Orthotopic transplantation of the bioengineered lung using a mouse-scale perfusion-based bioreactor and human primary endothelial cells.

Whole lung engineering and the transplantation of its products is an ambitious goal and ultimately a viable solution for alleviating the donor-shortage crisis for lung transplants. There are several limitations currently impeding progress in the field with a major obstacle being efficient revascularization of decellularized scaffolds, which requires an extremely large number of cells when using larger pre-clinical animal models. Here, we developed a simple but effective experimental pulmonary bioengineering platform by utilizing the lung as a scaffold. Revascularization of pulmonary vasculature using human umbilical cord vein endothelial cells was feasible using a novel in-house developed perfusion-based bioreactor. The endothelial lumens formed in the peripheral alveolar area were confirmed using a transmission electron microscope. The quality of engineered lung vasculature was evaluated using box-counting analysis of histological images. The engineered mouse lungs were successfully transplanted into the orthotopic thoracic cavity. The engineered vasculature in the lung scaffold showed blood perfusion after transplantation without significant hemorrhage. The mouse-based lung bioengineering system can be utilized as an efficient ex-vivo screening platform for lung tissue engineering.

Effect of revised organ transplant law in Japan on lung transplantation.

PURPOSE: To investigate how revision of the organ transplant law in Japan affected lung transplantation in this country. METHODS: Lung transplant candidates registered between January, 2000 and December, 2009 were designated as the pre-revision group (n = 396) and those registered between January, 2011 and December, 2020, as the post-revision group (n = 1326). Both groups were analyzed retrospectively using data collected by the Japanese Society of Lung and Heart-Lung Transplantation. RESULTS: The number of patients who underwent brain-dead donor lung transplantation (BDLT) increased significantly after the law amendment (32.2 vs. 13.8%, p < 0.01). The median waiting time for BDLT was significantly reduced (708 days vs. 1163 days, p < 0.01) and the mortality rate while waiting for BDLT improved significantly after the law amendment (33.1 vs. 42.6%, p < 0.01). In the post-revision group, 18 pediatric patients underwent BDLT. The 5-year survival rates after BDLT were comparable between the groups (73.5% in the pre-revision group vs. 73.2% in the post-revision group, p = 0.32). CONCLUSIONS: The organ transplant law revision shortened the waiting time for BDLT significantly and decreased the mortality rate while waiting for BDLT. The posttransplant outcomes in Japan remained favorable throughout the study period.

Native-lung complications following single-lung transplantation for interstitial lung disease: an in-depth analysis.

BACKGROUND: Interstitial lung disease (ILD) represents a heterogeneous group of lung disorders characterized by fibrotic lung tissue changes. In regions with severe donor shortages, single-lung transplantation (SLTx) is often preferred over bilateral lung transplantation for advanced ILD. However, temporal changes and complications in the retained native lung remain poorly understood. METHODS: A retrospective analysis of 149 recipients who had undergone SLTx was conducted, including 34 ILD SLTx recipients. Native-lung volume, radiological alterations, and perfusion were assessed at distinct post-SLTx time points. Statistical analyses compared ILD and non-ILD SLTx groups. RESULTS: Our study revealed a progressive reduction in native-lung volume over time, accompanied by radiographic deterioration and declining perfusion. Complications in the retained native lung were observed, such as pneumothorax (29.4%), pulmonary aspergillosis (11.8%), and acute exacerbation (8.9%). Long-term survival rates were similar between ILD and non-ILD SLTx recipients. CONCLUSIONS: This study illuminates the unique challenges and complications with respect to the native lung following SLTx for ILD. Ongoing monitoring and tailored management are essential. Despite limitations, this research contributes to our understanding of the temporal progression of native-lung complications post-SLTx for ILD, underscoring the need for further investigation.

Effects of case volume on short- and long-term outcomes following cadaveric lung transplantation in Japan.

Background: Despite the low number of lung transplantations (LTs) in Japan, 10 LT facilities are accredited and good outcomes have been reported. A database review was conducted to clarify the impact of case volume at LT facilities in Japan on short- and long-term outcomes. Methods: All cadaveric LT cases treated between 2000 and 2021 in Japan were analyzed using the database of the Japanese Society of Lung and Heart-Lung Transplantation (JSLHT). The nine institutions represented were categorized into the low-volume (LV; <80 cumulative LT cases, <8 LTs/year, n=5) and high-volume (HV; ≥80 cumulative LT cases, ≥8 LTs/year, n=4) centers. Ninety-day and 1-year mortality, as well as 5- and 10-year survival data were evaluated. Results: A total of 658 cadaveric LTs were performed at the nine institutions. The 90-day rates of mortality at the HV and LV centers were 3.5% and 3.9%, respectively (P=0.801), while the 1-year mortality rates were 9.2% and 11.5%, respectively (P=0.199). Additionally, log-rank analysis of Kaplan-Meier curves showing case volume did not reveal a significant difference in long-term survival between the HV and LV centers (P=0.272), though the LV centers had wide differences for long-term outcomes (P=0.030). Conclusions: Case volume did not have effects on short- or long-term outcomes following LT in Japan, while there were large variations in long-term outcomes among the LV centers compared to those of the HV centers.

Long-term survival and clinical outcomes of delayed chest closure following lung transplantation.

PURPOSES: Delayed chest closure (DCC) is a widely accepted procedure in the context of lung transplantation (LTx); yet there are few reports detailing its long-term survival and clinical outcomes. METHODS: We reviewed the medical records of recipients who underwent deceased-donor lung transplantation (LTx) at Tohoku University Hospital. Long-term survival, including overall survival, freedom from chronic lung allograft dysfunction (CLAD), and CLAD-free survival and the clinical outcomes of graft function and physical performance and constitution were reviewed in recipients with DCC. RESULTS: Between 2009 and 2022, 116 patients underwent LTx, 33 of whom (28.4%) required DCC. The intra-and post-operative courses of the recipients who required DCC were more complicated than those of the recipients who underwent primary chest closure (PCC), with frequent volume reduction surgery and longer periods of invasive mechanical ventilation. Pulmonary vascular disease was considered a risk factor for these complications and DCC. Nonetheless, long-term survival and graft functions were comparable between the DCC and PCC groups. The physical performance and constitution of recipients who required DCC continued to improve, and by 2 years after transplantation, exhibited almost no difference from those who underwent PCC. CONCLUSIONS: In view of the profoundly complicated intra- and post-operative courses, DCC should be performed cautiously and only when clinically indicated, despite which it can result in equivalent long-term survival and acceptable outcomes to PCC.

A Single-Center Analysis of How HLA Mismatch and Donor-Specific Antibodies Affect Short-Term Outcome After Lung Transplantation: A Pilot Study Before a Country-Wide Histocompatibility Study in Japan.

BACKGROUND: Analyzing HLA polymorphism in lung transplantation (LTx) is important, given its impact on LTx recipient survival and graft function. Accordingly, we conducted a retrospective study to examine the influence of HLA mismatch and donor-specific antibodies (DSA) on short-term outcomes and early-phase post-LTx complications. METHOD: HLA antigen or eplet mismatch in LTx patients at Tohoku University Hospital from 2018 to 2023 was determined, and DSA was measured on admission for surgery to identify preformed DSA and at weeks 4 to 12 post-LTx for de novo DSA, respectively. RESULTS: The participants were 45 LTx recipients, HLA-A/B/DR antigen mismatch (5-6 of 6) being identified in 57%, HLA-A/B/Cw/DR/DQ mismatch (8-10 of 10) in 57%, and HLA eplet mismatch (>61) in 46%. The prevalence of preformed DSA was 24%, and persistence (uncleared) was 16%. The incidence of de novo DSA was 16% after LTx. During the study,16 recipients experienced grade 3 primary graft dysfunction (PGD), 8 developed acute rejection, and 5 died. No HLA-related variables were significantly associated with post-LTx mortality and were not risk factors for high-grade PGD or acute rejection. CONCLUSION: Despite limitations in sample size, resulting in tentative findings, the study serves as a crucial pilot study for an ongoing multicenter prospective trial in Japan.

A comparative study of surgical outcomes for secondary spontaneous pneumothorax and the postoperative survival prognostic factor: interstitial vs. non-interstitial pneumonia.

PURPOSE: To investigate the surgical outcomes and postoperative survival prognostic factors of intractable secondary spontaneous pneumothorax. METHODS: A total of 95 patients who underwent thoracoscopic surgery for intractable secondary spontaneous pneumothorax between April 2010 and March 2020 were included in this study. These patients were classified into interstitial pneumonia and non-interstitial pneumonia groups, and a comparative study was performed on surgical outcomes and postoperative survival prognostic factors. RESULTS: There was no difference in the 1-year overall survival rate between the two groups. However, the 3-year overall survival rate was significantly lower in the interstitial pneumonia group than in the non-interstitial pneumonia group. The differences in short-term surgical outcomes (persistent air leakage, postoperative complications, etc.) were not significant between the two groups. Univariate analysis revealed that the drainage period, the development of postoperative complications, and recurrence were significant independent postoperative survival prognostic factors for all cases. Postoperative complications were the only associated postoperative survival prognostic factor for interstitial pneumonia pneumothorax in the multivariate analysis. CONCLUSION: The development of postoperative complications can cause poor postoperative survival prognosis of intractable secondary spontaneous pneumothorax due to interstitial pneumonia.

Single lung transplantation using a lung graft from a donor whose contralateral lung is not suitable for lung transplantation.

OBJECTIVE: This study aims to compare the post-transplant survival of untwinned single lung transplantation (SLT) to twinned SLT. In untwinned SLT, the contralateral lung is judged unsuitable for transplantation and might affect the lung graft within the donor body and recipient survival after SLT. METHODS: A retrospective analysis was conducted on 84 SLT recipients at our center, divided into untwinned SLT and twinned SLT groups. The demographics of donors and recipients, surgical characteristics, complications, mortality, and survival rates were compared. RESULTS: There were no significant differences in recipient and donor demographics between the two groups. Surgical characteristics showed no significant differences. Microbiological findings of the transplanted lungs indicated a low incidence of positive cultures in both groups. 3-month to 1-year mortality and overall survival rates were comparable between the two groups. CONCLUSION: At our institution, both untwinned and twinned SLT procedures exhibited excellent survival rates without significant differences between the two procedures. The favorable outcomes observed may be associated with the strategic advantages of Japan's MC system and the diligent management of marginal donor lungs although this requires further investigation to elucidate the specific contributory factors.

Systemic-to-pulmonary artery shunt treated with transcatheter arterial embolization and subsequent lung segmentectomy.

BACKGROUND: Systemic-to-pulmonary artery shunt (SPAS) is a rare condition that can occur as a result of congenital heart disease or chronic pulmonary inflammation, occasionally leading to life-threatening hemoptysis. Computed tomography (CT) imaging is crucial in the diagnosis of SPAS, and the optimal management approach for SPAS remains uncertain. This case report presents a novel approach to the treatment of SPAS, consisting of transcatheter arterial embolization of the systemic artery followed by lung segmentectomy. CASE PRESENTATION: A 42-year-old man with abnormal chest findings was referred to us and a diagnosis of SPAS was established based on the CT findings showing a blood flow regurgitation from the dilated left 4th intercostal artery to the Lt. A6. The patient was asymptomatic but we decided to treat him to prevent a risk of future hemoptysis. Transcatheter arterial embolization (TAE) of systemic arteries followed by S6 segmentectomy was successfully performed with minimal blood loss and complete removal of the dilated intra-pulmonary blood vessels. Histological analysis confirmed the diagnosis of SPAS. CONCLUSION: We reported a case of SPAS, who was successfully treated with the combination of TAE and subsequent segmentectomy. The blood loss during surgery was minimal and this strategy appeared to minimize future recanalization and hemoptysis. Further studies and long-term follow-up of SPAS patients are required to establish standardized management guidelines for this rare condition.

A straightforward guide to the swine left upper lobar transplant model: procedures and techniques.

With the rising demand for lung transplants, especially for adults with smaller chest cavities and children, a significant donor-recipient size mismatch challenge exists. A solution is lobar lung transplants from deceased donors with otherwise unsuitable lungs due to local damage. Despite its promise, early post-transplant mortality rates are comparatively high, emphasizing the need for meticulous donor selection and graft evaluation. This video tutorial introduces a detailed methodology for a porcine left upper lobar lung transplant model, from preoperative measures to reperfusion. Steps encompass preoperative measures, donor and recipient preparations, graft procurement and specific anastomosis procedures for the bronchus, pulmonary artery and left atrium. This guidance, derived from rigorous translational research, not only contributes to the knowledge of safe lobar lung transplants in animals but also promises potential implications for clinical practice.

Human umbilical cord mesenchymal stem cells in diabetes mellitus and its complications: applications and research advances.

Diabetes mellitus and its complications pose a major threat to global health and affect the quality of life and life expectancy of patients. Currently, the application of traditional therapeutic drugs for diabetes mellitus has great limitations and can only temporarily control blood glucose but not fundamentally cure it. Mesenchymal stem cells, as pluripotent stromal cells, have multidirectional differentiation potential, high self-renewal, immune regulation, and low immunogenicity, which provide a new idea and possible development direction for diabetes mellitus treatment. Regenerative medicine with mesenchymal stem cells treatment as the core treatment will become another treatment option for diabetes mellitus after traditional treatment. Recently, human umbilical cord mesenchymal stem cells have been widely used in basic and clinical research on diabetes mellitus and its complications because of their abundance, low ethical controversy, low risk of infection, and high proliferation and differentiation ability. This paper reviews the therapeutic role and mechanism of human umbilical cord mesenchymal stem cells in diabetes mellitus and its complications and highlights the challenges faced by the clinical application of human umbilical cord mesenchymal stem cells to provide a more theoretical basis for the application of human umbilical cord mesenchymal stem cells in diabetes mellitus patients.

Gain-of-function MYCN causes a megalencephaly-polydactyly syndrome manifesting mirror phenotypes of Feingold syndrome.

MYCN, a member of the MYC proto-oncogene family, regulates cell growth and proliferation. Somatic mutations of MYCN are identified in various tumors, and germline loss-of-function variants are responsible for Feingold syndrome, characterized by microcephaly. In contrast, one megalencephalic patient with a gain-of-function variant in MYCN, p.Thr58Met, has been reported, and additional patients and pathophysiological analysis are required to establish the disease entity. Herein, we report two unrelated megalencephalic patients with polydactyly harboring MYCN variants of p.Pro60Leu and Thr58Met, along with the analysis of gain-of-function and loss-of-function Mycn mouse models. Functional analyses for MYCN-Pro60Leu and MYCN-Thr58Met revealed decreased phosphorylation at Thr58 which reduced protein degradation mediated by FBXW7 ubiquitin ligase. The gain-of-function mouse model recapitulated the human phenotypes of megalencephaly and polydactyly, while brain analyses revealed excess proliferation of intermediate neural precursors during neurogenesis, which we determined to be the pathomechanism underlying megalencephaly. Interestingly, the kidney and female reproductive tract exhibited overt morphological anomalies, possibly as a result of excess proliferation during organogenesis. In conclusion, we confirm a MYCN gain-of-function-induced megalencephaly-polydactyly syndrome, which shows a mirror phenotype of Feingold syndrome, and reveal that MYCN plays a crucial proliferative role, not only in the context of tumorigenesis, but also organogenesis.

Impact of intraoperative use of venovenous extracorporeal membrane oxygenation on the status of von Willebrand factor large multimers during single lung transplantation.

Background: von Willebrand factors (vWFs), hemostatic factors, are produced as large multimers and are shear stress-dependently cleaved to become the appropriate size. A reduction in vWF large multimers develops in various conditions including the use of extracorporeal life support, which can cause excessive-high shear stress in the blood flow and result in hemostatic disorders. The objective of this prospective study was to investigate the impact of venovenous extracorporeal membrane oxygenation (VV ECMO) use on the status of vWF large multimers and hemostatic disorders during single lung transplantation (SLT). Methods: We prospectively enrolled 12 patients who underwent SLT at our center. Among them, seven patients were supported by VV ECMO intraoperatively (ECMO group) and the remaining five patients underwent SLT without ECMO support (control group). The vWF large multimer index (%) was defined as the ratio of the large multimer proportion in total vWF (vWF large multimer ratio) derived from a patient's plasma to that from standard human plasma. Results: The vWF large multimer index at the end of the surgery was significantly lower in the ECMO group than in the control group (112.6% vs. 75.8%, respectively; P<0.05). The intraoperative blood loss and the amounts of intraoperative transfusion products in the ECMO group tended to be greater than those in the control group; however, the differences were not significant. Conclusions: During SLT, the use of VV ECMO caused a decrease in the vWF large multimer index. The short duration of time of VV ECMO use in our study did not significantly affect the intra- and postoperative outcomes including blood loss, blood transfusion, and re-exploration thoracotomy for bleeding. Nevertheless, to comprehensively evaluate the actual influence of this decrease in the vWF large multimer index on intra- and postoperative outcomes, a multicenter larger-scale study is warranted.

Muscle p62 stimulates the expression of antioxidant proteins alleviating cancer cachexia.

Oxidative stress plays an important role in skeletal muscle atrophy during cancer cachexia, and more glycolytic muscles are preferentially affected. Sequestosome1/SQSTM1 (i.e., p62), particularly when phosphorylated at Ser 349 (Ser 351 in mice), competitively binds to the Kelch-like ECH-associated protein 1 (Keap1) activating Nuclear factor erythroid 2-related factor 2 (Nrf2). Nrf2 then stimulates the transcription of antioxidant/electrophile-responsive elements in target genes. However, a potential role for p62 in the protection of muscle wasting in cachexia remains to be determined. Here, using the well-established cachexia-inducing model of Lewis Lung Carcinoma (LLC) in mice we demonstrate higher expression of antioxidant proteins (i.e., NQO1, HO-1, GSTM1, CuZnSOD, MnSOD, and EcSOD) in the more oxidative and cachexia resistant soleus muscle than in the more glycolytic and cachexia prone extensor digitorum longus muscle. This was accompanied by higher p62 (total and phosphorylated) and nuclear Nrf2 levels in the soleus, which were paralleled by higher expression of proteins known to either phosphorylate or promote p62 phosphorylation (i.e., NBR1, CK1, PKCδ, and TAK1). Muscle-specific p62 gain-of-function (i.e., in p62 mTg mice) activated Nrf2 nuclear translocation and increased the expression of multiple antioxidant proteins (i.e., CuZnSOD, MnSOD, EcSOD, NQO1, and GSTM1) in glycolytic muscles. Interestingly, skeletal muscle Nrf2 haplodeficiency blunted the increases of most of these proteins (i.e., CuZnSOD, EcSOD, and NQO1) suggesting that muscle p62 stimulates antioxidant protein expression also via additional, yet to be determined mechanisms. Of note, p62 gain-of-function mitigated glycolytic muscle wasting in LLC-affected mice. Collectively, our findings identify skeletal muscle p62 as a potential therapeutic target for cancer cachexia.

Wavelength dependence of ultraviolet light inactivation for SARS-CoV-2 omicron variants.

Ultraviolet (UV) irradiation offers an effective and convenient method for the disinfection of pathogenic microorganisms. However, UV irradiation causes protein and/or DNA damage; therefore, further insight into the performance of different UV wavelengths and their applications is needed to reduce risks to the human body. In this paper, we determined the efficacy of UV inactivation of the SARS-CoV-2 omicron BA.2 and BA.5 variants in a liquid suspension at various UV wavelengths by the 50% tissue culture infection dose (TCID50) method and quantitative polymerase chain reaction (qPCR) assay. The inactivation efficacy of 220 nm light, which is considered safe for the human body, was approximately the same as that of health hazardous 260 nm light for both BA.2 and BA.5. Based on the inactivation rate constants determined by the TCID50 and qPCR methods versus the UV wavelength, the action spectra were determined, and BA.2 and BA.5 showed almost the same spectra. This result suggests that both variants have the same UV inactivation characteristics.

Bilateral lung transplant with pulmonary artery reconstruction using donor aorta for pulmonary hypertension with a giant pulmonary arterial aneurysm.

OBJECTIVES: Standard bilateral lung transplantation (BLT) is not feasible for patients with pulmonary arterial hypertension (PAH) complicated with a giant pulmonary arterial aneurysm (PAA). This study aimed to describe the outcomes of BLT with pulmonary artery reconstruction (PAR) using donor aorta for such patients. METHODS: This is a retrospective single-centre study reviewing PAH patients with a PAA who received BLT with PAR using donor aorta from January 2010 through December 2020. We compared the characteristics and short- and long-term outcomes of recipients receiving PAR (PAR group) with those who had no PAA and received standard BLT (non-PAR group). RESULTS: Nineteen adult PAH patients underwent cadaveric lung transplantation during the study period. Among them, 5 patients with a giant PAA (median pulmonary artery trunk diameter, 69.9 mm) underwent BLT with PAR using donor aorta and the others received standard BLT. Although the operation time tended to be longer in the PAR group compared with the non-PAR group (1239 vs 958 mins, P = 0.087), 90-day mortality (PAR group: 0% vs non-PAR group: 14.3%, P > 0.99), and 5-year survival rate (PAR group: 100% vs non-PAR group: 85.7%, P = 0.74) was comparable between the groups. No dilatation, constriction or infection of the aortic grafts were recorded during the study period with a median follow-up time of 94 months in the PAR group. CONCLUSIONS: Lung transplantation with PAR using donor aorta is a valid surgical option for PAH patients complicated with a giant PAA.

Morphometric analysis of nuclear shape irregularity as a novel predictor of programmed death-ligand 1 expression in lung squamous cell carcinoma.

Immune checkpoint inhibitor (ICI) therapy has been established as one of the key treatment strategies for lung squamous cell carcinoma (LUSQ). The status of programmed death-ligand 1 (PD-L1) in tumor cells and/or immune cells using immunohistochemistry has been primarily used as a surrogate marker for determining ICI treatment; however, when the tissues to be examined are small, false-negative results could be unavoidable due to the heterogeneity of PD-L1 immunoreactivity. To overcome this practical limitation, we attempted to explore the status of nuclear atypia evaluated using morphometry as a potential predictor of PD-L1 status in LUSQ. We correlated the parameters related to nuclear atypia with PD-L1 status using two different cohorts of LUSQ patients (95 cases from The Cancer Genome Atlas database and 30 cases from the Miyagi Cancer Center). Furthermore, we studied the gene mutation status to elucidate the genetic profile of PD-L1 predictable cases. The results revealed that nuclear atypia, especially morphometric parameters related to nuclear shape irregularity, including aspect ratio, circularity, roundness, and solidity, were all significantly associated with PD-L1 status. Additionally, LUSQ cases with high PD-L1 expression and pronounced nuclear atypia were significantly associated with C10orf71 and COL14A1 mutations compared with those with low PD-L1 expression and mild nuclear atypia. We demonstrated for the first time that nuclear shape irregularity could represent a novel predictor of PD-L1 expression in LUSQ. Including the morphometric parameters related to nuclear atypia in conjunction with PD-L1 status could help determine an effective ICI therapeutic strategy; however, further investigation is required.

Prognostic factors for lung transplant recipients focusing on age and gender: the Japanese lung transplantation report 2022.

PURPOSE: To clarify the impact of donor and recipient characteristics on the survival of recipients before and after lung transplantation in the Japanese population. METHODS: Patients' data were collected for retrospective analysis from all authorized lung transplant centers in Japan. We included 1963 patients listed for lung transplantation by the end of December 2021, comprised of 658 deceased-donor and 270 living-donor lung transplants. RESULTS: Primary disease had a significant impact on the mortality of patients waiting for transplantation. The indications for transplant significantly affected the post-transplant survival rate of deceased-donor lung transplant recipients. The recipient's age also significantly affected the post-transplant survival rate of the deceased-donor and living-donor lung transplant recipients. The recipients of grafts transplanted from donors aged 61 years or older showed a worse post-transplant survival rate (≧60 years old). The survival rate for the combination of a female donor to a male recipient among the deceased-donor lung transplant recipients was the worst among the four combinations. CONCLUSION: The donor and recipient characteristics significantly impacted the survival of recipients after lung transplantation. The underlying mechanism of the negative impact of the gender mismatch of female donor to male recipient on post-transplant survival needs to be investigated further.