Proximal Tubule β 2-Adrenergic Receptor Mediates Formoterol-Induced Recovery of Mitochondrial and Renal Function after Ischemia-Reperfusion Injury

Acute kidney injury (AKI) is the rapid loss of renal function after an insult, and renal proximal tubule cells (RPTCs) are central to the pathogenesis of AKI. The β 2-adrenergic receptor (β 2AR) agonist formoterol accelerates the recovery of renal function in mice after ischemia-reperfusion injury (IRI) with associated rescue of mitochondrial proteins; however, the cell type responsible for this recovery remains unknown. The role of RPTCs in formoterol-induced recovery of renal function was assessed in a proximal tubule-specific knockout of the β 2AR (γGT-Cre:ADRB2Flox/Flox). These mice and wild-type controls (ADRB2Flox/Flox) were subjected to renal IRI, followed by once-daily dosing of formoterol beginning 24 hours post-IRI and euthanized at 144 hours. Compared with ADRB2Flox/Flox mice, γGT-Cre:ADRB2Flox/Flox mice had decreased renal cortical mRNA expression of the β 2AR. After IRI, formoterol treatment restored renal function in ADRB2Flox/Flox but not γGT-Cre:ADRB2Flox/Flox mice as measured by serum creatinine, histopathology, and expression of kidney injury marker-1 (KIM-1). Formoterol-treated ADRB2Flox/Flox mice exhibited recovery of mitochondrial proteins and DNA copy number, whereas γGT-Cre:ADRB2Flox/Flox mice treated with formoterol did not. Analysis of mitochondrial morphology by transmission electron microscopy demonstrated that formoterol increased mitochondrial number and density in ADRB2Flox/Flox mice but not in γGT-Cre:ADRB2Flox/Flox mice. These data demonstrate that proximal tubule β 2AR regulates renal mitochondrial homeostasis. Formoterol accelerates the recovery of renal function after AKI by activating proximal tubule β 2AR to induce mitochondrial biogenesis and demonstrates the overall requirement of RPTCs in renal recovery.

Predictors of Outcomes After Thoracic Surgery in Orthotopic Liver Transplant Recipients With Pleural Disease

Orthotopic liver transplant (OLT) recipients are at high risk for postoperative pulmonary complications. We aim to determine factors associated with morbidity and mortality in OLT recipients that required thoracic surgery for pleural space complications. A retrospective review was performed of 42 patients who underwent thoracic surgery after OLT between 2005 and 2015. Preoperative data and postoperative outcomes were reviewed. Time to mortality was summarized using Kaplan-Meier curves. Outcomes associated with 30-day morbidity and mortality as well as long-term mortality were analyzed with univariate analysis. Between 2005 and 2015, 1735 OLTs were performed at our institution. We identified 42 patients who required thoracic surgery. Of these 42 OLT recipients, 33 patients required thoracic surgery for pleural space complications. The median interval between OLT and thoracic surgery for pleural space complications was 5.7 months (interquartile range 2.2-14.1). The most common surgical indications were chronic pleural effusion (n = 12, 36.4%) and empyema (n = 10, 30.3%). The most common thoracic operations were decortication and empyema evacuation. The 30-day morbidity was 69.7%. Bilirubin and empyema were significantly associated with 30-day morbidity (odds ratio [OR] = 2.3, P = 0.023; OR = 16.3, P = 0.015). The 30-day, 1-year, and 5-year mortality rates were 15.2%, 57.6%, and 70.2%, respectively. Vasopressor requirement was significantly associated with 30-day mortality (OR = 10.2, P = 0.031). The development of pleural space complications requiring surgery in OLT recipients suggests a poor prognosis. Hyperbilirubinemia and pleural space infections were associated with high postoperative morbidity in OLT recipients requiring thoracic surgery for pleural space complications.

Structural and pharmacological basis for the induction of mitochondrial biogenesis by formoterol but not clenbuterol

Mitochondrial dysfunction is associated with numerous acute and chronic degenerative diseases. The beta-2 adrenergic receptor (β₂AR) agonist formoterol induces mitochondrial biogenesis (MB), but other β₂AR agonists, such as clenbuterol, do not. We sought to identify the MB signaling pathway of formoterol and the differences in signaling between these two ligands that result in the differential induction of MB. While formoterol and clenbuterol increased cAMP, only formoterol increased the phosphorylation of Akt and its downstream target eNOS. The increase in Akt phosphorylation was Gβγ- and PI3K-dependent, and the increase in eNOS phosphorylation was Gβγ- and Akt-dependent. Only formoterol increased cGMP. Formoterol induced MB as measured by increases in uncoupled cellular respiration and PGC-1α and NDUFS1 mRNA expression and was blocked by inhibitors of Gβγ, Akt, NOS, and soluble guanylate cyclase. To identify distinct receptor-ligand interactions leading to these differences in signaling, we docked formoterol and clenbuterol to six structures of the β₂AR. Compared to clenbuterol, the methoxyphenyl group of formoterol interacted more frequently with V114 and F193, while its formamide group interacted more frequently with C191. These data indicate that the unique structural features of formoterol allow it to interact with the β₂AR to activate the Gβγ-Akt-eNOS-sGC pathway to induce MB.

WITHDRAWN: Advanced thoracoscopy: What is the critical information in case reports and how do we achieve the next level?

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Percutaneous Cryoablation for the Treatment of Recurrent Malignant Pleural Mesothelioma: Safety, Early-Term Efficacy, and Predictors of Local Recurrence

PURPOSE

To determine safety and early-term efficacy of CT-guided cryoablation for treatment of recurrent mesothelioma and assess risk factors for local recurrence.

MATERIALS AND METHODS

During the period 2008-2012, 24 patients underwent 110 cryoablations for recurrent mesothelioma tumors in 89 sessions. Median patient age was 69 years (range, 48-82 y). Median tumor size was 30 mm (range, 9-113 mm). Complications were graded using Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v4.0). Recurrence was diagnosed on CT or positron emission tomography/CT by increasing size, nodular enhancement, or hypermetabolic activity and analyzed using the Kaplan-Meier method. Cox proportional hazards model was used to determine covariates associated with local tumor recurrence.

RESULTS

Median duration of follow-up was 14.5 months. Complications occurred in 8 of 110 cryoablations (7.3%). All but 1 complication were graded CTCAE v4.0 1 or 2. No procedure-related deaths occurred. Freedom from local recurrence was observed in 100% of cases at 30 days, 92.5% at 6 months, 90.8% at 1 year, 87.3% at 2 years, and 73.7% at 3 years. Tumor recurrence was diagnosed 4.5-24.5 months after cryoablation (mean 5.7 months). Risk of tumor recurrence was associated with a smaller ablative margin from the edge of tumor to iceball ablation margin (multivariate hazard ratio 0.68, CI 0.48-0.95, P = .024).

CONCLUSIONS

CT-guided cryoablation is safe for local control of recurrent mesothelioma, with a low rate of complications and promising early-term efficacy. A smaller ablative margin may predispose to tumor recurrence.

Development of Therapeutics That Induce Mitochondrial Biogenesis for the Treatment of Acute and Chronic Degenerative Diseases

Mitochondria have various roles in cellular metabolism and homeostasis. Because mitochondrial dysfunction is associated with many acute and chronic degenerative diseases, mitochondrial biogenesis (MB) is a therapeutic target for treating such diseases. Here, we review the role of mitochondrial dysfunction in acute and chronic degenerative diseases and the cellular signaling pathways by which MB is induced. We then review existing work describing the development and application of drugs that induce MB in vitro and in vivo. In particular, we discuss natural products and modulators of transcription factors, kinases, cyclic nucleotides, and G protein-coupled receptors.

Tomotherapy improves local control and changes failure patterns in locally advanced malignant pleural mesothelioma

PURPOSE

The purpose of the study was to determine whether intensity modulated radiation therapy delivered via helical tomotherapy improves local control (LC) after pleurectomy/decortication (P/D) for malignant pleural mesothelioma compared with 3-dimensional conformal radiation therapy (3D-CRT).

METHODS AND MATERIALS

Forty-five consecutive patients were treated with adjuvant radiation to 45 Gy in 1.8 Gy fractions after P/D between 2006 and 2014; 23 received 3D-CRT, and 22 received tomotherapy. Kaplan-Meier analysis was used to calculate overall survival, time to in-field or local failure (LF), and time to out-of-field failure. The Student t test and Fisher exact test were used to detect between-group differences.

RESULTS

Median follow-up time was 19.4 months and 12.7 months for the 3D-CRT and tomotherapy groups, respectively. Eighty-two percent of patients had T3/T4 disease, and 64% had positive nodes; 17.4% and 41% of patients in the 3D-CRT and tomotherapy groups had nonepithelioid histology, respectively. Mean planning target volume dose, percentage of planning target volume receiving 100% of the prescription dose, and lung doses were significantly greater with tomotherapy (P < .05), but toxicity rates (including radiation pneumonitis rates) were equivalent. LC was significantly improved with tomotherapy on Kaplan-Meier analysis with outcomes censored at 2 years (P < .05); uncensored, this became a trend (P = .06). Median time to LF was 19 months with tomotherapy and 10.9 months in 3D-CRT (the latter interval being less than the median follow-up in the tomotherapy group). On univariate analysis, treatment modality was the only significant predictor of LC (P < .05). Isolated LF was significantly more frequent with 3D-CRT (P < .05). Conversely, isolated out-of-field failure was significantly more frequent with tomotherapy (P < .05). Overall survival and out-of-field control were not significantly different.

CONCLUSION

Tomotherapy after P/D for malignant pleural mesothelioma is associated with improved target coverage that translates into improved LC compared with 3D-CRT. This is related to a change in failure patterns, with isolated LF being more common in the 3D-CRT group and isolated out-of-field failures predominating in the tomotherapy group.

New and emerging therapeutic options for malignant pleural mesothelioma: review of early clinical trials

Malignant pleural mesothelioma (MPM) is a rare tumor that is challenging to control. Despite some benefit from using the multimodality-approach (surgery, combination chemotherapy and radiation), survival remains poor. However, current research produced a list of potential therapies. Here, we summarize significant new preclinical and early clinical developments in treatment of MPM, which include mesothelin specific antibody and toxin therapies, interleukin-4 (IL-4) receptor toxins, dendritic cell vaccines, immune checkpoint inhibitors, and gene-based therapies. In addition, several local modalities such as photodynamic therapy, postoperative lavage using betadine, and cryotherapy for local recurrence, have also shown to be effective for local control of disease.

Quantitative analysis of mitochondrial morphology and membrane potential in living cells using high-content imaging, machine learning, and morphological binning

Understanding the processes of mitochondrial dynamics (fission, fusion, biogenesis, and mitophagy) has been hampered by the lack of automated, deterministic methods to measure mitochondrial morphology from microscopic images. A method to quantify mitochondrial morphology and function is presented here using a commercially available automated high-content wide-field fluorescent microscopy platform and R programming-language-based semi-automated data analysis to achieve high throughput morphological categorization (puncta, rod, network, and large & round) and quantification of mitochondrial membrane potential. In conjunction with cellular respirometry to measure mitochondrial respiratory capacity, this method detected that increasing concentrations of toxicants known to directly or indirectly affect mitochondria (t-butyl hydroperoxide [TBHP], rotenone, antimycin A, oligomycin, ouabain, and carbonyl cyanide-p-trifluoromethoxyphenylhydrazone [FCCP]), decreased mitochondrial networked areas in cultured 661w cells to 0.60-0.80 at concentrations that inhibited respiratory capacity to 0.20-0.70 (fold change compared to vehicle). Concomitantly, mitochondrial swelling was increased from 1.4- to 2.3-fold of vehicle as indicated by changes in large & round areas in response to TBHP, oligomycin, or ouabain. Finally, the automated identification of mitochondrial location enabled accurate quantification of mitochondrial membrane potential by measuring intramitochondrial tetramethylrhodamine methyl ester (TMRM) fluorescence intensity. Administration of FCCP depolarized and administration of oligomycin hyperpolarized mitochondria, as evidenced by changes in intramitochondrial TMRM fluorescence intensities to 0.33- or 5.25-fold of vehicle control values, respectively. In summary, this high-content imaging method accurately quantified mitochondrial morphology and membrane potential in hundreds of thousands of cells on a per-cell basis, with sufficient throughput for pharmacological or toxicological evaluation.

Malignant pleural mesothelioma and the Society of Thoracic Surgeons Database: an analysis of surgical morbidity and mortality

BACKGROUND

To date, reported surgical morbidity and mortality for pleurectomy/decortication and extrapleural pneumonectomy performed for malignant pleural mesothelioma primarily represent the experience of a few specialized centers. For comparison, we examined early outcomes of pleurectomy/decortication and extrapleural pneumonectomy from a broader group of centers/surgeons participating in the Society of Thoracic Surgeons-General Thoracic Database.

METHODS

All patients in the Society of Thoracic Surgeons-General Thoracic Database (version 2.081, representing 2009-2011) who underwent pleurectomy/decortication or extrapleural pneumonectomy for malignant pleural mesothelioma were identified. Patient characteristics, morbidity, mortality, center volume, and procedure were examined using univariable and multivariable analyses.

RESULTS

A total of 225 patients underwent pleurectomy/decortication (n = 130) or extrapleural pneumonectomy (n = 95) for malignant pleural mesothelioma at 48 centers. Higher volumes of procedures (≥5/y) were performed at 3 pleurectomy/decortication and 2 extrapleural pneumonectomy centers. Patient characteristics were statistically equivalent between pleurectomy/decortication and extrapleural pneumonectomy groups, except those undergoing extrapleural pneumonectomy were younger (63.2 ± 7.8 years vs 68.3 ± 9.5 years; P < .001) and more likely to have received preoperative chemotherapy (30.1% vs 17.8%; P = .036). Major morbidity was greater after extrapleural pneumonectomy, including acute respiratory distress syndrome (8.4% vs 0.8%; P = .005), reintubation (14.7% vs 2.3%; P = .001), unexpected reoperation (9.5% vs 1.5%; P = .01), and sepsis (4.2% vs 0%; P = .03), as was mortality (10.5% vs 3.1%; P = .03). Multivariate analyses revealed that extrapleural pneumonectomy was an independent predictor of major morbidity or mortality (odds ratio, 6.51; P = .001). Compared with high-volume centers, increased acute respiratory distress syndrome was seen in low-volume centers performing extrapleural pneumonectomy (0% vs 12.5%; P = .05).

CONCLUSIONS

Extrapleural pneumonectomy is associated with greater morbidity and mortality compared with pleurectomy/decortication when performed by participating surgeons of the Society of Thoracic Surgeons-General Thoracic Database. Effects of center volume require further study.