Downregulation of G protein-coupled receptor kinase 4 protects against kidney ischemia-reperfusion injury.

Ischemia/reperfusion injury of the kidney is associated with high morbidity and mortality, and treatment of this injury remains a challenge. G protein-coupled receptor kinase 4 (GRK4) plays a vital role in essential hypertension and myocardial infarction, but its function in kidney ischemia/reperfusion injury remains undetermined. Among the GRK subtypes (GRK2-6) expressed in kidneys, the increase in GRK4 expression was much more apparent than that of the other four GRKs 24 hours after injury and was found to accumulate in the nuclei of injured mouse and human renal tubule cells. Gain- and loss-of-function experiments revealed that GRK4 overexpression exacerbated acute kidney ischemia/reperfusion injury, whereas kidney tubule-specific knockout of GRK4 decreased injury-induced kidney dysfunction. Necroptosis was the major type of tubule cell death mediated by GRK4, because GRK4 significantly increased receptor interacting kinase (RIPK)1 expression and phosphorylation, subsequently leading to RIPK3 and mixed lineage kinase domain-like protein (MLKL) phosphorylation after kidney ischemia/reperfusion injury, but was reversed by necrostatin-1 pretreatment (an RIPK1 inhibitor). Using co-immunoprecipitation, mass spectrometry, and siRNA screening studies, we identified signal transducer and activator of transcription (STAT)1 as a GRK4 binding protein, which co-localized with GRK4 in the nuclei of renal tubule cells. Additionally, GRK4 phosphorylated STAT1 at serine 727, whose inactive mutation effectively reversed GRK4-mediated RIPK1 activation and tubule cell death. Kidney-targeted GRK4 silencing with nanoparticle delivery considerably ameliorated kidney ischemia/reperfusion injury. Thus, our findings reveal that GRK4 triggers necroptosis and aggravates kidney ischemia/reperfusion injury, and its downregulation may provide a promising therapeutic strategy for kidney protection.

Exposure to maternal diabetes induces endothelial dysfunction and hypertension in adult male rat offspring.

The adverse environment in early life can modulate adult phenotype, including blood pressure. Our previous study shows, in a rat streptozotocin (STZ)-induced maternal diabetes model, fetal exposure to maternal diabetes is characterized by established hypertension in the offspring. However, the exact mechanisms are not known. Our present study found, as compared with male control mother offspring (CMO), male diabetic mother offspring (DMO) had higher blood pressure with arterial dysfunction, i.e., decreased acetylcholine (Ach)-induced vasodilation. But there is no difference in blood pressure between female CMO and DMO. The decreased Ach-induced vasodilation was related to decreased nitric oxide (NO) production in the endothelium, not NO sensitivity in vascular smooth muscle because sodium nitroprusside (SNP)-mediated vasodilation was preserved; there was decreased NO production and lower eNOS phosphorylation in male DMO. The reactive oxygen species (ROS) level was increased in male DMO than CMO; normalized ROS levels with tempol increased NO production, normalized Ach-mediated vasodilation, and lowered blood pressure in male DMO rats. It indicates that diabetic programming hypertension is related to arterial dysfunction; normalizing ROS might be a potential strategy for the prevention of hypertension in the offspring.

Role of GRK4 in the regulation of the renal ETB receptor in hypertension.

The endothelin receptor type B (ETBR) regulates water and electrolyte balance and blood pressure, in part, by inhibiting renal sodium transport. Our preliminary study found that the ETBR-mediated diuresis and natriuresis are impaired in hypertension with unknown mechanism. Persistently increased activity of G protein-coupled receptor kinase 4 (GRK4), caused by increased expression or genetic variants (eg, GRKγ142V), impairs the ability of the kidney to excrete a sodium load, in part, by impairing renal dopamine D1 receptor function through persistent phosphorylation. Our present study found that although renal ETBR expression was not different between Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHRs), renal ETBR phosphorylation was higher in SHRs. The role of hyper-phosphorylation in impaired ETBR-function was supported by results in human (h) GRK4γ transgenic mice. Stimulation of ETBR by BQ3020-induced natriuresis in human (h) GRK4γ wild-type (WT) mice. However, in hGRK4γ 142V transgenic mice, the renal ETBR was hyperphosphorylated and ETBR-mediated natriuresis and diuresis were not evident. There were co-localization and co-immunoprecipitation of ETBR and GRK4 in renal proximal tubule (RPT) cells from both WKY and SHRs but was greater in the latter than the former group. SiRNA-mediated downregulation of GRK4 expression, recovered the impaired inhibitory effect of ETBR on Na+ -K+ -ATPase activity in RPT cells from SHR. In vivo downregulation of renal GRK4 expression, via ultrasound-targeted microbubble destruction, decreased ETBR phosphorylation and restored ETBR-mediated natriuresis and diuresis in SHRs. This study provides a mechanism by which GRK4, via regulation of renal ETBR function, participates in the pathogenesis of hypertension.

Phase resetting and intermittent control at the edge of stability in a simple biped model generates 1/f-like gait cycle variability.

The 1/f-like gait cycle variability, characterized by temporal changes in stride-time intervals during steady-state human walking, is a well-documented gait characteristic. Such gait fractality is apparent in healthy young adults, but tends to disappear in the elderly and patients with neurological diseases. However, mechanisms that give rise to gait fractality have yet to be fully clarified. We aimed to provide novel insights into neuro-mechanical mechanisms of gait fractality, based on a numerical simulation model of biped walking. A previously developed heel-toe footed, seven-rigid-link biped model with human-like body parameters in the sagittal plane was implemented and expanded. It has been shown that the gait model, stabilized rigidly by means of impedance control with large values of proportional (P) and derivative (D) gains for a linear feedback controller, is destabilized only in a low-dimensional eigenspace, as P and D decrease below and even far below critical values. Such low-dimensional linear instability can be compensated by impulsive, phase-dependent actions of nonlinear controllers (phase resetting and intermittent controllers), leading to the flexible walking with joint impedance in the model being as small as that in humans. Here, we added white noise to the model to examine P-value-dependent stochastic dynamics of the model for small D-values. The simulation results demonstrated that introduction of the nonlinear controllers in the model determined the fractal features of gait for a wide range of the P-values, provided that the model operates near the edge of stability. In other words, neither the model stabilized only by pure impedance control even at the edge of linear stability, nor the model stabilized by specific nonlinear controllers, but with P-values far inside the stability region, could induce gait fractality. Although only limited types of controllers were examined, we suggest that the impulsive nonlinear controllers and criticality could be major mechanisms for the genesis of gait fractality.

Long-term low salt diet increases blood pressure by activation of the renin-angiotensin and sympathetic nervous systems.

Background The aim of this study was to investigate the effect of long-term low salt diet on blood pressure and its underlying mechanisms.Methods Male Sprague-Dawley (SD) rats were divided into normal salt diet group (0.4%) and low salt diet group (0.04%). Blood pressure was measured with the non-invasive tail-cuff method. The contractile response of isolated mesenteric arteries was measured using a small vessel myograph. The effects on renal function of the intrarenal arterial infusion of candesartan (10 µg/kg/min), an angiotensin II receptor type 1 (AT1R) antagonist, were also measured. The expressions of renal AT1R and mesenteric arterial α1A, α1B, and α1D adrenergic receptors were quantified by immunoblotting. Plasma levels of angiotensin II were also measured.Results Systolic blood pressure was significantly increased after 8 weeks of low salt diet. There were no obvious differences in the renal structure between the low and normal salt diet groups. However, the plasma angiotensin II levels and renal AT1R expression were higher in low than normal salt diet group. The intrarenal arterial infusion of candesartan increased urine flow and sodium excretion to a greater extent in the low than normal salt diet group. The expressions of α1A and α1D, but not α1B, adrenergic receptors, and phenylephrine-induced contraction were increased in mesenteric arteries from the low salt, relative to the normal salt diet group.Conclusion Activation of the renin-angiotensin and sympathetic nervous systems may be involved in the pathogenesis of long-term low salt diet-induced hypertension.

The characteristics of coronary stenosis in 11,267 patients from Southwest China: a retrospective study.

The characteristics of coronary stenosis vary among the different countries or areas. 11,267 patients who have undergone coronary angiography (CAG) from three Southwest China hospitals were investigated. Patient characteristics, coronary stenosis and stent-implant information were recorded and analyzed according to two criteria: "visible stenosis" and "≥ 50% stenosis". The patients who have undergone CAG increased year by year, with patients from 60 to 69 years-old taking the highest ratio (34.69%). Based on the "≥ 50% stenosis" criteria, the stenotic frequency was 40.54% for Southwest China patients getting CAG. Only 8.14% patients suffered ≥ 3 stenotic vessels, while 11.58 and 20.82% patients had 2 or 1 stenotic vessel, respectively. However, when using the "visible stenosis" criteria, the stenotic frequency increased to 64.68%. The prevalence of stenosis increased with age based on the "visible stenosis" criteria. There were more male patients with stenosis than female except patients over 80 years old. The stenosis affected almost all main coronary arteries and their branches, with the most affected artery being the left anterior descending artery. There were 3246 cases (28.8%) implanted with 5423 stents with a concurrent age-dependent increasing tendency for stent-implant frequency and average implanted stent number. The numbers of patients who have undergone CAG and suffered from CVD increased rapidly. In these patients, positive rate of CAG was 64.67%, which increased to 72.2% in patients over 60-years old. The incidence of ≥ 75% stenosis and multiple stenosis increased with age, however it should be noticed there were 18.93% for ≥ 75% stenosis and 19.52% for multiple stenosis in patients under 40 years old.

A New Perspective for Osteosarcoma Therapy: Proteasome Inhibition by MLN9708/2238 Successfully Induces Apoptosis and Cell Cycle Arrest and Attenuates the Invasion Ability of Osteosarcoma Cells in Vitro.

BACKGROUND: The proteasome exists in all eukaryotic cells and provides the main route of intracellular proteins degradation involved in cell growth and apoptosis. Proteasome inhibition could block protein degradation pathways and disturb regulatory networks, possibly leading to profound effects on cell growth, particularly in cancer cells. A proteasome inhibitor with an appropriate toxicity index for malignant cells rather than normal cells would be an attractive anticancer therapy. METHODS: The human osteosarcoma (OS) cell lines MG-63 and Saos-2 and normal osteoblast cells were used to study the antitumour activity of the proteasome inhibitor MLN9708/2238. RESULTS: MLN2238 inhibited cell growth, induced cell cycle arrest and apoptosis, and attenuated the invasion abilities of MG-63 and Saos-2 cells, with little cytotoxicity to normal cells. In addition, MLN2238 promoted antitumour mechanisms including the accumulation of E2F1, P53, P21 and other negative G2/M checkpoint proteins; up-regulated the relative expression ratio of BAX/BCL-2, APAF-1 and pro-apoptotic proteins of the BCL-2 family; triggered mitochondrial outer membrane permeabilization (MOMP); down-regulated BCL-2 and XIAP; activated caspase3/8/9; and suppressed MMP2/9 expression and secretion levels. CONCLUSIONS: The proteasome may be a novel biochemical target for OS treatment in vitro. Our study provides a promising mechanistic framework for MLN9708/2238 in OS treatment, supporting its clinical development.

Evaluation of platelet-rich plasma and fibrin matrix to assist in healing and repair of rotator cuff injuries: a systematic review and meta-analysis.

OBJECTIVE: To perform a meta-analysis examining the effectiveness of platelet-rich plasma and platelet-rich fibrin matrix for improving healing of rotator cuff injuries. Data sources/design: A meta-analysis of eligible studies was performed after searching Medline, Cochrane, and EMBASE on 14 December 2015. SETTING: University hospital. PARTICIPANTS: Patients with rotator cuff injuries. Review methods/intervention: Databases were searched using the keywords "PRP or platelet-rich plasma," "PRFM or platelet-rich fibrin matrix," "rotator cuff," and "platelet-rich" for studies comparing outcomes of patients with rotator cuff injuries that did and did not receive a platelet-rich product. MAIN MEASURES: The primary outcome was a functional score change from pre- to post-treatment (Scorepost-Scorepre). The secondary outcome was a visual analogue scale (VAS) pain score change from pre- to post-treatment (VASpost-VASpre). RESULTS: A total of 11 studies were included in the meta-analysis. The total number of patients that received platelet-rich plasma or platelet-rich fibrin matrix was 320 and the number of control patients was 318. The standard difference in means of the functional scores was similar between patients administered platelet-rich plasma/fibrin matrix and patients in the control group (standard difference in means for functional scores = 0.029; 95% confidence interval (CI): -0.132 to 0.190; p = 0.725). The standard difference in means was similar between patients administered platelet-rich plasma and the controls (standard difference in means = 0.142; 95% CI: -0.080 to 0.364; p = 0.209). CONCLUSION: The results of this meta-analysis do not support the use of platelet-rich plasma/platelet-rich fibrin matrix in patients with rotator cuff injuries.

MicroRNA-125b attenuates epithelial-mesenchymal transitions and targets stem-like liver cancer cells through small mothers against decapentaplegic 2 and 4.

UNLABELLED: Emerging evidence suggests that epithelial-mesenchymal transitions (EMTs) play important roles in tumor metastasis and recurrence. Understanding molecular mechanisms that regulate the EMT process is crucial for improving treatment of hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) play important roles in HCC; however, the mechanisms by which miRNAs target the EMT and their therapeutic potential remains largely unknown. To better explore the roles of miRNAs in the EMT process, we established an EMT model in HCC cells by transforming growth factor beta 1 treatment and found that several tumor-related miRNAs were significantly decreased. Among these miRNAs, miR-125b expression was most strongly suppressed. We also found down-regulation of miR-125b in most HCC cells and clinical specimens, which correlated with cellular differentiation in HCC patients. We then demonstrated that miR-125b overexpression attenuated EMT phenotype in HCC cancer cells, whereas knockdown of miR-125b promoted the EMT phenotype in vitro and in vivo. Moreover, we found that miR-125b attenuated EMT-associated traits, including chemoresistance, migration, and stemness in HCC cells, and negatively correlated with EMT and cancer stem cell (CSC) marker expressions in HCC specimens. miR-125b overexpression could inhibit CSC generation and decrease tumor incidence in the mouse xenograft model. Mechanistically, our data revealed that miR-125b suppressed EMT and EMT-associated traits of HCC cells by targeting small mothers against decapentaplegic (SMAD)2 and 4. Most important, the therapeutic delivery of synthetic miR-125b mimics decreased the target molecule of CSC and inhibited metastasis in the mice model. These findings suggest a potential therapeutic treatment of miR-125b for liver cancer. CONCLUSION: miR-125b exerts inhibitory effects on EMT and EMT-associated traits in HCC by SMAD2 and 4. Ectopic expression of miR-125b provides a promising strategy to treat HCC.

Long noncoding RNA FGFR3-AS1 promotes osteosarcoma growth through regulating its natural antisense transcript FGFR3.

Long noncoding RNAs (lncRNAs), a new class of RNAs with no protein-coding potential, have been reported to have crucial roles in the regulation of a variety of tumors. However, the functions and molecular mechanisms of lncRNAs to osteosarcoma are still largely unknown. The purpose of this study is to examine the expression, functions and molecular mechanisms of a new lncRNA FGFR3 antisense transcript 1 (FGFR3-AS1) in osteosarcoma. The expression of FGFR3-AS1 was examined by real-time quantitative PCR. The regulation of FGFR3 by FGFR3-AS1 was examined by RNase protection assay, real-time quantitative PCR, western blotting, and luciferase reporter assay. The effects of FGFR3-AS1 on osteosarcoma cell proliferation and cell cycle were determined by Cell Counting Kit-8, Ethynyl deoxyuridine incorporation assay and flow cytometry. FGFR3-AS1 was upregulated in osteosarcoma. Increased FGFR3-AS1 expression correlates with large tumor size, advanced Enneking stage, metastasis and poor survival. Through antisense pairing with FGFR3 3'UTR, FGFR3-AS1 increases FGFR3 mRNA stability and upregulates FGFR3 expression. The expression of FGFR3-AS1 and FGFR3 is positively correlated in osteosarcoma tissues. Knockdown of FGFR3-AS1 inhibits the proliferation and cell cycle progression of osteosarcoma cells in vitro. Moreover, knockdown of FGFR3-AS1 inhibits xenograft tumor growth of osteosarcoma cells in vivo. These data demonstrate the mechanisms of how antisense noncoding RNA regulate the expression of sense genes, and show the pivotal functions of FGFR3-AS1 in osteosarcoma.

APC is essential for targeting phosphorylated beta-catenin to the SCFbeta-TrCP ubiquitin ligase.

Ubiquitin-dependent proteolysis is an important mechanism that suppresses the beta-catenin transcription factor in cells without Wnt stimulation. A critical step in this regulatory pathway is to create a SCF(beta-TrCP) E3 ubiquitin ligase binding site for beta-catenin. Here we show that the SCF(beta-TrCP) binding site created by phosphorylation of beta-catenin is highly vulnerable to protein phosphatase 2A (PP2A) and must be protected by the adenomatous polyposis coli (APC) tumor suppressor protein. Specifically, phosphorylated beta-catenin associated with the wild-type APC protein is recruited to the SCF(beta-TrCP) complex, ubiquitin conjugated, and degraded. A mutation in APC that deprives this protective function exposes the N-terminal phosphorylated serine/threonine residues of beta-catenin to PP2A. Dephosphorylation at these residues by PP2A eliminates the SCF(beta-TrCP) recognition site and blocks beta-catenin ubiquitin conjugation. Thus, by acting to protect the E3 ligase binding site, APC ensures the ubiquitin conjugation of phosphorylated beta-catenin.

Hepatocellular carcinoma-associated mesenchymal stem cells promote hepatocarcinoma progression: role of the S100A4-miR155-SOCS1-MMP9 axis.

UNLABELLED: Cancer-associated mesenchymal stem cells (MSCs) play a pivotal role in modulating tumor progression. However, the interactions between liver cancer-associated MSCs (LC-MSCs) and hepatocellular carcinoma (HCC) remain unreported. Here, we identified the presence of MSCs in HCC tissues. We also showed that LC-MSCs significantly enhanced tumor growth in vivo and promoted tumor sphere formation in vitro. LC-MSCs also promoted HCC metastasis in an orthotopic liver transplantation model. Complementary DNA (cDNA) microarray analysis showed that S100A4 expression was significantly higher in LC-MSCs compared with liver normal MSCs (LN-MSCs) from adjacent cancer-free tissues. Importantly, the inhibition of S100A4 led to a reduction of proliferation and invasion of HCC cells, while exogenous S100A4 expression in HCC cells resulted in heavier tumors and more metastasis sites. Our results indicate that S100A4 secreted from LC-MSCs can promote HCC cell proliferation and invasion. We then found the expression of oncogenic microRNA (miR)-155 in HCC cells was significantly up-regulated by coculture with LC-MSCs and by S100A4 ectopic overexpression. The invasion-promoting effects of S100A4 were significantly attenuated by a miR-155 inhibitor. These results suggest that S100A4 exerts its effects through the regulation of miR-155 expression in HCC cells. We demonstrate that S100A4 secreted from LC-MSCs promotes the expression of miR-155, which mediates the down-regulation of suppressor of cytokine signaling 1, leading to the subsequent activation of STAT3 signaling. This promotes the expression of matrix metalloproteinases 9, which results in increased tumor invasiveness. CONCLUSION: S100A4 secreted from LC-MSCs is involved in the modulation of HCC progression, and may be a potential therapeutic target. (HEPATOLOGY 2013).

CYP4F2 genetic polymorphisms are associated with coronary heart disease in a Chinese population.

BACKGROUND: To explore the relationship between CYP4F2 gene polymorphism and coronary heart disease (CHD) in a Chinese Han population. METHODS: We selected 440 CHD patients and 440 control subjects to perform a case - control study. Four SNPs (rs2108622, rs3093100, rs3093105 and rs3093135) in CYP4F2 gene were genotyped using polymerase chain reaction - restriction fragment length polymorphism (PCR - RFLP) methods. The genotype and haplotype distributions were compared between the case and the control group. RESULTS: We found both rs2108622 and rs3093105 in CYP4F2 gene were associated with the risk for CHD (P <0.01). Haplotype analysis indicated that GGGT haplotype consisted by rs2108622-rs3093100-rs3093105-rs3093135 was associated with CHD risk (OR = 4.367, 95% CI: 2.241 ~ 8.510; P < 0.001), but GGTA haplotype was associated with decreased risk for CHD (OR = 0.450, 95% CI: 0.111 ~ 0.777; P <0.001). CONCLUSION: CYP4F2 gene polymorphisms were associated with the risk of CHD in Chinese population.

Relaxant effect of all-trans-retinoic acid via NO-sGC-cGMP pathway and calcium-activated potassium channels in rat mesenteric artery.

Intraperitoneal injection of all-trans-retinoic acid (ATRA) results in a reduction of blood pressure in spontaneously hypertensive rats. However, the mechanisms involved in this effect are not clear. We hypothesized that ATRA may relax resistance arteries. In this study, we found that ATRA relaxed phenylephrine-preconstricted mesenteric arterial rings, which were abrogated by the removal of the endothelium. Pretreatment of endothelium-intact arterial rings with an inhibitor of endothelial nitric oxide (NO) synthase, N(G)-nitro-l-arginine methyl ester (l-NAME), or soluble guanylyl cyclase, 1H-[1,2,4]-oxadiazole-[4,3-α]-quinoxaline-1-one, reduced the vasorelaxant effect of ATRA. Incubation of mesenteric arterial rings with ATRA increased the production of NO and cGMP, which were blocked by N(G)-nitro-l-arginine methyl ester. The vasorelaxant effect of ATRA was markedly attenuated in the presence of an inhibitor of big conductance calcium-activated potassium channels (charybdotoxin), but not with an inhibitor of voltage-dependent potassium channel (4-aminopyridine) or ATP-sensitive potassium channel (glibenclamide). Activation of retinoic acid receptors (RARs) with CH55 or retinoic X receptors (RXRs) with LGD1069 induced the vasorelaxation of phenylephrine-preconstricted mesenteric arterial rings. The RAR (BMS493) and RXR (UVI3003) antagonists blocked the ATRA-induced vasorelaxation. The vasorelaxant effect ATRA is physiologically relevant because the intravenous infusion of ATRA decreased blood pressure in normotensive rats. We conclude that ATRA relaxes resistance vessels via both RARs and RXRs receptors that are mediated by the endothelium-dependent NO-cGMP pathway, which may participate in the control of blood pressure.

Mesenchymal stem cells from primary breast cancer tissue promote cancer proliferation and enhance mammosphere formation partially via EGF/EGFR/Akt pathway.

Mesenchymal stem cells (MSCs) play a critical role in promoting cancer progression. However, it is not clear whether MSCs are located in breast cancer tissues and correlated with tumor proliferation. The aim of this study was to investigate the presence of MSCs in breast cancer tissues and evaluate their interactions with cancer cells. We successfully isolated and identified MSCs from primary breast cancer tissues. Breast cancer-associated MSCs (BC-MSCs) showed homogenous immunophenotype, and possessed tri-lineage differentiation potential (osteoblast, adipocyte, and chondrocyte). When co-transplanted with cancer cells in a xenograft model in vivo, BC-MSCs significantly increased the volume and weight of tumors. We observed that BC-MSCs stimulated mammosphere formation in the transwell co-culture system in vitro. This effect was significantly suppressed by the EGF receptor inhibitor. We verified that BC-MSCs could secrete EGF and activate cancer cell's EGF receptors. Furthermore, our data showed that EGF derived from BC-MSCs could promote mammosphere formation via the PI3K/Akt signaling pathway. Our results confirmed the presence of MSC in primary breast cancer tissues, and they could provide a favorable microenvironment for tumor cell growth in vivo, partially enhance mammosphere formation via the EGF/EGFR/Akt pathway.

Epimorphin promotes human hepatocellular carcinoma invasion and metastasis through activation of focal adhesion kinase/extracellular signal-regulated kinase/matrix metalloproteinase-9 axis.

UNLABELLED: The high incidence rate of hepatocellular carcinoma (HCC) is mainly the result of frequent metastasis and tumor recurrence. Unfortunately, the underlying molecular mechanisms driving HCC metastasis are still not fully understood. It has been demonstrated that tumor stroma cells contribute to primary tumor growth and metastasis. Within the HCC environment, activated hepatic stellate cells (HSCs) can release a number of molecules and enhance cancer cell proliferation and invasiveness in a paracrine manner. Here, for the first time, we demonstrate that epimorphin (EPM; also called syntaxin-2), an extracellular protein, is strongly elevated in activated HSCs within tumor stroma. We show that knockdown of EPM expression in HSCs substantially abolishes their effects on cancer cell invasion and metastasis. Ectopic expression of EPM in HCC cancer cells enhances their invasiveness; we demonstrate that the cells expressing EPM have markedly increased metastasis potential. Furthermore, EPM-mediated invasion and metastasis of cancer cells is found to require up-regulation of matrix metalloproteinase-9 (MMP-9) through the activation of focal adhesion kinase (FAK)/extracellular signal-regulated kinase (ERK) axis. CONCLUSION: Our results show that EPM, secreted by activated HSCs within HCC stroma, promotes invasion and metastasis of cancer cells by activating MMP-9 expression through the FAK-ERK pathway.

Stenotic coexistence among coronary, renal and extracrainal arteries in Chinese patients.

To investigate the stenotic coexistence among coronary, renal and extracranial arteries and check the predictive value of stenosis between these arteries in Chinese patients. The stenosis of three arteries was evaluated by angiography in 1,228 Chinese patients with clinically diagnosed coronary artery disease (CAD) or high CAD risk factors. Based on the criteria of stenotic diameter of ≥50%, we found that the rate of stenosis for the coronary artery was highest (48.5%), extracranial artery stenosis rate was intermediate at 20.2% and the renal artery with the stenosis rate of 14.3% was the lowest. The stenotic coexistence rates were 14.3% between the coronary and extracranial arteries, 10.9 % between coronary and renal arteries, 10.1% between the extracranial and renal arteries, and only 2.69% among all three arteries. The stenosis predictive value of the coronary artery for extracranial or renal arteries was lower, but the non-stenosis predictive value was higher. The predictive value of extracranial or renal artery for coronary artery stenosis was higher, while the non-stenosis predictive value was lower. Both the stenosis and non-stenosis predictive values were higher between the extracranial and renal arteries. Cohen's Kappa value was less than 0.40 between coronary and extracrainal or renal artery but more than 0.40 between extracranial and renal artery. The results were similar when the criteria of stenosis were judged as ≥75 or ≥25% respectively. We also did analysis within the subgroups with hypertension, diabetes, stroke and transient ischemia attach, got similar results. For Chinese patients with clinically diagnosed CAD or with highly risk factors, non-stenosis of the coronary artery is indicative of reduced stenosis of the extracranial and renal arteries, while extracranial or renal arteries stenosis is indicative of increased coronary artery stenosis.

Silencing of HMGA1 expression by RNA interference suppresses growth of osteogenic sarcoma.

The expression of high mobility group protein A1 (HMGA1) protein has been closely related to various malignant and prognostic degrees of tumor. To investigate the influence of down-regulating HMGA1 on the tumor and the mechanism underlying antitumor of HMGA1, we transfected the HMGA1 shRNA vector into the osteogenic sarcoma MG-63 cell and observed the changes of cell proliferation, invasion abilities, and the tumor growth. HMGA1 gene expression could be efficiently inhibited, and cell proliferation, migration, invasion, and matrix metalloprotease level were also decreased. BALB/C nude mice injected with the MG-63 cells transfected HMGA1 shRNA showed the significant lower tumor weight, tumor volume, and longer tumor-forming time compared with the control group. Our results suggest that knockdown of HMGA1 could inhibit growth and metastasis potentials of MG-63 cells, which may be a therapeutic target protein for osteogenic sarcoma and may be of biological importance.

Impaired stimulatory effect of ETB receptor on D3 receptor in immortalized renal proximal tubule cells of spontaneously hypertensive rats.

BACKGROUND: Activation of renal D3 receptor induces natriuresis and diuresis in Wistar-Kyoto (WKY) rats; in the presence of ETB receptor antagonist, the natriuretic effect of D3 receptor in WKY rats is reduced. We hypothesize that ETB receptor activation may regulate D3 receptor expression in renal proximal tubule (RPT) cells from WKY rats, which is impaired in RPT cells from spontaneously hypertensive rats (SHRs). METHODS: D3 receptor expression was determined by immunoblotting; the D3/ETB receptor linkage was checked by coimmunoprecipitation; Na(+)-K(+)-ATPase activity was determined as the rate of inorganic phosphate released in the presence or absence of ouabain. RESULTS: In RPT cells from WKY rats, the ETB receptor agonist BQ3020 increased D3 receptor protein. In contrast, in RPT cells from SHRs, BQ3020 did not increase D3 receptor. There was coimmunoprecipitation between D3 and ETB receptors in RPT cells from WKY and SHRs. Activation of ETB receptor increased D3/ETB coimmunoprecipitation in RPT cells from WKY rats, but not from SHRs. The basal levels of D3/ETB receptor coimmunoprecipitation were greater in RPT cells from WKY rats than in those from SHRs. Stimulation of D3 receptor inhibited Na(+)-K(+)-ATPase activity, which was augmented by the pretreatment with the ETB receptor agonist BQ3020 in WKY RPT cells, but not in SHR RPT cells. CONCLUSION: ETB receptors regulate and physically interact with D3 receptors differently in WKY rats and SHRs. The impaired natriuretic effect in SHRs may be, in part, related to impaired ETB and D3 receptor interactions.

[Effects of lipid-modulation and antiplatelet treatment on the endothelial lipase expression].

OBJECTIVE: To investigate the effects of lipid-modulation and antiplatelet treatment on the expression of endothelial lipase (EL) of patients with coronary artery disease (CAD), and investigate the role of EL in the development of CAD. METHODS: One hundred and fifty-seven cases were divided into three groups according to clinical manifestations and the results of coronary artery angiography: control group (n=41) with more than one risk factors of CAD and the vessel lesions was <30%; stable angina pectoris (SAP) group (n=55); acute coronary syndrome (ACS) group (n=61). The EL positive cell rate was measured 2 weeks after cessation of lipid-modulation and aspirin treatment, and 6 months after treatment with simvastatin and/or aspirin. The drug was ceased for the complications or not tolerance for the treatment. RESULTS: Except the patients in control group with aspirin treatment, the EL positive cell rate was significantly decreased among other groups [control group with simvastatin: (3.93±0.87)% vs. (5.28±1.05)%, SAP group: (8.16±2.11)% vs. (15.12±2.53)%, ACS group: (13.93±3.22)% vs. (38.44±4.36)%; SAP group with aspirin: (10.57±4.07)% vs. (14.66±2.29)%, ACS group: (18.28±5.14)% vs. (40.27±3.96)%; control group with aspirin and simvastatin: (3.13±0.87)% vs. (5.33±1.25)%, SAP group: (5.68±2.20)% vs. (14.89±2.15)%, ACS group: (7.81±3.96)% vs. (39.27±5.17)%, P<0.05 or P<0.01]. CONCLUSION: The treatment with lipid-modulation and/or antiplatelet drug may significantly decrease the expression of EL, implying that EL participates in the progression of CAD.