Involvement of Lamin B1 Reduction in Accelerated Cellular Senescence during Chronic Obstructive Pulmonary Disease Pathogenesis.

Downregulation of lamin B1 has been recognized as a crucial step for development of full senescence. Accelerated cellular senescence linked to mechanistic target of rapamycin kinase (MTOR) signaling and accumulation of mitochondrial damage has been implicated in chronic obstructive pulmonary disease (COPD) pathogenesis. We hypothesized that lamin B1 protein levels are reduced in COPD lungs, contributing to the process of cigarette smoke (CS)-induced cellular senescence via dysregulation of MTOR and mitochondrial integrity. To illuminate the role of lamin B1 in COPD pathogenesis, lamin B1 protein levels, MTOR activation, mitochondrial mass, and cellular senescence were evaluated in CS extract (CSE)-treated human bronchial epithelial cells (HBEC), CS-exposed mice, and COPD lungs. We showed that lamin B1 was reduced by exposure to CSE and that autophagy was responsible for lamin B1 degradation in HBEC. Lamin B1 reduction was linked to MTOR activation through DEP domain-containing MTOR-interacting protein (DEPTOR) downregulation, resulting in accelerated cellular senescence. Aberrant MTOR activation was associated with increased mitochondrial mass, which can be attributed to peroxisome proliferator-activated receptor γ coactivator-1ß-mediated mitochondrial biogenesis. CS-exposed mouse lungs and COPD lungs also showed reduced lamin B1 and DEPTOR protein levels, along with MTOR activation accompanied by increased mitochondrial mass and cellular senescence. Antidiabetic metformin prevented CSE-induced HBEC senescence and mitochondrial accumulation via increased DEPTOR expression. These findings suggest that lamin B1 reduction is not only a hallmark of lung aging but is also involved in the progression of cellular senescence during COPD pathogenesis through aberrant MTOR signaling.

Involvement of PARK2-Mediated Mitophagy in Idiopathic Pulmonary Fibrosis Pathogenesis.

Fibroblastic foci, known to be the leading edge of fibrosis development in idiopathic pulmonary fibrosis (IPF), are composed of fibrogenic myofibroblasts. Autophagy has been implicated in the regulation of myofibroblast differentiation. Insufficient mitophagy, the mitochondria-selective autophagy, results in increased reactive oxygen species, which may modulate cell signaling pathways for myofibroblast differentiation. Therefore, we sought to investigate the regulatory role of mitophagy in myofibroblast differentiation as a part of IPF pathogenesis. Lung fibroblasts were used in in vitro experiments. Immunohistochemical evaluation in IPF lung tissues was performed. PARK2 was examined as a target molecule for mitophagy regulation, and a PARK2 knockout mouse was employed in a bleomycin-induced lung fibrosis model. We demonstrated that PARK2 knockdown-mediated mitophagy inhibition was involved in the mechanism for activation of the platelet-derived growth factor receptor (PDGFR)/PI3K/AKT signaling pathway accompanied by enhanced myofibroblast differentiation and proliferation, which were clearly inhibited by treatment with both antioxidants and AG1296, a PDGFR inhibitor. Mitophagy inhibition-mediated activation of PDGFR signaling was responsible for further autophagy suppression, suggesting the existence of a self-amplifying loop of mitophagy inhibition and PDGFR activation. IPF lung demonstrated reduced PARK2 with concomitantly increased PDGFR phosphorylation. Furthermore, bleomycin-induced lung fibrosis was enhanced in PARK2 knockout mice and subsequently inhibited by AG1296. These findings suggest that insufficient mitophagy-mediated PDGFR/PI3K/AKT activation, which is mainly attributed to reduced PARK2 expression, is a potent underlying mechanism for myofibroblast differentiation and proliferation in fibroblastic foci formation during IPF pathogenesis.

Pirfenidone inhibits myofibroblast differentiation and lung fibrosis development during insufficient mitophagy.

BACKGROUND: Pirfenidone (PFD) is an anti-fibrotic agent used to treat idiopathic pulmonary fibrosis (IPF), but its precise mechanism of action remains elusive. Accumulation of profibrotic myofibroblasts is a crucial process for fibrotic remodeling in IPF. Recent findings show participation of autophagy/mitophagy, part of the lysosomal degradation machinery, in IPF pathogenesis. Mitophagy has been implicated in myofibroblast differentiation through regulating mitochondrial reactive oxygen species (ROS)-mediated platelet-derived growth factor receptor (PDGFR) activation. In this study, the effect of PFD on autophagy/mitophagy activation in lung fibroblasts (LF) was evaluated, specifically the anti-fibrotic property of PFD for modulation of myofibroblast differentiation during insufficient mitophagy. METHODS: Transforming growth factor-ß (TGF-ß)-induced or ATG5, ATG7, and PARK2 knockdown-mediated myofibroblast differentiation in LF were used for in vitro models. The anti-fibrotic role of PFD was examined in a bleomycin (BLM)-induced lung fibrosis model using PARK2 knockout (KO) mice. RESULTS: We found that PFD induced autophagy/mitophagy activation via enhanced PARK2 expression, which was partly involved in the inhibition of myofibroblast differentiation in the presence of TGF-ß. PFD inhibited the myofibroblast differentiation induced by PARK2 knockdown by reducing mitochondrial ROS and PDGFR-PI3K-Akt activation. BLM-treated PARK2 KO mice demonstrated augmentation of lung fibrosis and oxidative modifications compared to those of BLM-treated wild type mice, which were efficiently attenuated by PFD. CONCLUSIONS: These results suggest that PFD induces PARK2-mediated mitophagy and also inhibits lung fibrosis development in the setting of insufficient mitophagy, which may at least partly explain the anti-fibrotic mechanisms of PFD for IPF treatment.

Comparison of oncological results for early- and advanced-stage thymomas: thoracoscopic thymectomy versus open thymectomy.

BACKGROUND: This study evaluated the feasibility of thoracoscopic thymectomy (TT) for the treatment of early- and advanced-stage thymoma and compared patient outcomes with those following open thymectomy (OT). METHODS: A retrospective review was conducted for 140 patients who underwent TT or OT for Masaoka stage I-IV thymoma between 1996 and 2014. RESULTS: TT was performed in 88 patients and OT in 52 patients. The postoperative hospital stay was significantly shorter in the TT group than in the OT group (4 and 13 days, respectively; P < 0.0001). WHO types B3-C were identified in Masaoka stage III-IV disease with high frequency. There was a significant relationship between Masaoka stage and WHO type (P < 0.05); the numbers of advanced-stage thymoma progressively increased in WHO type B3-C. Eight patients in each group had recurrent disease, with greater recurrence for WHO types B3-C and stage III-IV tumors. Five-year disease-free survival (DFS) was not different between groups (P = 0.3906); however, survival for patients with stage III-IV thymomas (47 %) was significantly worse than that for patients with stage I and II tumors (97.5 and 94.1 %, respectively; P < 0.0001). Based on multivariate analysis, both Masaoka stage and WHO type were significant predictors of thymoma patient survival. CONCLUSIONS: These results demonstrate the safety and substantially decreased invasiveness of TT for thymoma. The oncological results were comparable between the TT and OT groups. Furthermore, Masaoka stage III-IV and WHO B3-C were revealed as independent prognostic factors for DFS.

Metformin attenuates lung fibrosis development via NOX4 suppression.

BACKGROUND: Accumulation of profibrotic myofibroblasts in fibroblastic foci (FF) is a crucial process for development of fibrosis during idiopathic pulmonary fibrosis (IPF) pathogenesis, and transforming growth factor (TGF)-ß plays a key regulatory role in myofibroblast differentiation. Reactive oxygen species (ROS) has been proposed to be involved in the mechanism for TGF-ß-induced myofibroblast differentiation. Metformin is a biguanide antidiabetic medication and its pharmacological action is mediated through the activation of AMP-activated protein kinase (AMPK), which regulates not only energy homeostasis but also stress responses, including ROS. Therefore, we sought to investigate the inhibitory role of metformin in lung fibrosis development via modulating TGF-ß signaling. METHODS: TGF-ß-induced myofibroblast differentiation in lung fibroblasts (LF) was used for in vitro models. The anti-fibrotic role of metfromin was examined in a bleomycin (BLM)-induced lung fibrosis model. RESULTS: We found that TGF-ß-induced myofibroblast differentiation was clearly inhibited by metformin treatment in LF. Metformin-mediated activation of AMPK was responsible for inhibiting TGF-ß-induced NOX4 expression. NOX4 knockdown and N-acetylcysteine (NAC) treatment illustrated that NOX4-derived ROS generation was critical for TGF-ß-induced SMAD phosphorylation and myofibroblast differentiation. BLM treatment induced development of lung fibrosis with concomitantly enhanced NOX4 expression and SMAD phosphorylation, which was efficiently inhibited by metformin. Increased NOX4 expression levels were also observed in FF of IPF lungs and LF isolated from IPF patients. CONCLUSIONS: These findings suggest that metformin can be a promising anti-fibrotic modality of treatment for IPF affected by TGF-ß.

Autophagy induction by SIRT6 through attenuation of insulin-like growth factor signaling is involved in the regulation of human bronchial epithelial cell senescence.

Cigarette smoke (CS)-induced cellular senescence has been implicated in the pathogenesis of chronic obstructive pulmonary disease, and SIRT6, a histone deacetylase, antagonizes this senescence, presumably through the attenuation of insulin-like growth factor (IGF)-Akt signaling. Autophagy controls cellular senescence by eliminating damaged cellular components and is negatively regulated by IGF-Akt signaling through the mammalian target of rapamycin (mTOR). SIRT1, a representative sirtuin family, has been demonstrated to activate autophagy, but a role for SIRT6 in autophagy activation has not been shown. Therefore, we sought to investigate the regulatory role for SIRT6 in autophagy activation during CS-induced cellular senescence. SIRT6 expression levels were modulated by cDNA and small interfering RNA transfection in human bronchial epithelial cells (HBECs). Senescence-associated ß-galactosidase staining and Western blotting of p21 were performed to evaluate senescence. We demonstrated that SIRT6 expression levels were decreased in lung homogenates from chronic obstructive pulmonary disease patients, and SIRT6 expression levels correlated significantly with the percentage of forced expiratory volume in 1 s/forced vital capacity. CS extract (CSE) suppressed SIRT6 expression in HBECs. CSE-induced HBEC senescence was inhibited by SIRT6 overexpression, whereas SIRT6 knockdown and mutant SIRT6 (H133Y) without histone deacetylase activity enhanced HBEC senescence. SIRT6 overexpression induced autophagy via attenuation of IGF-Akt-mTOR signaling. Conversely, SIRT6 knockdown and overexpression of a mutant SIRT6 (H133Y) inhibited autophagy. Autophagy inhibition by knockdown of ATG5 and LC3B attenuated the antisenescent effect of SIRT6 overexpression. These results suggest that SIRT6 is involved in CSE-induced HBEC senescence via autophagy regulation, which can be attributed to attenuation of IGF-Akt-mTOR signaling.

Prognostic factors in pulmonary metastases resection from colorectal cancer: impact of right-sided colon cancer and early recurrence.

OBJECTIVE: This retrospective cohort study aimed to explore the surgical outcomes and prognostic factors of resection of pulmonary metastases (PM) from colorectal cancer (CRC). METHODS: Overall, 60 patients who underwent resection of PM from CRC between 2015 and 2021 at two institutions were reviewed. The primary outcome were overall survival (OS) and early recurrence after PM resection. The association between OS and right-sided colon cancer (RCC) was investigated. Early recurrence after PM resection was defined as recurrence within one year. RESULTS: The 5-year OS after CRC resection was 83.8% (95% confidence interval [CI] 67.5-92.4) and after PM resection was 69.4% (95% CI 47.5-83.6). In total, 25 patients had recurrence after PM resection (16 within 1 year and 9 after 1 year). In multivariable analysis for OS, RCC (hazard ratio [HR] 4.370, 95% CI 1.020-18.73; p = 0.047) and early recurrence after resection of PM (HR 17.23, 95% CI 2.685-110.6; p = 0.003) were risk factors for poor OS. In multivariable analysis for early recurrence after PM resection, higher value of carcinoembryonic antigen (CEA) (> 5.0 mg/dL) before PM resection was a risk factor for early recurrence (HR 3.275, 95% CI 1.092-9.821; p = 0.034). CONCLUSION: The RCC and early recurrence after PM resection were poor prognosis factors of OS. Higher value of CEA before PM resection was an independent risk factor for early recurrence after resection of PM. Comparitive study between surgery and nonsurgery is necessary in patients with higher CEA values.

Reduction in drain-related adverse events using the barbed suture method for chest tube wound closure.

OBJECTIVE: A chest tube is usually placed in patients undergoing general thoracic surgery. Although the barbed suture method has been introduced for chest tube wound closure, its superiority to the conventional suture methods for drain management remains unclear. The study aimed to determine whether the barbed suture method could reduce drain-related adverse events compared to the conventional method. METHODS: We retrospectively reviewed the medical records of patients who underwent general thoracic surgery between January 2021 and December 2022, 1 year before and after the introduction of the barbed suture method at our institution. Patients who underwent the barbed suture or conventional method were included. Univariate and multivariate analyses of drain-related adverse events were performed. RESULTS: Of the 250 participants, 110 and 140 underwent the barbed suture method and conventional suture method, respectively. The univariate analysis showed that a higher body mass index, preoperative malignant diagnosis, lobectomy, longer operative time, larger tube size, longer chest drainage duration, surgical complications, and conventional method were risk factors for drain-related adverse events. The multivariate analysis showed that the barbed suture method was a protective factor against drain-related adverse events (odds ratio 0.267; 95% confidence interval 0.103-0.691; P = 0.007). CONCLUSIONS: The barbed suture method could reduce drain-related adverse events compared to the conventional method. Therefore, it might be a potential standard method for chest tube wound closure in patients undergoing general thoracic surgery.

Surgical treatment for pulmonary metastasis from ovarian cancer: a retrospective case series.

BACKGROUND: Distant metastases of ovarian cancer are rarely detected alone. The effectiveness of surgical intervention for pulmonary metastases from ovarian cancer remains uncertain. This study aimed to investigate the clinicopathologic characteristics and outcomes of patients undergoing resection for pulmonary metastasis from ovarian cancer. CASE PRESENTATION: The clinicopathologic characteristics and outcomes of radical surgery for pulmonary metastasis from ovarian cancer were investigated. Out of 537 patients who underwent pulmonary metastasis resection at two affiliated hospitals between 2010 and 2021, four (0.74%) patients who underwent radical surgery for pulmonary metastasis from ovarian cancer were included. The patients were aged 67, 47, 21, and 59 years; the intervals from primary surgery to detection of pulmonary metastasis from ovarian cancer were 94, 21, 36, and 50 months; and the overall survival times after pulmonary metastasectomy were 53, 50, 94, and 34 months, respectively. Three of the four patients experienced recurrence after pulmonary metastasectomy. Further, preoperative carbohydrate antigen (CA) 125 levels were normal in two surviving patients and elevated in the two deceased patients. CONCLUSION: In this study, three of the four patients experienced recurrence after pulmonary metastasectomy, but all patients survived for > 30 months after surgery. Patients with ovarian cancer and elevated CA125 levels may not be optimal candidates for pulmonary metastasectomy. To establish appropriate criteria for pulmonary metastasectomy in patients with ovarian cancer, further research on a larger patient cohort is warranted.

Mitochondrial fragmentation in cigarette smoke-induced bronchial epithelial cell senescence.

Mitochondria are dynamic organelles that continuously change their shape through fission and fusion. Disruption of mitochondrial dynamics is involved in disease pathology through excessive reactive oxygen species (ROS) production. Accelerated cellular senescence resulting from cigarette smoke exposure with excessive ROS production has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). Hence, we investigated the involvement of mitochondrial dynamics and ROS production in terms of cigarette smoke extract (CSE)-induced cellular senescence in human bronchial epithelial cells (HBEC). Mitochondrial morphology was examined by electron microscopy and fluorescence microscopy. Senescence-associated ß-galactosidase staining and p21 Western blotting of primary HBEC were performed to evaluate cellular senescence. Mitochondrial-specific superoxide production was measured by MitoSOX staining. Mitochondrial fragmentation was induced by knockdown of mitochondrial fusion proteins (OPA1 or Mitofusins) by small-interfering RNA transfection. N-acetylcysteine and Mito-TEMPO were used as antioxidants. Mitochondria in bronchial epithelial cells were prone to be more fragmented in COPD lung tissues. CSE induced mitochondrial fragmentation and mitochondrial ROS production, which were responsible for acceleration of cellular senescence in HBEC. Mitochondrial fragmentation induced by knockdown of fusion proteins also increased mitochondrial ROS production and percentages of senescent cells. HBEC senescence and mitochondria fragmentation in response to CSE treatment were inhibited in the presence of antioxidants. CSE-induced mitochondrial fragmentation is involved in cellular senescence through the mechanism of mitochondrial ROS production. Hence, disruption of mitochondrial dynamics may be a part of the pathogenic sequence of COPD development.

Insufficient autophagy in idiopathic pulmonary fibrosis.

Autophagy, a process that helps maintain homeostatic balance between the synthesis, degradation, and recycling of organelles and proteins to meet metabolic demands, plays an important regulatory role in cellular senescence and differentiation. Here we examine the regulatory role of autophagy in idiopathic pulmonary fibrosis (IPF) pathogenesis. We test the hypothesis that epithelial cell senescence and myofibroblast differentiation are consequences of insufficient autophagy. Using biochemical evaluation of in vitro models, we find that autophagy inhibition is sufficient to induce acceleration of epithelial cell senescence and myofibroblast differentiation in lung fibroblasts. Immunohistochemical evaluation of human IPF biospecimens reveals that epithelial cells show increased cellular senescence, and both overlaying epithelial cells and fibroblasts in fibroblastic foci (FF) express both ubiquitinated proteins and p62. These findings suggest that insufficient autophagy is an underlying mechanism of both accelerated cellular senescence and myofibroblast differentiation in a cell-type-specific manner and is a promising clue for understanding the pathogenesis of IPF.

Apoptosis inhibitor of macrophage (AIM) expression in alveolar macrophages in COPD.

BACKGROUND: Marked accumulation of alveolar macrophages (AM) conferred by apoptosis resistance has been implicated in pathogenesis of chronic obstructive pulmonary disease (COPD). Apoptosis inhibitor of macrophage (AIM), has been shown to be produced by mature tissue macrophages and AIM demonstrates anti-apoptotic property against multiple apoptosis-inducing stimuli. Accordingly, we attempt to determine if AIM is expressed in AM and whether AIM is involved in the regulation of apoptosis in the setting of cigarette smoke extract (CSE) exposure. METHODS: Immunohistochemical evaluations of AIM were performed. Immunostaining was assessed by counting total and positively staining AM numbers in each case (n = 5 in control, n = 5 in non-COPD smoker, n = 5 in COPD). AM were isolated from bronchoalveolar lavage fluid (BALF). The changes of AIM expression levels in response to CSE exposure in AM were evaluated. Knock-down of anti-apoptotic Bcl-xL was mediated by siRNA transfection. U937 monocyte-macrophage cell line was used to explore the anti-apoptotic properties of AIM. RESULTS: The numbers of AM and AIM-positive AM were significantly increased in COPD lungs. AIM expression was demonstrated at both mRNA and protein levels in isolated AM, which was enhanced in response to CSE exposure. AIM significantly increased Bcl-xL expression levels in AM and Bcl-xL was involved in a part of anti-apoptotic mechanisms of AIM in U937 cells in the setting of CSE exposure. CONCLUSIONS: These results suggest that AIM expression in association with cigarette smoking may be involved in accumulation of AM in COPD.

Insulin-dependent phosphatidylinositol 3-kinase/Akt and ERK signaling pathways inhibit TLR3-mediated human bronchial epithelial cell apoptosis.

TLR3, one of the TLRs involved in the recognition of infectious pathogens for innate and adaptive immunity, primarily recognizes viral-associated dsRNA. Recognition of dsRNA byproducts released from apoptotic and necrotic cells is a recently proposed mechanism for the amplification of toxicity, suggesting a pivotal participation of TLR3 in viral infection, as well as in lung diseases where apoptosis plays a critical role, such as asthma and chronic obstructive pulmonary disease. In addition to metabolic control, insulin signaling was postulated to be protective by inhibiting apoptosis. Therefore, we explored the role of insulin signaling in protecting against TLR3-mediated apoptosis of human bronchial epithelial cells. Significant TLR3-mediated apoptosis was induced by polyinosinic-polycytidylic acid, a dsRNA analog, via caspase-8-dependent mechanisms. However, insulin efficiently inhibited TLR3/polyinosinic-polycytidylic acid-induced human bronchial epithelial cell apoptosis via PI3K/Akt and ERK pathways, at least in part, via upregulation of cellular FLIPs and through protein synthesis-independent mechanisms. These results indicate the significance of TLR3-mediated dsRNA-induced apoptosis in the pathogenesis of apoptosis-driven lung disease and provide evidence for a novel protective role of insulin.

Pulmonary metastases of a borderline ovarian tumor with multiple cystic formations: a case report.

BACKGROUND: Metastatic lung tumors rarely present with cystic formations. This is the first report of multiple cystic formations in pulmonary metastases from mucinous borderline ovarian tumors written in English. CASE PRESENTATION: A 41-year-old woman underwent left adnexectomy + partial omentectomy + para-aortic lymphadenectomy for a left ovarian tumor 4 years ago. The pathological finding was mucinous borderline ovarian tumor with a microinvasion. A chest computed tomography performed 3 years after surgery revealed multiple cystic lesions in both lungs. After 1-year follow-up, the cysts increased in size and wall thickness. Subsequently, she was referred to our department with multiple cystic lesions in both lungs. No laboratory findings indicated infectious diseases or autoimmune disorders that could cause cystic lesions in both lungs. Positron emission tomography showed slight accumulation in the cyst wall. Partial resection of the left lower lobe was performed to confirm the pathological diagnosis. The diagnosis was consistent with pulmonary metastases from a previous mucinous borderline ovarian tumor. CONCLUSIONS: This is a rare case of lung metastases from a mucinous borderline ovarian tumor presenting with multiple lesions with cystic formation. Pulmonary cystic formations in patients with a borderline ovarian tumor should be considered as possible pulmonary metastases.

Comparative study of local versus general anesthesia in video-assisted thoracoscopic surgery for empyema.

OBJECTIVE: This study evaluated the feasibility of performing non-intubated video-assisted thoracoscopic surgery (VATS) with local anesthesia for parapneumonic effusion and empyema resistant to conservative treatment. METHODS: We retrospectively reviewed 80 patients who underwent surgery for parapneumonic effusions and empyema between 2015 and 2021. Patients were divided into those who received non-intubated local anesthesia and general anesthesia during surgery. Patient demographics, characteristics, laboratory findings, treatment progress, and treatment outcomes were compared. The primary outcomes were duration of postoperative drainage, postoperative complication rate, and postoperative mortality rate within 30 days. RESULTS: Among patients who received local (n = 21) and general anesthesia (n = 59), there was a significant difference in age (median 79.0 years [interquartile range (IQR) 77.0-80.0] vs. 68.0 years [IQR 54.5-77.5]; p < 0.001), preoperative performance status (3.0 [IQR 2.0-4.0] vs. 2.0 [IQR 1.0-3.0]; p < 0.001), and operative time (69 min [IQR 50-128] vs. 150 min [IQR 107-198]; p < 0.001) but not in preoperative white blood cell count (12,100/µL [IQR 8,400-18000] vs. 12,220/µL [IQR 8,950-16,724]; p = 0.840), C-reactive protein (15.2 mg/dL [8.8-21.3] vs. 17.9 mg/dL [IQR 9.5-23.6]; p = 0.623), postoperative drainage period (11 days [IQR 7-14] vs. 9 days [7-13]; p = 0.216), postoperative hospital stay (22 days [IQR 16-53] vs. 18 days [IQR 12-26]; p = 0.094), reoperation rate (9.5% vs. 15.3%; p = 0.775), postoperative complication rate (19.0% vs. 18.6%; p = 0.132), or postoperative 30-day mortality rate (4.8% vs. 0%; p = 0.587). CONCLUSIONS: VATS using local anesthesia is feasible for patients with treatment-resistant parapneumonic effusion and empyema with poor general condition.

Involvement of creatine kinase B in cigarette smoke-induced bronchial epithelial cell senescence.

Cigarette smoke induces damage to proteins and organelles by oxidative stress, resulting in accelerated epithelial cell senescence in the lung, which is implicated in chronic obstructive pulmonary disease (COPD) pathogenesis. Although the detailed molecular mechanisms are not fully understood, cellular energy status is one of the most crucial determinants for cell senescence. Creatine kinase (CK) is a constitutive enzyme, playing regulatory roles in energy homeostasis of cells. Among two isozymes, brain-type CK (CKB) is the predominant CK in lung tissue. In this study, we investigated the role of CKB in cigarette smoke extract (CSE)-induced cellular senescence in human bronchial epithelial cells (HBECs). Primary HBECs and Beas2B cells were used. Protein carbonylation was evaluated as a marker of oxidative protein damage. Cellular senescence was evaluated by senescence-associated ß-galactosidase staining. CKB inhibition was examined by small interfering RNA and cyclocreatine. Secretion of IL-8, a hallmark of senescence-associated secretary phenotype, was measured by ELISA. CKB expression levels were reduced in HBECs from patients with COPD compared with that of HBECs from nonsmokers. CSE induced carbonylation of CKB and subsequently decreased CKB protein levels, which was reversed by a proteasome inhibitor. CKB inhibition alone induced cell senescence, and further enhanced CSE-induced cell senescence and IL-8 secretion. CSE-induced oxidation of CKB is a trigger for proteasomal degradation. Concomitant loss of enzymatic activity regulating energy homeostasis may lead to the acceleration of bronchial epithelial cell senescence, which is implicated in the pathogenesis of COPD.

Accelerated epithelial cell senescence in IPF and the inhibitory role of SIRT6 in TGF-ß-induced senescence of human bronchial epithelial cells.

Reepithelialization of remodeled air spaces with bronchial epithelial cells is a prominent pathological finding in idiopathic pulmonary fibrosis (IPF) and is implicated in IPF pathogenesis. Recent studies suggest that epithelial senescence is a risk factor for development of IPF, indicating such reepithelialization may be influenced by the acceleration of cellular senescence. Among the sirtuin (SIRT) family, SIRT6, a class III histone deacetylase, has been demonstrated to antagonize senescence. We evaluated the senescence of bronchiolization in association with SIRT6 expression in IPF lung. Senescence-associated ß-galactosidase staining and immunohistochemical detection of p21 were performed to evaluate cellular senescence. As a model for transforming growth factor (TGF)-ß-induced senescence of abnormal reepithelialization, we used primary human bronchial epithelial cells (HBEC). The changes of SIRT6, p21, and interleukin (IL)-1ß expression levels in HBEC, as well as type I collagen expression levels in fibroblasts, were evaluated. In IPF lung samples, an increase in markers of senescence and SIRT6 expression was found in the bronchial epithelial cells lining cystically remodeled air spaces. We found that TGF-ß induced senescence in primary HBEC by increasing p21 expression, and, whereas TGF-ß also induced SIRT6, it was not sufficient to inhibit cellular senescence. However, overexpression of SIRT6 efficiently inhibited TGF-ß-induced senescence via proteasomal degradation of p21. TGF-ß-induced senescent HBEC secreted increased amounts of IL-1ß, which was sufficient to induce myofibroblast differentiation in fibroblasts. These findings suggest that accelerated epithelial senescence plays a role in IPF pathogenesis through perpetuating abnormal epithelial-mesenchymal interactions, which can be antagonized by SIRT6.

Thoracoscopic resection of a mediastinal venous hemangioma: Report of a case.

Mediastinal hemangioma is a rare tumor, accounting for 0.5% or fewer of all mediastinal tumors in most reports. We herein report a case of thoracoscopic resection of venous hemangioma in the middle mediastinum. A 48-year-old man was referred to our hospital for dysphagia. A chest computed tomography scan showed the mass to have a smooth surface and heterogeneous contents. Magnetic resonance imaging demonstrated the morphology of the vascular tumor to be a hyperintense mass on a T2-weighted image. Using thoracoscopic surgery, the tumor was completely extirpated and confirmed histologically to be a venous hemangioma. In this case, thoracoscopic surgery provided a satisfactory view and facilitated correct handling for the mediastinal venous hemangioma.

Intraoperative 99mTc-MIBI-guided detection of ectopic glands in secondary hyperparathyroidism.

99mTc-MIBI-guided detection of abnormal parathyroid glands in primary hyperparathyroidism (1-HPT) has become a popular and effective technique, but its efficacy for detecting the ectopic glands of secondary hyperparathyroidism (2-HPT) is still controversial. Of the 2-HPT cases from 2000 to 2004, 14 ectopic parathyroid glands in 11 patients were resected using intraoperative 99mTc-MIBI scintigraphy. We evaluated and compared the results of radioguided surgery with the preoperative findings from ultrasonography (US), computed tomography (CT), and scintigraphy. The overall results for intraoperative 99mTc-MIBI-guided detection of ectopic parathyroid glands were sensitivity of 100% (14/14) and accuracy of 84.2% (16/19) compared with 42.9% (6/14) and 31.6% (6/19), respectively, for preoperative US and 50.0% (6/12) and 42.9% (6/14), respectively, for preoperative 99mTc-MIBI scintigraphy. Using intraoperative 99mTc-MIBI-guided surgery in cases of 2-HPT will ensure all ectopic parathyroid glands are detected, making the surgery easier to perform and the outcome more successful.

Risk factors and cancer recurrence associated with postoperative complications after thoracoscopic lobectomy for clinical stage I non-small cell lung cancer.

BACKGROUND: Minimally invasive thoracoscopic lobectomy is the recommended surgery for clinical stage I non-small cell lung cancer (NSCLC). The purpose of this study was to identify the risk factors, including sarcopenia, for postoperative complications in patients undergoing a complete single-lobe thoracoscopic lobectomy for clinical stage I NSCLC, as well as the impact of complications on disease-free survival. METHODS: We retrospectively investigated 173 patients with pathologically-diagnosed NSCLC who underwent curative thoracoscopic lobectomies between April 2013 and March 2018. Sarcopenia was assessed using the psoas muscle index calculated from preoperative computed tomography images at the third lumbar vertebral level. RESULTS: Complications developed in 38 (22%) patients, including 21 with prolonged air leak. In univariate analysis, the significant risk factors for complications were advanced age, male sex, higher Charlson Comorbidity Index (CCI) score, lower cholinesterase, lower albumin, higher creatinine level, pleural adhesion, operative time ≥ five hours, nonadenocarcinoma cancer, and larger tumor size. Multivariate analysis showed that age ≥ 75 years (P = 0.002) and pleural adhesion (P = 0.026) were significant independent risk factors for complications. Compared with the patient group without complications, postoperative complications were independently associated with shorter disease-free survival (P = 0.01). CONCLUSIONS: Advanced age and pleural adhesion were independent risk factors for complications after complete single-lobe thoracoscopic lobectomies for clinical stage I NSCLC, and postoperative complications were statistically associated with poor prognosis. Surgical teams should ensure an experienced surgeon leads the operation for patients at higher risk to avoid prolonged postoperative hospitalization and a possible poor prognosis.