[Show abstract][Hide abstract] ABSTRACT: In epidemiologic and animal studies, a high fat diet (HFD) has been shown to be associated with lower bone mineral density (BMD) and a higher risk of osteoporotic fractures. Meanwhile, consuming a HFD containing diacylglycerol (DAG) instead of triacylglycerol (TAG) is known to offer metabolically beneficial effects of reductions in body weight and abdominal fat. The purpose of this study was to investigate the effects of a HFD containing DAG (HFD-DAG) on bone in mice.
Four-week-old male C57BL/6J mice (n=39) were divided into three weight-matched groups based on diet type: a chow diet group, a HFD containing TAG (HFD-TAG) group, and a HFD-DAG group. After 20 weeks, body composition and bone microstructure were analyzed using dual energy X-ray absorptiometry and micro-computed tomography. Reverse transcription-polymerase chain reaction (PCR) and real-time PCR of bone marrow cells were performed to investigate the expressions of transcription factors for osteogenesis or adipogenesis.
The HFD-DAG group exhibited lower body weight, higher BMD, and superior microstructural bone parameters, compared to the HFD-TAG group. The HFD-DAG group showed increased expression of Runx2 and decreased expression of PPARgamma in bone marrow cells, compared to the HFD-TAG group. The HFD-DAG group also had lower levels of plasma glucose, insulin, total cholesterol, and triglyceride than the HFD-TAG group.
Compared to HFD-TAG, HFD-DAG showed beneficial effects on bone and bone metabolism in C57BL/6J mice.
Yonsei medical journal 07/2015; 56(4):951-960. DOI:10.3349/ymj.2015.56.4.951 · 1.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: IFN-gamma releasing assays (IGRAs) such as T-SPOT.TB assay and QuantiFERON-TB In-Tube (QFT-GIT) have yielded promising results for the diagnosis of tuberculosis (TB). However, little is known about the usefulness of these assays for diagnosing disseminated TB. We therefore compared their usefulness with traditional tests in patients with disseminated TB. All adult patients with suspected disseminated TB were prospectively enrolled at a tertiary hospital in an intermediate TB-burden country during a 6-year period. Disseminated TB was defined as involvement of the bone marrow or ≥2 noncontiguous organs, or presence of miliary lung lesions. A total of 101 patients with confirmed and probable disseminated TB were finally analyzed. Of these 101 patients, 52 (52%) had miliary TB and the remaining 49 (48%) had nonmiliary disseminated TB. In addition, 63 (62%) had no underlying disease. Chronic granuloma with/without necrosis, acid-fast bacillus staining, Mycobacterium tuberculosis PCR, and culture for M tuberculosis were positive in 77% (41/53), 43% (43/101), 70% (67/96), and 72% (73/101), of the patients, respectively. The T-SPOT.TB assay was positive in 90% (91/101) of them. The sensitivity of the T-SPOT.TB assay in patients with miliary TB (90%) was similar to that in patients with nonmiliary TB (90%) (P > 0.99). In a subgroup analysis of the 58 patients in whom both QFT-GIT and the T-SPOT.TB results were available, the sensitivity of QFT-GIT (67%) was lower than that of T-SPOT.TB (95%) (P < 0.001).In conclusion, T-SPOT.TB assay may be a helpful adjunct test for disseminated TB.
Medicine 07/2015; 94(28):e1094. DOI:10.1097/MD.0000000000001094 · 5.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Limited data are available on which factors are associated with strong immunologic responses to T-SPOT.TB. We investigated the factors associated with strong positive responses in patients with extrapulmonary tuberculosis (E-TB). Of 173 patients with E-TB who gave positive results on T-SPOT.TB, 26 (15%) with a strong positive response (defined as ≥1,000 spot-forming units (SFU)/2.5×10(5) PBMC to ESAT-6 or CFP-10) and 71 (41%) with a low positive response (≤ 99 SFU (6-99 SFU)/2.5×10(5) PBMC) were further analyzed. Miliary TB was independently associated with a strong positive response to T-SPOT.TB, while advanced age and immunosuppression were independently associated with weak positive T-SPOT.TB responses.
[Show abstract][Hide abstract] ABSTRACT: In Pseudomonas aeruginosa, quorum sensing (QS) plays an essential role in pathogenesis and the QS response controls many virulence factors. Using a mealworm, Tenebrio molitor as a host model, we found that Protease IV, a QS-regulated exoprotease of P. aeruginosa functions as a key virulence effector causing the melanization and death of T. molitor larvae. Protease IV was able to degrade zymogens of spätzle processing enzyme (SPE) and SPE-activating enzyme (SAE) without the activation of the antimicrobial peptide (AMP) production. Since SPE and SAE function to activate spätzle, a ligand of Toll receptor in the innate immune system of T. molitor, we suggest that Protease IV may interfere with the activation of the Toll signaling. Independently of the Toll pathway, the melanization response, another innate immunity was still generated, since Protease IV directly converted Tenebrio prophenoloxidase into active phenoloxidase. Protease IV also worked as an important factor in the virulence to brine shrimp and nematode. These results suggest that Protease IV provides P. aeruginosa with a sophisticated way to escape the immune attack of host by interfering with the production of AMPs.
[Show abstract][Hide abstract] ABSTRACT: The profile of infective endocarditis (IE) has changed and is now showing an increasing prevalence of IE among congenital heart disease (CHD) patients. We studied the change of clinical profiles of IE over the past 25 years in patients with CHD at a single institution.
We reviewed medical records retrospectively for 325 patients diagnosed with IE between January 1, 1987, and March 31, 2012. We analyzed and compared the differences in patient characteristics and outcomes between 1987-2000 (group A) and 2001-2012 (group B).
Over the 25-year period, 93 cases of IE in CHD patients were diagnosed (59 cases in group A and 34 cases in group B). Ventricular septal defect was the most common underlying cardiac disease observed during the entire period. The most common causative pathogen was Streptococcus in both groups. Group A contained 16 cases (27.1%) that had undergone cardiac surgery, whereas this number was 19 (55.8%) in group B. The number of patients who had undergone palliative care or surgery using prosthetic materials was higher among group B patients (p<0.001). Surgical procedures due to uncontrolled infection were performed in three cases in group A and 10 cases in group B.
Infective endocarditis and CHD show a close correlation, and the profile of IE patients can change in line with an increase in the survival rate of patients with complex CHD and the improvement of surgical techniques. Ongoing reassessment and the systematic management of these patients is crucial in the prevention and treatment of IE.
Korean Circulation Journal 01/2014; 44(1):37-41. DOI:10.4070/kcj.2014.44.1.37 · 0.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective:
MicroRNAs (miRNAs), small noncoding RNA molecules, are involved in the pathogenesis of various diseases such as cancer and arthritis. The aim of this study was to determine whether miR-127-5p regulates interleukin-1β (IL-1β)-induced expression of matrix metalloproteinase 13 (MMP-13) and other catabolic factors in human chondrocytes.
Expression of miR-127-5p and MMP-13 by normal and osteoarthritic (OA) human cartilage was determined using real-time polymerase chain reaction. The effect of miR-127-5p on MMP-13 expression was evaluated using transient transfection of human chondrocytes or chondrogenic SW-1353 cells with miR-127-5p or its antisense inhibitor (anti-miR-127-5p). MMP-13 protein production was quantified by enzyme-linked immunosorbent assay, and the involvement of miR-127-5p in IL-1β-mediated catabolic effects was examined by immunoblotting. MicroRNA-127-5p binding with the putative site in the 3'-untranslated region (3'-UTR) of MMP-13 messenger RNA (mRNA) was validated by luciferase reporter assay.
There was a significant reduction in miR-127-5p expression in OA cartilage compared with normal cartilage. Up-regulation of MMP-13 expression by IL-1β was correlated with down-regulation of miR-127-5p expression in human chondrocytes. MicroRNA-127-5p suppressed IL-1β-induced MMP-13 production as well as the activity of a reporter construct containing the 3'-UTR of human MMP-13 mRNA. In addition, mutation of the miR-127-5p binding site in the 3'-UTR of MMP-13 mRNA abolished miR-127-5p-mediated repression of reporter activity. Conversely, treatment with anti-miR-127-5p remarkably increased reporter activity and MMP-13 production. Interestingly, the IL-1β-induced activation of JNK, p38, and NF-κB and expression of MMP-1 and cyclooxygenase 2 were significantly inhibited by miR-127-5p.
MicroRNA-127-5p is an important regulator of MMP-13 in human chondrocytes and may contribute to the development of OA.
[Show abstract][Hide abstract] ABSTRACT: Aims:
The collagen-stimulated generation of reactive oxygen species (ROS) regulates signal transduction in platelets, although the mechanism is unclear. The major targets of ROS include protein tyrosine phosphatases (PTPs). ROS-mediated oxidation of the active cysteine site in PTPs abrogates the PTP catalytic activity. The aim of this study was to elucidate whether collagen-induced ROS generation leads to PTP oxidation, which promotes platelet stimulation.
SH2 domain-containing PTP-2 (SHP-2) is oxidized in platelets by ROS produced upon collagen stimulation. The oxidative inactivation of SHP-2 leads to the enhanced tyrosine phosphorylation of spleen tyrosine kinase (Syk), Vav1, and Bruton's tyrosine kinase (Btk) in the linker for the activation of T cells signaling complex, which promotes the tyrosine phosphorylation-mediated activation of phospholipase Cγ2 (PLCγ2). Moreover, we found that, relative to wild-type platelets, platelets derived from glutathione peroxidase 1 (GPx1)/catalase double-deficient mice showed enhanced cellular ROS levels, oxidative inactivation of SHP-2, and tyrosine phosphorylation of Syk, Vav1, Btk, and PLCγ2 in response to collagen, which subsequently led to increased intracellular calcium levels, degranulation, and integrin αIIbβ3 activation. Consistent with these findings, GPx1/catalase double-deficiency accelerated the thrombotic response in FeCl3-injured carotid arteries.
The present study is the first to demonstrate that SHP-2 is targeted by ROS produced in collagen-stimulated platelets and suggests that a novel mechanism for the regulation of platelet activation by ROS is due to oxidative inactivation of SHP-2.
We conclude that collagen-induced ROS production leads to SHP-2 oxidation, which promotes platelet activation by upregulating tyrosine phosphorylation-based signal transduction.
[Show abstract][Hide abstract] ABSTRACT: Background: T-SPOT.TB, a recently developed T-cell based assay, has shown promising results in diagnosing tuberculosis (TB). It is hypothesized that the magnitude of response to early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10), which are encoded by genes in the region of difference-1 (RD-1), is influenced by difference of disease status or host condition. Although strong responses of T-SPOT.TB occasionally occur, limited data are available on which factors are associated with these strong immunologic responses. We thus investigated the factors associated with extremely high response of T-SPOT.TB in patients with extrapulmonary TB (E-TB).
Methods: Between April 2008 and November 2012, adult patients with suspected E-TB were prospectively enrolled at a tertiary hospital in an intermediate TB-burden country. Patients with extremely high response of T-SPOT.TB, defined as results of >= 1000 spot forming units (SFU)/2.5 x105 PBMC to ESAT-6 or CFP-10, were compared with control patients with low response of T-SPOT.TB, <= 99 SFU (6-99 SFU)/2.5 x 105 PBMC to ESAT-6 or CFP-10.
Results: Of the 350 patients with suspected E-TB, 208 (59%) patients with 153 (74%) confirmed and 55 (26%) probable E-TB were included in this study. Of these 208, 173 (49%) patients showed positive results of T-SPOT.TB. Of these 173 patients, 26 (15%), 76 (44%), and 71 (41%) revealed >= 1000 SFU, 100-999 SFU, and 6-99 SFU/2.5 x 105 PBMC to RD-1 in T-SPOT.TB assay, respectively. Thus, 26 (15%) patients with extremely high response and 71 (41%) with low response were finally included for further analysis. Univariate and multivariate analyses are shown in Table 1. Univariate analysis revealed that young age, confirmed TB, and miliary TB were significantly associated with extremely high response results of T-SPOT.TB. In a multivariate analysis, miliary TB (OR=14.5; 95% CI 3.9-53.8) was significantly associated with extremely high response results of T-SPOT.TB, while advanced age (OR=0.9; 95% CI 0.9-1.0), and immunosuppression (OR=0.2; 95% CI 0.02-0.9) was associated with low response T-SPOT.TB results.
Conclusion: Our data suggest that mycobacterial burden and host immune status may contribute to the strong responsiveness of T-SPOT.TB assay.
IDWeek 2013 Meeting of the Infectious Diseases Society of America; 10/2013
[Show abstract][Hide abstract] ABSTRACT: Objective:
Cyclooxygenase-2 (COX-2) is a major prostaglandin E2 (PGE2) synthetic enzyme and is involved in the pathogenesis of chronic inflammation and pain in osteoarthritis (OA). The objective of this study was to directly address whether microRNA (miR)-558 can control the interleukin (IL)-1β-mediated induction of COX-2 and catabolic effects in human articular chondrocytes.
Materials and methods:
Total RNA was extracted from the cartilage tissues of normal and OA donors or cultured human articular chondrocytes. The expression of miR-558 was quantified by TaqMan assay. To investigate the repressive effect of miR-558 on COX-2 expression, human chondrocytes and chondrogenic SW1353 cells were transfected with mature miR-558 or an antisense inhibitor (anti-miR-558). The expression of COX-2 protein was determined by Western blot analysis and the involvement of miR-558 in IL-1β-induced catabolic effects was examined by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). Direct interaction between miR-558 and the putative site in the 3'-untranslated region (UTR) of COX-2 messenger RNA (mRNA) was validated by luciferase reporter assay.
Normal human articular cartilage expressed miR-558, and its expression was significantly lower in OA cartilage. Stimulation with IL-1β led to a significant reduction in miR-558 expression in normal and OA chondrocytes. IL-1β-induced activation of MAP kinase (MAPK) and nuclear factor-κB (NF-κB) decreased miR-558 expression and induced COX-2 expression in chondrocytes. The overexpression of miR-558 directly suppressed the luciferase activity of a reporter construct containing the 3'-UTR of human COX-2 mRNA and significantly inhibited IL-1β-induced upregulation of COX-2, while treatment with anti-miR-558 enhanced IL-1β-induced COX-2 expression and reporter activity in chondrocytes. Interestingly, IL-1β-induced activation of NF-κB and expression of matrix metalloproteinase (MMP)-1 and MMP-13 was significantly inhibited by miR-558 overexpression.
These findings demonstrated that cartilage homeostasis is influenced by miR-558, which directly targets COX-2 and regulates IL-1β-stimulated catabolic effects in human chondrocytes.
Osteoarthritis and Cartilage 04/2013; 21(7). DOI:10.1016/j.joca.2013.04.012 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The two interferon-γ release assays such as QuantiFERON-TB Gold / In-Tube (QFT-TB) and T-SPOT.TB-are useful tools for the rapid diagnosis of tuberculosis (TB) but can yield indeterminate test results (ITRs). While some studies have identified risk factors for ITRs in the QFT-TB test, there have been few such studies for the T-SPOT.TB test. The aim of this study was to investigate the risk factors associated with ITRs in the T-SPOT.TB test.
From April 2008 to August 2010, all patients with suspected extrapulmonary tuberculosis (E-TB) were enrolled in a tertiary hospital in Korea. ITR was defined as < 20 spots in the positive control well or > 10 spots in the negative control well.
Out of a total of 368 patients, 32 (8.7%, 95% CI, 6.0% to 11.7%) had ITRs in their T-SPOT.TB tests. The ITRs were due to a low mitogen response in 13 (40.6%) patients and to a high nil response in the other 19 (59.4%) patients. Statistical analysis revealed that old age, underlying diseases, immunosuppressive treatment, lymphopenia, and clinical manifestations of E-TB were not significantly associated with ITRs.
Indeterminate results in the T-SPOT.TB test are not affected by age, underlying disease, immunosuppressive treatment, lymphopenia, or clinical manifestations of E-TB, which are known risk factors for indeterminate results in the QFT-TB test.
[Show abstract][Hide abstract] ABSTRACT: Hemolytic disease in a newborn that causes early jaundice is common. It is often due to the Rh (D) and ABO incompatibility, but rarely due to unexpected antibodies. Among these unexpected antibodies, the anti-Dia antibody rarely occurs. The anti-Dia antibody was observed in the serum and red-cell eluate of an infant, and in the serum of his mother. The frequency of the appearance of the Dia antigen in the Korean population is estimated to be 6.4-14.5%. This paper reports a case of hemolytic disease in a newborn associated with the anti-Dia antibody. A full-term male infant was transferred to the authors' hospital due to hyperbilirubinemia the day after his birth. The laboratory data indicated a hemoglobin value of 11.6 g/dL, a reticulocyte count of 10.6%, a total bilirubin count of 14.4 mg/dL, a direct bilirubin count of 0.6 mg/dL, and a positive result in the direct Coombs' test. Due to the identification of an irregular antibody from the maternal serum, an anti-Dia antibody was detected, which was also found in the eluate made from the infant's blood. The infant had been treated with phototherapy and intravenous immunoglobulin since the second day after his birth and was discharged due to an improved condition without exchange transfusion. Therefore, in cases of iso-immune hemolytic disease in a newborn within 24 hours from birth who had a negative result in an antibody screening test, the conduct of an anti-Dia antibody identification test is recommended due to the suspicion of an anti-Dia antigen, followed by early administration of intravenous immunoglobulin.
[Show abstract][Hide abstract] ABSTRACT: Forty-three patients with miliary tuberculosis (TB) were evaluated for diagnostic usefulness of ELISPOT assay. Among non-invasive rapid tests available within 3-5 days, ELISPOT had the highest sensitivity (93%), compared with acid-fast bacilli stain (sputum 32% and bronchoalveolar lavage 7%), M.TB-PCR (sputum 53% and bronchoalveolar lavage 36%), and tuberculin skin test (22%). In comparison to 44 patients with lymph node TB, the sensitivity of the ELISPOT assay in patients with miliary TB (93%) was as high as in those with lymph node TB (95%, P = 0.63), whereas the sensitivity of the tuberculin skin test was substantially lower in patients with miliary TB (22%) than in those with lymph node TB (73%, P <.001).
[Show abstract][Hide abstract] ABSTRACT: Uncontrolled oxidative stress impairs bone formation and induces age-related bone loss in humans. The FoxO family is widely accepted to play an important role in protecting diverse cells from reactive oxygen species (ROS). Activation of FoxO1, the main FoxO in bone, stimulates proliferation and differentiation as well as inhibits apoptosis of osteoblast lineage cells. Despite the important role of FoxO1, little is known about how FoxO1 expression in bone is regulated. Meanwhile, several recent studies reported that microRNAs (miRNAs) could play a role in osteoblast differentiation and bone formation by targeting various transcriptional factors. Here, we identified one additional crucial miRNA, miR-182, which regulates osteoblastogenesis by repressing FoxO1 and thereby negatively affecting osteogenesis. Overexpression of miR-182 in osteoblast lineage cells increased cell apoptosis and inhibited osteoblast differentiation, whereas in vivo overexpression of miR-182 in zebrafish impaired bone formation. From in silico analysis and validation experiments, FoxO1 was identified as the target of miR-182, and restoration of FoxO1 expression in miR-182-overexpressing osteoblasts rescued them from the inhibitory effects of miR-182. These results indicate that miR-182 functions as a FoxO1 inhibitor to antagonize osteoblast proliferation and differentiation, with a subsequent negative effect on osteogenesis. To treat bone aging, an antisense approach targeting miR-182 could be of therapeutic value.
Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 08/2012; 27(8):1669-79. DOI:10.1002/jbmr.1604 · 6.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It has been reported that human mesenchymal stem cells (MSCs) can transfer mitochondria to the cells with severely compromised mitochondrial function. We tested whether the reported intercellular mitochondrial transfer could be replicated in different types of cells or under different experimental conditions, and tried to elucidate possible mechanism. Using biochemical selection methods, we found exponentially growing cells in restrictive media (uridine(-) and bromodeoxyuridine [BrdU](+)) during the coculture of MSCs (uridine-independent and BrdU-sensitive) and 143B-derived cells with severe mitochondrial dysfunction induced by either long-term ethidium bromide treatment or short-term rhodamine 6G (R6G) treatment (uridine-dependent but BrdU-resistant). The exponentially growing cells had nuclear DNA fingerprint patterns identical to 143B, and a sequence of mitochondrial DNA (mtDNA) identical to the MSCs. Since R6G causes rapid and irreversible damage to mitochondria without the removal of mtDNA, the mitochondrial function appears to be restored through a direct transfer of mitochondria rather than mtDNA alone. Conditioned media, which were prepared by treating mtDNA-less 143B ρ(0) cells under uridine-free condition, induced increased chemotaxis in MSC, which was also supported by transcriptome analysis. Cytochalasin B, an inhibitor of chemotaxis and cytoskeletal assembly, blocked mitochondrial transfer phenomenon in the above condition. However, we could not find any evidence of mitochondrial transfer to the cells harboring human pathogenic mtDNA mutations (A3243G mutation or 4,977 bp deletion). Thus, the mitochondrial transfer is limited to the condition of a near total absence of mitochondrial function. Elucidation of the mechanism of mitochondrial transfer will help us create a potential cell therapy-based mitochondrial restoration or mitochondrial gene therapy for human diseases caused by mitochondrial dysfunction.
PLoS ONE 03/2012; 7(3):e32778. DOI:10.1371/journal.pone.0032778 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: As Mycoplasma pneumoniae pneumonia has increased in Korea, its relevance to infants, toddlers, and adolescents has magnified as well as. However, it is difficult to perform the serological test and PCR test routinely for diagnosis in actual clinical practice. Thus, the authors conducted this study to help clinicians do presumptive diagnosis of Mycoplasma pneumoniae pneumonia using clinical, radiological, and hematological findings.