Irisin Prevents Cell Death in High Glucose via NLRP3 Inhibition.

Background: Impaired cardiac microvascular function has been implied in the pathophysiology of diabetic cardiovascular disease. However, the specific mechanism remains to be determined. Pyroptosis is a type of cell death that differs from apoptosis and autophagy. It is caused by the formation of plasma membrane pores through amino-terminal fragments of Gasdermin D (GSDMD), leading to the secretion of IL-1ß and IL-18. Recent studies have shown that irisin, a myokine cleaved by the extracellular domain of FNDC5, plays a protective role in cardiovascular diseases. Here, we investigated the potential role of pyroptosis on the cardiac microvascular endothelial cells (CMECs) injury induced by high glucose (HG) and further determined the protective effect of irisin on pyroptosis. Methods: CMECs were cultured with normal glucose (control group, 5.5 mM) and high glucose (25 mM) medium for 12, 24, and 48 h respectively. The pyroptosis of CMECs was measured by immunofluorescence staining, ELISA, and Western blot assays. Moreover, the apoptosis level was determined by flow cytometry and TUNEL staining. Results: Our results showed that HG promoted apoptosis and pyroptosis. However, irisin reversed the increased apoptosis and pyroptosis. To investigate the underlying mechanism, we overexpressed the NLRP3 protein. We found the protective effect of irisin on apoptosis and pyroptosis was abolished by NLRP3 over-expression. Conclusions: Our data suggest that irisin protects CMECs against apoptosis and pyroptosis, at least in part, by inhibiting NLRP3 inflammasome.

Irisin-pretreated BMMSCs Secrete Exosomes to Alleviate Cardiomyocytes Pyroptosis and Oxidative Stress to Hypoxia/reoxygenation Injury.

BACKGROUND: The cardiomyocytes pyroptosis and bone marrow-derived mesenchymal stem cells have been well considered as novel therapies to attenuate myocardial ischemia/reperfusion injury, however, the relationship has not yet been determined. OBJECTIVE: We aim to evaluate whether pre-treatment bone marrow-derived mesenchymal stem cells protect against myocardial ischemia/reperfusion injury by repressing cardiomyocytes pyroptosis, as well as to further elucidate the potential mechanisms. METHODS: Cardiomyocytes were treated with hypoxia, followed by reoxygenation to mimic myocardial ischemia/reperfusion injury. Pre-treatment bone marrow-derived mesenchymal stem cells or their exosomes were co-cultured with cardiomyocytes following hypoxia/reoxygenation. Cell Counting Kit-8 assay was used to determine cell viability. Reactive oxygen species production was determined by dihydroethidium stain. Enzyme-linked immunosorbent assays were used to detect IL-1ß and IL-18. RESULTS: We observed that Irisin pre-treatment bone marrow-derived mesenchymal stem cells protected cardiomyocytes against hypoxia/reoxygenation-induced injuries. The underlying molecular mechanism was further identified. Irisin-BMMSCs were found to secrete exosomes, which repressed cardiomyocytes pyroptosis and oxidative stress response by suppressing NLRP3 under hypoxia/reoxygenation conditions. CONCLUSION: Based on our findings, we revealed a promising target that exosomes derived from bone marrow-derived mesenchymal stem cells with Irisin treatment to elevate the therapeutic benefits for hypoxia/ reoxygenation injury.

FNDC5/irisin reduces ferroptosis and improves mitochondrial dysfunction in hypoxic cardiomyocytes by Nrf2/HO-1 axis.

Myocardial infarction is characterized by cardiomyocyte death and mitochondrial dysfunction induced by ischemia. Ferroptosis, a novel form of cell death, has been found to play critical roles under ischemic conditions. Recently, several studies have shown that fibronectin type III domain-containing 5 (FNDC5) and its cleaved form, irisin, protect the heart against injury. However, its protective effect on ferroptosis and mitochondrial impairments is still unclear. Thus, our aim was to investigate the role of irisin in ferroptosis and mitochondrial dysfunction in cardiomyocytes under hypoxic conditions. Cardiomyocytes were treated with FNDC5 overexpression and/or irisin under normoxic and hypoxic conditions. Cell viability was assessed by Cell Counting Kit-8 assay. Reactive oxygen species production was evaluated by dihydroethidium staining. In addition, the intracellular ferrous iron level (Fe2+ ) and the relative concentration of malondialdehyde and ATP content were determined using an Iron Assay Kit, Lipid Peroxidation Assay Kit, and ATP Bioluminescent Assay Kit. The superoxide dismutase level in cells was measured using an Enzyme-Linked Immunosorbent Assay Kit. Furthermore, an immunoblotting assay was used to determine ferroptosis-related mitochondrial proteins. Hypoxia promoted cell death, increased ferroptosis, and caused mitochondrial dysfunction in cardiomyocytes. Interestingly, FNDC5 overexpression and/or irisin administration elevated cell viability, decreased ferroptosis, and reversed mitochondrial impairments induced by hypoxia. Mechanistically, FNDC5/irisin reduced ferroptosis and reversed mitochondrial impairments by Nrf2/HO-1 axis in hypoxic cardiomyocytes. Thus, we have demonstrated that FNDC5/irisin plays a protective role in ferroptosis and mitochondrial dysfunction in hypoxia-induced cardiomyocytes.

Machine learning-based integration develops biomarkers initial the crosstalk between inflammation and immune in acute myocardial infarction patients.

Great strides have been made in past years toward revealing the pathogenesis of acute myocardial infarction (AMI). However, the prognosis did not meet satisfactory expectations. Considering the importance of early diagnosis in AMI, biomarkers with high sensitivity and accuracy are urgently needed. On the other hand, the prevalence of AMI worldwide has rapidly increased over the last few years, especially after the outbreak of COVID-19. Thus, in addition to the classical risk factors for AMI, such as overwork, agitation, overeating, cold irritation, constipation, smoking, and alcohol addiction, viral infections triggers have been considered. Immune cells play pivotal roles in the innate immunosurveillance of viral infections. So, immunotherapies might serve as a potential preventive or therapeutic approach, sparking new hope for patients with AMI. An era of artificial intelligence has led to the development of numerous machine learning algorithms. In this study, we integrated multiple machine learning algorithms for the identification of novel diagnostic biomarkers for AMI. Then, the possible association between critical genes and immune cell infiltration status was characterized for improving the diagnosis and treatment of AMI patients.

Irisin ameliorates high glucose-induced cardiomyocytes injury via AMPK/mTOR signal pathway.

High glucose (HG)-induced cardiomyocytes (CMs) injury is a leading cause of diabetic cardiomyopathy with little treatment options. Irisin, a new myokine, which is cleaved from its precursor fibronectin type III domain-containing protein 5 (FNDC5), has aroused great attention as an essential cardioprotective factor and glucose metabolism regulator but little was known on diabetic cardiomyopathy yet. Here, we aim to clarify the role of irisin in the HG-induced CMs injury. Neonatal Sprague-Dawley rat CMs were cultured in a normal or HG medium for 12, 24, and 48 hr, respectively before exposing to irisin. The apoptosis level was determined by terminal-deoxynucleotidyl transferase-mediated-dUTP nick end-labeling assay. Cell viability was measured with the conventional methyl thiazolyl tetrazolium assay. Moreover, reactive oxygen species production was evaluated by dihydroethidium staining. Inflammatory factors, namely tumor necrosis factor-α, interleukin-6, interleukin-1ß were determined by enzyme-linked immunosorbent assay kits. Furthermore, protein and messenger RNA (mRNA) expressions were measured by western blot and quantitative real-time polymerase chain reaction, respectively. HG increases the apoptosis of CMs and activated the inflammatory responses and oxidative stress in CMs. Meanwhile, the mRNA and protein expressions of FNDC5 are decreased after HG exposure. Nevertheless, the increased apoptosis is alleviated by irisin treatment. Notably, irisin suppresses the inflammatory responses and oxidative stress in injured CMs. Mechanically, after the administration of Compound C, AMP-activated protein kinase (AMPK) inhibitor, these cardioprotective effects resulting from irisin are reversed. Irisin plays a significant role in antiapoptosis, anti-inflammation, antioxidative stress in HG-induced CMs via AMPK/mammalian target of the rapamycin signaling pathway.

ß-arrestin1 inhibits hypoxic injury-induced autophagy in human pulmonary artery endothelial cells via the Akt/mTOR signaling pathway.

Autophagy has been greatly implicated in injured endothelial cells during pulmonary arterial hypertension (PAH). ß-arrestin1, a multifunctional cytoplasmic protein, has attracted considerable attention as an essential protective factor in PAH. However, its role in autophagy of injured pulmonary arterial endothelial cells (PAECs) remains to be determined. Here, we investigated the potential effects of ß-arrestin1 on autophagy and apoptosis in human PAECs (hPAECs) under hypoxic stress. Hypoxic stimuli increases autophagy and decreases the level of ß-arrestin1 in hPAECs. Furthermore, pathologic changes, namely increased proliferation, migration, and apoptosis resistance, are observed after hypoxia exposure. These are reversed after ß-arrestin1 overexpression (ß-arrestin1-OV) or treatment with 3-MA, an autophagy inhibitor. Finally, ß-arrestin1 suppresses the increase in autophagy and apoptosis resistance of hypoxic hPAECs. Mechanistically, ß-arrestin1 upregulates the activity of the Akt/mTOR signaling pathway and downregulates the expression of BNIP3 and Nix after hypoxic stress. Collectively, we have demonstrated, for the first time, that ß-arrestin1 reduces excessive autophagy and apoptosis resistance by activating the Akt/mTOR axis in hypoxic hPAECs. This knowledge suggests a promising therapeutic target for PAH.

Inositol pyrophosphates mediated the apoptosis induced by hypoxic injury in bone marrow-derived mesenchymal stem cells by autophagy.

OBJECTIVE: To investigate the potential effect of IP7 on the autophagy and apoptosis of bone marrow mesenchymal stem cells (BM-MSCs) caused by hypoxia. METHODS: BM-MSCs isolated from adult male C57BL/6 mice were exposed to normoxic condition and hypoxic stress for 6 h, 12 h, and 24 h, respectively. Then, flow cytometry detected the characteristics of BM-MSCs. Furthermore, N6-(p-nitrobenzyl) purine (TNP) was administrated to inhibit inositol pyrophosphates (IP7). TUNEL assay determined the apoptosis in BM-MSCs with hypoxia. Meanwhile, RFP-GFP-LC3 plasmid transfection and transmission microscope was used for measuring autophagy. In addition, Western blotting assay evaluated protein expressions. RESULTS: Hypoxic injury increased the autophagy and apoptosis of BM-MSCs. At the same time, hypoxic injury enhanced the production of IP7. Moreover, hypoxia decreased the activation of Akt/mTOR signaling pathway. At last, TNP (inhibitor of IP7) repressed the increased autophagy and apoptosis of BM-MSCs under hypoxia. CONCLUSION: The present study indicated that hypoxia increased autophagy and apoptosis via IP7-mediated Akt/mTOR signaling pathway of BM-MSCs. It may provide a new potential therapy target for myocardial infarction (MI).

Autophagy inhibits high glucose induced cardiac microvascular endothelial cells apoptosis by mTOR signal pathway.

Cardiac microvascular endothelial cells (CMECs) dysfunction is an important pathophysiological event in the cardiovascular complications induced by diabetes. However, the underlying mechanism is not fully clarified. Autophagy is involved in programmed cell death. Here we investigated the potential role of autophagy on the CMECs injury induced by high glucose. CMECs were cultured in normal or high glucose medium for 6, 12 and 24 h respectively. The autophagy of CMECs was measured by green fluorescence protein (GFP)-LC3 plasmid transfection. Moreover, the apoptosis of CMEC was determined by flow cytometry. Furthermore, 3-Methyladenine (3MA), ATG7 siRNA and rapamycin were administrated to regulate the autophagy state. Moreover, Western blotting assay was performed to measure the expressions of Akt, mTOR, LC3 and p62. High glucose stress decreased the autophagy, whereas increased the apoptosis in CMECs time dependently. Meanwhile, high glucose stress activated the Akt/mTOR signal pathway. Furthermore, autophagy inhibitor, 3-MA and ATG7 siRNA impaired the autophagy and increased the apoptosis in CMECs induced by high glucose stress. Conversely, rapamycin up-regulated the autophagy and decreased the apoptosis in CMECs under high glucose condition. Our data provide evidence that high glucose directly inhibits autophagy, as a beneficial adaptive response to protect CMECs against apoptosis. Furthermore, the autophagy was mediated, at least in part, by mTOR signaling.

Autophagy mediates the beneficial effect of hypoxic preconditioning on bone marrow mesenchymal stem cells for the therapy of myocardial infarction.

BACKGROUND: Stem cell therapy has emerged as a promising therapeutic strategy for myocardial infarction (MI). However, the poor viability of transplanted stem cells hampers their therapeutic efficacy. Hypoxic preconditioning (HPC) can effectively promote the survival of stem cells. The aim of this study was to investigate whether HPC improved the functional survival of bone marrow mesenchymal stem cells (BM-MSCs) and increased their cardiac protective effect. METHODS: BM-MSCs, isolated from Tg(Fluc-egfp) mice which constitutively express both firefly luciferase (Fluc) and enhanced green fluorescent protein (eGFP), were preconditioned with HPC (1% O2) for 12 h, 24 h, 36 h, and 48 h, respectively, followed by 24 h of hypoxia and serum deprivation (H/SD) injury. RESULTS: HPC dose-dependently increased the autophagy in BM-MSCs. However, the protective effects of HPC for 24 h are most pronounced. Moreover, hypoxic preconditioned BM-MSCs (HPCMSCs) and nonhypoxic preconditioned BM-MSCs (NPCMSCs) were transplanted into infarcted hearts. Longitudinal in vivo bioluminescence imaging (BLI) and immunofluorescent staining revealed that HPC enhanced the survival of engrafted BM-MSCs. Furthermore, HPCMSCs significantly reduced fibrosis, decreased apoptotic cardiomyocytes, and preserved heart function. However, the beneficial effect of HPC was abolished by autophagy inhibition with 3-methyladenine (3-MA) and Atg7siRNA. CONCLUSION: This study demonstrates that HPC may improve the functional survival and the therapeutic efficiencies of engrafted BM-MSCs, at least in part through autophagy regulation. Hypoxic preconditioning may serve as a promising strategy for optimizing cell-based cardiac regenerative therapy.

Efficacy and safety of fenofibrate as an add-on in patients with elevated triglyceride despite receiving statin treatment.

BACKGROUND: Since the withdrawal of cerivastatin, statin-fibrate combination therapy has been questioned in China due to safety concern. The objective of this study was to evaluate the efficacy and safety profile of fenofibrate as an add-on in patients with dyslipidemia despite receiving statin therapy. METHODS: This was a prospective, multi-center, single-arm, open-label study conducted in Chinese dyslipidemia patients with high CV risk. Fenofibrate (200mg daily) was added to the existing statin treatment for 8weeks. Lipid profile and safety parameters were measured and compared between baseline and after the treatment. Five hundred and six subjects were enrolled from 28 sites from 14 cities nationwide across China. RESULTS: After 8weeks of fenofibrate treatment, the mean blood triglyceride level decreased to 1.77mmol/L (38.1% reduction vs. 3.00mmol/L at the baseline; p<0.01). Mean high-density lipoprotein cholesterol (high density lipoprotein cholesterol) was increased to 1.22mmol/L (by 17.4% from 1.07mmol/L at the baseline; p<0.01). No case of severe muscle damage (defined as elevated creatine kinase over 5 times of upper limit of normal (ULN) or rhabdomyolysis was observed. CONCLUSION: In statin-treated patients with high CV risk who had elevated triglyceride, adding fenofibrate could improve lipid profile with acceptable safety profiles.

Autophagy regulates the apoptosis of bone marrow-derived mesenchymal stem cells under hypoxic condition via AMP-activated protein kinase/mammalian target of rapamycin pathway.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) have been demonstrated as an ideal autologous stem cells source for cell-based therapy for myocardial infarction (MI). However, poor viability of donor stem cells after transplantation limits their therapeutic efficiency, whereas the underlying mechanism is still poorly understood. Autophagy, a highly conserved process of cellular degradation, is required for maintaining homeostasis and normal function. Here, we investigated the potential role of autophagy on apoptosis in BM-MSCs induced by hypoxic injury. BM-MSCs, isolated from male C57BL/6 mice, were subjected to hypoxia and serum deprivation (H/SD) injury for 6, 12, and 24 h, respectively. The autophagy state was regulated by 3-methyladenine (3MA) and rapamycin administration. Furthermore, compound C was administrated to inhibit AMPK. The apoptosis induced by H/SD was determined by TUNEL assays. Meanwhile, autophagy was measured by GFP-LC3 plasmids transfection and transmission electron microscope. Moreover, protein expressions were evaluated by Western blot assay. In the present study, we found that hypoxic stress increased autophagy and apoptosis in BM-MSCs time dependently. Meanwhile, hypoxia increased the activity of AMPK/mTOR signal pathway. Moreover, increased apoptosis in BM-MSCs under hypoxia was abolished by 3-MA, whereas was aggravated by rapamycin. Furthermore, the increased autophagy and apoptosis in BM-MSCs induced by hypoxia were abolished by AMPK inhibitor compound C. These data provide evidence that hypoxia induced AMPK/mTOR signal pathway activation which regulated the apoptosis and autophagy in BM-MSCs. Furthermore, the apoptosis of BM-MSCs under hypoxic condition was regulated by autophagy via AMPK/mTOR pathway.

Short-term rosuvastatin treatment for the prevention of contrast-induced acute kidney injury in patients receiving moderate or high volumes of contrast media: a sub-analysis of the TRACK-D study.

BACKGROUND: Current randomized trials have demonstrated the effects of short-term rosuvastatin therapy in preventing contrast-induced acute kidney injury (CIAKI). However, the consistency of these effects on patients administered different volumes of contrast media is unknown. METHODS: In the TRACK-D trial, 2998 patients with type 2 diabetes and concomitant chronic kidney disease (CKD) who underwent coronary/peripheral arterial angiography with or without percutaneous intervention were randomized to short-term (2 days before and 3 days after procedure) rosuvastatin therapy or standard-of-care. This prespecified analysis compared the effects of rosuvastatin versus standard therapy in patients exposed to (moderate contrast volume [MCV], 200-300 ml, n = 712) or (high contrast volume [HCV], ≥ 300 ml, n = 220). The primary outcome was the incidence of CIAKI. The secondary outcome was a composite of death, dialysis/hemofiltration or worsened heart failure at 30 days. RESULTS: Rosuvastatin treatment was associated with a significant reduction in CIAKI compared with the controls (2.1% vs. 4.4%, P = 0.050) in the overall cohort and in patients with MCV (1.7% vs. 4.5%, P = 0.029), whereas no benefit was observed in patients with HCV (3.4% vs. 3.9%, P = 0.834). The incidence of secondary outcomes was significantly lower in the rosuvastatin group compared with control group (2.7% vs. 5.3%, P = 0.049) in the overall cohort, but it was similar between the patients with MCV (2.0% vs. 4.2%, P = 0.081) or HCV (5.1% vs. 8.8%, P = 0.273). CONCLUSIONS: Periprocedural short-term rosuvastatin treatment is effective in reducing CIAKI and adverse clinical events for patients with diabetes and CKD after their exposure to a moderate volume of contrast medium.

Nebivolol protects against myocardial infarction injury via stimulation of beta 3-adrenergic receptors and nitric oxide signaling.

Nebivolol, third-generation ß-blocker, may activate ß3-adrenergic receptor (AR), which has been emerged as a novel and potential therapeutic targets for cardiovascular diseases. However, it is not known whether nebivolol administration plays a cardioprotective effect against myocardial infarction (MI) injury. Therefore, the present study was designed to clarify the effects of nebivolol on MI injury and to elucidate the underlying mechanism. MI model was constructed by left anterior descending (LAD) artery ligation. Nebivolol, ß3-AR antagonist (SR59230A), Nitro-L-arginine methylester (L-NAME) or vehicle was administered for 4 weeks after MI operation. Cardiac function was monitored by echocardiography. Moreover, the fibrosis and the apoptosis of myocardium were assessed by Masson's trichrome stain and TUNEL assay respectively 4 weeks after MI. Nebivolol administration reduced scar area by 68% compared with MI group (p<0.05). Meanwhile, nebivolol also decreased the myocardial apoptosis and improved the heart function after MI (p<0.05 vs. MI). These effects were associated with increased ß3-AR expression. Moreover, nebivolol treatment significantly increased the phosphorylation of endothelial NOS (eNOS) and the expression of neuronal NOS (nNOS). Conversely, the cardiac protective effects of nebivolol were abolished by SR and L-NAME. These results indicate that nebivolol protects against MI injury. Furthermore, the cardioprotective effects of nebivolol may be mediated by ß3-AR-eNOS/nNOS pathway.

Efficacy of cilostazol in patients with acute coronary syndrome after percutaneous coronary intervention.

The objective of this study was to explore the long-term effect of cilostazol-optimized antiplatelet therapy after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). One hundred forty-six patients with ACS who underwent PCI were enrolled. Patients were randomly divided into 2 groups based on clot rate (CR), and both groups received antiplatelet therapy: aspirin and clopidogrel plus cilostazol (intensification group, n = 72) or aspirin and clopidogrel (control group, n = 74). Clinical follow-up was up to 12 months after PCI. During follow-up, CR was determined at day 1 and at 1, 3, 6, and 12 months post-PCI. Efficacy endpoints included second acute myocardial infarction, in-stent thrombosis, revascularization (second PCI), sudden death, and hemorrhage. CR was significantly lower in the intensification group than in the control group at 1, 3, and 6 months after PCI (P < 0.05). The incidences of second acute myocardial infarction, in-stent thrombosis, revascularization (second PCI), and sudden cardiac death were also lower but insignificant; there were no hemorrhage events (P > 0.05). Cilostazol-optimized antiplatelet therapy can significantly decrease CR after PCI in patients with acute coronary syndrome.

[Prognostic effects on percutaneous coronary intervention of different time windows in patients with acute myocardial infarction].

OBJECTIVE: To compare the prognostic effects of different time windows on initiating PCI (percutaneous coronary intervention) in AMI (acute myocardial infarction) patients. METHODS: Ninety-five AMI patients undergoing PCI were enrolled continuously from January 2007 to September 2008. According to the timing of direct PCI, the patients were divided into 3 groups: after AMI, < 6 h (Group A, n = 45), 6 - 12 h (Group B, n = 45) and 12 - 24 h (Group C, n = 35). Comparisons were made among these 3 groups in terms of the post-PCI incidence of heart failure and mortality. The left ventricular ejection fraction (LVEF) and left ventricular end-diastolic inside diameter (LVEDV) were measured by echocardiogram at Month 6. RESULTS: During the hospitalization and follow-up, Group A had a lower incidence of heart failure and mortality than Groups B and C. And Group B had a lower rate than Group C. The difference was significant (P < 0.05). Compared with LVEF(%) (52.25 ± 4.27) in Group B and LVEF (%) (47.75 ± 6.86) in Group C, LVEF(%) (57.51 ± 6.9) in Group A were significantly improved on ECG at Month 6 months. LVEDV (mm) (45.89 ± 4.23) in Group A were significantly lower than LVEDV (mm) (49.0 ± 3.1) in Group B and LVEDV (mm) (52.46 ± 4.9) in Group C. The differences were both statistically significant (P < 0.05). CONCLUSION: An early time windows of initiating PCI in AMI patients can significantly improve the left ventricular functions and reduce the incidence of heart failure, left ventricular remodeling and the mortality rate. All these measures could improve left ventricular functions and prognosis.

Association between -455G/A and fibrinogen in a Chinese population.

OBJECTIVE: The aim of the study was to evaluate the association between beta-fibrinogen gene -455G/A polymorphism and the plasma fibrinogen level in Chinese patients with different subtypes of coronary heart disease (CHD). METHODS AND RESULTS: We investigated beta-fibrinogen gene -455G/A polymorphism and plasma fibrinogen level in non-CHD control subjects (n = 466) and CHD patients (n = 1,019) including patients with stable angina pectoris (SAP) (n = 674), and acute coronary syndrome (ACS) (n = 345). Increased plasma fibrinogen levels were observed in the CHD groups compared with the control subjects (ACS: 380.92 +/- 92.35 mg/dl, SAP: 352.49 +/- 94.89 mg/dl, control: 311.72 +/- 87.09* mg/dl, *P < 0.001 vs. ACS and SAP). Individuals with the -455A/A genotype were associated with the highest plasma fibrinogen in the control subjects (P < 0.001) and patients with SAP (P < 0.001) but not in patients with ACS (P > 0.05). Allele frequency and genotype distribution were similar among the three groups (P = 0.314). CONCLUSIONS: This study demonstrated that elevated plasma fibrinogen level is related to increased CHD risk. The presence of -455A allele is significantly associated with higher fibrinogen in non-CHD control subjects and SAP patients but not in ACS patients while -455G/A polymorphism is not a risk factor for CHD in the Chinese population.