Emerging roles of RNA binding proteins in intervertebral disc degeneration and osteoarthritis.

The etiology of intervertebral disc degeneration (IDD) and osteoarthritis (OA) is complex and multifactorial. Both predisposing genes and environmental factors are involved in the pathogenesis of IDD and OA. Moreover, epigenetic modifications affect the development of IDD and OA. Dysregulated phenotypes of nucleus pulposus (NP) cells and OA chondrocytes, including apoptosis, extracellular matrix disruption, inflammation, and angiogenesis, are involved at all developmental stages of IDD and OA. RNA binding proteins (RBPs) have recently been recognized as essential post-transcriptional regulators of gene expression. RBPs are implicated in many cellular processes, such as proliferation, differentiation, and apoptosis. Recently, several RBPs have been reported to be associated with the pathogenesis of IDD and OA. This review briefly summarizes the current knowledge on the RNA-regulatory networks controlled by RBPs and their potential roles in the pathogenesis of IDD and OA. These initial findings support the idea that specific modulation of RBPs represents a promising approach for managing IDD and OA.

JNK signaling is required for the MIP­1α­associated regulation of Kupffer cells in the heat stroke response.

Severe heat stroke (HS) consists of extreme hyperthermia with thermoregulatory failure, leading to high morbidity and mortality. Liver injury is a complication of HS that is associated with inflammatory responses and Kupffer cells (KCs), which are resident macrophages in the liver that serve as a major source of inflammatory cytokines; however, the association and the underlying mechanisms of KC functions in HS­induced endotoxemia and inflammation require an improved understanding. The important chemokine macrophage inflammatory protein­1α (MIP­1α) increases inflammatory responses and the secretion of inflammatory molecules from KCs, including tumor necrosis factor­α, interleukin (IL)­1ß and IL­6. In addition, the activation of c­Jun N­terminal kinase (JNK) signaling is responsible for the development of liver inflammation. Therefore, HS animal and cell models were constructed in order to investigate the pathways involved in the HS­induced dysfunction of KCs. The results of the present study suggest that JNK may be involved in the MIP­1α­associated pathogenesis of KCs in HS injury.

High-sensitivity cardiac troponin T: A biomarker for the early risk stratification of type-A acute aortic dissection?

BACKGROUND: High-sensitivity cardiac troponin is the most specific and sensitive biomarker of myocardial injury. However, no study has investigated whether the early concentration of high-sensitivity cardiac troponin is increased or is of value in predicting short-term prognosis in patients with type-A acute aortic dissection (AAD) in the emergency department. AIMS: To measure the high-sensitivity cardiac troponin T (hs-TnT) concentration in patients with type-A AAD upon hospital admission, and to assess its value in predicting short-term prognosis. METHODS: We enrolled consecutive patients with type-A AAD. Blood samples were collected on admission; hs-TnT concentrations were measured on the Elecsys 2010 system. High-sensitivity C-reactive protein (hs-CRP), D-dimer and other biochemical indicators were measured. Patients were divided into two groups according to hs-TnT concentration on admission (< or ≥0.014ng/mL). RESULTS: More than half (61.2%) of the 103 included patients had an hs-TnT concentration ≥0.014ng/mL. hs-TnT concentrations were significantly higher in those who died compared with survivors (0.292±0.516 vs. 0.069±0.154ng/mL; P=0.003). Multivariable Cox regression analysis suggested that hs-TnT is an independent factor for predicting in-hospital mortality risk (odds ratio: 2.202, 95% confidence interval: 1.111-4.367; P=0.024). Kaplan-Meier curves revealed a significant increase in hospital mortality in the hs-TnT(+) group compared with the hs-TnT(-) group (P=0.021). When hs-TnT was ≥0.042ng/mL, the sensitivity and specificity in predicting hospital short-term mortality were 70.8% and 76.4%, respectively. CONCLUSIONS: Our study suggests that hs-TnT concentration could be used as an early biomarker for the risk stratification of patients with type-A AAD in the emergency department; the relationship between hs-TnT concentration and long-term prognosis needs further investigation.

Admission hypoxia-inducible factor 1α levels and in-hospital mortality in patients with acute decompensated heart failure.

BACKGROUND: Hypoxia-inducible factor 1 (HIF-1) is a critical regulator for cellular oxygen balance. Myocardial hypoxia can induce the increased expression of HIF-1α. Our goals were to evaluate the value of HIF-1α in predicting death of patients with acute decompensated heart failure (ADHF) and describe the in vivo relationship between serum HIF-1α and N-terminal-pro-brain natriuretic peptide (NT-proBNP) levels. METHOD: We included 296 patients who were consecutively admitted to the emergency department for ADHF. The primary end point was in-hospital death. The patients were categorized as HFrEF (patients with reduced systolic function) and HFpEF (patients with preserved systolic function) groups. RESULTS: In our patients, the median admission HIF-1α level was 2.95 ± 0.85 ng/ml. The HIF-1α level was elevated significantly in HFrEF patients and deceased patients compared with HFpEF patients and patients who survived. The HIF-1α level was positively correlated with NT-proBNP and cardiac troponin T levels, and negatively correlated with left ventricular ejection fraction and systolic blood pressure. Kaplan-Meier curves revealed a significant increase in in-hospital mortality in ADHF patients with higher HIF-1α levels. Multivariable Cox regression analysis showed that HIF-1α levels were not correlated with the short-term prognosis of ADHF patients. CONCLUSIONS: This is the first study to evaluate the circulating levels of HIF-1α in ADHF patients. Serum HIF-1α levels may reflect a serious state in patients with ADHF. Due to the limitations of the study, serum HIF-1α levels were not correlated with the in-hospital mortality based on regression analysis. Further studies are needed to demonstrate the diagnostic and/or prognostic role of HIF-1α as a risk biomarker in patients with ADHF.

microRNA-23b regulates the expression of inflammatory factors in vascular endothelial cells during sepsis.

miR-23b is a multifunctional microRNA that contributes to the regulation of multiple signaling pathways. It has been reported that miR-23b prevents multiple autoimmune diseases through the regulation of inflammatory cytokine pathways. In addition, the function and underlying mechanisms of miR-23b on sepsis are currently being investigated. In the present study, miR-23b inhibitor and mimics sequences were transfected into human vascular endothelial cells to inhibit and upregulate the expression of miR-23b, respectively. In addition, respective negative control (NC) sequences were transfected. The expression of miR-23b was found to be downregulated in the cells transfected with the mimics NC or inhibitor NC sequences following stimulation with lipopolysaccharide (LPS; P<0.01); however, higher expression levels were maintained in the cells transfected with the mimics sequence and very low levels were observed in the cells transfected with the inhibitor sequence. In addition, the expression levels of nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α, interleukin (IL)-6, intercellular adhesion molecule (ICAM)-1, E-selectin and vascular cell adhesion molecule (VCAM)-1 were shown to increase following induction by LPS in the cells transfected with inhibitor/mimics NC sequences (P<0.05). However, the expression levels of these inflammatory factors decreased in the cells transfected with the mimics sequence, and increased to a greater degree in the cells transfected with the inhibitor sequence, as compared with the inhibitor NC sequences (P<0.05). Therefore, miR-23b may play a significant role in the pathogenesis and progression of sepsis by inhibiting the expression of inflammatory factors, including NF-κB, TNF-α, IL-6, ICAM-1, E-selectin and VCAM-1.

Protective effects of embelin on myocardial ischemia-reperfusion injury following cardiac arrest in a rabbit model.

Embelin has been used to treat fever and inflammatory diseases for thousands of years. Although reports indicate that embelin has antiinflammatory effects, its effects on myocardial injury following cardiac arrest (CA) have not been previously explored. In this study, we aim to investigate the protective effects of embelin on myocardial ischemia-reperfusion injury (IRI) following CA in a rabbit model. Pro-inflammatory (TNF-α, IL-1ß, and IL-6) cytokines, cardiac troponin I (cTnI), necrosis ratio, apoptotic index (AI), hemodynamics, nuclear factor-kappa B (NF-κB) p65, and histological damage have been measured or evaluated. Embelin reverts TNF-α, IL-1ß, and IL-6 to basal levels and reduces the serum level of cTnI, the necrosis ratio, the AI, and the expression of NF-κB p65. Meanwhile, it improves the hemodynamics and myocardial function. Moreover, embelin-treated groups also showed improved myocardial morphology. Our results indicate that embelin may protect the heart against myocardial IRI following CA via its antiinflammatory abilities.

Effect of atorvastatin on the expression of gamma-glutamyl transferase in aortic atherosclerotic plaques of apolipoprotein E-knockout mice.

BACKGROUND: Gamma-glutamyl transpeptidase (GGT) is now considered to be one of the risk factors for cardiovascular disease. However, whether statins can alter GGT levels in arterial atheromatous plaque has not yet been studied. Therefore, the aim of this study is to determine whether statins can effectively decrease the expression of GGT in arterial atheromatous plaques. METHODS: We randomly divided 45 apolipoprotein E-knockout (ApoE KO) male mice into three groups: normal diet (ND) group,high-cholesterol diet (HCD) group and high-cholesterol diet and atorvastatin (HCD + Ato) group. We fed high-cholesterol food to the HCD and HCD + Ato group. After eight weeks, atorvastatin 5 mg•kg-1•d-1 was given to HCD + Ato group mice. The serum GGT-1, intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell-adhesion molecule-1 (VCAM-1) levels were measured at end of 16 weeks by using ELISA methods. The expressions of GGT-1, ICAM-1 and VCAM-1 in aorta were measured by RT-PCR and Western Blot. RESULTS: The ApoE KO mice with HCD were associated with a marked increase in plasma lipid, inflammatory factors, GGT-1, ICAM-1 and VCAM-1. The expressions of GGT-1, ICAM-1 and VCAM-1 in HCD aortic tissue were increased. At the HCD + Ato group were treated with atorvastatin, the levels of lipid, GGT-1, ICAM-1 and VCAM-1 were suppressed. Meanwhile, the expressions of GGT-1, ICAM-1 and VCAM-1 were significantly decreased in the whole aorta plaques. CONCLUSIONS: The effect of statins on the expression of GGT in aorta plaque was firstly observed in animal model. The research shows that statins can significantly decrease the expression of GGT in aortic atherosclerotic plaques.

The relationship between serum hypoxia-inducible factor 1α and coronary artery calcification in asymptomatic type 2 diabetic patients.

BACKGROUND: Hypoxia-inducible factor 1 (HIF-1), a master regulator of oxygen homeostasis, is a heterodimer consisting of HIF-1α and HIF-1ß subunits, and is implicated in calcification of cartilage and vasculature. The goal of this study was to determine the relationship between serum HIF-1α with coronary artery calcification (CAC) in patients with type 2 diabetes. METHODS: The subjects were 405 (262 males, 143 females, age 51.3 ± 6.4 years) asymptomatic patients with type 2 diabetes mellitus. Serum HIF-1α and interleukin-6 (IL-6) levels were measured by ELISA. CAC scores were assessed by a 320-slice CT scanner. The subjects were divided into 4 quartiles depending on serum HIF-1α levels. RESULTS: Average serum HIF-1α was 184.4 ± 66.7 pg/ml. Among patients with higher CAC scores, HIF-1α levels were also significantly increased (p <0.001). HIF-1α levels positively correlated with CRP, IL-6, UKPDS risk score, HbA1c, FBG, and CACS, but did not correlate with diabetes duration, age, and LDL. According to the multivariate analysis, HIF-1α levels significantly and independently predict the presence of CAC. ROC curve analysis showed that the serum HIF-1α level can predict the extent of CAC, but the specificity was lower than the traditional risk factors UKPDS and HbA1c. CONCLUSION: As a marker of hypoxia, serum HIF-1α level may be an independent risk factor for the presence of CAC. These findings indicate that elevated serum HIF-1α may be involved in vascular calcification in patients with type 2 diabetes mellitus.

Protective effect of autophagy inhibition on ischemia-reperfusion-induced injury of N2a cells.

Autophagy is a conserved and programmed catabolic process that degrades damaged proteins and organelles. But the underlying mechanism and functions of autophagy in the ischemia-reperfusion (IR)-induced injury are unknown. In this study, we employed simulated IR of N2a cells as an in vitro model of IR injury to the neurons and monitored autophagic processes. It was found that the levels of Beclin-1 (a key molecule of autophay complex, Beclin-1/class III PI3K) and LC-3II (an autophagy marker) were remarkably increased with time during the process of ischemia and the process of reperfusion after 90 min of ischemia, while the protein kinases p70S6K and mTOR which are involved in autophagy regulation showed delayed inactivation after reperfusion. Administration of 3-methyladenine (3MA), an inhibitor of class III PI3K, abolished autophagy during reperfusion, while employment of rapamycin, an inhibitor of mTORC1 (normally inducing autophagy), surprisingly weakened the induction of autophagy during reperfusion. Analyses of mitochondria function by relative cell viability demonstrated that autophagy inhibition by 3-MA attenuated the decline of mitochondria function during reperfusion. Our data demonstrated that there were two distinct dynamic patterns of autophagy during IR-induced N2a injury, Beclin-1/class III PI3K complex-dependent and mTORC1-dependent. Inhibition of over-autophagy improved cell survival. These suggest that targeting autophagy therapy will be a novel strategy to control IR-induced neuronal damage.

[Effect of tanshinone IIA on the growth behavior of human hepatoma cell line BEL-7402 in vitro and its mechanism].

OBJECTIVE: To investigate the effect of tanshinone IIA on the growth behavior of human hepatoma cell line BEL-7402 in vitro and explore the mechanism. METHODS: Human hepatoma cell line BEL-7402 was exposed to tanshinoneIIA at different concentrations for 72 h, and the suppression of the cell growth was observed under inverted-phase contrast microscope. Apoptosis-related alterations in the cell morphology and biochemistry were examined under fluorescence microscope and transmission electron microscope (TEM) and by DNA agarose gel electrophoresis, and the apoptotic rate was quantified by flow cytometry (FCM). RESULTS: After treatment with 0-10 microg/ml tanshinone IIA for 72 h, the proliferation of BEL-7402 cells was significantly suppressed, and cell apoptosis occurred characterized by cell shrinkage, nuclear chromatin condensation and fragmentation, formation of membrane blebs and apoptotic bodies as observed under fluorescence microscope and TEM. DNA ladder was presented in DNA electrophoresis. FCM analysis yielded the cell apoptotic rates of (20.78+/-2.17) %, (24.64+/-2.07) %, (31.47+/-3.86) %, (43.65+/-4.04) % and (52.36+/-3.75) % at tanshinone IIA concentrations of 0.5, 1.0, 2.0, 5.0 and 10.0 microg/ml respectively, all significantly higher than those of the control group [(2.37+/-0.29)%]. CONCLUSION: Tanshinone IIA can inhibit the growth of human hepatoma BEL-7402 cells possibly through the mechanism of apoptosis induction.