Casein kinase-2 inhibition promotes retinal ganglion cell survival after acute intraocular pressure elevation

Intraocular pressure elevation can induce retinal ganglion cell death and is a clinically reversible risk factor for glaucoma,the leading cause of irreversible blindness.We previously demonstrated that casein kinase-2 inhibition can promote retinal ganglion cell survival and axonal regeneration in rats after optic nerve injury.To investigate the underlying mechanism,in the current study we increased the intraocular pressure of adult rats to 75 mmHg for 2 hours and then administered a casein kinase-2 inhibitor(4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole)by intravitreal injection.We found that intravitreal injection of 4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole promoted retinal ganglion cell survival and reduced the number of infiltrating macrophages.Transcriptomic analysis showed that the mitogen activated protein kinase signaling pathway was involved in the response to intraocular pressure elevation but was not modulated by the casein kinase-2 inhibitors.Furthermore,casein kinase-2 inhibition downregulated the expression of genes(Cck,Htrsa,Nef1,Htrlb,Prph,Chat,Slc18a3,Slc5a7,Scn1b,Crybb2,Tsga10ip,and Vstm21)involved in intraocular pressure elevation.Our data indicate that inhibition of casein kinase-2 can enhance retinal ganglion cell survival in rats after acute intraocular pressure elevation via macrophage inactivation.

Increased endothelin receptor B and G protein coupled kinase-2 in the mesentery of portal hypertensive rats

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.

Interleukin-1 receptor-associated kinase-2 is involved in IL-18-induced NF-κB activation

objective: To investigate whether interleukin-1 receptor-associated kinase-2 (IRAK-2) is involved in interleukin-18 (IL-18)-induced nuclear factor- κ B (NF-κ B) activation. Methods: Phosphorothioate oligodeoxynucleotide (ODN) was designed antisense to sequences of IRAK-2. Antisense IRAK-2 ODN was delivered by lipofectin encapsulation into cultured HepG2 cells. IRAK-2 mRNA expression was assayed by semiquantitative reverse transcription-PCR. The levels of NF- K B were measured by sandwich ELISA. Results: Antisense IRAK-2 ODN blocked IRAK -2expression. IL-18 activated NT- K B and the A value increased from a basal level of 0.115±0.004 to 2.141 ±0.038. Antisense IRAK-2 ODN inhibited IL-18-induced NT- K B activation in a dose (1-8μg )-dependent fashion. When the cells were treated with 4μg antisense IRAK-2 ODN for 8 h, a maximum inhibition of 45.4% was induced as shown by the reduction of the OD value from a control level of 2.141±0.038 down to 1.168±0.026. Conclusion: IRAK-2 can regulate IL-18-stimulated NF- K B activation.

MiRNA-145-5p inhibits gastric cancer progression via the serpin family E member 1-extracellular signal-regulated kinase-1/2 axis

BACKGROUND MicroRNAs(miRNAs)regulate gene expression and play a critical role in cancer physiology.However,there is still a limited understanding of the function and regulatory mechanism of miRNAs in gastric cancer(GC).AIM To investigate the role and molecular mechanism of miRNA-145-5p(miR145-5p)in the progression of GC.METHODS Real-time polymerase chain reaction(RT-PCR)was used to detect miRNA expression in human GC tissues and cells.The ability of cancer cells to migrate and invade was assessed using wound-healing and transwell assays,respectively.Cell proliferation was measured using cell counting kit-8 and colony formation assays,and apoptosis was evaluated using flow cytometry.Expression of the epithelial-mesenchymal transition(EMT)-associated protein was determined by Western blot.Targets of miR-145-5p were predicated using bioinformatics analysis and verified using a dual-luciferase reporter system.Serpin family E member 1(SERPINE1)expression in GC tissues and cells was evaluated using RT-PCR and immunohistochemical staining.The correlation between SERPINE1 expression and overall patient survival was determined using Kaplan-Meier plot analysis.The association between SERPINE1 and GC progression was also tested.A rescue experiment of SERPINE1 overexpression was conducted to verify the relationship between this protein and miR-145-5p.The mechanism by which miR-145-5p influences GC progression was further explored by assessing tumor formation in nude mice.RESULTS GC tissues and cells had reduced miR-145-5p expression and SERPINE1 was identified as a direct target of this miRNA.Overexpression of miR-145-5p was associated with decreased GC cell proliferation,invasion,migration,and EMT,and these effects were reversed by forcing SERPINE1 expression.Kaplan-Meier plot analysis revealed that patients with higher SERPINE1 expression had a shorter survival rate than those with lower SERPINE1 expression.Nude mouse tumorigenesis experiments confirmed that miR-145-5p targets SERPINE1 to regulate extracellular signal-regulated kinase-1/2(ERK1/2).CONCLUSION This study found that miR-145-5p inhibits tumor progression and is expressed in lower amounts in patients with GC.MiR-145-5p was found to affect GC cell proliferation,migration,and invasion by negatively regulating SERPINE1 levels and controlling the ERK1/2 pathway.

Different effects of antisense IRAK-2 oligonucleotide on IL-1 and TNF-stimulated NF-kappa B activation

Objective: To investigate the role of interleukin-1 (IL-1) receptor associated kinase-2 (IRAK-2) in IL1 and TNF-stimulated nuclear factor-kappa B (NF-kappa B ) activation. Metbods: The 293 cell was trans fectedwith antisense IRAK-2 oligonucleotide (IRAK-2 ODN) followed by stimulating the cell with IL-1 or tumor necrosis factor (TNF), and then the levels of NF-kappa B activation was analyzed by sandwich enzyme-linked immunosorbent assay (ELISA ). Result: Pre-transfecting with antisense IRAK-2 ODN could remarkably decreasethe levels of NF-kappa B activation stimulated by IL-1 in time- and concentration-dependent manner, it can not attenuate the one stimulated by TNF. Conclusion: The responses of IL-1 and TNF-stimulated NF-kappa B activation to antisense IRAK-2 oligonucleotids were different. IRAK-2 plays a key role in the IL-1 signaling events leading to NF kappa B activation.

Human ciliary muscle cell responses to kinins:Activation of ERK1/2 and pro-matrix metalloproteinases secretion

AIM To study activation of extracellular signal-regulated kinase-1/2(ERK1/2) and pro-matrix metalloproteinases(pro-MMPs) secretion from isolated primary human ciliary muscle(h-CM) cells in response to bradykinin(BK) and other agonists. METHODS Serum-starved h-CM cells were challenged with vehicle, BK agonists or antagonists. Cell lysates were evaluated for phosphorylated ERK1/2 using homogeneous timeresolved fluorescence technology based on a sandwich immunoassay. Rabbit polyclonal anti-pro-MMP antibodies were used to measure pro-MMPs using immunoblot analysis.RESULTS A 10 min incubation time using 5 × 104 h-CM cells/well was optimum condition for studying stimulation of ERK1/2 phosphorylation. BK(100 nmol/L) caused a 1.86 ± 0.26 fold(n = 3) increase in ERK1/2 phosphorylation above baseline. BK analogs, Met-Lys-BK and RMP-7(100 nmol/L), also stimulated ERK1/2 phosphorylation by 1.57 ± 0.04 and 1.55 ± 0.09 fold, respectively. However, DesArg9-Bradykinin, a B1 receptor-selective agonist(0.1-1 μmol/L), was essentially inactive. HOE-140 or WIN-64338(B2-antagonists) appreciably blocked phosphorylation of ERK1/2 induced by various BK agonists. Pre-treatmentof cells with a prostaglandin(PG) synthase inhibitor(bromfenac; 1 μmol/L) failed to alter kinin-induced ERK1/2 activation. BK and a non-peptide BK agonist(FR-190997)(10 nmol/L-1 μmol/L) also enhanced pro-MMPs secretion(pro-MMP-1 > pro-MMP-3 > pro-MMP-2; 1.45-1.75-fold over baseline) from h-CM cells. CONCLUSION These collective data suggest that B2 kinin receptors initiate signaling in h-CM cells by a relatively rapid mechanism(within minutes) involving ERK1/2 activation which in turn regulates MMPs production(within hours). The latter process does not involve PGs.

mRNA expression of DOK1-6 in human breast cancer

AIM:To examine the expression of downstream of tyrosine kinase(DOK)1-6 genes in normal and breast cancer tissue and correlated this with several clinicopathological and prognostic factors.METHODS:DOK1-6 m RNA extraction and reverse transcription were performed on fresh frozen breast cancer tissue samples(n = 112) and normal background breast tissue(n = 31). Tissues were collected between 1991 and 1996 at two centres and all patients underwent mastectomy and ipsilateral axillary node dissection. All tissues were randomly numbered and the details were only made known after all analyses were completed. Transcript levels of expression were determined using real-time polymerase chain reaction and analyzed against TNM stage, tumour grade and clinical outcome over a 10-year follow-up period.RESULTS:DOK-2 and DOK-6 expression decreased with increasing TNM stage. DOK-6 expression decreased with increasing Nottingham Prognostic Index(NPI) [NPI-1 vs NPI-3(mean copy number 15.4 vs 0.22, 95%CI:2.7-27.6, P = 0.018) and NPI-2 vs NPI-3(mean copy number 7.6 vs 0.22, 95%CI:0.1-14.6, P = 0.048)]. After a median follow up period of 10 years, higherlevels of DOK-2 expression were found among patients who remained disease-free compared to those who developed local or distant recurrence(mean copy number 3.94 vs 0.0000096, 95%CI:1.0-6.85, P = 0.0091), and distant recurrence(mean copy number 3.94 vs 0.0025, 95%CI:1.0-6.84, P = 0.0092). Patients who remained disease-free had higher levels of DOK-6 expression compared to those who died from breast cancer.CONCLUSION:Decreasing expression levels of DOK-2 and DOK-6 with increased breast tumour progression supports the notion that DOK-2 and DOK-6 behave as tumour suppressors in human breast cancer.

Modeling protein-protein interactions in axon initial segment to understand their potential impact on action potential initiation

The axon initial segment(AIS)region is crucial for action potential initiation due to the presence of high-density AIS protein voltage-gated sodium channels(Nav).Nav channels comprise several serine residues responsible for the recruitment of Nav channels into the structure of AIS through interactions with ankyrin-G(AnkG).In this study,a series of computational experiments are performed to understand the role of AIS proteins casein kinase 2 and AnkG on Nav channel recruitment into the AIS.The computational simulation results using Virtual cell software indicate that Nav channels with all serine sites available for phosphorylation bind to AnkG with strong affinity.At the low initial concentration of AnkG and casein kinase 2,the concentration of Nav channels reduces significantly,suggesting the importance of casein kinase 2 and AnkG in the recruitment of Nav channels.

The Role of SDF-1/CXCR4 Axis in Ovarian Cancer Metastasis

This study was aimed to explore the role of stromal-derived factor 1 （SDF-1）/CXC chemokine receptor 4 （CXCR4） axis in mediating the metastasis of ovarian cancer cells through activation of extracellular signal-regulated kinase-1/2 （ERK-1/2） signaling pathway. A highly metastatic ovarian cancer cell line, SKOV3, was used in the study. Intracellular calcium mobilization was detected by using laser scanning confocal fluorescence microscopy. Western blotting was used to detect the phosphorylation of ERK1/2 in SDF-1α-treated SKOV3 cells. Adhesion capability and matrix metalloproteinase （MMP） activity of ovarian cancer cells after exposure to SDF-1 a were measured by adhesion assay and gelatin zymography. The results showed that SDF-1α induced rapid intracellular calcium mobilization in SKOV3 cells, as well as the phosphorylation of ERK-1/2. The adhesion of ovarian cancer cells to fibronectin and collagen Ⅳ was increased after SDF-1α treatment. An inhibitor of ERK-1/2 signaling, PD98059, could antagonize such effects of SDF-1α. SDF-1α could also increase the secretion of active MMP-2 and MMP-9. It was concluded that the SDF-1/CXCR4 axis played a critical role in the metastasis of human ovarian cancer by increasing the adhesion capability of cancer cells and the activity of MMP-2 and MMP-9 via ERK1/2 signaling pathway.

Precision medicine in Parkinson's disease patients with LRRK2 and GBA risk variants-Let's get even more personal

Parkinson's disease(PD)is characterized by motor deficits and a wide variety of non-motor symptoms.The age of onset,rate of disease progression and the precise profile of motor and non-motor symptoms display considerable individual variation.Neuropathologically,the loss of substantia nigra dopaminergic neurons is a key feature of PD.The vast majority of PD patients exhibit alpha-synuclein aggregates in several brain regions,but there is also great variability in the neuropathology between individuals.While the dopamine replacement therapies can reduce motor symptoms,current therapies do not modify the disease progression.Numerous clinical trials using a wide variety of approaches have failed to achieve disease modification.It has been suggested that the heterogeneity of PD is a major contributing factor to the failure of disease modification trials,and that it is unlikely that a single treatment will be effective in all patients.Precision medicine,using drugs designed to target the pathophysiology in a manner that is specific to each individual with PD,has been suggested as a way forward.PD patients can be stratified according to whether they carry one of the risk variants associated with elevated PD risk.In this review we assess current clinical trials targeting two enzymes,leucine-rich repeat kinase 2(LRRK2)and glucocerebrosidase(GBA),which are encoded by two most common PD risk genes.Because the details of the pathogenic processes coupled to the different LRRK2 and GBA risk variants are not fully understood,we ask if these precision medicinebased intervention strategies will prove"precise"or"personalized"enough to modify the disease process in PD patients.We also consider at what phases of the disease that such strategies might be effective,in light of the genes being primarily associated with the risk of developing disease in the first place,and less clearly linked to the rate of disease progression.Finally,we critically evaluate the notion that therapies targeting LRRK2 and GBA might be relevant to a wider segment of PD patients,beyond those that actually carry risk variants of these genes.

Scaffold protein MAPK8IP2 expression is a robust prognostic factor in prostate cancer associated with AR signaling activity

Mitogen-activated protein kinase-8-interacting protein 2(MAPK8IP2)is a scaffold protein that modulates MAPK signal cascades.Although MAPK pathways were heavily implicated in prostate cancer progression,the regulation of MAPK8IP2 expression in prostate cancer is not yet reported.We assessed MAPK8IP2 gene expression in prostate cancer related to disease progression and patient survival outcomes.MAPK8IP2 expression was analyzed using multiple genome-wide gene expression datasets derived from The Cancer Genome Atlas(TCGA)RNA-sequence project and complementary DNA(cDNA)microarrays.Multivariable Cox regressions and log-rank tests were used to analyze the overall survival outcome and progression-free interval.MAPK8IP2 protein expression was evaluated using the immunohistochemistry approach.The quantitative PCR and Western blot methods analyzed androgen-stimulated MAPK8IP2 expression in LNCaP cells.In primary prostate cancer tissues,MAPK8IP2 mRNA expression levels were significantly higher than those in the case-matched benign prostatic tissues.Increased MAPK8IP2 expression was strongly correlated with late tumor stages,lymph node invasion,residual tumors after surgery,higher Gleason scores,and preoperational serum prostate-specific antigen(PSA)levels.MAPK8IP2 upregulation was significantly associated with worse overall survival outcomes and progression-free intervals.In castration-resistant prostate cancers,MAPK8IP2 expression strongly correlated with androgen receptor(AR)signaling activity.In cell culture-based experiments,MAPK8IP2 expression was stimulated by androgens in AR-positive prostate cancer cells.However,MAPK8IP2 expression was blocked by AR antagonists only in androgen-sensitive LNCaP but not castration-resistant C4-2B and 22RV1 cells.These results indicate that MAPK8IP2 is a robust prognostic factor and therapeutic biomarker for prostate cancer.The potential role of MAPK8IP2 in the castration-resistant progression is under further investigation.

Evodiamine Inhibits Angiotensin Ⅱ-Induced Rat Cardiomyocyte Hypertrophy

Objective: To investigate the effects of evodiamine(Evo), a component of Evodiaminedia rutaecarpa(Juss.) Benth, on cardiomyocyte hypertrophy induced by angiotensin Ⅱ(Ang Ⅱ) and further explore the potential mechanisms. Methods: Cardiomyocytes from neonatal Sprague Dawley rats were isolated and characterized, and then the cadiomyocyte cultures were randomly divided into control, model(Ang Ⅱ 0.1 μmol/L), and Evo(0.03, 0.3, 3 μmol/L) groups. The cardiomyocyte surface area, protein level, intracellular free calcium([Ca]i) concentration, activity of nitric oxide synthase(NOS) and content of nitric oxide(NO) were measured, respectively. The m RNA expressions of atrial natriuretic factor(ANF), calcineurin(CaN), extracellular signal-regulated kinase-2(ERK-2), and endothelial nitric oxide synthase(e NOS) of cardiomyocytes were analyzed by real-time reverse transcriptionpolymerase chain reaction. The protein expressions of calcineurin catalytic subunit(CnA) and mitogen-activated protein kinase phosphatase-1(MKP-1) were detected by Western blot analysis. Results: Compared with the control group, Ang Ⅱ induced cardiomyocytes hypertrophy, as evidenced by increased cardiomyocyte surface area, protein content, and ANF m RNA expression; increased intracellular free calcium([Ca]i) concentration and expressions of CaN m RNA, CnA protein, and ERK-2 m RNA, but decreased MKP-1 protein expression(P<0.05 or P<0.01). Compared with Ang Ⅱ, Evo(0.3, 3 μmol/L) significantly attenuated Ang Ⅱ-induced cardiomyocyte hypertrophy, decreased the [Ca]i concentration and expressions of CaN m RNA, CnA protein, and ERK-2 m RNA, but increased MKP-1 protein expression(P<0.05 or P<0.01). Most interestingly, Evo increased the NOS activity and NO production, and upregulated the e NOS m RNA expression(P<0.05). Conclusion: Evo significantly attenuated Ang Ⅱ-induced cardiomyocyte hypertrophy, and this effect was partly due to promotion of NO production, reduction of [Ca]i concentration, and inhibition of CaN and ERK-2 signal transduction pathways.

Growth Differentiation Factor-15 Produces Analgesia by Inhibiting Tetrodotoxin-Resistant Nav1.8 Sodium Channel Activity in Rat Primary Sensory Neurons

Growth differentiation factor 15(GDF-15)is a member of the transforming growth factor-βsuperfamily.It is widely distributed in the central and peripheral nervous systems.Whether and how GDF-15 modulates nociceptive signaling remains unclear.Behaviorally,we found that peripheral GDF-15 significantly elevated nociceptive response thresholds to mechanical and thermal stimuli in naïve and arthritic rats.Electrophysiologically,we demonstrated that GDF-15 decreased the excitability of small-diameter dorsal root ganglia(DRG)neurons.Furthermore,GDF-15 concentration-dependently suppressed tetrodotoxin-resistant sodium channel Nav1.8 currents,and shifted the steady-state inactivation curves of Nav1.8 in a hyperpolarizing direction.GDF-15 also reduced window currents and slowed down the recovery rate of Nav1.8 channels,suggesting that GDF-15 accelerated inactivation and slowed recovery of the channel.Immunohistochemistry results showed that activin receptor-like kinase-2(ALK2)was widely expressed in DRG medium-and small-diameter neurons,and some of them were Nav1.8-positive.Blockade of ALK2 prevented the GDF-15-induced inhibition of Nav1.8 currents and nociceptive behaviors.Inhibition of PKA and ERK,but not PKC,blocked the inhibitory effect of GDF-15 on Nav1.8 currents.These results suggest a functional link between GDF-15 and Nav1.8 in DRG neurons via ALK2 receptors and PKA associated with MEK/ERK,which mediate the peripheral analgesia of GDF-15.