biosynthesis, glutamine metabolism, uridine metabolism, histidine metabolism, fatty acid biosynthesis, and polyamine biosynthesis. Six abnormally expressed metabolic enzymes that are closely associated with the altered metabolic pathways were further discovered in esophageal squamous cell carcinoma (ESCC). Notably, pyrroline-5-carboxylate reductase 2 (PYCR2) and uridine phosphorylase 1 (UPase1) were found to be altered in ESCC. The spatially resolved metabolomics reveal what occurs in cancer at the molecular level, from metabolites to enzymes, and thus provide insights into the understanding of cancer metabolic reprogramming.

Molecular Pathological Diagnosis of Thyroid Tumors Using Spatially Resolved Metabolomics.

The pathological diagnosis of benign and malignant follicular thyroid tumors remains a major challenge using the current histopathological technique. To improve diagnosis accuracy, spatially resolved metabolomics analysis based on air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) technique was used to establish a molecular diagnostic strategy for discriminating four pathological types of thyroid tumor. Without any specific labels, numerous metabolite features with their spatial distribution information can be acquired by AFADESI-MSI. The underlying metabolic heterogeneity can be visualized in line with the cellular heterogeneity in native tumor tissue. Through micro-regional feature extraction and in situ metabolomics analysis, three sets of metabolic biomarkers for the visual discrimination of benign follicular adenoma and differentiated thyroid carcinomas were discovered. Additionally, the automated prediction of tumor foci was supported by a diagnostic model based on the metabolic profile of 65 thyroid nodules. The model prediction accuracy was 83.3% when a test set of 12 independent samples was used. This diagnostic strategy presents a new way of performing in situ pathological examinations using small molecular biomarkers and provides a model diagnosis for clinically indeterminate thyroid tumor cases.

Transmission dynamics of SARS-CoV-2 in a mid-size city of China.

BACKGROUND: An outbreak of pneumonia, COVID-19 associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan city and then rapidly spread to other cities. Wenzhou is located approximately 900 km from Wuhan, which was experiencing an outbreak that was severe at the time but is considered modest as the epidemic became a pandemic. We described the epidemiological characteristics of SARS-CoV-2 outside of the epicenter to help understand the transmission pattern in a mid-sized Chinese city. METHODS: To investigate the epidemiological and clinical characteristics of the COVID-19, we described case series of 473 patients with confirmed COVID-19 in Wenzhou, China from January 27 to March 16, 2020. We described the public health interventions of COVID-19 and evaluated the effect of interventions by the effective reproduction number (Rt). RESULTS: The median age of all patients was 47.6 years, 48.4% of whom were female. 33.8% of the patients had a history of residence in Wuhan. Fever (71.7%) and cough (43.1%) were the most common symptoms. In addition, three kinds of unconventional cases were observed, namely 4.9% asymptomatic patients, 7.6% confirmed patients who had no link to Wuhan city but contact with individuals from Wuhan without any symptoms at the time of contact, and 12.9% confirmed patients who had an unknown source of transmission. We estimated that the basic reproductive number (R0) was 2.75 (95% CI: 2.37-3.23). The Rt fluctuated within the range of 2.50 to 3.74 from January 11 to January 16 while gradually reached a peak of 3.74 on January 16. Rt gradually decreased after January 16 and decreased to 1.00 on January 30. Rt continually decreased and reached the lowest point (0.03) on February 21, 2020. CONCLUSION: Our study presented the possibility of asymptomatic carriers affected with SARS-CoV-2, and transmission by these three kinds of unconventional patients in Wenzhou may be an important characteristic of SARS-CoV-2 transmission. The evaluation showed that a series of multifaceted interventions proved effective in controlling the epidemic of COVID-19. These findings might provide valuable examples of control policies for countries or areas in combatting the global pandemic of COVID-19.

Lp-PLA2 inhibition prevents Ang II-induced cardiac inflammation and fibrosis by blocking macrophage NLRP3 inflammasome activation.

Macrophage-mediated inflammation plays an important role in hypertensive cardiac remodeling, whereas effective pharmacological treatments targeting cardiac inflammation remain unclear. Lipoprotein-associated phospholipase A2 (Lp-PLA2) contributes to vascular inflammation-related diseases by mediating macrophage migration and activation. Darapladib, the most advanced Lp-PLA2 inhibitor, has been evaluated in phase III trials in atherosclerosis patients. However, the role of darapladib in inhibiting hypertensive cardiac fibrosis remains unknown. Using a murine angiotensin II (Ang II) infusion-induced hypertension model, we found that Pla2g7 (the gene of Lp-PLA2) was the only upregulated PLA2 gene detected in hypertensive cardiac tissue, and it was primarily localized in heart-infiltrating macrophages. As expected, darapladib significantly prevented Ang II-induced cardiac fibrosis, ventricular hypertrophy, and cardiac dysfunction, with potent abatement of macrophage infiltration and inflammatory response. RNA sequencing revealed that darapladib strongly downregulated the expression of genes and signaling pathways related to inflammation, extracellular matrix, and proliferation. Moreover, darapladib substantially reduced the Ang II infusion-induced expression of nucleotide-binding oligomerization domain-like receptor with pyrin domain 3 (NLRP3) and interleukin (IL)-1ß and markedly attenuated caspase-1 activation in cardiac tissues. Furthermore, darapladib ameliorated Ang II-stimulated macrophage migration and IL-1ß secretion in macrophages by blocking NLRP3 inflammasome activation. Darapladib also effectively blocked macrophage-mediated transformation of fibroblasts into myofibroblasts by inhibiting the activation of the NLRP3 inflammasome in macrophages. Overall, our study identifies a novel anti-inflammatory and anti-cardiac fibrosis role of darapladib in Lp-PLA2 inhibition, elucidating the protective effects of suppressing NLRP3 inflammasome activation. Lp-PLA2 inhibition by darapladib represents a novel therapeutic strategy for hypertensive cardiac damage treatment.

An outbreak of norovirus-related acute gastroenteritis associated with delivery food in Guangzhou, southern China.

BACKGROUND: A large number of students at a school in Guangzhou city developed a sudden onset of symptoms of diarrhea and vomiting. To help control the outbreak, we conducted an epidemiological investigation to determine the causative agent, sources, role of transmission and risk factors of the infections. METHODS: The study population consisted of probable and confirmed cases. An active search was conducted for cases among all students, teachers and other school staff members. A case control study was carried out using standardized online questionnaires. Data were obtained regarding demographic characteristics, gastrointestinal symptoms, personal hygiene habits, history of contact with a person who had diarrhea and/or vomiting and dining locations during the past 3 days. Rectal swabs or stool samples of the cases and, food handlers, as well as environmental samples were collected to detect potential intestinal viruses and bacteria. We calculated odds ratios and 95% confidence intervals (CIs). RESULTS: A total of 157 individuals fit the definition of a probable case, including 46 with laboratory-confirmed norovirus infection between March 8 and March 22, 2018. The proportion of students who had eaten delivery food 3 days before the onset of illness in the case group was 2.69 times that in the control group (95%CI: 1.88-3.85). Intake of take-out food 3 days earlier, and exposure to similar cases 72 h before onset and case in the same dormitory were risk factors. A total of 20 rectal swab samples from students, 10 rectal swabs from food handlers and 2 environmental swab samples from the out-campus restauranttested positive for norovirus (GII, genogroup II strain). CONCLUSIONS: We investigated an outbreak of norovirus infectious diarrhea. Food handling practices carry potential risk of acute gastroenteritis outbreaks owing to a lack of surveillance and supervision. Greater attention should be paid to the monitoring and supervision of food handlers in off campus restaurant to reduce the incidence of norovirus-related acute gastroenteritis associated with delivery food.

Attention-based recurrent neural network for influenza epidemic prediction.

BACKGROUND: Influenza is an infectious respiratory disease that can cause serious public health hazard. Due to its huge threat to the society, precise real-time forecasting of influenza outbreaks is of great value to our public. RESULTS: In this paper, we propose a new deep neural network structure that forecasts a real-time influenza-like illness rate (ILI%) in Guangzhou, China. Long short-term memory (LSTM) neural networks is applied to precisely forecast accurateness due to the long-term attribute and diversity of influenza epidemic data. We devise a multi-channel LSTM neural network that can draw multiple information from different types of inputs. We also add attention mechanism to improve forecasting accuracy. By using this structure, we are able to deal with relationships between multiple inputs more appropriately. Our model fully consider the information in the data set, targetedly solving practical problems of the Guangzhou influenza epidemic forecasting. CONCLUSION: We assess the performance of our model by comparing it with different neural network structures and other state-of-the-art methods. The experimental results indicate that our model has strong competitiveness and can provide effective real-time influenza epidemic forecasting.

The increasing menace of dengue in Guangzhou, 2001-2016: the most important epicenter in mainland China.

BACKGROUND: Dengue is the most prevalent mosquito-borne disease in the world, with China affected seriously in recent years. 65.8% of dengue cases identified in mainland China since 2005 were reported from the city of Guangzhou. METHODS: In this study, we described the incidence rate and distribution of dengue cases using data collected form National Notifiable Infectious Disease Reporting Information System data in Guangzhou for 2001 to 2016. All dengue cases were investigated using standardized questionnaire. RESULTS: A total of 42,469 dengue cases were reported, with an average annual incidence rate of 20.99 per 100,000 resident population. Over this time period, the incidence rate of indigenous cases increased. Dengue affected areas also expanded sharply geographically from 58.1% of communities affected during 2001-2005 to 96.4% of communities affected in 2011-2016. Overall 95.30% of the overseas imported cases were reported during March and December, while 99.79% of indigenous cases were reported during July and November. All four dengue virus serotypes were identified both in imported cases and indigenous cases. The Aedes albopictus mosquito was the only vector for dengue transmission in the area. CONCLUSIONS: Guangzhou has become the dengue epicenter in mainland China. Control strategies for dengue should be adjusted to the epidemiological characteristics above and intensive study need to be conducted to explore the factors that driving the rapid increase of dengue.

Risk factors of upper gastrointestinal hemorrhage with acute coronary syndrome.

BACKGROUND: Research showed that the mortality of upper gastrointestinal hemorrhage (UGH) complicated with acute coronary syndrome (ACS) was higher than single UGH in elderly patients. This study aimed to determine the risk factors that associated with an increased risk of ACS occurrence after UGH. METHODS: A population-based nested case-control study was conducted analyzing the hospital information system database of Shengjing Hospital of China Medical University from September 1, 2009 to December 31, 2014. We included 3217 elderly patients who experienced a UGH, among which 152 cases were identified and matched 604 selected controls. Multivariate conditional logistic regression models were used to characterize risk factors associated with ACS occurrence and death after UGH. RESULTS: Diabetes (odds ratio (OR) = 1.84, 95% confidence interval (CI) 1.13-2.71, P = 0.039), smoking (OR = 1.87, 95% CI 1.19-2.73, P = 0.028), vasopressin or terlipressin use (OR = 1.51, 95% CI 1.02-2.14, P = 0.043), liver cirrhosis (OR = 2.43, 95% CI 1.45-4.38, P = 0.013), hemoglobin level (OR = 2.36, 95% CI 1.65-3.79, P = 0.014) and history of ACS (OR = 1.98, 95% CI 1.13-3.49, P = 0.017) increased risk of ACS incidence in elderly patients with UGH. Moreover, diabetes (OR = 2.14, 95% CI 1.15-4.21, P = 0.041), smoking (OR = 2.93, 95% CI 1.17-5.31, P = 0.043) and hemoglobin levels (OR = 1.95, 95% CI 1.24-3.16, P = 0.038) were independent variables for the mortality underwent UGH with ACS in elderly patients. CONCLUSIONS: History of diabetes, vasopressin or terlipressin use, smoking, liver cirrhosis, hemoglobin level and history of ACS are risk factors to develop ACS in elderly patients with UGH. Importantly, diabetes, smoking and lower hemoglobin level are key variables for mortality.

Gadolinium-Labeled Aminoglycoside and Its Potential Application as a Bacteria-Targeting Magnetic Resonance Imaging Contrast Agent.

Magnetic resonance imaging (MRI) is a powerful diagnostic technique that can penetrate deep into tissue providing excellent spatial resolution without the need for ionizing radiation or harmful radionuclides. However, diagnosing bacterial infections in vivo with clinical MRI is severely hampered by the lack of contrast agents with high relaxivity, targeting capabilities, and bacterial penetration and specificity. Here, we report the development of the first gadolinium (Gd)-based bacteria-specific targeting MRI contrast agent, probe 1, by conjugating neomycin, an aminoglycoside antibiotic, with Dotarem (Gd-DOTA, an FDA approved T1-weighted MRI contrast agent). The T1 relaxivity of probe 1 was found to be comparable to that of Gd-DOTA; additionally, probe 1-treated bacteria generated a significantly brighter T1-weighted MR signal than Gd-DOTA-treated bacteria. More importantly, in vitro cellular studies and preliminary in vivo MRI demonstrated probe 1 exhibits the ability to efficiently target bacteria over macrophage-like cells, indicating its great potential for high-resolution imaging of bacterial infections in vivo.

The SGK1 inhibitor EMD638683, prevents Angiotensin II-induced cardiac inflammation and fibrosis by blocking NLRP3 inflammasome activation.

Inflammation has emerged as a critical biological process contributing to hypertensive cardiac remodeling. Effective pharmacological treatments targeting the cardiac inflammatory response, however, are still lacking. Prior studies suggested that the serum- and glucocorticoid-inducible kinase (SGK1) plays a key role in inflammation and cardiac remodeling. Recently, a highly selective SGK1 inhibitor, EMD638683, was developed, though whether EMD638683 can prevent hypertension-induced cardiac fibrosis and the mechanisms by which this inhibitor may alter the disease process remain unknown. Using a murine Angiotension II (Ang II) infusion-induced hypertension model we found that EMD638683 treatment inhibited cardiac fibrosis and remodeling, with significant abatement of cardiac inflammation. EMD638683 was shown to suppress Ang II infusion-induced interleukin (IL)-1ß release, and substantially reduce nucleotide-binding oligomerization domain-like receptor with pyrin domain 3 (NLRP3) expression and caspase-1 activation in cardiac tissues. In vitro experiments revealed that EMD638683 ameliorated Ang II-stimulated IL-1ß secretion in macrophages by blocking NLRP3 inflammasome activation. By reducing IL-1ß production in macrophages, the transformation of fibroblasts to myofibroblasts was inhibited. The effects of EMD638683 on cardiac fibrosis were abolished by supplementation with exogenous IL-1ß. Administration of the NLRP3 inflammasome inhibitor MCC950 indicated that EMD638683 attenuated Ang II-induced cardiac inflammation and fibrosis by inhibiting the NLRP3 inflammasome/IL-1ß secretion axis. These findings indicate that the SGK1 inhibitor EMD638683 can negatively regulate NLRP3 inflammasome activation, and may represent a promising approach to the treatment of hypertensive cardiac damage.

Serum-glucocorticoid-regulated kinase 1 contributes to mechanical stretch-induced inflammatory responses in cardiac fibroblasts.

Excessive mechanical stretch induces production of proinflammatory mediators in cardiac fibroblasts, which could act as inflammatory supporter cells in heart failure. Accumulation evidence and our previous studies suggest that serum-glucocorticoid-regulated kinase 1 (SGK1) contributes to cardiac remodeling and fibrosis, development of heart failure. However, the role and mechanism of SGK1 in mechanical stretch-induced inflammation of cardiac fibroblasts remain unclear. Here, cardiac fibroblasts isolated from wild-type (WT) and SGK1 knockout (SGK1-/-) mice were stimulated by 18% cyclic stretch, under static condition as the control. The results showed that mechanical stretch increased SGK1 expression and activation in WT cardiac fibroblasts but not its isoform, SGK2 or SGK3 expression. Bio-Plex array revealed hyperstretch could enhance chemokines release in WT cardiac fibroblasts, but SGK1 knockout significantly attenuated chemokines production through blocking activation of nuclear factor-kappa B (NF-κB). Moreover, supernatants from WT cardiac fibroblasts subjected to hyperstretch promoted macrophage migration, enhanced expression of macrophage-derived profibrotic mediators, whereas supernatants from SGK1 deficiency suppressed these effects. Although SGK1 did not directly affect mechanical stretch-induced myofibroblast differentiation, SGK1 activation of cardiac fibroblasts facilitated myofibroblast differentiation through the upregulation of the profibrotic mediators secreted by macrophages. These results suggest that SGK1 may play a critical role in the inflammatory cascade of cardiac fibroblasts triggered by mechanical stretch; SGK1 could be used as a potential target for treatment of cardiac fibrosis and heart failure.

Investigation of cochlear hair cells and the perception of ultrasound signals in guinea pigs.

We established a specific ultrasound frequency-dependent model of cochlear injury using bone conduction ultrasounds in the inner ear of guinea pigs at 50 kHz and 83 kHz, to explore the effects of bone conduction ultrasound in the cochlea. To establish a unilateral cochlear damage model, the unilateral cochlea was destroyed. The control group consisted of 50 kHz and 83 kHz bone conduction ultrasounds in unaltered guinea pigs. In each group, cerebral blood oxygenation level dependent (BOLD) effects were determined by functional magnetic resonance imaging (fMRI). The cochlear outer hair cell motor protein, Prestin, and the microfilament protein, F-Actin, were detected. We found that bone conduction ultrasound irradiation at 50 kHz and 83 kHz on the guinea pig inner ear for six hours leads to hair cell damage. Furthermore, low frequency bone conduction ultrasound induces major damage to outer hair cells, while high frequency ultrasound damages both internal and external hair cells. fMRI analysis of cerebral BLOD effects revealed an affected cerebral cortex region of interest (ROI) of 4 and 2, respectively, for the normal control group at 50 kHz or 83 kHz, and 2 for the 83 kHz bone conduction ultrasound cochlear injury group, while 50 kHz bone conduction ultrasound failed to induce the cortical ROI within injury model. Results reveal that the spatial location of guinea pig cochlear hair cells determines coding function for lower ultrasound frequencies, and high frequency bone conduction ultrasound may affect the cochlear spiral ganglion or cranial nerve nucleus in bone conduction ultrasound periphery perception.

Establishment of a cochlear injury model using bone-conducted ultrasound irradiation in guinea pigs and investigation on peripheral coding and recognition of ultrasonic signals.

The cochlea of guinea pigs was irradiated with different frequencies of bone-conducted ultrasound (BCU) at a specific dose to induce cochlear hair cell-specific injuries, in order to establish frequency-related cochlear hair cell-specific injury models. Cochlear near-field potentials were then evoked using BCU of different frequencies and intensities to explore the peripheral coding and recognition of BCU by the cochlea. The inner ears of guinea pigs were irradiated by 30 kHz at 100 db and 80 kHz at100 db BCU for 6h to create frequency-related, ultrasound-specific cochlear injury models. Then, 30 kHz and 80 kHz BCU of different intensities were used to evoke auditory brainstem response (ABR) thresholds, compound action potential (CAP) thresholds, and action potential (AP) intensity-amplitude input-output curves in the normal control group and the ultrasonic cochlear injury group. This allowed us to explore the coding and recognition of BCU frequencies and intensities by cochlear hair cells. Immunofluorescence assay of outer hair cell (OHC) Prestin and inner hair cell (IHC) Otofelin was performed to verify the injury models. Irradiation of guinea pig inner ears by 30 kHz and 80 kHz BCU at a specific dose induced hair cell injuries at different sites. Irradiation with low frequency BCU mainly induced OHC injury, whereas irradiation with high frequency BCU induced IHC injury; moreover, IHC injury was more serious than OHC injury. The 30 kHz-evoked ABR threshold was significantly higher in the 30 kHz ultrasonic cochlear injury group compared to the normal control group. The 30 kHz-evoked ABR threshold was significantly higher in the 30 kHz ultrasonic cochlear injury group compared to the 80 kHz ultrasonic cochlear injury group. The difference in the 80 kHz-evoked ABR thresholds were not significant between the 30 kHz and 80 kHz ultrasonic cochlear injury groups. The click- and 30 kHz-evoked AP intensity-amplitude curves for the 30 kHz ultrasonic cochlear injury group indicate that the AP amplitude evoked at the same intensity was higher in the 30 kHz-evoked group than the click-evoked group. The spatial positions of cochlear hair cells in guinea pigs had a coding function for the frequencies of low-frequency ultrasound. OHCs have an amplification effect on the coding of low-frequency ultrasonic intensities. The peripheral perception of high frequency BCU may not require the participation of cochlear hair cells.

Establishment of a Gentamicin Cochlear Poisoning Model in Guinea Pigs and Cochlear Nerve Endings Recognition of Ultrasound Signals.

BACKGROUND Aminoglycosides, a type of gram-negative antibacterial, are broad-spectrum antibiotics that are highly potent and have satisfactory therapeutic efficacy in the treatment of life-threatening infections. Our study aimed to establish a gentamicin-induced cochlear injury model and to investigate the cochlear nerve endings' recognition of ultrasound signals. MATERIAL AND METHODS A guinea pig cochlear injury model was established by intraperitoneal injection of gentamycin. Auditory brainstem response (ABR) and fMRI an affected cerebral cortex region of interest (ROI) of the cerebral cortex blood oxygenation level dependent (BOLD) effect was induced by bone-conducted ultrasound. Immunofluorescence was used to detect expression of Prestin in outer hair cells, Otoferlin in inner hair cells, and cochlear hair cell microfilament protein (F-Actin). RESULTS For 30-35 KHz bone-conducted ultrasound, the induction rate of ABR threshold or ROI in the control group and the cochlear injury group was 40% and 0%, respectively, and for 80-90 KHz the induction rate was 20% and 20%, respectively. Gentamicin poisoning induced downregulation of expression of Prestin in cochlear outer cochlea, and Otoferlin and F-Actin in cochlear hair cells in different regions. CONCLUSIONS Gentamicin poisoning can cause different degrees of damage to cochlea hair cells in different regions. Guinea pigs with gentamicin poisoning can recognize high-frequency ultrasonic signals.