Single hormone or synthetic agonist induces Gs/Gi coupling selectivity of EP receptors via distinct binding modes and propagating paths.

To accomplish concerted physiological reactions, nature has diversified functions of a single hormone at at least two primary levels: 1) Different receptors recognize the same hormone, and 2) different cellular effectors couple to the same hormone-receptor pair [R.P. Xiao, Sci STKE 2001, re15 (2001); L. Hein, J. D. Altman, B.K. Kobilka, Nature 402, 181-184 (1999); Y. Daaka, L. M. Luttrell, R. J. Lefkowitz, Nature 390, 88-91 (1997)]. Not only these questions lie in the heart of hormone actions and receptor signaling but also dissecting mechanisms underlying these questions could offer therapeutic routes for refractory diseases, such as kidney injury (KI) or X-linked nephrogenic diabetes insipidus (NDI). Here, we identified that Gs-biased signaling, but not Gi activation downstream of EP4, showed beneficial effects for both KI and NDI treatments. Notably, by solving Cryo-electron microscope (cryo-EM) structures of EP3-Gi, EP4-Gs, and EP4-Gi in complex with endogenous prostaglandin E2 (PGE2)or two synthetic agonists and comparing with PGE2-EP2-Gs structures, we found that unique primary sequences of prostaglandin E2 receptor (EP) receptors and distinct conformational states of the EP4 ligand pocket govern the Gs/Gi transducer coupling selectivity through different structural propagation paths, especially via TM6 and TM7, to generate selective cytoplasmic structural features. In particular, the orientation of the PGE2 ω-chain and two distinct pockets encompassing agonist L902688 of EP4 were differentiated by their Gs/Gi coupling ability. Further, we identified common and distinct features of cytoplasmic side of EP receptors for Gs/Gi coupling and provide a structural basis for selective and biased agonist design of EP4 with therapeutic potential.

Role of prostaglandin E2 and its receptors in chronic liver disease.

Chronic liver disease (CLD) is a major global health burden in terms of growing morbidity and mortality. Although many conditions can cause CLD, leading to cirrhosis and hepatocellular carcinoma (HCC), viral hepatitis, drug-induced liver injury (DILI), alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) are the most common culprits. Prostaglandin E2 (PGE2), produced in the liver, is an important lipid mediator derived from the ω-6 polyunsaturated fatty acid, arachidonic acid, and plays a critical role in hepatic homeostasis. The physiological effects of PGE2 are mediated through four classes of E-type prostaglandin (EP) receptors, namely EP1, EP2, EP3 and EP4. In recent years, an increasing number of studies has been done to clarify the effects of PGE2 and EP receptors in regulating liver function and the pathogenesis of CLD to create a new potential clinical impact. In this review, we overview the biosynthesis and regulation of PGE2 and discuss the role of its synthesizing enzymes and receptors in the maintenance of normal liver function and the development and progress of CLD. We also discuss the potential of the PGE2-EP receptors system in treating CLD with various etiologies.

Realization of Broadband Near-Infrared Emission with High Thermal Stability in YGa3(BO3)4: Cr3+ Borate Phosphor.

As a key material for phosphor-converted light-emitting diodes (pc-LEDs) applications, broadband near-infrared (NIR) phosphors currently face poor thermal stability issues. In this work, we synthesized a broadband near-infrared phosphor YGa3(BO3)4: Cr3+ (YGBO: Cr3+) with a high thermal stability. The YGBO: Cr3+ sample exhibits a broadband near-infrared emission centered at 770 nm with a full width at half-maximum (fwhm) of 2130 cm-1 under blue light excitation. Benefiting from the borate host crystal's strong structural rigidity, wide optical band gap, and weak electron-phonon coupling strength, YGBO: Cr3+ demonstrates strong luminescence thermal stability, and the corresponding luminescence intensity can maintain 80% at 150 °C compared to room temperature. Furthermore, we fabricated a pc-LED device using a blue light chip and YGBO: Cr3+ phosphor, and confirmed its application potential as a near-infrared light source in the spectral analysis of fruit freshness.

Pregnane X receptor activation alleviates renal fibrosis in mice via interacting with p53 and inhibiting the Wnt7a/ß-catenin signaling.

Renal fibrosis is a common pathological feature of chronic kidney disease (CKD) with various etiologies, which seriously affects the structure and function of the kidney. Pregnane X receptor (PXR) is a member of the nuclear receptor superfamily and plays a critical role in regulating the genes related to xenobiotic and endobiotic metabolism in mammals. Previous studies show that PXR is expressed in the kidney and has protective effect against acute kidney injury (AKI). In this study, we investigated the role of PXR in CKD. Adenine diet-induced CKD (AD) model was established in wild-type and PXR humanized (hPXR) mice, respectively, which were treated with pregnenolone-16α-carbonitrile (PCN, 50 mg/kg, twice a week for 4 weeks) or rifampicin (RIF, 10 mg·kg-1·d-1, for 4 weeks). We showed that both PCN and RIF, which activated mouse and human PXR, respectively, improved renal function and attenuated renal fibrosis in the two types of AD mice. In addition, PCN treatment also alleviated renal fibrosis in unilateral ureter obstruction (UUO) mice. On the contrary, PXR gene deficiency exacerbated renal dysfunction and fibrosis in both adenine- and UUO-induced CKD mice. We found that PCN treatment suppressed the expression of the profibrotic Wnt7a and ß-catenin in AD mice and in cultured mouse renal tubular epithelial cells treated with TGFß1 in vitro. We demonstrated that PXR was colocalized and interacted with p53 in the nuclei of tubular epithelial cells. Overexpression of p53 increased the expression of Wnt7a, ß-catenin and its downstream gene fibronectin. We further revealed that p53 bound to the promoter of Wnt7a gene to increase its transcription and ß-catenin activation, leading to increased expression of the downstream profibrotic genes, which was inhibited by PXR. Taken together, PXR activation alleviates renal fibrosis in mice via interacting with p53 and inhibiting the Wnt7a/ß-catenin signaling pathway.

Apheresis Technique for Acute Hyperlipidemic Pancreatitis: A Systemic Review and Meta-Analysis.

BACKGROUND: The apheresis technique is increasingly used in patients with hypertriglyceridemia-induced pancreatitis (HTGP), while its role in this context is still not well established. Thus, we aimed to evaluate the clinical outcomes of an apheresis therapy compared to usual care in such a patient population. METHODS: We searched PubMed, Embase, and Cochrane library databases up to July 10, 2021. Studies were included if they focused on HTGP treated with or without apheresis technique. We used the Newcastle-Ottawa Scale to assess the quality of the included studies. The primary outcome was the mortality rate. We also explored the heterogeneity, sensitivity analysis, subgroup analysis, and publication bias. RESULTS: Sixteen observational studies with 1476 adults were included. The overall quality of included studies was moderate. Despite better TG level reduction with apheresis therapy (mean difference [MD], 12.27 mmol/L, 95% CI, 3.74 to 20.81; I2 = 78%; P = 0.005), use of apheresis did not reduce the mortality (odds ratio [OR], 1.01; 95% CI, 0.65 to 1.59; P = 0.95) compared with usual care. This result was further confirmed by sensitivity analysis, subgroup analysis. The length of stay in hospital (MD, 0.96 days; 95% CI, - 1.22 to 3.14; I2 = 70%; P = 0.39) and most complications were similar between the groups, while hospital cost was significantly higher in the apheresis group. CONCLUSIONS: The apheresis technique did not decrease the mortality in HTGP patients compared with usual care. Until the results of high-quality RCTs are known, these findings do not support the routine use of the apheresis technique in such a patient population.

Joint polarization detection and degradation mechanisms for underwater image enhancement.

Light absorption and scattering exist in the underwater environment, which can lead to blurring, reduced brightness, and color distortion in underwater images. Polarized images have the advantages of eliminating underwater scattering interference, enhancing contrast, and detecting material information of the object in underwater detection. In this paper, from the perspective of polarization imaging, different concentrations (0.15 g/ml, 0.30 g/ml, and 0.50 g/ml), different wave bands (red, green, and blue), different materials (copper, wood, high-density PVC, aluminum, cloth, foam, cloth sheet, low-density PVC, rubber, and porcelain tile), and different depths (10 cm, 20 cm, 30 cm, and 40 cm) are set up in a chamber for the experimental environment. By combining the degradation mechanism of underwater images and the analysis of polarization detection results, it is proved that the degree of polarization images have greater advantages than degree of linear polarization images, degree of circular polarization images, S1, S2, and S3 images, and visible images underwater. Finally, a fusion algorithm of underwater visible images and polarization images based on compressed sensing is proposed to enhance underwater degraded images. To improve the quality of fused images, we introduce orthogonal matching pursuit (OMP) in the high-frequency part to improve image sparsity and consistency detection in the low-frequency part to improve the image mutation phenomenon. The fusion results show that the peak SNR values of the fusion result maps using OMP in this paper are improved by 32.19% and 22.14% on average over those using backpropagation and subspace pursuit methods. With different materials and concentrations, the underwater image enhancement algorithm proposed in this paper improves information entropy, average gradient, and standard deviation by 7.76%, 18.12%, and 40.8%, respectively, on average over previous algorithms. The image NIQE value shows that the image quality obtained by this paper's algorithm is improved by about 69.26% over the original S0 image.

Electroacupuncture Improves Learning and Memory Abilities via Activating AMPK/mTOR-Induced Autophagy in APP/PS1 Mice.

Alzheimer's disease (AD) has become a global public health problem characterized by memory and cognitive impairments. Electroacupuncture (EA) has been indicated to exert promising therapeutic effects on AD. This study aimed to further investigate the underlying mechanism of EA in AD treatment. APP/PS1 transgenic mice and wide-type mice underwent with or without EA treatment at GV20 and BL23 acupoints. Morris water maze test was utilized for examining the learning and memory of mice. Hematoxylin-eosin, Congo red, immunofluorescence, and TUNEL staining were employed for detecting the pathological changes of mouse brain hippocampus. Western blotting was implemented for measuring protein levels of autophagy- and AMPK/mTOR pathway-associated markers. APP/PS1 mice exhibited significant impairments in the spatial learning and memory. EA treatment improved the cognitive impairments, reduced amyloid-beta (Aß) deposition, and alleviated neuronal apoptosis in the hippocampal tissues of APP/PS1 mice. EA promoted autophagy and activated the AMPK/mTOR signaling pathway in the hippocampus of APP/PS1 mice. EA improves the cognitive deficits, enhances Aß clearance, and attenuates neuronal apoptosis in APP/PS1 mice in part by activating AMPK/mTOR-mediated autophagy.

Polarized Object Surface Reconstruction Algorithm Based on RU-GAN Network.

There are six possible solutions for the surface normal vectors obtained from polarization information during 3D reconstruction. To resolve the ambiguity of surface normal vectors, scholars have introduced additional information, such as shading information. However, this makes the 3D reconstruction task too burdensome. Therefore, in order to make the 3D reconstruction more generally applicable, this paper proposes a complete framework to reconstruct the surface of an object using only polarized images. To solve the ambiguity problem of surface normal vectors, a jump-compensated U-shaped generative adversarial network (RU-Gan) based on jump compensation is designed for fusing six surface normal vectors. Among them, jump compensation is proposed in the encoder and decoder parts, and the content loss function is reconstructed, among other approaches. For the problem that the reflective region of the original image will cause the estimated normal vector to deviate from the true normal vector, a specular reflection model is proposed to optimize the dataset, thus reducing the reflective region. Experiments show that the estimated normal vector obtained in this paper improves the accuracy by about 20° compared with the previous conventional work, and improves the accuracy by about 1.5° compared with the recent neural network model, which means the neural network model proposed in this paper is more suitable for the normal vector estimation task. Furthermore, the object surface reconstruction framework proposed in this paper has the characteristics of simple implementation conditions and high accuracy of reconstructed texture.

A naturally occurring FXR agonist, alisol B 23-acetate, protects against renal ischemia-reperfusion injury.

The ligand-activated nuclear receptor, farnesoid X receptor (FXR), plays a pivotal role in regulating renal function. Activation of FXR by its specific agonists exerts renoprotective action in animals with acute kidney injury (AKI). In the present study, we aimed to identify naturally occurring agonists of FXR with potential as therapeutic agents in renal ischemia-reperfusion injury. In vitro and in vivo FXR activation was determined by a dual-luciferase assay, docking analysis, site-directed mutagenesis, and whole kidney transcriptome analysis. Wild-type (WT) and FXR knockout (FXR-/-) mice were used to determine the effect of potential FXR agonist on renal ischemia-reperfusion injury (IRI). We found that alisol B 23-acetate (ABA), a major active triterpenoid extracted from Alismatis rhizoma, a well-known traditional Chinese medicine, can activate renal FXR and induce FXR downstream gene expression in mouse kidney. ABA treatment significantly attenuated renal ischemia-reperfusion-induced AKI in WT mice but not in FXR-/- mice. Our results demonstrate that ABA can activate renal FXR to exert renoprotection against ischemia-reperfusion injury-induced AKI. Therefore, ABA may represent a potential therapeutic agent in the treatment of ischemic AKI.NEW & NOTEWORTHY In the present study, we found that alisol B 23-acetate (ABA), an identified natural farnesoid X receptor (FXR) agonist from the well-known traditional Chinese medicine Alismatis rhizoma, protects against ischemic acute kidney injury (AKI) in an FXR-dependent manner, as reflected by improved renal function, reduced renal tubular apoptosis, ameliorated oxidative stress, and suppressed inflammatory factor expression. Therefore, ABA may have great potential as a novel therapeutic agent in the treatment of AKI in the future.

The risk factors of heart failure in elderly patients with hip fracture: what should we care.

BACKGROUND: Heart failure is a common adverse postoperative complication in elderly patients. It is necessary to explore the risk factors of heart after the operation of elderly patients with hip fracture during hospitalization. METHODS: Patients with hip fractures admitted to our hospital from January 1, 2019 to December 31 2020 were included, all the patients received internal fixation surgery. The characteristics of patients with and without postoperative heart failure were compared. Multivariate logistic regression analyses were applied to analyze the risk factors of heart failure in elderly patients with hip fracture. RESULTS: A total of 283 patients with hip fractures were included, the incidence of heart failure was 12.37 %. There were significant differences in the age, hypertension, anemia hypoalbuminemia and duration of surgery between heart failure and no heart failure group(all p < 0.05). There were no significant differences in the gender, BMI, diabetes mellitus, hyperlipidemia, history of heart failure, cognitive dysfunction, type of fracture, preoperative oxygen saturation, white blood cell count, platelet count, red blood cell count, creatinine, alanine aminotransferase, aspartate aminotransferase and estimated blood loss during surgery between heart failure and no heart failure group(all p > 0.05). Logistic regression analyses indicated that age ≥ 70y(OR2.446, 95% CI1.044 ~ 4.149), hypertension(OR2.152, 95% CI1.125 ~ 4.023), anemia(OR3.094, 95% CI1.294 ~ 5.907), hypoalbuminemia(OR2.377, 95% CI1.205 ~ 4.537), duration of surgery ≥ 120 min(OR1.683, 95% CI1.094 ~ 2.782) were the risk factors of heart failure in elderly patients with hip fracture(all p < 0.05). CONCLUSIONS: The incidence of postoperative heart failure in elderly patients with hip fracture is relatively high, which is the result of a combination of high-risk factors. Peri-period risk assessment and prevention of related risks are the keys to a good prognosis for patients.

[Arachidonic acid metabolism in liver glucose and lipid homeostasis].

Arachidonic acid (AA) is an ω-6 polyunsaturated fatty acid, which mainly exists in the cell membrane in the form of phospholipid. Three major enzymatic pathways including the cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 monooxygenase (CYP450) pathways are involved in AA metabolism leading to the generation of a variety of lipid mediators such as prostaglandins, leukotrienes, hydroxyeicosatetraenoic acids (HETEs) and epoxyeicoastrienoic acids (EETs). These bioactive AA metabolites play an important role in the regulation of many physiological processes including the maintenance of liver glucose and lipid homeostasis. As the central metabolic organ, the liver is essential in metabolism of carbohydrates, lipids and proteins, and its dysfunction is associated with the pathogenesis of many metabolic diseases such as type 2 diabetes mellitus, dyslipidemia and nonalcoholic fatty liver disease (NAFLD). This article aims to provide an overview of the enzymatic pathways of AA and discuss the role of AA-derived lipid mediators in the regulation of hepatic glucose and lipid metabolism and their associations with the pathogenesis of major metabolic disorders.

[Overexpression of human EP4 receptor in vascular smooth muscle cells attenuates angiotensin II-induced hypertension in mice].

Prostaglandin E2 (PGE2) plays an important role in cardiovascular system. PGE2 regulates blood pressure through its 4 G protein coupled receptors, i.e., EP1, EP2, EP3, and EP4. The aim of this study was to investigate the role of EP4 receptors in vascular smooth muscle cells (VSMC) in blood pressure regulation. VSMC-specific human EP4 transgenic (VSMC-hEP4 Tg) mice were generated and genotyped. The systolic blood pressure (SBP) of the VSMC-hEP4 Tg mice and the wild-type (WT) littermates was measured under normal, low-salt (LSD) and high-salt diet (HSD) conditions using a tail-cuff method. Both WT and VSMC-hEP4 Tg mice were administered with a chronic infusion of angiotensin II (Ang II) with an osmotic pump and SBP levels were monitored every week. The mean arterial blood pressure (MAP) of WT and VSMC-hEP4 Tg mice upon Ang II intravenous infusion was measured via carotid arterial catheterization. Ang II-induced vasoconstriction of the mesenteric arterial rings from WT and VSMC-hEP4 Tg mice was measured using the multi myograph system. The effect of PGE1-OH (a selective EP4 agonist) on Ang II-induced phosphorylation of myosin phosphatase target subunit 1 (MYPT1) was detected by Western blot. The effect of two additional EP4 specific agonists (CAY10580 and CAY10598, 0.5 mg/kg) on blood pressure of WT mice was measured by carotid arterial catheterization. The results showed that the VSMC-hEP4 Tg mice were successfully generated and their basal SBP levels were lower than those of WT mice. Although blood pressure levels were significantly altered in WT mice under LSD and HSD, little change was observed in the VSMC-hEP4 Tg mice. After a chronic infusion and an acute intravenous injection of Ang II, SBP levels of VSMC-hEP4 Tg mice were significantly lower than those of WT mice. In addition, both CAY10580 and CAY10598 significantly reduced MAP levels of WT mice. Ex vivo study showed that treatment of isolated mesenteric arteries with PGE1-OH inhibited Ang II-induced phosphorylation of MYPT1. Collectively, these results demonstrate that specific overexpression of human EP4 gene in VSMCs significantly reduces basal blood pressure levels and attenuates Ang II-induced hypertension, possibly via inhibiting Ang II/AT1 signaling pathway. Our findings suggest that EP4 may represent an attractive target for the treatment of hypertension.

Farnesoid X receptor (FXR) inhibits coagulation process via inducing hepatic antithrombin III expression in mice.

Farnesoid X receptor (FXR) has been identified as an inhibitor of platelet function and an inducer of fibrinogen protein complex. However, the regulatory mechanism of FXR in hemostatic system remains incompletely understood. In this study, we aimed to investigate the functions of FXR in regulating antithrombin III (AT III). C57BL/6 mice and FXR knockout (FXR KO) mice were treated with or without GW4064 (30 mg/kg per day). FXR activation significantly prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT), lowered activity of activated factor X (FXa) and concentrations of thrombin-antithrombin complex (TAT) and activated factor II (FIIa), and increased level of AT III, whereas all of these effects were markedly reversed in FXR KO mice. In vivo, hepatic AT III mRNA and protein expression levels were up-regulated in wild-type mice after FXR activation, but down-regulated in FXR KO mice. In vitro study showed that FXR activation induced, while FXR knockdown inhibited, AT III expression in mouse primary hepatocytes. The luciferase assay and ChIP assay revealed that FXR can bind to the promoter region of AT III gene where FXR activation increased AT III transcription. These results suggest FXR activation inhibits coagulation process via inducing hepatic AT III expression in mice. The present study reveals a new role of FXR in hemostatic homeostasis and indicates that FXR might act as a potential therapeutic target for diseases related to hypercoagulation.

Design and synthesis of a folate-receptor targeted diazepine-ring-opened pyrrolobenzodiazepine prodrug conjugate.

Pyrrolobenzodiazepines (PBDs) and their dimers (bis-PBDs) have emerged as some of the most potent chemotherapeutic compounds and are currently under development as novel payloads in antibody-drug conjugates (ADCs). However, when used as stand-alone therapeutics or as warheads for small molecule drug conjugates (SMDCs), dose-limiting toxicities are often observed. As an elegant solution to this inherent problem, we designed and synthesized a diazepine-ring-opened bis-PBD prodrug (pro-PBD-PBD) folate conjugate lacking the one of the two imine moieties found in the corresponding free bis-PBD. Upon entering a targeted cell, cleavage of the linker system, including the hydrolysis of an oxazolidine moiety, results in the formation of a reactive intermediate which possesses a newly formed aldehyde as well as an aromatic amine. A fast and spontaneous intramolecular ring-closing reaction subsequently takes place as the aromatic amine adds to the aldehyde with the loss of water to give the imine, and as a result, the diazepine ring, thereby delivering the bis-PBD to the targeted cell. The in vitro and in vivo activity of this conjugate has been evaluated on folate receptor positive KB cells. Sub-nanomolar activity with good specificity and high cure rates with minimal toxicity have been observed.

[Role of systematic integration teaching reform at the basic medicine teaching stage in Chinese medical education system].

Systematic integration teaching is a curriculum system focusing on organs and systems, which is an important direction of medical education reform in China. Based on the practice of integrated curriculum teaching in Dalian Medical University for more than 10 years, combined with the experience in 15 medical colleges and universities in China, this paper analyzed the modes of systematic integrated teaching at the basic medicine teaching stage for medical higher education, and specified the purpose and significance of this teaching reform. The results showed that: (1) The systematic integrated teaching is a well-accepted and widely used teaching mode in domestic medical colleges and universities, which mainly includes three types of methodologies, i.e., integration of basic medicine courses, integration of clinical medicine courses and integration of basic and clinical medicine courses. The systematic integrated teaching is carried out by reforming various teaching methods including problem-based learning (PBL), case-based learning (CBL) and team-based learning (TBL). (2) The systematic integration teaching at the basic medicine teaching stage can significantly optimize the transition between basic and clinical courses, promote the cooperation and exchange between basic and clinical teachers, and improve the medical students' knowledge construction and critical thinking, and teachers' teaching ability as well. (3) The systematic integration teaching concept of "Six focuses" and "Five combinations" effectively guides the design and implementation of the integrated curriculum at the basic medical teaching stage of Dalian Medical University. With the deepening and development of medical education system reform in China, giving full play to the respective advantages of the systematic integrated teaching and traditional single-subject teaching at the basic medicine stage, and strengthening the integration of basic and clinical courses will play an important role in optimizing medical education curriculum system with Chinese characteristics.

Oligomeric ricinoleic acid preparation promoted by an efficient and recoverable Brønsted acidic ionic liquid.

Raw material from biomass and green preparation processes are the two key features for the development of green products. As a bio-lubricant in metalworking fluids, estolides of ricinoleic acid are considered as the promising substitute to mineral oil with a favorable viscosity and viscosity index. Thus, an efficient and sustainable synthesis protocol is urgently needed to make the product really green. In this work, an environment-friendly Brønsted acidic ionic liquid (IL) 1-butanesulfonic acid diazabicyclo[5.4.0]undec-7-ene dihydrogen phosphate ([HSO3-BDBU]H2PO4) was developed as the efficient catalyst for the production of oligomeric ricinoleic acid from ricinoleic acid under solvent-free conditions. The reaction parameters containing reaction temperature, vacuum degree, amount of catalyst and reaction time were optimized and it was found that the reaction under the conditions of 190 °C and 50 kPa with 15 wt % of the [HSO3-BDBU]H2PO4 related to ricinoleic acid can afford a qualified product with an acid value of 51 mg KOH/g (which corresponds to the oligomerization degree of 4) after 6 h. Furthermore, the acid value of the product can be adjusted by regulating the reaction time, implying this protocol can serve as a versatile method to prepare the products with different oligomerization degree and different applications. The other merit of this protocol is the facile product separation by stratification and decantation ascribed to the immiscibility of the product and catalyst at room temperature. It is also worth mentioning that the IL catalyst can be used at least for five cycles with high catalytic activity. As a result, the protocol based on the IL catalyst, i.e. [HSO3-BDBU]H2PO4 shows great potential in industrial production of oligomeric ricinoleic acid from ricinoleic acid.

[Role of prostaglandin E2 receptor EP4 in the regulation of adipogenesis and adipose metabolism].

Adipose tissue is the energy storage organ of the body, and excess energy is stored in adipocytes in the form of lipid droplets. The homeostasis of adipose tissue is the basis for the body to maintain normal metabolic activity. Prostaglandin E2 (PGE2) is an important lipid mediator in the body. It is synthesized in almost all tissues and participates in the regulation of many physiological processes such as blood pressure, glucose and lipid metabolism, and inflammation. PGE2 is abundant in white adipose tissue, where it is involved in the regulation of fat metabolism. PGE2 plays its biological role through binding to four G protein coupled receptors (prostaglandin E2 receptors), including EP-1, -2, -3, and -4. The EP4 subtype has been proved to play an important role in adipogenesis and adipose metabolism: it could inhibit adipogenesis while it was activated, whereas its knockout could promote lipolysis. This review summarized the relationship between EP4 and adipose metabolism, hoping to identify new targets of drug development for metabolic disorders.

[Role of pregnane X receptor (PXR) in endobiotic metabolism].

As a member of the nuclear receptor superfamily, the pregnane X receptor (PXR) is a ligand-activated transcription factor. PXR is highly expressed in liver and intestinal tissues, and also found in other tissues and organs, such as stomach and kidney. After heterodimerization with retinoid X receptor (RXR), PXR recruits numerous co-activating factors, and binds to specific DNA response elements to perform transcriptional regulation of the downstream target genes. As an acknowledged receptor for xenobiotics, PXR was initially considered as a nuclear receptor regulating drug metabolizing enzymes and transporters. However, nowadays, PXR has also been recognized as an important endobiotic receptor. Recent studies have shown that PXR activation can regulate glucose metabolism, lipid metabolism, steroid endocrine homeostasis, detoxification of cholic acid and bilirubin, bone mineral balance, and immune inflammation in vivo. This review focuses on the role of PXR in metabolism of endogenous substances.

[Role of prostaglandin E2 receptor 4 in cardiovascular diseases].

Prostaglandin E2 (PGE2) is a cyclooxygenase metabolite of arachidonic acid. It acts as a bioactive lipid and plays an important role in regulating many biological processes. PGE2 binds to 4 different G protein-coupled receptors including prostaglandin E2 receptor subtypes EP1, EP2, EP3 and EP4. The EP4 receptor is widely expressed in most of human organs and tissues. Increasing evidence demonstrates that EP4 is essential for cardiovascular homeostasis and participates in the pathogenesis of many cardiovascular diseases. Here we summarize the role of EP4 in the regulation of cardiovascular function and discuss potential mechanisms by which EP4 is involved in the development of cardiovascular disorders with a focus on its effect on inflammation.

[Epidemiological Features of Lung Cancer Mortality between 1990 and 2016 in Xuanwei City,Yunnan Province].

Objective To describe the trend of lung cancer mortality in Xuanwei City,Yunnan Province,from 1990 to 2016 and provide scientific evidence for the prevention and control of lung cancer in Xuanwei.Methods Mortality data from the 2nd(year 1990-1992)and 3rd(year 2004-2005)Retrospective Survey on Causes of Death,and the Routine Death Registration System(year 2011-2013 and 2014-2016)in Xuanwei were used in this study.We calibrated the missing report of the mortality data for the corresponding periods,calculated the crude mortality rates,standardized mortality rates and corresponding 95% CI of different types of lung cancers in the above four periods.Results The crude mortality rates of all lung cancers in Xuanwei for these four periods(1990-1992,2004-2005,2011-2013,and 2014-2016)were 34.0/100 000,89.8/100 000,102.3/100 000 and 87.2/100 000 respectively.The standardized morality rate of lung cancer remain high in Xuanwei although it has been decreasing since 2004.Morality rates of lung cancer for most age groups showed decreasing trends.The decrease has been statistically significant in the ≤ 40 year group since 2014.Except for Longchang,the standardized mortality rates have decreased in all other townships with high lung cancer prevalence.Conclusions Although the mortality rate of lung cancer remains high in Xuanwei,it has shown a decreasing trend since 2004.The decrease in lung cancer mortality in populations younger than 40 years is statistically significant.