Plasminogen activator inhibitor-1 is involved in glucocorticoid-induced decreases in angiogenesis during bone repair in mice

INTRODUCTION

Glucocorticoids delay fracture healing and induce osteoporosis. Angiogenesis plays an important role in bone repair after bone injury. Plasminogen activator inhibitor-1 (PAI-1) is the principal inhibitor of plasminogen activators and an adipocytokine that regulates metabolism. However, the mechanisms by which glucocorticoids delay bone repair remain unclear.

MATERIALS AND METHODS

Therefore, we herein investigated the roles of PAI-1 and angiogenesis in glucocorticoid-induced delays in bone repair after femoral bone injury using PAI-1-deficient female mice intraperitoneally administered dexamethasone (Dex).

RESULTS

PAI-1 deficiency significantly attenuated Dex-induced decreases in the number of CD31-positive vessels at damaged sites 4 days after femoral bone injury in mice. PAI-1 deficiency also significantly ameliorated Dex-induced decreases in the number of CD31- and endomucin-positive type H vessels and CD31-positive- and endomucin-negative vessels at damaged sites 4 days after femoral bone injury. Moreover, PAI-1 deficiency significantly mitigated Dex-induced decreases in the expression of vascular endothelial growth factor as well as hypoxia inducible factor-1α, transforming growth factor-β1, and bone morphogenetic protein-2 at damaged sites 4 days after femoral bone injury.

CONCLUSION

The present results demonstrate that Dex-reduced angiogenesis at damaged sites during the early bone-repair phase after femoral bone injury partly through PAI-1 in mice.

Roles of Plasminogen Activator Inhibitor-1 in Heterotopic Ossification Induced by Achilles Tenotomy in Thermal Injured Mice

Heterotopic ossification (HO) is the process by which ectopic bone forms at an extraskeletal site. Inflammatory conditions induce plasminogen activator inhibitor 1 (PAI-1), an inhibitor of fibrinolysis, which regulates osteogenesis. In the present study, we investigated the roles of PAI-1 in the pathophysiology of HO induced by trauma/burn treatment using PAI-1-deficient mice. PAI-1 deficiency significantly promoted HO and increased the number of alkaline phosphatase (ALP)-positive cells in Achilles tendons after trauma/burn treatment. The mRNA levels of inflammation markers were elevated in Achilles tendons of both wild-type and PAI-1-deficient mice after trauma/burn treatment and PAI-1 mRNA levels were elevated in Achilles tendons of wild-type mice. PAI-1 deficiency significantly up-regulated the expression of Runx2, Osterix, and type 1 collagen in Achilles tendons 9 weeks after trauma/burn treatment in mice. In in vitro experiments, PAI-1 deficiency significantly increased ALP activity and mineralization in mouse osteoblasts. Moreover, PAI-1 deficiency significantly increased ALP activity and up-regulated osteocalcin expression during osteoblastic differentiation from mouse adipose-tissue-derived stem cells, but suppressed the chondrogenic differentiation of these cells. In conclusion, the present study showed that PAI-1 deficiency promoted HO in Achilles tendons after trauma/burn treatment partly by enhancing osteoblast differentiation and ALP activity in mice. Endogenous PAI-1 may play protective roles against HO after injury and inflammation.

Plasminogen deficiency exacerbates skeletal muscle loss during mechanical unloading in developing mice

Mechanical-unloading-induced skeletal muscle atrophy results in physical frailty and disability. Elucidating its mechanism is required to establish effective countermeasures for this muscle adaptation. First, we analyzed the proteome profile in the gastrocnemius (Gast) and soleus muscles of space-flown mice raised under microgravity or artificial 1-g for 30 days, and found that the expression levels of fibrinolysis-related proteins were significantly elevated in the mechanical-unloaded muscles. Next, we investigated the roles of the fibrinolytic system in skeletal muscle atrophy induced by mechanical unloading on the ground. Eight-week-old male mice with plasminogen gene deficiency (Plg-/-) and their wild-type littermates were divided into control and hindlimb-suspended groups and were raised for 21 days. Plasminogen deficiency significantly enhanced the decrease in muscle mass at the lower limbs of mice following hindlimb unloading, and the Gast muscle atrophy was more prominent in Plg-/- mice. In addition, plasminogen deficiency significantly increased the expression of autophagy-related markers, beclin1 mRNA and LC3B protein, in the mechanical-unloaded Gast muscles, but did not affect the increase in the gene expression of ubiquitin ligases, atrogin-1 and MuRF1. Neither plasminogen deficiency nor hindlimb unloading affected the Akt/mechanistic target of rapamycin pathway in the Gast muscles. These results suggested that plasminogen deficiency might accelerate protein breakdown via the autophagy-lysosome, but not the ubiquitin-proteasome, system in the mechanical-unloaded Gast muscles. In conclusion, we first showed that plasminogen deficiency exacerbated the Gast muscle atrophy in hindlimb-unloaded mice. Plasminogen and the fibrinolysis system might play some protective roles against muscle atrophy induced by mechanical unloading in developing mice.NEW & NOTEWORTHY The expression levels of fibrinolysis-related proteins, including plasminogen, were significantly elevated in the gastrocnemius (Gast) and soleus muscles of mice following 30-day microgravity exposure. Plasminogen deficiency exacerbated atrophy of the Gast, but not the soleus, muscles in mice following 21-day hindlimb suspension. It was also suggested that protein breakdown via the autophagy-lysosome system was accelerated in the Gast muscles. Plasminogen might play some protective roles against muscle atrophy induced by mechanical unloading in developing mice.

Targeted single-cell gene induction by optimizing the dually regulated CRE/loxP system by a newly defined heat-shock promoter and the steroid hormone in Arabidopsis thaliana

Multicellular organisms rely on intercellular communication systems to organize their cellular functions. In studies focusing on intercellular communication, the key experimental techniques include the generation of chimeric tissue using transgenic DNA recombination systems represented by the CRE/loxP system. If an experimental system enables the induction of chimeras at highly targeted cell(s), it will facilitate the reproducibility and precision of experiments. However, multiple technical limitations have made this challenging. The stochastic nature of DNA recombination events, especially, hampers reproducible generation of intended chimeric patterns. Infrared laser-evoked gene operator (IR-LEGO), a microscopic system that irradiates targeted cells using an IR laser, can induce heat shock-mediated expression of transgenes, for example, CRE recombinase gene, in the cells. In this study, we developed a method that induces CRE/loxP recombination in the target cell(s) of plant roots and leaves in a highly specific manner. We combined IR-LEGO, an improved heat-shock-specific promoter, and dexamethasone-dependent regulation of CRE. The optimal IR-laser power and irradiation duration were estimated via exhaustive irradiation trials and subsequent statistical modeling. Under optimized conditions, CRE/loxP recombination was efficiently induced without cellular damage. We also found that the induction efficiency varied among tissue types and cellular sizes. The developed method offers an experimental system to generate a precisely designed chimeric tissue, and thus, will be useful for analyzing intercellular communication at high resolution in roots and leaves.

Tumor Necrosis Factor-α Blunts the Osteogenic Effects of Muscle Cell-Derived Extracellular Vesicles by Affecting Muscle Cells

Extracellular vesicles (EVs) play crucial roles in physiological and pathophysiological processes. Although studies have described muscle-bone interactions via humoral factors, we reported that EVs from C2C12 muscle cells (Myo-EVs) suppress osteoclast formation. Current clinical evidence suggests that inflammation induces both sarcopenia and osteoporosis. Although tumor necrosis factor-α (TNF-α) is a critical proinflammatory factor, the influences of TNF-α on muscle-bone interactions and Myo-EVs are still unclear. In the present study, we investigated the effects of TNF-α stimulation of C2C12 cells on osteoclast formation and osteoblastic differentiation modulated by Myo-EVs in mouse cells. TNF-α significantly decreased the protein amount in Myo-EVs, but did not affect the Myo-EV size distribution. TNF-α treatment of C2C12 myoblasts significantly decreased the suppression of osteoclast formation induced by Myo-EVs from C2C12 myoblasts in mouse bone marrow cells. Moreover, TNF-α treatment of C2C12 myoblasts in mouse preosteoclastic Raw 264.7 cells significantly limited the Myo-EV-induced suppression of osteoclast formation and decreased the Myo-EV-induced increase in mRNA levels of osteoclast formation-related genes. On the other hand, TNF-α treatment of C2C12 muscle cells significantly decreased the degree of Myo-EV-promoted mRNA levels of Osterix and osteocalcin, as well as ALP activity in mouse mesenchymal ST-2 cells. TNF-α also significantly decreased miR196-5p level in Myo-EVs from C2C12 myoblasts in quantitative real-time PCR. In conclusion, TNF-α stimulation of C2C12 muscle cells blunts both the osteoclast formation suppression and the osteoblastic differentiation promotion that occurs due to Myo-EVs in mouse cells. Thus, TNF-α may disrupt the muscle-bone interactions by direct Myo-EV modulation.

Extracellular vesicles secreted from mouse muscle cells improve delayed bone repair in diabetic mice

Humoral factors that are secreted from skeletal muscles can regulate bone metabolism and contribute to muscle-bone relationships. Although extracellular vesicles (EVs) play important roles in physiological and pathophysiological processes, the roles of EVs that are secreted from skeletal muscles in bone repair have remained unclear. In the present study, we investigated the effects of the local administration of muscle cell-derived EVs on bone repair in control and streptozotocin-treated diabetic female mice. Muscle cell-derived EVs (Myo-EVs) were isolated from the conditioned medium from mouse muscle C2C12 cells by ultracentrifugation, after which Myo-EVs and gelatin hydrogel sheets were transplanted on femoral bone defect sites. The local administration of Myo-EVs significantly improved delayed bone repair that was induced by the diabetic state in mice 9 days after surgery. Moreover, this administration significantly enhanced the ratio of bone volume to tissue volume at the damaged sites 9 days after surgery in the control mice. Moreover, the local administration of Myo-EVs significantly blunted the number of Osterix-positive cells that were suppressed by the diabetic state at the damage sites after bone injury in mice. Additionally, Myo-EVs significantly blunted the mRNA levels of Osterix and alkaline phosphatase (ALP), and ALP activity was suppressed by advanced glycation end product 3 in ST2 cells that were treated with bone morphogenetic protein-2. In conclusion, we have shown for the first time that the local administration of Myo-EVs improves delayed bone repair that is induced by the diabetic state through an enhancement of osteoblastic differentiation in female mice.

Matrix vesicles promote bone repair after a femoral bone defect in mice

Matrix vesicles (MtVs) are one of the extracellular vesicles (EVs) secreted by osteoblasts. Although MtVs have a classically-defined function as an initiator of ossification and recent findings suggest a role for MtVs in the regulation of bone cell biology, the effects of MtVs on bone repair remain unclear. In the present study, we employed collagenase-released EVs (CREVs) containing abundant MtVs from mouse osteoblasts. CREVs were administered locally in gelatin hydrogels to damaged sites after a femoral bone defect in mice. CREVs exhibited the characteristics of MtVs with a diameter <200 nm. The local administration of CREVs significantly promoted the formation of new bone with increases in the number of alkaline phosphatase (ALP)-positive cells and cartilage formation at the damaged site after the femoral bone defect. However, the addition of CREVs to the medium did not promote the osteogenic differentiation of ST2 cells or the ALP activity or mineralization of mouse osteoblasts in vitro. In conclusion, we herein showed for the first time that MtVs enhanced bone repair after a femoral bone defect partly through osteogenesis and chondrogenesis in mice. Therefore, MtVs have potential as a tool for bone regeneration.

Clinical trajectory and outcomes of patients with heart failure with preserved ejection fraction with normal or indeterminate diastolic function

Background

Heart failure (HF) with preserved ejection fraction (HFpEF) is a chronic and progressive disease, but limited therapeutic strategies are currently available. Although left ventricular diastolic dysfunction (DD) is a prominent mechanism of HFpEF, a certain number of patients with HFpEF have a normal diastolic function (ND) or indeterminate diastolic function (ID). With the progressive nature of HFpEF, diastolic function may change over time. However, the change of diastolic function, its predictor and prognosis in patients with clinically established HFpEF remains unknown.

Purpose

To investigate the clinical trajectory and outcomes of patients with HFpEF with ND or ID and to identify factors associated with progression from ND or ID at discharge to DD at 1-year follow-up.

Methods

Using data from a prospective multicenter observational study of patients with HFpEF, we extracted 289 patients with HFpEF with ND or ID at discharge who had echocardiographic data at 1-year follow-up for the re-evaluation of diastolic function. Diastolic function was assessed according to the 2016 American Society of Echocardiography recommendations. Patients were classified according to the absence or presence of progression from ND or ID to DD at 1 year. The primary endpoint was a composite of all-cause death and HF rehospitalization.

Results

Median age was 81 years, and 138 (47.8%) patients were female. At 1 year, 107 (37%) patients progressed to DD. During a median follow-up of 709 days, the composite endpoint occurred in 90 (31.1%) patients. Compared to patients without progression to DD, those with progression to DD had a significantly higher cumulative incidence rate of the composite endpoint (incidence rate: 11.7/100 person-year versus 23.3/100 person-year, P&lt;0.001). Progression to DD (adjusted HR: 2.014, 95% CI: 1.239–3.273, P=0.005) was independently associated with the composite endpoint. Age (adjusted OR: 1.046, 95% CI: 1.008–1.087, P=0.018), body mass index (BMI) (adjusted OR: 1.107, 95% CI: 1.029–1.192, P=0.006), and serum albumin (adjusted OR: 0.459, 95% CI: 0.216–0.974, P=0.042) were independently associated with progression from ND or ID to DD at 1 year.

Conclusion

More than one-third of patients with HFpEF with ND or ID progressed to DD at 1 year and had poor clinical outcomes. Age, BMI, and serum albumin were independently associated with this progression.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by grants from Japan Society for the Promotion of Science KAKENHI (No. JP 17K09496) and Japan Agency for Medical Research and Development (No. JP16lk1010013).

Association between prognosis and the use of angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blocker in frail patients with heart failure with preserved ejection fraction

Background

The effectiveness of angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARB) has not been demonstrated in patients with heart failure with preserved ejection fraction (HFpEF). We recently reported significant interaction between the use of ACE-I and/or ARB (ACE-I/ARB) and frailty on prognosis in patients with HFpEF.

Purpose

In the present study, we examined the association between ACE-I/ARB and prognosis in patients with HFpEF stratified by the presence or absence of frailty.

Methods

We examined the association between the use of ACE-I/ARB and prognosis according to the presence (Clinical Frailty Scale (CFS) ≥5) or absence (CFS ≤4) of frailty in patients with HFpEF in a post-hoc analysis of registry data. Primary endpoint was the composite of all-cause mortality and heart failure admission. Secondary endpoints were all-cause mortality and heart failure admission.

Results

Of 1059 patients, median age was 83 years and 45% were male. Kaplan-Meier analysis showed that the risk of composite endpoint (log-rank P=0.001) and all-cause death (log-rank P=0.005) in patients with ACE-I/ARB was lower in those with CFS ≥5, but similar between patients with and without ACE-I/ARB in patients with CFS ≤4 (composite endpoint: log-rank P=0.830; all-cause death: log-rank P=0.192). In a multivariable Cox proportional hazards model, use of ACE-I/ARB was significantly associated with lower risk of the composite endpoint (hazard ratio = 0.52, 95% CI: 0.33–0.83, P=0.005) and heart failure admission (hazard ratio = 0.45, 95% CI: 0.25–0.83, P=0.010) in patients with CFS ≥5, but not in patients with CFS ≤4 (composite endpoint: hazard ratio = 1.41, 95% CI: 0.99–2.02, P=0.059; heart failure admission: hazard ratio = 1.43, 95% CI: 0.94–2.18, P=0.091). The association between ACE-I or ARB and prognosis did not significantly differ by CFS (CFS ≤4: log-rank P=0.562; CFS ≥5: log-rank P=0.100, for with ACE-I vs. ARB, respectively). Adjusted HRs for CFS 1–4 were higher than 1.0, but were less than 1.0 at CFS 5.

Conclusions

In patients with HFpEF, use of ACE-I/ARB was associated with better prognosis in patients with frailty as assessed with the CFS, but not in those without frailty.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Roche

Premature atrial contraction on Holter electrocardiogram predicts the recurrence of atrial fibrillation after catheter ablation

Introduction

It is important to detect the recurrence of atrial fibrillation (AF) after catheter ablation (CA) early, but the method of detection has not been established. The purpose of this study is to determine whether 24-h Holter electrocardiogram (ECG) can predict the recurrence of AF after CA.

Methods

We studied 336 patients of 497 patients enrolled in EARNEST-PVI trial to investigate whether the total number of premature atrial contraction (PAC) and the maximum number of PAC run by 24-h Holter ECG at 6 months after CA predicted AF recurrence after 6 months. We excluded 86 patients with recurrence by 6 months after CA and 75 patients without Holter ECG at 6 months after CA.

Results

Median age was 66 years, male were 77% and median follow-up period was 1138 days. Receiver operating characteristic curve analysis identified the total number of PAC ≥270 beats and the maximum number of PAC run ≥8 beats as the optimal cutoff for prediction of AF recurrence. Kaplan-Meier analysis showed patients with the total number of PAC ≥270 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 34% vs. 17%, Log-rank P=0.001) and patients with the maximum number of PAC run ≥8 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 33% vs. 20%, Log-rank P=0.006). Multivariate analysis revealed that the total number of PAC ≥270 beats and the maximum number of PAC run were significantly associated with AF recurrence (hazard ratio [95% confidence interval] 1.83 [1.16–2.91], P=0.01 and 1.01 [1.01–1.02], P=0.001, respectively)

Conclusion

The total number of PAC and the maximum number of PAC run on the Holter ECG may be useful in predicting AF recurrence after CA.

Funding Acknowledgement

Type of funding sources: None.

Urokinase-type plasminogen activator (uPA) negatively regulates α-smooth muscle actin expression via Endo180 and the uPA receptor in corneal fibroblasts

Corneal fibroblasts are embedded within an extracellular matrix composed largely of collagen type 1, proteoglycans, and other proteins in the corneal stroma, and their morphology and function are subject to continuous regulation by collagen. During wound healing and in various pathological conditions, corneal fibroblasts differentiate into myofibroblasts characterized by the expression of α-smooth muscle actin (α-SMA). Endo180, also known as urokinase-type plasminogen activator (uPA) receptor-associated protein (uPARAP), is a collagen receptor. Here we investigated whether targeting of Endo180 and the uPA receptor (uPAR) by uPA might play a role in the regulation of α-SMA expression by culturing corneal fibroblasts derived from uPA-deficient (uPA^-/-) or wild-type (uPA^+/+) mice in a collagen gel or on plastic. The expression of α-SMA was upregulated, the amounts of full-length Endo180 and uPAR were increased, and the levels of both transforming growth factor-b (TGF-β) expression and Smad3 phosphorylation were higher in uPA^-/- corneal fibroblasts compared with uPA^+/+ cells under the collagen gel culture condition. Antibodies to Endo180 inhibited these effects of uPA deficiency on a-SMA and TGF-b expression, whereas a TGF-b signaling inhibitor blocked the effects on Smad3 phosphorylation and a-SMA expression. Our results suggest that uPA deficiency might promote the interaction between collagen and Endo180 and thereby increase a-SMA expression in a manner dependent on TGF-β signaling. Expression of α-SMA is thus negatively regulated by uPA through targeting of Endo180 and uPAR.

KOMPEITO, an Atypical Arabidopsis Rhomboid-Related Gene, Is Required for Callose Accumulation and Pollen Wall Development

Fertilization is a key event for sexually reproducing plants. Pollen-stigma adhesion, which is the first step in male-female interaction during fertilization, requires proper pollen wall patterning. Callose, which is a β-1.3-glucan, is an essential polysaccharide that is required for pollen development and pollen wall formation. Mutations in CALLOSE SYNTHASE 5 (CalS5) disrupt male meiotic callose accumulation; however, how CalS5 activity and callose synthesis are regulated is not fully understood. In this paper, we report the isolation of a kompeito-1 (kom-1) mutant defective in pollen wall patterning and pollen-stigma adhesion in Arabidopsis thaliana. Callose was not accumulated in kom-1 meiocytes or microspores, which was very similar to the cals5 mutant. The KOM gene encoded a member of a subclass of Rhomboid serine protease proteins that lacked active site residues. KOM was localized to the Golgi apparatus, and both KOM and CalS5 genes were highly expressed in meiocytes. A 220 kDa CalS5 protein was detected in wild-type (Col-0) floral buds but was dramatically reduced in kom-1. These results suggested that KOM was required for CalS5 protein accumulation, leading to the regulation of meiocyte-specific callose accumulation and pollen wall formation.

Role of Macrophages and Plasminogen Activator Inhibitor-1 in Delayed Bone Repair Induced by Glucocorticoids in Mice

Glucocorticoids delay fracture healing and induce osteoporosis. However, the mechanisms by which glucocorticoids delay bone repair have yet to be clarified. Plasminogen activator inhibitor-1 (PAI-1) is the principal inhibitor of plasminogen activators and an adipocytokine that regulates metabolism. We herein investigated the roles of macrophages in glucocorticoid-induced delays in bone repair after femoral bone injury using PAI-1-deficient female mice intraperitoneally administered with dexamethasone (Dex). Dex significantly decreased the number of F4/80-positive macrophages at the damaged site two days after femoral bone injury. It also attenuated bone injury-induced decreases in the number of hematopoietic stem cells in bone marrow in wild-type and PAI-1-deficient mice. PAI-1 deficiency significantly weakened Dex-induced decreases in macrophage number and macrophage colony-stimulating factor (M-CSF) mRNA levels at the damaged site two days after bone injury. It also significantly ameliorated the Dex-induced inhibition of macrophage phagocytosis at the damaged site. In conclusion, we herein demonstrated that Dex decreased the number of macrophages at the damaged site during early bone repair after femoral bone injury partly through PAI-1 and M-CSF in mice.

Role of plasminogen activator inhibitor-1 in muscle wasting induced by a diabetic state in female mice

Muscle wasting is a complication in patients with diabetes and leads to a reduced quality of life. However, the detailed mechanisms of diabetes-induced muscle wasting remain unknown. Plasminogen activator inhibitor-1 (PAI-1), a serine protease inhibitor that suppresses plasminogen activator activity, is involved in the pathophysiology of various diseases, including diabetes. In the present study, we examined the role of endogenous PAI-1 in the decrease in muscle mass and the impaired grip strength induced by the diabetic state by employing streptozotocin (STZ)-treated PAI-1-deficient female mice. The analyses of skeletal muscles and grip strength were performed in PAI-1-deficient and wild-type mice 4 weeks after the induction of a diabetic state by STZ administration. PAI-1 deficiency did not affect muscle mass in the lower limbs measured by quantitative computed tomography or tissue weights of the tibialis anterior, gastrocnemius and soleus muscles of female mice with or without STZ treatment. On the other hand, PAI-1 deficiency significantly aggravated grip strength decreased by STZ in female mice. PAI-1 deficiency did not affect the mRNA levels of Pax7, MyoD, myogenin or myosin heavy chain in either the tibialis anterior or soleus muscles of female mice with or without STZ treatment. In conclusion, we revealed for the first time that PAI-1 deficiency aggravates grip strength impaired by the diabetic state in female mice, although it did not affect diabetes-decreased muscle mass.

Fibronectin plays a major role in hypoxia-induced lenvatinib resistance in hepatocellular carcinoma PLC/PRF/5 cells

Resistance to lenvatinib mesylate (LEN), a systemic chemotherapy that can be administered orally, has been a major issue for treatment of hepatocellular carcinoma (HCC). Although HCC is the tumor that most exhibits intratumoral hypoxia, which has been shown to be involved in the development of treatment resistance, there are no reports of LEN resistance in HCC treatment under hypoxia. The purpose of our study was to elucidate the mechanism of treatment resistance to LEN under hypoxia using HCC cell lines. We confirmed LEN resistance under hypoxic conditions in HCC cell lines. There was a significant increase in the IC₅₀ value of PLC/PRF/5 cells from 13.0±0.8 μM in normoxia to 21.3±1.1 μM in hypoxia, but in HepG2 cells, the increase was not significant. To elucidate the LEN resistance mechanism of PLC/PRF/5 cells under hypoxia, we performed microarray analysis and extracted genes that are thought to be related to this mechanism. Furthermore, in-silico analysis confirmed significant changes in the extracellular matrix, and among them, FN1 encoding fibronectin was determined as the hub of the gene cluster. The expression of fibronectin in PLC/PRF/5 cells examined with immunofluorescence staining was significantly elevated in and outside of cells under hypoxia, and tended to decrease when cells were exposed to LEN under normoxia. Furthermore, the fibronectin concentration in the culture solution of PLC/PRF/5 cells examined by ELISA was 2.3 times higher under hypoxia than under normoxia under LEN(-) conditions, and 1.6 times higher under hypoxia than under normoxia under LEN(+) conditions. It is assumed that in PLC/PRF/5 cells, fibronectin is probably suppressed as an indirect effect of LEN under normoxia, but transcription factors such as HIF-1α are induced under hypoxia, thus enhancing the production of fibronectin and attenuating the effect of LEN, resulting in drug resistance. This behavior of fibronectin with LEN exposure under hypoxia is probably specific to PLC/PRF/5 cells. Further studies should verify the combined effective inhibition of fibronectin and the MAPK pathway as a promising therapeutic strategy to enhance the value of LEN in HCC treatment.

Role of tissue factor in delayed bone repair induced by diabetic state in mice

Background

Tissue factor (TF) is the primary activator of the extrinsic coagulation protease cascade. Although TF plays roles in various pathological states, such as thrombosis, inflammatory diseases, cancer, and atherosclerosis, its involvement in bone metabolism remains unknown.

Materials and methods

The present study examined the roles of TF in delayed bone repair induced by a diabetic state in mice using wild-type (WT) and low TF-expressing (LTF) male mice. A diabetic state was induced by intraperitoneal injections of streptozotocin (STZ).

Results

A prolonged diabetic state significantly reduced total and trabecular bone mineral densities (BMD) as well as cortical bone thickness in WT and LTF mice; these BMD parameters were similar between WT and LTF mice treated with or without STZ. The diabetic state induced in WT mice delayed the repair of the femur following injury. The diabetic state induced in LTF mice was associated with further delays in bone repair. In in vitro experiments, TF significantly decreased receptor activator of nuclear factor-κB ligand-induced osteoclast formation and osteoclastogenic gene expression in RAW264.7 cells. However, it did not affect the gene expression levels of runt-related transcription factor 2 and osterix as well as alkaline phosphatase activity in mouse primary osteoblasts.

Conclusion

Low TF state was associated with enhanced bone repair delay induced by diabetic state in mice. The TF-induced suppression of bone remodeling may be a contributing factor to the protective effects of TF against delayed bone repair in a diabetic state.

Inflammation-frailty linkage and its long-term prognostic impact in patients with acute coronary syndrome

Introduction

Chronic inflammation has been receiving considerable attention as an emerging risk factor for cardiovascular disease. In contrast, with the aging of the population, frailty has been also attracting a great deal of attention as the residual risk for cardiovascular disease. Although inflammation and frailty exacerbate each other and have an adverse effect on many diseases, the relationship between chronic inflammation and frailty and the impact of these combination on long-term prognosis in patients with acute coronary syndrome (ACS) are not elucidated.

Purpose

The aims of this study were to determine the association between chronic inflammation and frailty and its impact on long-term cardiovascular outcomes in patients with ACS.

Methods

A total of 482 consecutive ACS patients with obstructive coronary artery disease (age 66±12 years, male 81%) were enrolled in this observational study. We evaluated patients' gait speed as a measure of frailty before discharge. C-reactive protein (CRP) levels at 1 month after discharge were also evaluated as inflammation in the chronic phase. According to commonly used criteria of the residual inflammation (CRP&gt;0.2 mg/dL) and the definition of the European Working Group for Sarcopenia (gait speed ≤0.8 m/sec), patients were stratified by 4 subgroups: low/high CRP with slow/normal gait speed. The primary endpoint was composite outcomes of cardiovascular death, myocardial infarction and ischemic stroke.

Results

While there was no significant association between CRP levels and gait speed in all patients, a significant negative association between two variables was observed in the high CRP group (Spearman's ρ = −0.31, p=0.001). During the median follow-up of 6 years, primary endpoints have occurred in 82 patients. Overall, event-free rates differed significantly among the 4 groups, demonstrating the lowest event-free rate in the patients with high CRP and slow gait speed (p&lt;0.0001; Figure). In the multivariate analysis, high CRP (adjusted HR 1.99, 95% CI 1.14–3.46, p=0.02) and slow gait speed (adjusted HR 1.82, 95% CI 1.09–3.04, p=0.02) were independently and significantly associated with the primary endpoint. Moreover, the patients with both high CRP and slow gait speed had a 2.6-fold higher risk of cardiovascular events compared to others (adjusted HR 2.62, 95% CI 1.36–5.05, p=0.004).

Conclusion

In the patients with ACS, CRP levels and gait speed were negatively associated in the high CRP group. Chronic inflammation and frailty were both associated with poor prognosis in ACS and in particular, the combination of these factors was strongly associated with poor prognosis.

Funding Acknowledgement

Type of funding sources: None. Figure 1