AIM: To investigate the effect of different dietary fatty acids on hepatic inflammasome activation.METHODS: Wild-type C57BL/6 mice were fed either a high-fat diet or polyunsaturated fatty acid(PUFA)-enriched diet. Pri...AIM: To investigate the effect of different dietary fatty acids on hepatic inflammasome activation.METHODS: Wild-type C57BL/6 mice were fed either a high-fat diet or polyunsaturated fatty acid(PUFA)-enriched diet. Primary hepatocytes were treated with either saturated fatty acids(SFAs) or PUFAs as well as combined with lipopolysaccharide(LPS). The expression of NOD-like receptor protein 3(NLRP3) inflammasome, peroxisome proliferator-activated receptor-γ and nuclear factor-kappa B(NF-κB) was determined by real-time PCR and Western blot. The activity of Caspase-1 and interleukine-1β production were measured.RESULTS: high-fat diet-induced hepatic steatosis was sufficient to induce and activate hepatic NLRP3 inflammasome. SFA palmitic acid(PA) directly activated NLRP3 inflammasome and increased sensitization to LPS-induced inflammasome activation in hepatocytes. In contrast, PUFA docosahexaenoic acid(Dh A) had thepotential to inhibit NLRP3 inflammasome expression in hepatocytes and partly abolished LPS-induced NLRP3 inflammasome activation. Furthermore, a highfat diet increased but PUFA-enriched diet decreased sensitization to LPS-induced hepatic NLRP3 inflammasome activation in vivo. Moreover, PA increased but Dh A decreased phosphorylated NF-κB p65 protein expression in hepatocytes.CONCLUSION:Hepatic NLRP 3 inflammasome activation played an important role in the development of non-alcoholic fatty liver disease. Dietary SFAs and PUFAs oppositely regulated the activity of NLRP3 inflammasome through direct activation or inhibition of NF-κB.展开更多
A DNA fragment encoding the intracellular part of tyrosine phosphatase RPTPα designated as RPTPα-2D gene was amplified by PCR from a human prostate cDNA library and cloned into the pT7 E. coli expression vector. The...A DNA fragment encoding the intracellular part of tyrosine phosphatase RPTPα designated as RPTPα-2D gene was amplified by PCR from a human prostate cDNA library and cloned into the pT7 E. coli expression vector. The resulting plasmid pT7-RPTPα-2D was used to transform Rosetta DE3 E. coli cells. RPTPα-2D was predominately expressed in the insoluble inclusion body and was effectively purified using preparative electrophoresis gels. Polyclonal antibodies were obtained after immunization of a rabbit with purified RPTPα-2D. The antibodies displayed a high titer and sensitivity. This study thus provided a valuable tool for further researches on RPTPα.展开更多
Recently,the roles of pyroptosis,a form of cell death induced by activated NODlike receptor protein 3(NLRP3)inflammasome,in the pathogenesis of diabetic cardiomyopathy(DCM)have been extensively investigated.However,mo...Recently,the roles of pyroptosis,a form of cell death induced by activated NODlike receptor protein 3(NLRP3)inflammasome,in the pathogenesis of diabetic cardiomyopathy(DCM)have been extensively investigated.However,most studies have focused mainly on whether diabetes increases the NLRP3 inflammasome and associated pyroptosis in the heart of type 1 or type 2 diabetic rodent models,and whether various medications and natural products prevent the development of DCM,associated with decreased levels of cardiac NLRP3 inflammasome and pyroptosis.The direct link of NLRP3 inflammasome and associated pyroptosis to the pathogenesis of DCM remains unclear based on the limited evidence derived from the available studies,with the approaches of NLRP3 gene silencing or pharmaceutical application of NLRP3 specific inhibitors.We thus emphasize the requirement for more systematic studies that are designed to provide direct evidence to support the link,given that several studies have provided both direct and indirect evidence under specific conditions.This editorial emphasizes that the current investigation should be circumspect in its conclusion,i.e.,not overemphasizing its role in the pathogenesis of DCM with the fact of only significantly increased expression or activation of NLRP3 inflammasome and pyroptosis in the heart of diabetic rodent models.Only clear-cut evidence-based causative roles of NLRP3 inflammasome and pyroptosis in the pathogenesis of DCM can help to develop effective and safe medications for the clinical management of DCM,targeting these biomarkers.展开更多
17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body wei...17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body weight gain. This study aimed to better understand the interferences that could exist between 17β-estradiol, D2 receptors and the selection of carbohydrate, fat and protein consumption, as well as their consequences on body weight gain by using an animal model of the menopause. Ovariectomy exacerbates the consumption of foods rich in lipids. Thus confirming an inhibitory action of 17β-estradiol (E2) on the consumption of these types of foods. This consumption stimulates body weight gain, which is promoted by the high caloric content of these foods and not by the amount consumed. Our results showed a direct involvement of D2 receptors in food choice. This choice would be made according to the two (2) isoforms of the D2 receptors. The D2/BR isoform directs towards a high carbohydrate consumption, without causing a gain in body weight. While D2/SUL, promotes high fat food consumption, causing an increase in body weight. In women, 17β-estradiol modulates the activity ratio between these two D2 receptor isoforms to ensure energy and homeostatic balance, stabilizing food intake and body weight.展开更多
Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibi...Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.展开更多
Bone morphogenetic proteins (BMPs) have multiple roles in skeletal development, homeostasis and regeneration. BMPs signal via type I and type II serine/threonine kinase receptors (BMPRI and BMPRII). In recent deca...Bone morphogenetic proteins (BMPs) have multiple roles in skeletal development, homeostasis and regeneration. BMPs signal via type I and type II serine/threonine kinase receptors (BMPRI and BMPRII). In recent decades, genetic studies in humans and mice have demonstrated that perturbations in BMP signaling via BMPRI resulted in various diseases in bone, cartilage, and muscles. In this review, we focus on all three types of BMPRI, which consist of activin-like kinase 2 (ALK2, also called type IA activin receptor), activin- llke kinase 3 (ALK3, also called BMPRIA), and activin-like kinase 6 (ALK6, also called BMPRIB). The research areas covered include the current progress regarding the roles of these receptors during myogenesis, chondrogenesis, and osteogenesis. Understanding the physiological and pathological functions of these receptors at the cellular and molecular levels will advance drug development and tissue regeneration for treating musculoskeletal diseases and bone defects in the future.展开更多
Heart failure(HF), the number one cause of death in the western world, is caused by the insufficient performance of the heart leading to tissue underperfusion in response to an injury or insult. It comprises complex i...Heart failure(HF), the number one cause of death in the western world, is caused by the insufficient performance of the heart leading to tissue underperfusion in response to an injury or insult. It comprises complex interactions between important neurohormonal mechanisms that try but ultimately fail to sustain cardiac output. The most prominent such mechanism is the sympathetic(adrenergic) nervous system(SNS), whose activity and outflow are greatly elevated in HF. SNS hyperactivity confers significant toxicity to the failing heart and markedly increases HF morbidity and mortality via excessive activation of adrenergic receptors, which are G protein-coupled receptors. Thus, ligand binding induces their coupling to heterotrimeric G proteins that transduce intracellular signals. G protein signaling is turned-off by the agonist-bound receptor phosphorylation courtesy of G protein-coupled receptor kinases(GRKs), followed by βarrestin binding, which prevents the GRK-phosphorylated receptor from further interaction with the G proteins and simultaneously leads it inside the cell(receptor sequestration). Recent evidence indicates that adrenal GRK2 and βarrestins can regulate adrenal catecholamine secretion, thereby modulating SNS activity in HF. The present review gives an account of all these studies on adrenal GRKs and βarrestins in HF and discusses the exciting new therapeutic possibilities for chronic HF offered by targeting these proteins pharmacologically.展开更多
AIM: To construct fusion protein of a single-chain antibody(scFv) against transferrin receptor (TfR) with alkalinephosphatase (AP).METHODS: The VH-linker-VL, namely scFv gene, wasprepared by amplifying the VH and VL g...AIM: To construct fusion protein of a single-chain antibody(scFv) against transferrin receptor (TfR) with alkalinephosphatase (AP).METHODS: The VH-linker-VL, namely scFv gene, wasprepared by amplifying the VH and VL genes from plasmid pGEM-T-VH and pGEM-T-VL with splicing overlap extension polymerase chain reaction (SOE PCR). After the ScFv gene was modified by SfiⅠ and NotⅠ, it was subcloned into the secretory expression vector pUC19/119, and then was transformed into E. coli TG1. The positive colonies were screened by colony PCR and their expressions were induced by IPTG. ScFv gene was gained by digesting ScFv expression vector pUC19/119 with Sfi I and NotⅠ restriction enzymes, then subcloned into expression vector pDAP2, followed by transformation in E. coli TG1. The positive colonies were selected by bacterial colony PCR. The expression of fusion protein (scFv-AP) was induced by IPTG. Its activity was detected by enzyme immunoassay. The molecular weights of scFv and scFv-AP were measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).RESULTS: The product of SOE PCR formed a band of 700 bp in agarose gel electrophoresis. SDS-PAGE demonstrated the molecular weight of scFv was 27 ku. Immunofluorescent assay (IFA) demonstrated its reactivity with TfR. The molecular weight of scFv-AP was 75 ku. Enzyme immunoassay showed that scFv-AP could specifically bind to human TfR and play AP activity.CONCLUSION: We have successfully prepared the antihuman TfR scFv and constructed the fusion protein of scFv and AP. It is promising for immunological experiments.展开更多
AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP...AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP) was measured directly via catheters placed in the portal vein tract. The level of endothelin-1 (ET-1) in the mesenteric circulation was determined by radioimmunoassay, and the expression of the endothelin A receptor (ETAR) and endothelin B receptor (ETBR) was assessed by immunofluorescence and Western blot. Additionally, expression of G protein coupled kinase-2 (GRK2) and β-arrestin 2, which influence endothelin receptor sensitivity, were also studied by Western blot. RESULTS: PP of CBDL rats increased significantly (11.89 ± 1.38 mmHg vs 16.34 ± 1.63 mmHg). ET-1 expression decreased in the mesenteric circulation 2 and 4 wk after CBDL. ET-1 levels in the systemic circulation of CBDL rats were increased at 2 wk and decreased at 4 wk. There was no change in ETAR expression in response to CBDL; however, increased expression of ETBR in the endothelial cells of mesenteric arterioles and capillaries was observed. In sham-operated rats, ETBR was mainly expressed in the CD31+ endothelial cells of the arterioles. With development of PHT, in addition to the endothelial cells, ETBR expression was noticeably detectable in the SMA+ smooth muscle cells of arterioles and in the CD31+ capillaries. Following CBDL, increased expression of GRK2 was also found in mesenteric tissue, though there was no change in the level of β-arrestin 2. CONCLUSION: Decreased levels of ET-1 and increased ETBR expression in the mesenteric circulation following CBDL in rats may underlie mesenteric vasodilation in individuals with PHT. Mechanistically, increased GRK2 expression may lead to desensitization of ETAR, as well as other vasoconstrictors, promoting this vasodilatory effect.展开更多
AIM: To investigate the influence of bone morphogenetic protein type IA receptor [BMPR-IA(ALK3)] conditional knockout in lens on expression of bone morphogenetic protein 4(BMP4) in lens during the development of the v...AIM: To investigate the influence of bone morphogenetic protein type IA receptor [BMPR-IA(ALK3)] conditional knockout in lens on expression of bone morphogenetic protein 4(BMP4) in lens during the development of the vertebrate eye.METHODS: Cre-positive mice were mated with Crenegative mice to generate 50% Cre-positive(conditional knockout, CKO) 4 embryos, 8 eyes and 50% Cre-negative offspring(wild type, WT) 4 embryos, 8 eyes. The embryos were fixed in 4% paraformaldehyde, embedded in paraffin, and sectioned to a thickness of 4 μm.Removal of paraffin wax and dehydrating for sections,and then the procedure of in situ hybridization was processed, BMP4 MK1784-m(BOSTER) was used, and observed the expression of BMP4 in the lens in experimental group and control group. We selected SPSS11.0 software for statistical analysis, P【0.05 showed that the difference was statistically significant.· RESULTS: Four embryos of each genotype were examined, totally we had 8 embryos, 16 eyes. We got the uniform outcomes in all the embryos. We found ALK3 was required during lens growing, but was not essential for the formation of lens. We observed that the expression of BMP4 in the lens was significantly reduced in all 8 ALK3 CKO lens, BMP4 expression was normal in all the 8 WT lens, P 【0.01. This phenomenon became increasingly visible in accordance with embryo development. The most apparent alteration was present at stage E15.5.CONCLUSION: ALK3 is essential for lens growth. The influence of ALK3 on the expression of BMP4 is present during the development of mice lens.展开更多
Objective. To research the relations between low- density lipoprotein receptor- related protein gene (LRP) polymorphism, butyrylcholinesterase gene (BchE) polymorphism and Alzheimer’s disease (AD) in Chinese. Methods...Objective. To research the relations between low- density lipoprotein receptor- related protein gene (LRP) polymorphism, butyrylcholinesterase gene (BchE) polymorphism and Alzheimer’s disease (AD) in Chinese. Methods. The gene polymorphisms of LRP and BchE were genotyped in 38 AD cases and 40 controls with polymerase chain reaction- restriction fragment length polymorphism (PCR- RFLP) methods. AD groups were classified according to the LRP C/C genotype and compared with matched controls. Results. AD group had higher frequencies of C/C homozygote (81.6% vs 60.0% , P< 0.05) and of C allele (89.5% vs 76.3% , P< 0.05),with no significant difference between any of these LRP genotypes classified AD groups and their respective control groups. Conclusions. A positive correlation was found between LRP gene polymorphism and AD, but not between BchE gene polymorphism and AD in Chinese AD cases.展开更多
Regulation of the number of aetivin receptors that are present in the cell membrane plays a key role in the modulation of cellular responses to activin. In order to find the regulators, a novel protein ARIPzip, intera...Regulation of the number of aetivin receptors that are present in the cell membrane plays a key role in the modulation of cellular responses to activin. In order to find the regulators, a novel protein ARIPzip, interacting with activin type II receptors, was searched and identified by using yeast two-hybrid screening. ARIPzip is a splicing variant of ARIP2. This has been discussed previously. ARIPzip can specifically interact with ActR Ⅱ A, and is widely distributed in mouse tissues. Overexpression of ARIPzip can cause the activin-induced transcriptional activities to increase in a dose-dependent manner while the overexpression of ARIV2 can decrease these activities. These data suggest that the C-terminal rezions of ARIP2 and ARIPzip are involved in the regulation of activin signaling.展开更多
Protein tyrosine phosphatases(PTPs) play an important role in regulating cell signaling events in coordination with tyrosine kinases to control cell proliferation, apoptosis, survival, migration, and invasion. Recepto...Protein tyrosine phosphatases(PTPs) play an important role in regulating cell signaling events in coordination with tyrosine kinases to control cell proliferation, apoptosis, survival, migration, and invasion. Receptor-type protein tyrosine phosphatases(PTPRs) are a subgroup of PTPs that share a transmembrane domain with resulting similarities in function and target specificity. In this review, we summarize genetic and epigenetic alterations including mutation, deletion, amplification, and promoter methylation of PTPRs in cancer and consider the consequences of PTPR alterations in different types of cancers. We also summarize recent developments using PTPRs as prognostic or predictive biomarkers and/or direct targets. Increased understanding of the role of PTPRs in cancer may provide opportunities to improve therapeutic approaches.展开更多
BACKGROUND Gastric cancer(GC)has become a serious threat to people's health.Accumulative evidence reveals that dysregulation of numerous microRNAs(miRNAs)has been found during malignant formation.So far,the role o...BACKGROUND Gastric cancer(GC)has become a serious threat to people's health.Accumulative evidence reveals that dysregulation of numerous microRNAs(miRNAs)has been found during malignant formation.So far,the role of microRNA-760(miR-760)in the development of GC is largely unknown.AIM To measure the expression level of miR-760 in GC and investigate its role in gastric tumorigenesis.METHODS Real-time quantitative polymerase chain reaction and Western blot analysis were used to measure the expression of miR-760 and G-protein-coupled receptor kinase interacting protein-1(GIT1).Cell growth was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide(MTT)and cell colony formation assays.Apoptosis was assessed by flow cytometric analysis.The relationship between miR-760 and GIT1 was verified by luciferase reporter assay.RESULTS The results showed that the expression of miR-760 was decreased in GC and associated with poor clinical outcomes in GC patients.Furthermore,miR-760 restrained cell proliferation and cell colony formation and induced apoptosis in GC cells.In addition,miR-760 directly targeted GIT1 and negatively regulated its expression in GC.GIT1 was upregulated in GC and predicted a worse prognosis in GC patients.We also found that upregulation of GIT1 weakened the inhibitory CONCLUSION In conclusion,miR-760 targets GIT1 to inhibit cell growth and promote apoptosis in GC cells.Our data demonstrate that miR-760 may be a potential target for the treatment of GC.展开更多
AIM: To investigate the regulation of activin receptor-interacting protein 2 (ARIP2) expression and its possible relationships with collagen type Ⅳ (collagen Ⅳ) in mouse hepatoma cell line Hepal-6 cells. METHODS: Th...AIM: To investigate the regulation of activin receptor-interacting protein 2 (ARIP2) expression and its possible relationships with collagen type Ⅳ (collagen Ⅳ) in mouse hepatoma cell line Hepal-6 cells. METHODS: The ARIP2 mRNA expression kinetics in Hepal-6 cells was detected by RT-PCR,and its regulation factors were analyzed by treatment with signal transduction activators such as phorbol 12-myristate 13-acetate (PMA),forskolin and A23187. After pcDNA3-ARIP2 was transfected into Hepal-6 cells,the effects of ARIP2 overexpression on activin type Ⅱ receptor (ActRⅡ) and collagen Ⅳ expression were evaluated. RESULTS: The expression levels of ARIP2 mRNA in Hapel-6 cells were elevated in time-dependent manner 12 h after treatment with activin A and endotoxin LPS,but not changed evidently in the early stage of stimulation (2 or 4 h). The ARIP2 mRNA expression was increased after stimulated with signal transduction activators such as PMA and forskolin in Hepal-6 cells,whereas decreased after treatment with A23187 (25.3% ± 5.7% vs 48.1% ± 3.6%,P < 0.01). ARIP2 overexpression could remarkably suppress the expression of ActRⅡA mRNA in dose-dependent manner,but has no effect on ActRⅡB in Hepal-6 cells induced by activin A. Furthermore,we have found that overexpression of ARIP2 could inhibit collagen Ⅳ mRNA and protein expressions induced by activin A in Hapel-6 cells. CONCLUSION: These findings suggest that ARIP2 expression can be influenced by various factors. ARIP2 may participate in the negative feedback regulation of signal transduction in the late stage by affecting the expression of ActRⅡA and play an important role in regulation of development of liver fibrosis induced by activin.展开更多
AIM To validate the effects of receptor interacting protein kinase-3(RIP3) deletion in non-alcoholic fatty liver disease(NAFLD) and to clarify the mechanism of action.METHODS Wild-type(WT) and RIP3 knockout(KO) mice w...AIM To validate the effects of receptor interacting protein kinase-3(RIP3) deletion in non-alcoholic fatty liver disease(NAFLD) and to clarify the mechanism of action.METHODS Wild-type(WT) and RIP3 knockout(KO) mice werefed normal chow and high fat(HF) diets for 12 wk. The body weight was assessed once weekly. After 12 wk, the liver and serum samples were extracted. The liver tissue expression levels of RIP3, microsomal triglyceride transfer protein, protein disulfide isomerase, apolipoprotein-B, X-box binding protein-1, sterol regulatory element-binding protein-1c, fatty acid synthase, cluster of differentiation-36, diglyceride acyltransferase, peroxisome proliferator-activated receptor alpha, tumor necrosis factor-alpha(TNF-α), and interleukin-6 were assessed. Oleic acid treated primary hepatocytes from WT and RIP3 KO mice were stained with Nile red. The expression of inflammatory cytokines, including chemokine(C-X-C motif) ligand(CXCL) 1, CXCL2, and TNF-α, in monocytes was evaluated.RESULTS RIP3 KO HF diet fed mice showed a significant gain in body weight, and liver weight, liver to body weight ratio, and liver triglycerides were increased in HF diet fed RIP3 KO mice compared to HF diet fed WT mice. RIP3 KO primary hepatocytes also had increased intracellular fat droplets compared to WT primary hepatocytes after oleic acid treatment. RIP3 overexpression decreased hepatic fat content. Quantitative real-time polymerase chain reaction analysis showed that the expression of very-low-density lipoproteins secretion markers(microsomal triglyceride transfer protein, protein disulfide isomerase, and apolipoprotein-B) was significantly suppressed in RIP3 KO mice. The overall NAFLD Activity Score was the same between WT and RIP3 KO mice; however, RIP3 KO mice had increased fatty change and decreased lobular inflammation compared to WT mice. Inflammatory signals(CXCL1/2, TNF-α, and interleukin-6) increased after lipopolysaccharide and pancaspase inhibitor(necroptotic condition) treatment in monocytes. Neutrophil chemokines(CXCL1, and CXCL2) were decreased, and TNF-α was increased after RIP3 inhibitor treatment in monocytes.CONCLUSION RIP3 deletion exacerbates steatosis, and partially inhibits inflammation in the HF diet induced NAFLD model.展开更多
Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibrobl...Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibroblasts,neurons,astrocytes,macrophages,smooth muscle cells,and malignant cells.Emerging in vitro and in vivo evidence demonstrates that LRP1 is critically involved in many processes that drive tumorigenesis and tumor progression.For example,LRP1 not only promotes tumor cell migration and invasion by regulating matrix metalloproteinase(MMP)-2and MMP-9 expression and functions but also inhibits cell apoptosis by regulating the insulin receptor,the serine/threonine protein kinase signaling pathway,and the expression of Caspase-3.LRPI-mediated phosphorylation of the extracellular signal-regulated kinase pathway and c-jun N-terminal kinase are also involved in tumor cell proliferation and invasion.In addition,LRP1 has been shown to be down-regulated by microRNA-205 and methylation of LRP1CpG islands.Furthermore,a novel fusion gene,LRP1-SNRNP25,promotes osteosarcoma cell invasion and migration.Only by understanding the mechanisms of these effects can we develop novel diagnostic and therapeutic strategies for cancers mediated by LRP1.展开更多
G-protein-coupled receptor kinases (GRKs) interact with the agonist-activated form of G-protein-coupled receptor (GPCR) to affect receptor phosphorylation and to initiate profound impairment of receptor signaling, or ...G-protein-coupled receptor kinases (GRKs) interact with the agonist-activated form of G-protein-coupled receptor (GPCR) to affect receptor phosphorylation and to initiate profound impairment of receptor signaling, or desensitization. GPCR forms the largest family of cell surface receptors, and defects in GRK function have the potential consequence to affect GPCR-stimulated biological responses in many pathological situations.展开更多
Objective To investigate the association between low-density lipoprotein receptor-related protein 5 (LRPS) variants (rs12363572 and rs4930588) and type 2 diabetes mellitus (T2DM) in Han Chinese. Methods A total ...Objective To investigate the association between low-density lipoprotein receptor-related protein 5 (LRPS) variants (rs12363572 and rs4930588) and type 2 diabetes mellitus (T2DM) in Han Chinese. Methods A total of 1842 T2DM cases (507 newly diagnosed cases and 1335 previously diagnosed cases) and 7777 controls were included in this case-control study. PCR-RFLP was conducted to detect the genotype of the two single nucleotide polymorphisms (SNPs). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to describe the strength of the association by logistic regression. Results In the study subjects, neither rs12363572 nor rs4930588 was significantly associated with T2DM, even after adjusting for relevant covariates. When stratified by body mass index (BMI), the two SNPs were also not associated with T2DM. Among the 3 common haplotypes, only haplotype ~ was associated with reduced risk of T2DM (OR 0.820, 95% CI 0.732-0.919). In addition, rs12363572 was associated with BMI (P〈0.001) and rs4930588 was associated with triglyceride levels (P=0.043) in 507 newly diagnosed T2DM cases but not in healthy controls. Conclusion No LRP5 variant was found to be associated with T2DM in Han Chinese, but haplotype TT was found to be associated with T2DM.展开更多
Soluble Nogo66 receptor-Fc protein(sNgR-Fc)enhances axonal regeneration following central nervous system injury.However,the underlying mechanisms remain unclear.In this study,we investigated the effects of sNgR-Fc on ...Soluble Nogo66 receptor-Fc protein(sNgR-Fc)enhances axonal regeneration following central nervous system injury.However,the underlying mechanisms remain unclear.In this study,we investigated the effects of sNgR-Fc on the proliferation and differentiation of neural progenitor cells.The photothrombotic cortical injury model of ischemic stroke was produced in the parietal cortex of Sprague-Dawley rats.The rats with photothrombotic cortical injury were randomized to receive infusion of 400μg/kg sNgR-Fc(sNgR-Fc group)or an equal volume of phosphate-buffered saline(photothrombotic cortical injury group)into the lateral ventricle for 3 days.The effects of sNgR-Fc on the proliferation and differentiation of endogenous neural progenitor cells were examined using BrdU staining.Neurological function was evaluated with the Morris water maze test.To further examine the effects of sNgR-Fc treatment on neural progenitor cells,photothrombotic cortical injury was produced in another group of rats that received transplantation of neural progenitor cells from the hippocampus of embryonic Sprague-Dawley rats.The animals were then given an infusion of phosphate-buffered saline(neural progenitor cells group)or sNgR-Fc(sNgR-Fc+neural progenitor cells group)into the lateral ventricle for 3 days.sNgR-Fc enhanced the proliferation of cultured neural progenitor cells in vitro as well as that of endogenous neural progenitor cells in vivo,compared with phosphate-buffered saline,and it also induced the differentiation of neural progenitor cells into neurons.Compared with the photothrombotic cortical injury group,escape latency in the Morris water maze and neurological severity score were greatly reduced,and distance traveled in the target quadrant was considerably increased in the sNgR-Fc group,indicating a substantial improvement in neurological function.Furthermore,compared with phosphate-buffered saline infusion,sNgR-Fc infusion strikingly improved the survival and differentiation of grafted neural progenitor cells.Our findings show that sNgR-Fc regulates neural progenitor cell proliferation,migration and differentiation.Therefore,sNgR-Fc is a potential novel therapy for stroke and neurodegenerative diseases,The protocols were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong(approval No.4560-17)in November,2015.展开更多
基金Supported by The National Natural Science Foundation of ChinaNO.81170374 and NO.81470842 to Hua J
文摘AIM: To investigate the effect of different dietary fatty acids on hepatic inflammasome activation.METHODS: Wild-type C57BL/6 mice were fed either a high-fat diet or polyunsaturated fatty acid(PUFA)-enriched diet. Primary hepatocytes were treated with either saturated fatty acids(SFAs) or PUFAs as well as combined with lipopolysaccharide(LPS). The expression of NOD-like receptor protein 3(NLRP3) inflammasome, peroxisome proliferator-activated receptor-γ and nuclear factor-kappa B(NF-κB) was determined by real-time PCR and Western blot. The activity of Caspase-1 and interleukine-1β production were measured.RESULTS: high-fat diet-induced hepatic steatosis was sufficient to induce and activate hepatic NLRP3 inflammasome. SFA palmitic acid(PA) directly activated NLRP3 inflammasome and increased sensitization to LPS-induced inflammasome activation in hepatocytes. In contrast, PUFA docosahexaenoic acid(Dh A) had thepotential to inhibit NLRP3 inflammasome expression in hepatocytes and partly abolished LPS-induced NLRP3 inflammasome activation. Furthermore, a highfat diet increased but PUFA-enriched diet decreased sensitization to LPS-induced hepatic NLRP3 inflammasome activation in vivo. Moreover, PA increased but Dh A decreased phosphorylated NF-κB p65 protein expression in hepatocytes.CONCLUSION:Hepatic NLRP 3 inflammasome activation played an important role in the development of non-alcoholic fatty liver disease. Dietary SFAs and PUFAs oppositely regulated the activity of NLRP3 inflammasome through direct activation or inhibition of NF-κB.
基金the Scientific Innovation Foundation of Jilin University for Undergraduates(No.2007CX02)
文摘A DNA fragment encoding the intracellular part of tyrosine phosphatase RPTPα designated as RPTPα-2D gene was amplified by PCR from a human prostate cDNA library and cloned into the pT7 E. coli expression vector. The resulting plasmid pT7-RPTPα-2D was used to transform Rosetta DE3 E. coli cells. RPTPα-2D was predominately expressed in the insoluble inclusion body and was effectively purified using preparative electrophoresis gels. Polyclonal antibodies were obtained after immunization of a rabbit with purified RPTPα-2D. The antibodies displayed a high titer and sensitivity. This study thus provided a valuable tool for further researches on RPTPα.
文摘Recently,the roles of pyroptosis,a form of cell death induced by activated NODlike receptor protein 3(NLRP3)inflammasome,in the pathogenesis of diabetic cardiomyopathy(DCM)have been extensively investigated.However,most studies have focused mainly on whether diabetes increases the NLRP3 inflammasome and associated pyroptosis in the heart of type 1 or type 2 diabetic rodent models,and whether various medications and natural products prevent the development of DCM,associated with decreased levels of cardiac NLRP3 inflammasome and pyroptosis.The direct link of NLRP3 inflammasome and associated pyroptosis to the pathogenesis of DCM remains unclear based on the limited evidence derived from the available studies,with the approaches of NLRP3 gene silencing or pharmaceutical application of NLRP3 specific inhibitors.We thus emphasize the requirement for more systematic studies that are designed to provide direct evidence to support the link,given that several studies have provided both direct and indirect evidence under specific conditions.This editorial emphasizes that the current investigation should be circumspect in its conclusion,i.e.,not overemphasizing its role in the pathogenesis of DCM with the fact of only significantly increased expression or activation of NLRP3 inflammasome and pyroptosis in the heart of diabetic rodent models.Only clear-cut evidence-based causative roles of NLRP3 inflammasome and pyroptosis in the pathogenesis of DCM can help to develop effective and safe medications for the clinical management of DCM,targeting these biomarkers.
文摘17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body weight gain. This study aimed to better understand the interferences that could exist between 17β-estradiol, D2 receptors and the selection of carbohydrate, fat and protein consumption, as well as their consequences on body weight gain by using an animal model of the menopause. Ovariectomy exacerbates the consumption of foods rich in lipids. Thus confirming an inhibitory action of 17β-estradiol (E2) on the consumption of these types of foods. This consumption stimulates body weight gain, which is promoted by the high caloric content of these foods and not by the amount consumed. Our results showed a direct involvement of D2 receptors in food choice. This choice would be made according to the two (2) isoforms of the D2 receptors. The D2/BR isoform directs towards a high carbohydrate consumption, without causing a gain in body weight. While D2/SUL, promotes high fat food consumption, causing an increase in body weight. In women, 17β-estradiol modulates the activity ratio between these two D2 receptor isoforms to ensure energy and homeostatic balance, stabilizing food intake and body weight.
基金a Ph D fellowship by FCT-Fundacao para a Ciência Tecnologia (SFRH/BD/135868/2018)(to SSC)。
文摘Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.
基金supported by the National Natural Science Foundation of China (No. 81500814) (SXL)the National Natural Science Foundation of China (No. 81430012 and No. 81170939) (XJ)+2 种基金the National Basic Research Program of China (973 Program, 2012CB933604)the National Science Fund for Distinguished Young Scholars of China (No. 81225006)the National Institutes of Health Grants DE025014 and R56DE022789 (JQF)
文摘Bone morphogenetic proteins (BMPs) have multiple roles in skeletal development, homeostasis and regeneration. BMPs signal via type I and type II serine/threonine kinase receptors (BMPRI and BMPRII). In recent decades, genetic studies in humans and mice have demonstrated that perturbations in BMP signaling via BMPRI resulted in various diseases in bone, cartilage, and muscles. In this review, we focus on all three types of BMPRI, which consist of activin-like kinase 2 (ALK2, also called type IA activin receptor), activin- llke kinase 3 (ALK3, also called BMPRIA), and activin-like kinase 6 (ALK6, also called BMPRIB). The research areas covered include the current progress regarding the roles of these receptors during myogenesis, chondrogenesis, and osteogenesis. Understanding the physiological and pathological functions of these receptors at the cellular and molecular levels will advance drug development and tissue regeneration for treating musculoskeletal diseases and bone defects in the future.
文摘Heart failure(HF), the number one cause of death in the western world, is caused by the insufficient performance of the heart leading to tissue underperfusion in response to an injury or insult. It comprises complex interactions between important neurohormonal mechanisms that try but ultimately fail to sustain cardiac output. The most prominent such mechanism is the sympathetic(adrenergic) nervous system(SNS), whose activity and outflow are greatly elevated in HF. SNS hyperactivity confers significant toxicity to the failing heart and markedly increases HF morbidity and mortality via excessive activation of adrenergic receptors, which are G protein-coupled receptors. Thus, ligand binding induces their coupling to heterotrimeric G proteins that transduce intracellular signals. G protein signaling is turned-off by the agonist-bound receptor phosphorylation courtesy of G protein-coupled receptor kinases(GRKs), followed by βarrestin binding, which prevents the GRK-phosphorylated receptor from further interaction with the G proteins and simultaneously leads it inside the cell(receptor sequestration). Recent evidence indicates that adrenal GRK2 and βarrestins can regulate adrenal catecholamine secretion, thereby modulating SNS activity in HF. The present review gives an account of all these studies on adrenal GRKs and βarrestins in HF and discusses the exciting new therapeutic possibilities for chronic HF offered by targeting these proteins pharmacologically.
基金Supported by Natural Key and Basic Research Development Program,No.2002CB513109
文摘AIM: To construct fusion protein of a single-chain antibody(scFv) against transferrin receptor (TfR) with alkalinephosphatase (AP).METHODS: The VH-linker-VL, namely scFv gene, wasprepared by amplifying the VH and VL genes from plasmid pGEM-T-VH and pGEM-T-VL with splicing overlap extension polymerase chain reaction (SOE PCR). After the ScFv gene was modified by SfiⅠ and NotⅠ, it was subcloned into the secretory expression vector pUC19/119, and then was transformed into E. coli TG1. The positive colonies were screened by colony PCR and their expressions were induced by IPTG. ScFv gene was gained by digesting ScFv expression vector pUC19/119 with Sfi I and NotⅠ restriction enzymes, then subcloned into expression vector pDAP2, followed by transformation in E. coli TG1. The positive colonies were selected by bacterial colony PCR. The expression of fusion protein (scFv-AP) was induced by IPTG. Its activity was detected by enzyme immunoassay. The molecular weights of scFv and scFv-AP were measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).RESULTS: The product of SOE PCR formed a band of 700 bp in agarose gel electrophoresis. SDS-PAGE demonstrated the molecular weight of scFv was 27 ku. Immunofluorescent assay (IFA) demonstrated its reactivity with TfR. The molecular weight of scFv-AP was 75 ku. Enzyme immunoassay showed that scFv-AP could specifically bind to human TfR and play AP activity.CONCLUSION: We have successfully prepared the antihuman TfR scFv and constructed the fusion protein of scFv and AP. It is promising for immunological experiments.
基金Supported by Grant from National Key New Drug Creation Project of China, No. 2009ZX09102
文摘AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP) was measured directly via catheters placed in the portal vein tract. The level of endothelin-1 (ET-1) in the mesenteric circulation was determined by radioimmunoassay, and the expression of the endothelin A receptor (ETAR) and endothelin B receptor (ETBR) was assessed by immunofluorescence and Western blot. Additionally, expression of G protein coupled kinase-2 (GRK2) and β-arrestin 2, which influence endothelin receptor sensitivity, were also studied by Western blot. RESULTS: PP of CBDL rats increased significantly (11.89 ± 1.38 mmHg vs 16.34 ± 1.63 mmHg). ET-1 expression decreased in the mesenteric circulation 2 and 4 wk after CBDL. ET-1 levels in the systemic circulation of CBDL rats were increased at 2 wk and decreased at 4 wk. There was no change in ETAR expression in response to CBDL; however, increased expression of ETBR in the endothelial cells of mesenteric arterioles and capillaries was observed. In sham-operated rats, ETBR was mainly expressed in the CD31+ endothelial cells of the arterioles. With development of PHT, in addition to the endothelial cells, ETBR expression was noticeably detectable in the SMA+ smooth muscle cells of arterioles and in the CD31+ capillaries. Following CBDL, increased expression of GRK2 was also found in mesenteric tissue, though there was no change in the level of β-arrestin 2. CONCLUSION: Decreased levels of ET-1 and increased ETBR expression in the mesenteric circulation following CBDL in rats may underlie mesenteric vasodilation in individuals with PHT. Mechanistically, increased GRK2 expression may lead to desensitization of ETAR, as well as other vasoconstrictors, promoting this vasodilatory effect.
基金Supported by National Natural Science Foundation of China(No.30872836)Natural Science Foundation of Liaoning Province,China(No.201102054)
文摘AIM: To investigate the influence of bone morphogenetic protein type IA receptor [BMPR-IA(ALK3)] conditional knockout in lens on expression of bone morphogenetic protein 4(BMP4) in lens during the development of the vertebrate eye.METHODS: Cre-positive mice were mated with Crenegative mice to generate 50% Cre-positive(conditional knockout, CKO) 4 embryos, 8 eyes and 50% Cre-negative offspring(wild type, WT) 4 embryos, 8 eyes. The embryos were fixed in 4% paraformaldehyde, embedded in paraffin, and sectioned to a thickness of 4 μm.Removal of paraffin wax and dehydrating for sections,and then the procedure of in situ hybridization was processed, BMP4 MK1784-m(BOSTER) was used, and observed the expression of BMP4 in the lens in experimental group and control group. We selected SPSS11.0 software for statistical analysis, P【0.05 showed that the difference was statistically significant.· RESULTS: Four embryos of each genotype were examined, totally we had 8 embryos, 16 eyes. We got the uniform outcomes in all the embryos. We found ALK3 was required during lens growing, but was not essential for the formation of lens. We observed that the expression of BMP4 in the lens was significantly reduced in all 8 ALK3 CKO lens, BMP4 expression was normal in all the 8 WT lens, P 【0.01. This phenomenon became increasingly visible in accordance with embryo development. The most apparent alteration was present at stage E15.5.CONCLUSION: ALK3 is essential for lens growth. The influence of ALK3 on the expression of BMP4 is present during the development of mice lens.
文摘Objective. To research the relations between low- density lipoprotein receptor- related protein gene (LRP) polymorphism, butyrylcholinesterase gene (BchE) polymorphism and Alzheimer’s disease (AD) in Chinese. Methods. The gene polymorphisms of LRP and BchE were genotyped in 38 AD cases and 40 controls with polymerase chain reaction- restriction fragment length polymorphism (PCR- RFLP) methods. AD groups were classified according to the LRP C/C genotype and compared with matched controls. Results. AD group had higher frequencies of C/C homozygote (81.6% vs 60.0% , P< 0.05) and of C allele (89.5% vs 76.3% , P< 0.05),with no significant difference between any of these LRP genotypes classified AD groups and their respective control groups. Conclusions. A positive correlation was found between LRP gene polymorphism and AD, but not between BchE gene polymorphism and AD in Chinese AD cases.
文摘Regulation of the number of aetivin receptors that are present in the cell membrane plays a key role in the modulation of cellular responses to activin. In order to find the regulators, a novel protein ARIPzip, interacting with activin type II receptors, was searched and identified by using yeast two-hybrid screening. ARIPzip is a splicing variant of ARIP2. This has been discussed previously. ARIPzip can specifically interact with ActR Ⅱ A, and is widely distributed in mouse tissues. Overexpression of ARIPzip can cause the activin-induced transcriptional activities to increase in a dose-dependent manner while the overexpression of ARIV2 can decrease these activities. These data suggest that the C-terminal rezions of ARIP2 and ARIPzip are involved in the regulation of activin signaling.
文摘Protein tyrosine phosphatases(PTPs) play an important role in regulating cell signaling events in coordination with tyrosine kinases to control cell proliferation, apoptosis, survival, migration, and invasion. Receptor-type protein tyrosine phosphatases(PTPRs) are a subgroup of PTPs that share a transmembrane domain with resulting similarities in function and target specificity. In this review, we summarize genetic and epigenetic alterations including mutation, deletion, amplification, and promoter methylation of PTPRs in cancer and consider the consequences of PTPR alterations in different types of cancers. We also summarize recent developments using PTPRs as prognostic or predictive biomarkers and/or direct targets. Increased understanding of the role of PTPRs in cancer may provide opportunities to improve therapeutic approaches.
文摘BACKGROUND Gastric cancer(GC)has become a serious threat to people's health.Accumulative evidence reveals that dysregulation of numerous microRNAs(miRNAs)has been found during malignant formation.So far,the role of microRNA-760(miR-760)in the development of GC is largely unknown.AIM To measure the expression level of miR-760 in GC and investigate its role in gastric tumorigenesis.METHODS Real-time quantitative polymerase chain reaction and Western blot analysis were used to measure the expression of miR-760 and G-protein-coupled receptor kinase interacting protein-1(GIT1).Cell growth was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide(MTT)and cell colony formation assays.Apoptosis was assessed by flow cytometric analysis.The relationship between miR-760 and GIT1 was verified by luciferase reporter assay.RESULTS The results showed that the expression of miR-760 was decreased in GC and associated with poor clinical outcomes in GC patients.Furthermore,miR-760 restrained cell proliferation and cell colony formation and induced apoptosis in GC cells.In addition,miR-760 directly targeted GIT1 and negatively regulated its expression in GC.GIT1 was upregulated in GC and predicted a worse prognosis in GC patients.We also found that upregulation of GIT1 weakened the inhibitory CONCLUSION In conclusion,miR-760 targets GIT1 to inhibit cell growth and promote apoptosis in GC cells.Our data demonstrate that miR-760 may be a potential target for the treatment of GC.
基金Supported by the National Natural Science Foundation of China, No. 30170478 and 30571688Science Projects of Jilin Province of China, No. 20060928-01
文摘AIM: To investigate the regulation of activin receptor-interacting protein 2 (ARIP2) expression and its possible relationships with collagen type Ⅳ (collagen Ⅳ) in mouse hepatoma cell line Hepal-6 cells. METHODS: The ARIP2 mRNA expression kinetics in Hepal-6 cells was detected by RT-PCR,and its regulation factors were analyzed by treatment with signal transduction activators such as phorbol 12-myristate 13-acetate (PMA),forskolin and A23187. After pcDNA3-ARIP2 was transfected into Hepal-6 cells,the effects of ARIP2 overexpression on activin type Ⅱ receptor (ActRⅡ) and collagen Ⅳ expression were evaluated. RESULTS: The expression levels of ARIP2 mRNA in Hapel-6 cells were elevated in time-dependent manner 12 h after treatment with activin A and endotoxin LPS,but not changed evidently in the early stage of stimulation (2 or 4 h). The ARIP2 mRNA expression was increased after stimulated with signal transduction activators such as PMA and forskolin in Hepal-6 cells,whereas decreased after treatment with A23187 (25.3% ± 5.7% vs 48.1% ± 3.6%,P < 0.01). ARIP2 overexpression could remarkably suppress the expression of ActRⅡA mRNA in dose-dependent manner,but has no effect on ActRⅡB in Hepal-6 cells induced by activin A. Furthermore,we have found that overexpression of ARIP2 could inhibit collagen Ⅳ mRNA and protein expressions induced by activin A in Hapel-6 cells. CONCLUSION: These findings suggest that ARIP2 expression can be influenced by various factors. ARIP2 may participate in the negative feedback regulation of signal transduction in the late stage by affecting the expression of ActRⅡA and play an important role in regulation of development of liver fibrosis induced by activin.
基金Supported by National Research Foundation of Korea(NRF)funded by the South Korean Government,No.NRF-2017M3A9C8028794
文摘AIM To validate the effects of receptor interacting protein kinase-3(RIP3) deletion in non-alcoholic fatty liver disease(NAFLD) and to clarify the mechanism of action.METHODS Wild-type(WT) and RIP3 knockout(KO) mice werefed normal chow and high fat(HF) diets for 12 wk. The body weight was assessed once weekly. After 12 wk, the liver and serum samples were extracted. The liver tissue expression levels of RIP3, microsomal triglyceride transfer protein, protein disulfide isomerase, apolipoprotein-B, X-box binding protein-1, sterol regulatory element-binding protein-1c, fatty acid synthase, cluster of differentiation-36, diglyceride acyltransferase, peroxisome proliferator-activated receptor alpha, tumor necrosis factor-alpha(TNF-α), and interleukin-6 were assessed. Oleic acid treated primary hepatocytes from WT and RIP3 KO mice were stained with Nile red. The expression of inflammatory cytokines, including chemokine(C-X-C motif) ligand(CXCL) 1, CXCL2, and TNF-α, in monocytes was evaluated.RESULTS RIP3 KO HF diet fed mice showed a significant gain in body weight, and liver weight, liver to body weight ratio, and liver triglycerides were increased in HF diet fed RIP3 KO mice compared to HF diet fed WT mice. RIP3 KO primary hepatocytes also had increased intracellular fat droplets compared to WT primary hepatocytes after oleic acid treatment. RIP3 overexpression decreased hepatic fat content. Quantitative real-time polymerase chain reaction analysis showed that the expression of very-low-density lipoproteins secretion markers(microsomal triglyceride transfer protein, protein disulfide isomerase, and apolipoprotein-B) was significantly suppressed in RIP3 KO mice. The overall NAFLD Activity Score was the same between WT and RIP3 KO mice; however, RIP3 KO mice had increased fatty change and decreased lobular inflammation compared to WT mice. Inflammatory signals(CXCL1/2, TNF-α, and interleukin-6) increased after lipopolysaccharide and pancaspase inhibitor(necroptotic condition) treatment in monocytes. Neutrophil chemokines(CXCL1, and CXCL2) were decreased, and TNF-α was increased after RIP3 inhibitor treatment in monocytes.CONCLUSION RIP3 deletion exacerbates steatosis, and partially inhibits inflammation in the HF diet induced NAFLD model.
基金the National Natural Science Foundation of China(81372872 to J.Yang,81402215 to X.Du,and 81320108022 to K.Chen)funds from the University Cancer Foundation via the Sister Institution Network Fund at the Tianjin Medical University Cancer Institute and Hospital,Fudan University Shanghai Cancer Center,and University of Texas MD Anderson Cancer Centersupported by the program for Innovative Research Team in University in China(IRT1076 to K.Chen)
文摘Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibroblasts,neurons,astrocytes,macrophages,smooth muscle cells,and malignant cells.Emerging in vitro and in vivo evidence demonstrates that LRP1 is critically involved in many processes that drive tumorigenesis and tumor progression.For example,LRP1 not only promotes tumor cell migration and invasion by regulating matrix metalloproteinase(MMP)-2and MMP-9 expression and functions but also inhibits cell apoptosis by regulating the insulin receptor,the serine/threonine protein kinase signaling pathway,and the expression of Caspase-3.LRPI-mediated phosphorylation of the extracellular signal-regulated kinase pathway and c-jun N-terminal kinase are also involved in tumor cell proliferation and invasion.In addition,LRP1 has been shown to be down-regulated by microRNA-205 and methylation of LRP1CpG islands.Furthermore,a novel fusion gene,LRP1-SNRNP25,promotes osteosarcoma cell invasion and migration.Only by understanding the mechanisms of these effects can we develop novel diagnostic and therapeutic strategies for cancers mediated by LRP1.
基金Supported by the National Natural Science Foundation of China, No. 30300465 Scientific Research Fund of Medical College of Chinese People’s Armed Police Forces, No. WY2002-19
文摘G-protein-coupled receptor kinases (GRKs) interact with the agonist-activated form of G-protein-coupled receptor (GPCR) to affect receptor phosphorylation and to initiate profound impairment of receptor signaling, or desensitization. GPCR forms the largest family of cell surface receptors, and defects in GRK function have the potential consequence to affect GPCR-stimulated biological responses in many pathological situations.
基金supported by the National Natural Science Foundation of China(No.81072359)Natural Science Foundation of Guangdong Province(No.S2013010016791)+1 种基金Science and Technology Development Foundation of Shenzhen(No.JCYJ20120613112221107 and JCYJ20130326110246234)Natural Science Foundation of Shenzhen University(No.801-00035911)
文摘Objective To investigate the association between low-density lipoprotein receptor-related protein 5 (LRPS) variants (rs12363572 and rs4930588) and type 2 diabetes mellitus (T2DM) in Han Chinese. Methods A total of 1842 T2DM cases (507 newly diagnosed cases and 1335 previously diagnosed cases) and 7777 controls were included in this case-control study. PCR-RFLP was conducted to detect the genotype of the two single nucleotide polymorphisms (SNPs). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to describe the strength of the association by logistic regression. Results In the study subjects, neither rs12363572 nor rs4930588 was significantly associated with T2DM, even after adjusting for relevant covariates. When stratified by body mass index (BMI), the two SNPs were also not associated with T2DM. Among the 3 common haplotypes, only haplotype ~ was associated with reduced risk of T2DM (OR 0.820, 95% CI 0.732-0.919). In addition, rs12363572 was associated with BMI (P〈0.001) and rs4930588 was associated with triglyceride levels (P=0.043) in 507 newly diagnosed T2DM cases but not in healthy controls. Conclusion No LRP5 variant was found to be associated with T2DM in Han Chinese, but haplotype TT was found to be associated with T2DM.
基金supported by the National Natural Science Foundation of China,No.81671882,81471832(to XL)the Natural Science Foundation of Guangdong Province of China,No.2016A030311039(to XL)+1 种基金the Science and Technology Foundation of Guangdong Province of China,No.2015A020212012,2017A020224012(to XL)the Science and Technology Foundation of Guangzhou City of China,No.201707010373(to XL)
文摘Soluble Nogo66 receptor-Fc protein(sNgR-Fc)enhances axonal regeneration following central nervous system injury.However,the underlying mechanisms remain unclear.In this study,we investigated the effects of sNgR-Fc on the proliferation and differentiation of neural progenitor cells.The photothrombotic cortical injury model of ischemic stroke was produced in the parietal cortex of Sprague-Dawley rats.The rats with photothrombotic cortical injury were randomized to receive infusion of 400μg/kg sNgR-Fc(sNgR-Fc group)or an equal volume of phosphate-buffered saline(photothrombotic cortical injury group)into the lateral ventricle for 3 days.The effects of sNgR-Fc on the proliferation and differentiation of endogenous neural progenitor cells were examined using BrdU staining.Neurological function was evaluated with the Morris water maze test.To further examine the effects of sNgR-Fc treatment on neural progenitor cells,photothrombotic cortical injury was produced in another group of rats that received transplantation of neural progenitor cells from the hippocampus of embryonic Sprague-Dawley rats.The animals were then given an infusion of phosphate-buffered saline(neural progenitor cells group)or sNgR-Fc(sNgR-Fc+neural progenitor cells group)into the lateral ventricle for 3 days.sNgR-Fc enhanced the proliferation of cultured neural progenitor cells in vitro as well as that of endogenous neural progenitor cells in vivo,compared with phosphate-buffered saline,and it also induced the differentiation of neural progenitor cells into neurons.Compared with the photothrombotic cortical injury group,escape latency in the Morris water maze and neurological severity score were greatly reduced,and distance traveled in the target quadrant was considerably increased in the sNgR-Fc group,indicating a substantial improvement in neurological function.Furthermore,compared with phosphate-buffered saline infusion,sNgR-Fc infusion strikingly improved the survival and differentiation of grafted neural progenitor cells.Our findings show that sNgR-Fc regulates neural progenitor cell proliferation,migration and differentiation.Therefore,sNgR-Fc is a potential novel therapy for stroke and neurodegenerative diseases,The protocols were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong(approval No.4560-17)in November,2015.