Interferon-gamma signaling promotes cartilage regeneration after injury

Osteoarthritis is a common chronic disease and major cause of disability and chronic pain in ageing populations. In this pathology, the entire joint is involved, and the regeneration of articular cartilage still remains one of the main challenges. Here, we investigated the molecular mechanisms underlying cartilage regeneration in young mice using a full-thickness cartilage injury (FTCI) model. FTCI-induced cartilage defects were created in the femoral trochlea of young and adult C57BL/6 mice. To identify key molecules and pathways involved in the early response to cartilage injury, we performed RNA sequencing (RNA-seq) analysis of cartilage RNA at 3 days after injury. Young mice showed superior cartilage regeneration compared to adult mice after cartilage injury. RNA-seq analysis revealed significant upregulation of genes associated with the immune response, particularly in the IFN-γ signaling pathway and qRT-PCR analysis showed macrophage polarization in the early phase of cartilage regeneration (3 days) in young mice after injury, which might promote the removal of damaged or necrotic cells and initiate cartilage regeneration in response to injury. IFN-γR1- and IFN-γ-deficient mice exhibited impaired cartilage regeneration following cartilage injury. DMM-induced and spontaneous OA phenotypes were exacerbated in IFN-γR1-/- mice than in wild-type mice. Our data support the hypothesis that IFN-γ signaling is necessary for cartilage regeneration, as well as for the amelioration of post-traumatic and age-induced OA.

The acute phase reactant orosomucoid-2 directly promotes rheumatoid inflammation

Acute phase proteins involved in chronic inflammatory diseases have not been systematically analyzed. Here, global proteome profiling of serum and urine revealed that orosomucoid-2 (ORM2), an acute phase reactant, was differentially expressed in rheumatoid arthritis (RA) patients and showed the highest fold change. Therefore, we questioned the extent to which ORM2, which is produced mainly in the liver, actively participates in rheumatoid inflammation. Surprisingly, ORM2 expression was upregulated in the synovial fluids and synovial membranes of RA patients. The major cell types producing ORM2 were synovial macrophages and fibroblast-like synoviocytes (FLSs) from RA patients. Recombinant ORM2 robustly increased IL-6, TNF-α, CXCL8 (IL-8), and CCL2 production by RA macrophages and FLSs via the NF-κB and p38 MAPK pathways. Interestingly, glycophorin C, a membrane protein for determining erythrocyte shape, was the receptor for ORM2. Intra-articular injection of ORM2 increased the severity of arthritis in mice and accelerated the infiltration of macrophages into the affected joints. Moreover, circulating ORM2 levels correlated with RA activity and radiographic progression. In conclusion, the acute phase protein ORM2 can directly increase the production of proinflammatory mediators and promote chronic arthritis in mice, suggesting that ORM2 could be a new therapeutic target for RA.

BTN1A1 is a novel immune checkpoint mutually exclusive to PD-L1

BACKGROUND

While Programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) blockade is a potent antitumor treatment strategy, it is effective in only limited subsets of patients with cancer, emphasizing the need for the identification of additional immune checkpoints. Butyrophilin 1A1 (BTN1A1) has been reported to exhibit potential immunoregulatory activity, but its ability to function as an immune checkpoint remains to be systematically assessed, and the mechanisms underlying such activity have yet to be characterized.

METHODS

BTN1A1 expression was evaluated in primary tumor tissue samples, and its ability to suppress T-cell activation and T cell-dependent tumor clearance was examined. The relationship between BTN1A1 and PD-L1 expression was further characterized, followed by the development of a BTN1A1-specific antibody that was administered to tumor-bearing mice to test the amenability of this target to immune checkpoint inhibition.

RESULTS

BTN1A1 was confirmed to suppress T-cell activation in vitro and in vivo. Robust BTN1A1 expression was detected in a range of solid tumor tissue samples, and BTN1A1 expression was mutually exclusive with that of PD-L1 as a consequence of its inhibition of Janus-activated kinase/signal transducer and activator of transcription signaling-induced PD-L1 upregulation. Antibody-mediated BTN1A1 blockade suppressed tumor growth and enhanced immune cell infiltration in syngeneic tumor-bearing mice.

CONCLUSION

Together, these results confirm that the potential of BTN1A1 is a bona fide immune checkpoint and a viable immunotherapeutic target for the treatment of individuals with anti-PD-1/PD-L1 refractory or resistant disease, opening new avenues to improving survival outcomes for patients with a range of cancers.

Nuclear receptor coactivator 6 is a critical regulator of NLRP3 inflammasome activation and gouty arthritis

Transcriptional coactivators regulate the rate of gene expression in the nucleus. Nuclear receptor coactivator 6 (NCOA6), a coactivator, has been implicated in embryonic development, metabolism, and cancer pathogenesis, but its role in innate immunity and inflammatory diseases remains unclear. Here, we demonstrated that NCOA6 was expressed in monocytes and macrophages and that its level was increased under proinflammatory conditions. Unexpectedly, nuclear NCOA6 was found to translocate to the cytoplasm in activated monocytes and then become incorporated into the inflammasome with NLRP3 and ASC, forming cytoplasmic specks. Mechanistically, NCOA6 associated with the ATP hydrolysis motifs in the NACHT domain of NLRP3, promoting the oligomerization of NLRP3 and ASC and thereby instigating the production of IL-1β and active caspase-1. Of note, Ncoa6 deficiency markedly inhibited NLRP3 hyperactivation caused by the Nlrp3R258W gain-of-function mutation in macrophages. Genetic ablation of Ncoa6 substantially attenuated the severity of two NLRP3-dependent diseases, folic-induced acute tubular necrosis and crystal-induced arthritis, in mice. Consistent with these findings, NCOA6 was highly expressed in macrophages derived from gout patients, and NCOA6-positive macrophages were significantly enriched in gout macrophages according to the transcriptome profiling results. Conclusively, NCOA6 is a critical regulator of NLRP3 inflammasome activation and is therefore a promising target for NLRP3-dependent diseases, including gout.

Mycobacterium potentiates protection from colorectal cancer by gut microbial alterations

Not only are many Mycobacteria pathogens, but they can act as strong non-specific immunopotentiators, generating beneficial effects on the pathogenesis of some diseases. However, there has been no direct evidence of the effect of mycobacterial species on colorectal cancer (CRC). Herein, we showed that there may be a meaningful inverse correlation between the incidence of tuberculosis and CRC based on global statistics and that heat-killed Mycobacterial tuberculosis and live Mycobacterium bovis (Bacillus Calmette-Guérin strain) could ameliorate CRC development. In particular, using a faecal microbiota transplantation and a comparison between separate housing and cohousing, we demonstrated that the gut microbiota is involved in the protective effects. The microbial alterations can be elucidated by the modulation of antimicrobial activities including those of the Reg3 family genes. Furthermore, interleukin-22 production by T helper cells contributed to the anti-inflammatory activity of Mycobacteria. Our results revealed a novel role of Mycobacteria involving gut microbial alterations in dampening inflammation-associated CRC and an immunological mechanism underlying the interaction between microbes and host immunity.

Myocardial extracellular space expansion is related to burden of premature ventricular contractions in patients with hypertrophic cardiomyopathy without non-sustained ventricular tachycardia

Funding Acknowledgements

Type of funding sources: None.

Background

Current guidelines suggest the presence of non-sustained ventricular tachycardia (NSVT) as a risk factor of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, high burden of premature ventricular contraction (PVC) may reflect myocardial fibrosis although the absence of NSVT.

Purpose

We investigated the association between PVC burden and myocardial extracellular space expansion in HCM patients without NSVT.

Methods

Of the 212 patients prospectively enrolled to the HCM registry of genetics, 84 patients were evaluated with both cardiac magnetic resonance and 24hr holter. Among them, 71 patients (58 males, mean age: 71 ± 13 years) have not been diagnosed with NSVT.

Results

Patients with NSVT (n = 13) showed more impaired LA functional indices and higher myocardial fibrosis burden compared with patients without NSVT (n = 71). Among patients who have not been diagnosed with NSVT, patients with late gadolinium enhancement (LGE, n = 46) had a higher total beats (109 ± 332 vs. 7 ± 13 beats per a day, p = 0.003) and burden (0.114 ± 0.225 vs. 0.008 ± 0.014 %, p = 0.003) of PVC during 24-hour compared with patients without LGE (n = 25). %LGE was correlated with total beats of PVC (r = 0.358, p = 0.002) and PVC burden (r = 0.377, p = 0.001). ECV also correlated with total beats of PVC (r = 0.387, p = 0.001) and PVC burden (r = 0.401, p = 0.001). The optimal cutoff value for PVC number was 45 (37.0% of sensitivity and 100% of specificity) with 0.733 of the area under the ROC curve (p < 0.001). Pathogenic or likely pathogenic sarcomere mutation was higher in NSVT group than no NSVT group (p < 0.05), and had a higher tendency in higher PVC burden group (0.05 < p < 0.1) than lower PVC burden group.

Conclusions

Total beats and burden of PVC are significantly related to increase in myocardial fibrosis in HCM patients without NSVT.

Abstract Figure. Mechanism of ventricular arrhythmia

Regulation of tumor growth by leukocyte-specific protein 1 in T cells

BACKGROUND

Clinical efficacy of T cell-based cancer immunotherapy is limited by the lack of T cell infiltration in the tumor mass, especially in solid tumors. Our group demonstrated previously that leukocyte-specific protein 1 (LSP1), an intracellular signal regulator, negatively regulates T cell infiltration in inflamed tissues.

METHODS

To determine the immuno-regulatory effects of LSP1 in T cells on tumor progression, we investigated the growth of B16 melanoma in Lsp1 knockout (KO) mice and T cell-specific Lsp1 transgenic (Tg) mice. The immune cell subpopulation infiltrated into the tumor mass as well as the expression of interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) in T cells was assessed by flow cytometry and/or immunohistochemistry. Chemotactic migration was assayed with Lsp1 KO and Lsp1 Tg T cells. Adoptive transfer of Lsp1 KO or Lsp1 Tg T cells was performed in B16 melanoma-challenged Rag1 KO mice.

RESULTS

Lsp1 KO mice showed decreased growth of B16 melanoma and increased infiltration of T cells in the tumor mass, which were completely reversed in T cell-specific Lsp1 Tg mice. Lsp1 KO CD8⁺ T cells also exhibited elevated migratory capacity in response to CXCL9 and CXCL10, whereas Lsp1 Tg CD8⁺ T cells did the opposite. LSP1 expression was increased in tumor-infiltrating T cells and could be induced by T cell receptor activation. Intriguingly, gene expression profiling of Lsp1 KO T cells suggested enhanced cytotoxicity. Indeed, expression of IFN-γ and TNF-α was increased in tumor-infiltrating CD4⁺ and CD8⁺ T cells of Lsp1 KO mice, while it was markedly reduced in those of Lsp1 Tg mice. Adoptive transfer of Lsp1 KO T cells to Rag1 KO mice was more effective in suppressing melanoma growth than transfer of Lsp1 Tg T cells. Of note, when treated with antiprogrammed cell death protein 1 (PD-1) antibody, inhibition of melanoma growth was more pronounced in Lsp1 KO mice than in Lsp1-sufficient mice, suggesting that Lsp1 depletion additively increases the antitumor effects of anti-PD-1 antibody.

CONCLUSIONS

LSP1 in T cells regulates the growth of B16 melanoma in mice, possibly by affecting migration and infiltration of T cells into the tumor and by modulating production of antitumor effector cytokines by CD8⁺ T cells. These findings provide evidence that LSP1 can be a target to improve the efficacy of T cell-based immunotherapy.

The xanthine oxidase-NFAT5 pathway regulates macrophage activation and TLR-induced inflammatory arthritis

NFAT5 (nuclear factor of activated T cells), a well-known osmoprotective factor, can be activated by isotonic stimuli such as Toll-like receptor (TLR) triggering. However, it is unclear how NFAT5 discriminates between isotonic and hypertonic stimuli to produce different functional and molecular outcomes. Here, we identified a novel XO-ROS-p38 MAPK-NFAT5 pathway (XO is xanthine oxidase, ROS is reactive oxygen species) that is activated in RAW 264.7 macrophages upon isotonic TLR stimulation. Unlike what is seen under hypertonic conditions, XO-derived ROS were selectively required for the TLR-induced NFAT5 activation and NFAT5 binding to the IL-6 promoter in RAW 264.7 macrophages under isotonic conditions. In mouse peritoneal macrophages and human macrophages, TLR ligation also induced NFAT5 activation, which was dependent on XO and p38 kinase. The involvement of XO in NFAT5 activation by TLR was confirmed in RAW 264.7 macrophages implanted in BALB/c mice. Moreover, allopurinol, an XO inhibitor, suppressed arthritis severity and decreased the expression of NFAT5 and IL-6 in splenic macrophages in C57BL/6 mice. Collectively, these data support a novel function of the XO-NFAT5 axis in macrophage activation and TLR-induced arthritis, and suggest that XO inhibitor(s) could serve as a therapeutic agent for chronic inflammatory arthritis.

Reactive oxygen species regulate context-dependent inhibition of NFAT5 target genes

The activation of nuclear factor of activated T cells 5 (NFAT5), a well-known osmoprotective factor, can be induced by isotonic stimuli, such as activated Toll-like receptors (TLRs). It is unclear, however, how NFAT5 discriminates between isotonic and hypertonic stimuli. In this study we identified a novel context-dependent suppression of NFAT5 target gene expression in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS) or a high salt (NaCl) concentration. Although LPS and NaCl both used NFAT5 as a core transcription factor, these stimuli mutually inhibited distinct sets of NFAT5 targets within the cells. Although reactive oxygen species (ROS) are essential for this inhibition, the source of ROS differed depending on the context: mitochondria for high salt and xanthine oxidase for TLRs. Specifically, the high salt-induced suppression of interleukin-6 (IL-6) production was mediated through the ROS-induced inhibition of NFAT5 binding to the IL-6 promoter. The context-dependent inhibition of NFAT5 target gene expression was also confirmed in mouse spleen and kidney tissues that were cotreated with LPS and high salt. Taken together, our data suggest that ROS function as molecular sensors to discriminate between TLR ligation and osmotic stimuli in RAW 264.7 macrophages, directing NFAT5 activity toward proinflammatory or hypertonic responses in a context-dependent manner.

Total occlusion of left main coronary artery by dilated main pulmonary artery in a patient with severe pulmonary hypertension

A 34-year-old woman was admitted to the hospital because of recently aggravated right heart failure without angina for 5 months. When she was 25 years old, patch repair with Polytetrafluoroethylene (PTFE) was performed for the secondum type of atrial septal defect (ASD) with moderate pulmonary hypertension. The chest PA, echocardiography and cardiac catheterization at current admission revealed Eisenmenger syndrome without intracardiac shunt. Chest CT scan with contrast revealed markedly dilated pulmonary trunk, both pulmonary arteries and concave disfigurement of the left side of the ascending aorta suggesting extrinsic compression, as well as total occlusion of the ostium of the left main coronary artery that was retrogradly filled with collateral circulation from the right coronary artery. The coronary angiography showed normal right coronary artery and the collaterals that come out from the conus branch to the mid-left anterior descending artery (LAD) and that from distal right coronary artery to the left circumflex artery (LCX) and to the distal LAD, respectively. On aortography, the left main coronary artery was not visualized with no stump, suggestive of total occlusion of the ostium of the left main coronary artery. From our experience, it is possible to say that the occlusion of the ostium of the left main coronary can be induced by the dilated pulmonary artery trunk due to ASD with pulmonary hypertension and that, if the ASD closure was too late, the narrowing or obstruction of the left coronary artery could not be resolved even after operation owing to irreversible pulmonary hypertension.

Hemodynamic effects on atherosclerosis-prone coronary artery: wall shear stress/rate distribution and impedance phase angle in coronary and aortic circulation

The objective of the present study was to evaluate the hemodynamic characteristics of an atherosclerosis-prone coronary artery compared to the aorta. We describe three- dimensional spatial patterns of wall shear stress (WSS) according to the impedance phase angle in pulsatile coronary and aorta models using in vivo hemodynamic parameters and computed numerical simulations both qualitatively and quantitatively. Angiography of coronary arteries and aortas were done to obtain a standard model of vascular geometry. Simultaneously to the physiologic studies, flow-velocity and pressure profiles from in vivo data of the intravascular Doppler and pressure wire studies allowed us to include in vitro numerical simulations. Hemodynamic variables, such as flow-velocity, pressure and WSS in the coronary and aorta models were calculated taking into account the effects of vessel compliance and phase angle between pressure and flow waveforms. We found that there were spatial fluctuations of WSS and in the recirculation areas at the curved outer wall surface of the coronary artery. The mean WSS of the calculated negative phase angle increased in the coronary artery model over that in the aorta model and the phase angle effect was most prominent on the calculated amplitude of WSS of the coronary artery. This study suggests that the rheologic property of coronary circulation, such as the fluctuation of WSS/WSR induces several hemodynamic characteristics. A separation of flow-velocity, a difference in phase between pressure conductance and blood flow and prominent temporal and/or spatial oscillatory fluctuations of the shear forces as a function of pulsatile flow might be important factors in atherogenesis and progression of atherosclerosis.

Potential role of leptin in angiogenesis: leptin induces endothelial cell proliferation and expression of matrix metalloproteinases in vivo and in vitro

Leptin, the product of ob gene, is an endocrine hormone that regulates adipose tissue mass. Recently, leptin has been found to generate a growth signal involving a tyrosine kinase-dependent intracellular pathway and promote angiogenic processes via activation of leptin receptor (Ob-R) in endothelial cells. However, it is not clear how leptin functions to promote multi-step processes involved in the neovascularization at the atherosclerotic plaque. We have examined the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) and Ob-R in human atherosclerotic lesions, leptin-mediated angiogenesis in vivo and in vitro. Immunohistochemical analysis of human atherosclerotic aorta revealed an increased expression of Ob-R in the intima of neorevascularized regions and of both MMPs and TIMPs predominantly in the endothelial lining of intimal neovessels and macrophages/foam cells. In the rat corneal angiogenesis assay, leptin elicited a comparable sensitivity of angiogenic activity to those of vascular endothelial growth factor (VEGF). The immunohistological analysis of the leptin-treated rat cornea showed definitive rises in Ob-R, MMPs and TIMPs expression as well as those of VEGF receptor (VEGFR-1). Leptin (10-40 ng/ml) induced proliferation of the human umbilical vein endothelial cells (HUVECs) and elevation of MMP-2, MMP-9, TIMP-1, and TIMP-2 expression in a dose-dependent manner. Leptin also induced increases of MMP-2, MMP-9, TIMP-1, and Up-regulated the human coronary artery smooth muscle cells (HCASMCs). These findings suggest that leptin, a hormone with pluralistic properties including a mitogenic activity on vascular endothelial cells, plays a role in matrix remodeling by regulating the expression of MMPs and TIMPs. Taken together, our findings further provide evidences for leptin's role as an angiogenesis inducer in the normal organ (rat cornea) and in aberrant vasculature under duress like atherosclerosis.

Expression of osteopontin in calcified coronary atherosclerotic plaques

Advanced atherosclerosis is often associated with dystrophic calcification and remodeling of extracellular matrix of vascular wall. Recently many studies have documented a general relationship between calcification and severity of coronary disease, and discussed the feasibility of electron beam computed tomography for detecting and quantifying the coronary artery calcification in the patients. The present study investigated the expression and the localization of osteopontin, one of noncollagenous bone matrix protein, within the calcified coronary arteries. Autopsy-derived coronary artery specimens were scanned and reconstructed to visualize the pattern of coronary calcification using a novel microscopic computed tomography technique. The localization of the osteopontin were evaluated by immunohistochemial stain with LF7. The present study showed that the pattern of coronary calcification is variable and the expression of osteopontin is localized mainly to calcified lesion. The smooth muscle cells in addition to macrophage expressed osteopontin protein in human coronary atherosclerotic plaques. Soluble osteopontin released near to the sites of vascular calcification may represent an adaptive mechanism aimed at regulating the process of vascular calcification.

Serologic and histopathologic study of Chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by Chlamydia pneumoniae

Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.

Expression of leptin receptor (Ob-R) in human atherosclerotic lesions: potential role in intimal neovascularization

Neovascularization of the adventitial vasa vasorum with extension into the intima of atherosclerotic lesions is frequently observed, but its pathophysiological significance is still subject to debate. Recently, leptin, the product of the Ob gene, was identified. Leptin, via activation of the endothelial receptor (Ob-R), generates a growth signal involving a tyrosine kinase-dependent intracellular pathway and promotes angiogenic processes. We hypothesized that a high concentration of leptin within vasa vasorum and plaque itself, may influence inflammatory and vascular neovascularization coupling with functional upregulation of the vascular endothelial growth factor (VEGF). Microscopic computerized tomography was utilized for the spatial distribution of vasa vasorum and intimal neovascularization from atherosclerotic human coronary arteries. Atherosclerotic coronary arteries showed a dense plexus of microvessels in the adventitia and plaque itself. Microscopic analysis from human atherosclerotic aortas revealed an increase in the intimal thickness with neovascularization. The immunoreactivity for Ob-R, VEGF and matrix metalloproteinase (MMP) increased in atherosclerotic plaque, predominantly in the endothelial lining of the intimal neovessel and macrophages/foam cells. Our observation of a prominent colocalization between Ob-R, VEGF and MMP supports this hypothesis and these factors participate in the neovascularization of atherosclerotic lesions. The present study is the first report on vascular tissue and it opens a promising perspective concerning future investigations of leptin-dependent modulation of atherogenesis and vascular neovascularization under pathophysiolgical conditions.

Coexpression of cyclooxygenase-2 and matrix metalloproteinases in human aortic atherosclerotic lesions

Inflammation appears to have a major role in the development of atherosclerosis. Cyclooxygenase-2 (COX-2) is involved in the inflammatory response via the generation of prostanoids that, in turn, are involved in the production of matrix metalloproteinases (MMPs). This study aimed to investigate atherosclerosis in human aortas for in situ tissue distribution of COX-2, MMPs including MMP-9 and membrane type 1 MMP (MT1-MMP), and tissue inhibitor of metalloproteinase-2 (TIMP-2). Immunohistochemical studies were performed on atherosclerotic lesions of aortas from patients with aortic aneurysms (n = 4) and dissections (n = 3) by using antibodies to COX-2, MMP-9, MT1-MMP, and TIMP-2. Control tissues were obtained from traumatically dissected aortas (n = 2). All specimens from diseased aortas had atherosclerotic lesions ranging from fatty streak to atheromatous plaques. In control, there was no expression of COX-2, MMP-9, and MT1-MMP in all aortic layers. Immunoreactivity for COX-2 was predominantly noted in macrophages and smooth muscle cells (SMCs) of the intima including atherosclerotic plaque itself and the medial layer of the plaque base, as well as in SMCs and endothelial lining of the vasa vasorum in the adventitia. Immunoreactivity for MMP-9 and MT1-MMP was found in the same distribution as that of COX-2. Additionally, the expression of TIMP-2 increased in relation to MMP-9 expression. This study demonstrates that COX-2 is coexpressed with MMP-9 and MT1-MMP, not only by macrophages and SMCs in atherosclerotic lesions, but also in endothelial lining of the vasa vasorum of human aortas. Thus, vascular inflammatory reactions may influence extracellular matrix remodeling by coactivation of MMPs in the development of atherosclerosis and, in turn, the progression of disease.

Apoptosis in dilated cardiomyopathy

OBJECTIVE

Cardiomyopathy, a popular diagnosis that always obscures more than it reveals, nevertheless has several characteristic histological features. These prominently include widespread focal myocardial fibrosis and associated hypertrophy of surviving cardiac myocyte. In fact, focal noninflammatory degeneration (not necrosis) has been demonstrated as a feature of many forms of cardiac hypertrophy. We hypothesized that this loss of myocardial cells in dilated cardiomyopathy (DCMP) may result from cell death by apoptosis.

METHODS

Endomyocardial biopsy specimens from the right ventricles of six patients who suffered from DCMP were studied, and myocardial specimens from two persons who died in motor vehicle accidents were used as negative controls. For identification of apoptosis, immunohistochemistry with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling was performed. In addition, apoptosis was confirmed morphologically by confocal laser scanning microscopy with propidium iodide.

RESULTS

Apoptosis, that was represented by an apoptotic index ranging from 19.8 to 25.4%, could be extensively seen in myocytes and also rarely in non-myocytes of interstitium and vascular endothelium. Morphologically, there were a lot of nuclei with clumps of condensed chromatin, suggestive of apoptosis.

CONCLUSION

The present study demonstrated that myocyte loss in DCMP might be mainly due to the apoptosis of myocytes and interstitial cells, rather than inflammation or cell necrosis.

Percutaneous transmyocardial revascularization induces angiogenesis: a histologic and 3-dimensional micro computed tomography study

The purpose of this study was to visualize the spatial patterns and connection of channels created after percutaneous transmyocardial revascularization (PTMR) in normal porcine hearts, and to estimate the relative contributions of transmyocardial and coronary perfusion. Six pigs underwent PTMR creating channels using radiofrequency ablative energy. Three-dimensional computed tomography imaging of channels 1 hr after PTMR showed the direct connection of PTMR channels to the myocardial capillary network and to epicardial coronary vessels. In the heart, examined 28 day after PTMR, there was a fine, extensive, network of microvessels originating from the site of the original PTMR channel, also connecting the left ventricular cavity to myocardial capillaries. Histopathologic examination of the 1-hr specimens showed numerous regions of myocardial hemorrhage and associated inflammatory cell infiltration. In the 28-day specimens, newly developed new vascular network suggested neovascularization within the core of these channel remnants. The immunoreactivity for basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) were intense within myocardium and neovascular structure surrounding PTMR channel remnants. The vascular connections occur by direct communication with existing myocardial vasculature acutely, and angiogenesis in these channel remnant chronically.

Apolipoprotein E polymorphism in non-diabetic patients with acute coronary syndrome

Since a decade ago, apolipoprotein (apo) E polymorphism has been focussed as a risk factor for cardiovascular disease. ApoE plays a central role as a receptor ligand for the uptake of lipoproteins from the circulation. There was an agreement on apoE polymorphism being one of the major risk factors for coronary artery disease (CAD) by its effects on lipid profiles. However, the effects of apoE have not been noted in all populations and conflicting results in the risk of CAD have been noted. Recently, in situ expression of apoE on the atherosclerotic plaque has been studied. We, therefore, investigated the effects of apoE genotype on patients with acute coronary syndrome, including unstable angina and acute myocardial infarction, in non-diabetic patients. While we could not find significant risk effects of apoE on coronary artery disease and lipid profiles on simple comparison with the normal control group, we could find significantly decreased frequencies of apo epsilon 3 allele in patients with acute coronary syndrome compared with stable angina patients (77.8% vs 88.8%). We suggest that the apoE genotype could be associated with acute coronary events in CAD and further study with in situ biochemical methods will be needed on the effects of apoE polymorphism on plaque stability.

Ultrastructural changes of the external elastic lamina in experimental hypercholesterolemic porcine coronary arteries

The external elastic lamina (EEL) serves as a barrier for cells and macromolecules between the media and adventitia in the vascular wall. We evaluated the morphological changes and quantitative assessments of the EEL architecture in the coronary circulation of pigs fed with a high cholesterol diet. Confocal microscopy analysis of the EEL from hypercholesterolemic coronary arteries revealed an altered pattern characterized by fragmentation and disorganization of the EEL associated with an increase in the thickness. Computerized digital analysis of the images obtained by confocal scanning microscopy demonstrated that compared to normal coronary arteries, the EEL of hypercholesterolemic coronary arteries decreased in the percentage of their elastin content (30.80 +/- 1.64% vs. 47.85 +/- 1.82%, p = 0.001). The percentage of elastin content was negatively correlated with the vessel wall area (r = -0.82, p = 0.001). The immunoreactivity for matrix metalloproteinase-3 (MMP-3) increased in cholesterol-fed coronary arteries, predominantly in the neointima and adventitia. This study demonstrates that experimental hypercholesterolemia induced ultrastructural changes of the EEL in coronary circulation. The EEL may also be an atherosclerosis-prone area compared with the intima. The EEL may play an important role in the development of structural changes which characterizes the early phase of coronary atherosclerosis and vascular remodeling.

Ultrastructural changes of the internal elastic lamina in experimental hypercholesterolemic porcine coronary arteries

The internal elastic lamina (IEL) serves as a barrier for cells and macromolecules between the intima and media in the vascular wall. We evaluated the morphological changes and quantitative assessments of the IEL architecture in the coronary circulation of pigs fed with a high cholesterol diet. Transmission electron microscopy (TEM) analysis of the IEL from hypercholesterolemic coronary arteries revealed fragmentation of the IEL associated with a decrease in the thickness. Confocal microscopy and scanning electron microscopy (SEM) revealed an altered pattern characterized by a large oval fenestration in the IEL of hypercholesterolemic vessels. Morphometric analysis of confocal microscopy images demonstrated that the IEL of cholesterol-fed animals were characterized by an increase in the minor diameter of the fenestrae (2.16+/-0.04 microm vs 3.32+/-0.06 microm, p=0.003) and a decrease in the fenestrae density (22,333+/-1,334/mm2 vs 17,552+/-931/mm2, p=0.015) compared to controls. The percentage of the IEL area covered by the fenestrae correlated with the intimal thickness (r=0.79, p=0.004). The immunoreactivity for matrix metalloproteinase-3 (MMP-3) increased in cholesterol-fed coronary arteries, predominantly in the neointima. This study demonstrates experimental hypercholesterolemia induced ultrastructural changes of the IEL in the coronary circulation. The IEL may play an important role in the development of structural changes which characterize the early phase of coronary atherosclerosis.

Experimental hypercholesterolemia induces ultrastructural changes in the elastic laminae of rabbit aortic valve

Atherosclerosis is the most severe problem in the high-pressure systemic circulation and similar changes also occur in the high-pressure loading valve. This study was designed to test the hypothesis that early atherosclerosis, induced by a high cholesterol diet in rabbits, is characterized by significant ultrastructural change in the elastic laminae of the aortic valve. However, it is not known whether this process is also taking place in the cardiac valve at the early stage of atherosclerosis. Animals were fed either a high cholesterol diet (n = 5) or a control diet (n = 5) for 10-12 weeks. Histologic analysis demonstrated that subendothelial thickening and foam-cell infiltration were evident in the arterialis of aortic valves. Confocal microscopy revealed an altered pattern characterized by fragmentation and disorganization of the arterialis elastic laminae of hypercholesterolemic valves. Computerized digital analysis of the images obtained by confocal scanning microscopy demonstrated that compared to normal valves, the arterialis elastic laminae of hypercholesterolemic valves decreased in percentage of their elastin content (29.03 +/- 1.10% vs. 42.94 +/- 1.35%, p = 0.023). Immunohistochemical staining for matrix metalloproteinase-3 (MMP-3) revealed MMP-3 immunoreactivity was increased in hypercholesterolemic valves, predominantly in the arterialis. This study demonstrated that early atherosclerosis, induced by a high cholesterol diet in rabbits, is characterized by significant ultrastructural change in the elastic laminae of the aortic valve. The arterialis endothelium of the aortic valve may be a more atherosclerosis-prone area compared with the ventricularis. The presence of ultrastructural defect in the elastic laminae may play a role in chronic degenerative change and a resultant valvular dysfunction.

Prospective comparison of laparoscopic and traditional colposuspensions in the treatment of genuine stress incontinence

OBJECTIVE

To compare prospectively the results of laparoscopic and traditional colposuspensions in the treatment of genuine stress incontinence and to evaluate the efficacy, technique, and functional and anatomical changes after these two procedures.

MATERIALS AND METHODS

Ninety-two patients with urodynamically proven genuine stress incontinence participated in this study, with 46 patients randomly allocated to laparoscopic colposuspension, and the other 46 patients to the traditional procedures. All patients had repeat studies at least 3 months after operation.

RESULTS

The bladder neck position was significantly elevated after operation either at rest or during straining in both groups (all p < 0.001), but it was higher in the traditional group than the laparoscopy group during straining (p < 0.05). Comparison of urodynamics before and after operation in both groups showed significantly increased minimal urethral resistance and improved pressure transmission ratios at the proximal urethra (Q2). The blood loss was less in the laparoscopy group. The duration of bladder drainage after laparoscopic colposuspension was shorter, and was not affected by subsequent laparotomy. The operative time was almost the same. The success rate of the laparoscopy group was lower than that of the traditional group (80.4% vs. 95.6%, p = 0.044). The complication rates were 10.8% and 17.4% respectively.

CONCLUSION

Laparoscopic colposuspension is an effective method for the treatment of GSI, as documented by anatomical and functional assessments. However, the success rate is still lower than for the traditional procedure.

Sonographic and clinical findings of granulosa cell tumor

BACKGROUND

Granulosa cell tumor (GCT) accounts for roughly 1.5% of all ovarian neoplasms and 5-10% of ovarian cancers. GCT, which may have profound end-organ effects, has attracted a significant amount of attention despite its rarity. This tumor is rare, and difficult to diagnose before operation. Until now, no specific sonographic findings have been reported.

METHODS

Twelve cases of pathologically proven GCTs were diagnosed from June 1985 to March 1993. Nine of those cases had preoperative sonographic pictures taken.

RESULTS

Eight out of the nine cases tested exhibited a complex multicystic sonographic pattern. For a case evaluated by a transvaginal color and pulsed Doppler assessment, the blood vessels located in the central part with diffuse dispersed vascular arrangement were found to have a resistance index of 0.38 and a pulsatility index of 0.50. The most common complaints of our patients were postmenopausal bleeding and lower abdominal pain.

CONCLUSIONS

We conclude that complex multicystic sonographic features observed by high-resolution ultrasonography, in conjuction with a high preoperative estradiol level and clinical symptoms, may help to establish a preoperative diagnosis of GCT.

Laparoscopic para-aortic lymph node sampling in the staging of invasive cervical carcinoma: including a comparative study of 21 laparotomy cases

OBJECTIVES

To assess the efficacy and risks of laparoscopic para-aortic lymph node sampling compared with standard laparotomy in staging cervical carcinoma.

METHODS

From August 1993 through July 1994, 38 patients with biopsy-proven invasive cervical carcinoma (24 early and 14 advanced invasive cancers) were entered into the study. This was a prospective study of laparoscopic para-aortic lymphadenectomy in invasive cervical carcinoma, with patients serving as their own controls. Video laparoscopic lymph node sampling was performed. In patients with early invasive cancer, the nodes were sent for frozen section and, if negative, laparotomy was performed to look for any residual nodes. Radical hysterectomy was performed immediately if residual nodes were negative. Patients with either nodal metastasis on frozen section or with advanced cancer underwent para-aortic lymphadenectomy only. The operative technique was also evaluated.

RESULTS

Laparoscopy required an average of 77 min (S.D. 40), with an average blood loss of 116 ml (S.D. 321). The average number of nodes was 15 (S.D. 7). At subsequent laparotomy the average number of residual nodes found was 0.4 (S.D. 0.9) and none showed metastasis. One vena cava laceration and one ureteral injury required immediate repair, and two patients were too obese to undergo laparoscopy.

CONCLUSIONS

Laparoscopic para-aortic lymph node sampling is a less invasive, reliable method for staging invasive cervical carcinoma and can substitute for traditional open procedures. The incidence of risks with this method appears to be low.

Acute myocardial infarction in the young adults

A review was done on 631 patients with acute myocardial infarction who underwent coronary angiography within 30 days after onset of myocardial infarction at Yonsei University Severance Hospital from January, 1985, to August, 1993. The incidence of acute myocardial infarction in patients under 40 years of age was 10.3% (65/631). Acute myocardial infarction below the fourth decades was the predominant disease of men. Risk factor analysis revealed a history of cigarette smoking and hypercholesterolemia were more frequently found in the young patients, but a history of hypertension and diabetes were more frequently found in the elderly patients. Angiographically, the incidence of one vessel disease and normal or minimal lesion coronary anatomy were more frequent in the young patients and incidence of multi-vessel disease were more frequent in the elderly patients. Of the 65 patients under 40 with acute myocardial infarction, the patients with multi-vessel disease tended to have a history of diabetes mellitus in comparison with those with normal coronary anatomy or one vessel disease.