Expression of Tenascin-C Is Upregulated in the Early Stages of Radiation Pneumonitis/Fibrosis in a Novel Mouse Model.

The lung is a major dose-limiting organ for radiation therapy (RT) for cancer in the thoracic region, and the clarification of radiation-induced lung damage (RILD) is important. However, there have been few reports containing a detailed comparison of radiographic images with the pathological findings of radiation pneumonitis (RP)/radiation fibrosis (RF). We recently reported the upregulated expression of tenascin-C (TNC), an inflammation-associated extracellular matrix molecule, in surgically resected lung tissue, and elevated serum levels were elevated in a RILD patient. Therefore, we have developed a novel mouse model of partial lung irradiation and studied it with special attention paid to the computed tomography (CT) images and immunohistological findings. The right lungs of mice (BALB/c) were irradiated locally at 30 Gy/1fr, and the following two groups were created. In Group 1, sequential CT was performed to confirm the time-dependent changes in RILD. In Group 2, the CT images and histopathological findings of the lung were compared. RP findings were detected histologically at 16 weeks after irradiation; they were also observed on the CT images from 20 weeks. The immunostaining of TNC was observed before the appearance of RP on the CT images. The findings suggest that TNC could be an inflammatory marker preceding lung fibrosis.

Cardiovascular Magnetic Resonance Radiomics to Identify Components of the Extracellular Matrix in Dilated Cardiomyopathy.

BACKGROUND: Current cardiovascular magnetic resonance sequences cannot discriminate between different myocardial extracellular space (ECSs), including collagen, noncollagen, and inflammation. We sought to investigate whether cardiovascular magnetic resonance radiomics analysis can distinguish between noncollagen and inflammation from collagen in dilated cardiomyopathy. METHODS: We identified data from 132 patients with dilated cardiomyopathy scheduled for an invasive septal biopsy who underwent cardiovascular magnetic resonance at 3 T. Cardiovascular magnetic resonance imaging protocol included native and postcontrast T1 mapping and late gadolinium enhancement (LGE). Radiomic features were computed from the midseptal myocardium, near the biopsy region, on native T1, extracellular volume (ECV) map, and LGE images. Principal component analysis was used to reduce the number of radiomic features to 5 principal radiomics. Moreover, a correlation analysis was conducted to identify radiomic features exhibiting a strong correlation (r>0.9) with the 5 principal radiomics. Biopsy samples were used to quantify ECS, myocardial fibrosis, and inflammation. RESULTS: Four histopathological phenotypes were identified: low collagen (n=20), noncollagenous ECS expansion (n=49), mild to moderate collagenous ECS expansion (n=42), and severe collagenous ECS expansion (n=21). Noncollagenous expansion was associated with the highest risk of myocardial inflammation (65%). Although native T1 and ECV provided high diagnostic performance in differentiating severe fibrosis (C statistic, 0.90 and 0.90, respectively), their performance in differentiating between noncollagen and mild to moderate collagenous expansion decreased (C statistic: 0.59 and 0.55, respectively). Integration of ECV principal radiomics provided better discrimination and reclassification between noncollagen and mild to moderate collagen (C statistic, 0.79; net reclassification index, 0.83 [95% CI, 0.45-1.22]; P<0.001). There was a similar trend in the addition of native T1 principal radiomics (C statistic, 0.75; net reclassification index, 0.93 [95% CI, 0.56-1.29]; P<0.001) and LGE principal radiomics (C statistic, 0.74; net reclassification index, 0.59 [95% CI, 0.19-0.98]; P=0.004). Five radiomic features per sequence were identified with correlation analysis. They showed a similar improvement in performance for differentiating between noncollagen and mild to moderate collagen (native T1, ECV, LGE C statistic, 0.75, 0.77, and 0.71, respectively). These improvements remained significant when confined to a single radiomic feature (native T1, ECV, LGE C statistic, 0.71, 0.70, and 0.64, respectively). CONCLUSIONS: Radiomic features extracted from native T1, ECV, and LGE provide incremental information that improves our capability to discriminate noncollagenous expansion from mild to moderate collagen and could be useful for detecting subtle chronic inflammation in patients with dilated cardiomyopathy.

Comprehensive phenotypic and genomic characterization of venous malformations.

Venous malformations (VMs) are the most common vascular malformations. TEK and PIK3CA are the causal genes of VMs, and may be involved in the PI3K/AKT pathway. However, the downstream mechanisms underlying the TEK or PIK3CA mutations in VMs are not completely understood. This study aimed to identify a possible association between genetic mutations and clinicopathological features. A retrospective clinical, pathological, and genetic study of 114 patients with VMs was performed. TEK, PIK3CA, and combined TEK/PIK3CA mutations were identified in 49 (43%), 13 (11.4%), and 2 (1.75%) patients, respectively. TEK-mutant VMs more commonly occurred in younger patients than TEK and PIK3CA mutation-negative VMs (other-mutant VMs), and showed more frequent skin involvement and no lymphocytic aggregates. No significant differences were observed in sex, location of occurrence, malformed vessel size, vessel density, or thickness of the vascular smooth muscle among the VM genotypes. Immunohistochemical analysis revealed that the expression levels of phosphorylated AKT (p-AKT) were higher in the TEK-mutant VMs than those in PIK3CA-mutant and other-mutant VMs. The expression levels of p-mTOR and its downstream effectors were higher in all the VM genotypes than those in normal vessels. Spatial transcriptomics revealed that the genes involved in "blood vessel development", "positive regulation of cell migration", and "extracellular matrix organization" were up-regulated in a TEK-mutant VM. Significant genotype-phenotype correlations in clinical and pathological features were observed among the VM genotypes, indicating gene-specific effects. Detailed analysis of gene-specific effects in VMs may offer insights into the underlying molecular pathways and implications for targeted therapies.

Left Main Bronchus Obstruction in a Patient with Small-cell Lung Cancer Successfully Treated with Venovenous Extracorporeal Membrane Oxygenation.

Lung cancer can cause fatal central airway obstruction. Rapid airway clearance is necessary in some cases, but ventilator management may be insufficient to maintain oxygenation levels. Venovenous extracorporeal membrane oxygenation (VV-ECMO) may be an effective rescue therapy for respiratory failure, but its efficacy in treating tumor-related airway obstruction is unknown. We herein report a case of central airway obstruction and severe acute respiratory failure due to small-cell lung cancer successfully treated with VV-ECMO, bronchoscopic airway intervention, and chemotherapy. VV-ECMO can be an effective option for the treatment of central airway obstruction with acute respiratory failure due to lung cancer.

Improved Antitumor Effect of NK Cells Activated by Neutrophils in a Bone Marrow Transplant Model.

The licensing process mediated by inhibitory receptors of the Ly49 C-type lectin superfamily that recognizes self-major histocompatibility complex (MHC) class I in mice is essential for the proper antitumor function of natural killer (NK) cells. Several models for NK cell licensing can be exploited for adoptive immunotherapy for cancer. However, the appropriate adoptive transfer setting to induce efficient graft versus tumor/leukemia effects remains elusive, especially after hematopoietic stem cell transplantation (HSCT). In our previous experiment, we showed that intraperitoneal neutrophil administration with their corresponding NK receptor ligand-activated NK cells using congenic mice without HSCT. In this experiment, we demonstrate enhanced antitumor effects of licensed NK cells induced by weekly intraperitoneal injections of irradiated neutrophil-enriched peripheral blood mononuclear cells (PBMNCs) in recipient mice bearing lymphoma. Bone marrow transplantation was performed using BALB/c mice (H-2d) as the recipient and B10 mice (H-2b) as the donor. The tumor was A20, a BALB/c-derived lymphoma cell line, which was injected subcutaneously into the recipient at the same time as the HSCT. Acute graft versus host disease was not exacerbated in this murine MHC class I mismatched HSCT setting. The intraperitoneal injection of PBMNCs activated a transient licensing of NK subsets expressed Ly49G2, its corresponding NK receptor ligand to H-2d, and reduced A20 tumor growth in the recipient after HSCT. Pathological examination revealed that increased donor-oriented NK1.1+NK cells migrated into the recipient tumors, depending on neutrophil counts in the administered PBMNCs. Collectively, our data reveal a pivotal role of neutrophils in promoting NK cell effector functions and adoptive immunotherapy for cancer.

Adipocytes contribute to tumor progression and invasion of peritoneal metastasis by interacting with gastric cancer cells as cancer associated fibroblasts.

BACKGROUND: Peritoneal metastasis (PM) is one of the most common causes of noncurative surgery and the most frequent recurrence pattern in gastric cancer (GC). During the process of PM, GC cells detached from primary tumor interact with human peritoneal mesothelial cells (HPMC) overlapped with adipose tissues such as the omentum or mesentery. Although the interaction with HPMC promotes the malignancy of GC, the role of adipose tissues remains unclear. AIMS: We aimed to clarify how adipose tissue are affected by adjacent primary tumors during the expression of adipokines and to elucidate whether GC cells transform adipocytes into CAFs in vitro. In addition, we investigated whether GC cells are affected by adipocytes in their ability to infiltrate. METHODS: We investigated the phenotypic conversion of adipocytes during the malignant process of GC cells in vivo and in vitro. We evaluated the expression levels of adiponectin in the omental adipose tissue of gastric cancer patients by western blotting. Following adipocytes/gastric cancer cells coculture, adipocyte markers, adiponectin receptors, and inflammatory cytokine markers were detected by real-time PCR and/or western blotting in the single-cultured and co-cultured adipocytes; cancer-associated fibroblast (CAF) markers were detected by immunofluorescence and western blotting in the single-cultured and co-cultured adipocytes; invasion assays were performed in single cultured and co-cultured MKN45 and OCUM. RESULTS: In omental adipose tissues that are situated close to the primary tumors, the expression of adiponectin tended to decrease in patients with subserosal or serosal invasion. By co-culturing with GC cells, adipocytes were dedifferentiated and the expression levels of CAF marker FSP1 and inflammatory cytokines, PAI-1 and IL-6, significantly increased (p < 0.05). Furthermore, GC cells co-cultured with adipocytes showed enhanced invasion ability. CONCLUSION: Our findings suggest that the phenotypic conversion of adipocytes may promote the malignancy of GC in the construction of the cancer microenvironment of PM.

Tenascin C in radiation-induced lung damage: Pathological expression and serum level elevation.

Radiation-induced lung damage (RILD) is a critical problem in lung cancer radiotherapy, and it is difficult to predict its severity. Although no biomarkers for RILD have been established, tenascin C (TNC) is an extracellular matrix glycoprotein involved in the remodeling of damaged tissues and has been implicated in inflammation and fibrosis. We report the unique case of a 36-year-old man with adenocarcinoma of the lung, Union for International Cancer Control stage IIIB, who was treated with radiotherapy before lung surgery. The surgical specimen showed histopathological expression of TNC in the region where radiation pneumonitis was observed radiographically. Serum TNC levels were elevated after radiotherapy. In this case, TNC is suggested to be implicated in RILD and may be a potential candidate as a biomarker for the onset and severity of the condition.

Peripartum Mid-Ventricular-Type Takotsubo Cardiomyopathy After Cesarean Delivery.

There are several causes of heart failure during pregnancy and the peripartum period, which include peripartum cardiomyopathy, Takotsubo cardiomyopathy or stress cardiomyopathy, exacerbation of a preexisting cardiomyopathy, and acute myocarditis. It is important to determine the cause of the heart failure as the medical treatment may be different based on the diagnosis. However, it has been sometimes challenging to diagnose the cause because of the limited diagnostic tools, especially in pregnant women. Cardiac MRI can characterize myocardial injury and can be used to track the changes in myocardial tissue. We herein report a 35-year-old woman diagnosed with peripartum mid-ventricular-type Takotsubo cardiomyopathy, who was referred to our hospital due to worsening dyspnea the day after cesarean delivery. On admission, electrocardiography showed sinus tachycardia and poor progression of R waves in the precordial leads. Bedside echocardiography revealed severe hypokinesis in the mid- and apical left ventricle (LV) with a LV ejection fraction of 20%. Cardiac catheterization showed normal coronary arteries, and myocardial biopsy revealed contraction band necrosis. On acute phase (Day 4), cardiac MRI showed prolonged native T1 and T2, and severe hypokinesis and decreased regional longitudinal peak strain in the mid-anterior LV wall. During the 1st week, precordial ST fluctuation was observed, and LV wall motion had gradually recovered. Repeat cardiac MRI revealed normalized LV wall motion and shortened values for global native T1 and T2. Thus, she was diagnosed with peripartum Takotsubo cardiomyopathy. Serial cardiac MRI may be able to differentiate Takotsubo cardiomyopathy during pregnancy and the peripartum period from other preexisting cardiomyopathies.

Multiscale model of heart growth during pregnancy: integrating mechanical and hormonal signaling.

Pregnancy stands at the interface of mechanics and biology. The growing fetus continuously loads the maternal organs as circulating hormone levels surge, leading to significant changes in mechanical and hormonal cues during pregnancy. In response, maternal soft tissues undergo remarkable growth and remodeling to support the mother and baby for a healthy pregnancy. We focus on the maternal left ventricle, which increases its cardiac output and mass during pregnancy. This study develops a multiscale cardiac growth model for pregnancy to understand how mechanical and hormonal cues interact to drive this growth process. We coupled a cell signaling network model that predicts cell-level hypertrophy in response to hormones and stretch to a compartmental model of the rat heart and circulation that predicts organ-level growth in response to hemodynamic changes. We calibrated this multiscale model to data from experimental volume overload and hormonal infusions of angiotensin 2 (AngII), estrogen (E2), and progesterone (P4). We then validated the model's ability to capture interactions between inputs by comparing model predictions against published observations for the combinations of VO + E2 and AngII + E2. Finally, we simulated pregnancy-induced changes in hormones and hemodynamics to predict heart growth during pregnancy. Our model produced growth consistent with experimental data. Overall, our analysis suggests that the rise in P4 during the first half of gestation is an important contributor to heart growth during pregnancy. We conclude with suggestions for future experimental studies that will provide a better understanding of how hormonal and mechanical cues interact to drive pregnancy-induced heart growth.

Aryl Hydrocarbon Receptor Directly Regulates VTCN1 Gene Expression in MCF-7 Cells.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxicity of dioxins and polycyclic aromatic hydrocarbons. Recent studies have suggested that AhR is involved in cancer immunity. In the present study, we examined whether AhR regulates the expression of immune checkpoint genes in breast cancer cells. We discovered that the mRNA expression of V-set domain containing T cell activation inhibitor 1 (VTCN1) that negatively regulates T cell immunity was upregulated by AhR agonists in breast cancer cell lines, MCF-7 and T47D. Furthermore, AhR knockout or knockdown experiments clearly demonstrated that upregulation of VTCN1 gene expression by 3-methylcholanthrene was AhR dependent. Luciferase reporter and chromatin immunoprecipitation assays revealed that this upregulation of VTCN1 gene expression was induced by the recruitment of AhR to the AhR responsive element in the VTCN1 gene promoter in MCF-7 cells. Taken together, AhR directly regulates VTCN1 gene expression in MCF-7 cells.

Myocardial T-Lymphocytes as a Prognostic Risk-Stratifying Marker of Dilated Cardiomyopathy　- Results of the Multicenter Registry to Investigate Inflammatory Cell Infiltration in Dilated Cardiomyopathy in Tissues of Endomyocardial Biopsy (INDICATE Study).

BACKGROUND: Dilated cardiomyopathy (DCM) associated with inflammation is diagnosed by endomyocardial biopsy; patients with this have a poorer prognosis than patients without inflammation. To date, standard diagnostic criteria have not been established.Methods and Results: This study analyzed clinical records and endomyocardial biopsy samples of 261 patients with DCM (201 males, median left ventricular ejection fraction; 28%) from 8 institutions in a multicenter retrospective study. Based on the European Society of Cardiology criteria and CD3 (T-lymphocytes) and CD68 (macrophages) immunohistochemistry, 48% of patients were categorized as having inflammatory DCM. For risk-stratification, we divided patients into 3 groups using Akaike Information Criterion/log-rank tests, which can determine multiple cut-off points: CD3+-Low, <13/mm2(n=178, 68%); CD3+-Moderate, 13-24/mm2(n=58, 22%); and CD3+-High, ≥24/mm2(n=25, 10%). The survival curves for cardiac death or left ventricular assist device implantation differed significantly among the 3 groups (10-year survival rates: CD3+-Low: 83.4%; CD3+-Moderate: 68.4%; CD3+-High: 21.1%; Log-rank P<0.001). Multivariate Cox analysis revealed CD3+count as a potent independent predictive factor for survival (fully adjusted hazard ratio: CD3+-High: 5.70, P<0.001; CD3+-Moderate: 2.64, P<0.01). CD3+-High was also associated with poor left ventricular functional and morphological recovery at short-term follow up. CONCLUSIONS: Myocardial CD3+T-lymphocyte infiltration has a significant prognostic impact in DCM and a 3-tiered risk-stratification model could be helpful to refine patient categorization.

Subtle-but-smouldering myocardial injury after immune checkpoint inhibitor treatment accompanied by amyloid deposits.

Although cardiac troponin is a highly specific biomarker for myocardial cell injury, it is important to recognize the pitfalls of this test in the diagnosis and management of immune checkpoint inhibitor (ICI) myocarditis. We describe the challenging case of an 81-year-old woman with persistently high troponin after undergoing immunotherapy with ipilimumab and nivolumab, and histological evidence of amyloid deposition in the myocardium. The patient received immunosuppressive treatments based on the magnitude of troponin changes because myocarditis was clinically suspected. However, histological examination revealed the deposition of transthyretin amyloid fibrils with only minimal T-lymphocyte infiltration and no myocyte necrosis, suggesting transthyretin cardiac amyloidosis rather than ICI myocarditis. This case highlights the importance of assessing other causes of persistently high troponin, and the necessity of incorporating comprehensive histological and immunohistochemical examinations of the endomyocardial biopsy, especially when cardiovascular magnetic resonance imaging is inconclusive.

Clinical significance of chronic myocarditis: systematic review and meta-analysis.

Chronic myocarditis is a prolonged inflammatory condition in the myocardium and its histological manifestation is defined by the presence of an inflammatory infiltrate. Chronic myocarditis has not been well known and its treatment of chronic myocarditis has not been established. Primary outcome of this study was to assess the efficacy of immunomodulatory treatment in addition to conventional treatment, and secondary outcomes were to clarity the prognosis of natural history of chronic myocarditis and incidence of chronic myocarditis in patients with dilated cardiomyopathy (DCM). We searched for studies in Medline, Embase, Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi published between January 1946 and June 2020. Sixteen studies met the inclusion criteria. A meta-analysis revealed that patients receiving immunomodulatory treatment showed an improvement in left ventricular ejection fraction after immunomodulatory treatment compared to the control group (hazard ratio, 16.65; confidence interval, 4.55-28.74; p = 0.007). Five-year survival rate of the patients with inflammatory DCM (iDCM) and DCM was 52.7-70.3% and 51.9-91.1%, respectively. Moreover, 51.5%-62.7% of patients with DCM met the criteria of iDCM. Our systematic review revealed that patients with chronic myocarditis had poor prognosis and immunomodulatory treatment was significantly effective in addition to conventional treatment.

Pathological Q-Waves With Coronary Artery Spasm.

This case highlights the diagnostic challenge associated with myocarditis, especially when accompanied by coronary spasm. Any coronary spasm with hemodynamic instability and/or an inexplicable widespread electrocardiogram should alert the clinician to the possibility of fulminant myocarditis and the necessity of endomyocardial biopsy for treatment decisions. (Level of Difficulty: Beginner.).

Case Report: Acute Eosinophilic Myocarditis With a Low-Flow Heart Failure With Preserved Ejection Fraction Phenotype.

Eosinophilic myocarditis is a rare subtype of myocarditis characterized by myocardial eosinophilic infiltration, and it is potentially fatal if left untreated. Although endomyocardial biopsy (EMB) is a cornerstone for the histological diagnosis of acute eosinophilic myocarditis (AEM), as it is an invasive procedure and has a low diagnostic accuracy, the diagnosis of AEM with hemodynamic instability remains challenging. We describe a case of AEM presenting as low-flow heart failure with preserved ejection fraction (HFpEF), with rapid progression to cardiogenic shock. The constellation of peripheral eosinophilia, increased left ventricular wall thickness, and HFpEF raised the suspicion of AEM. Contrast-enhanced computed tomography (CT) scan revealed heterogeneous hypoenhancement localized in the basal-to-mid septal and mid anterolateral walls of the left ventricle, strongly suggestive of acute inflammation. Based upon these findings, we performed CT-guided EMB, which lead to a definitive diagnosis. Subsequent high-dose corticosteroids allowed a rapid and dramatic recovery and normalization of cardiac structure and function. This case highlights the clinical importance of assessing AEM as a rare cause of HFpEF and the usefulness of CT-guided EMB in patients with hemodynamic instability.

Trajectory of left ventricular geometry and diastolic dysfunction in hereditary transthyretin cardiac amyloidosis.

Amyloid transthyretin (ATTR) depositions cause left ventricular (LV) hypertrophy, diastolic dysfunction, and heart failure. The time course of changes in LV geometry and diastolic dysfunction has not been fully reported in patients with ATTR cardiomyopathy. A 79-year-old woman with previous myocardial infraction presented with shortness of breath on exertion, and progressive bilateral lower extremity weakness and polyneuropathy. She was diagnosed with Val30Met hereditary ATTR cardiomyopathy by cardiac biopsy and genetic testing. During the past 5 year period, significant LV concentric remodelling with small LV cavity occurred, resulting in an increased LV stiffness and prolonged LV relaxation. This case report highlights the time course of changes in LV geometry and diastolic function and the importance of early diagnosis of ATTR cardiomyopathy.

Tenascin-C in Heart Diseases-The Role of Inflammation.

Tenascin-C (TNC) is a large extracellular matrix (ECM) glycoprotein and an original member of the matricellular protein family. TNC is transiently expressed in the heart during embryonic development, but is rarely detected in normal adults; however, its expression is strongly up-regulated with inflammation. Although neither TNC-knockout nor -overexpressing mice show a distinct phenotype, disease models using genetically engineered mice combined with in vitro experiments have revealed multiple significant roles for TNC in responses to injury and myocardial repair, particularly in the regulation of inflammation. In most cases, TNC appears to deteriorate adverse ventricular remodeling by aggravating inflammation/fibrosis. Furthermore, accumulating clinical evidence has shown that high TNC levels predict adverse ventricular remodeling and a poor prognosis in patients with various heart diseases. Since the importance of inflammation has attracted attention in the pathophysiology of heart diseases, this review will focus on the roles of TNC in various types of inflammatory reactions, such as myocardial infarction, hypertensive fibrosis, myocarditis caused by viral infection or autoimmunity, and dilated cardiomyopathy. The utility of TNC as a biomarker for the stratification of myocardial disease conditions and the selection of appropriate therapies will also be discussed from a clinical viewpoint.