Mitochondrial Transfer Regulates Bioenergetics in Healthy and Chronic Obstructive Pulmonary Disease Airway Smooth Muscle.

Mitochondrial dysfunction has been reported in chronic obstructive pulmonary disease (COPD). Transfer of mitochondria from mesenchymal stem cells to airway smooth muscle cells (ASMCs) can attenuate oxidative stress-induced mitochondrial damage. It is not known whether mitochondrial transfer can occur between structural cells in the lungs or what role this may have in modulating bioenergetics and cellular function in healthy and COPD airways. Here, we show that ASMCs from both healthy ex-smokers and subjects with COPD can exchange mitochondria, a process that happens, at least partly, via extracellular vesicles. Exposure to cigarette smoke induces mitochondrial dysfunction and leads to an increase in the donation of mitochondria by ASMCs, suggesting that the latter may be a stress response mechanism. Healthy ex-smoker ASMCs that receive mitochondria show increases in mitochondrial biogenesis and respiration and a reduction in cell proliferation, irrespective of whether the mitochondria are transferred from healthy ex-smoker or COPD ASMCs. Our data indicate that mitochondrial transfer between structural cells is a homeostatic mechanism for the regulation of bioenergetics and cellular function within the airways and may represent an endogenous mechanism for reversing the functional consequences of mitochondrial dysfunction in diseases such as COPD.

Role of Metabolic Reprogramming in Pulmonary Innate Immunity and Its Impact on Lung Diseases.

Lung innate immunity is the first line of defence against inhaled allergens, pathogens and environmental pollutants. Cellular metabolism plays a key role in innate immunity. Catabolic pathways, including glycolysis and fatty acid oxidation (FAO), are interconnected with biosynthetic and redox pathways. Innate immune cell activation and differentiation trigger extensive metabolic changes that are required to support their function. Pro-inflammatory polarisation of macrophages and activation of dendritic cells, mast cells and neutrophils are associated with increased glycolysis and a shift towards the pentose phosphate pathway and fatty acid synthesis. These changes provide the macromolecules required for proliferation and inflammatory mediator production and reactive oxygen species for anti-microbial effects. Conversely, anti-inflammatory macrophages use primarily FAO and oxidative phosphorylation to ensure efficient energy production and redox balance required for prolonged survival. Deregulation of metabolic reprogramming in lung diseases, such as asthma and chronic obstructive pulmonary disease, may contribute to impaired innate immune cell function. Understanding how innate immune cell metabolism is altered in lung disease may lead to identification of new therapeutic targets. This is important as drugs targeting a number of metabolic pathways are already in clinical development for the treatment of other diseases such as cancer.

Systemically administered IgG anti-toxin antibodies protect the colonic mucosa during infection with Clostridium difficile in the piglet model.

The use of anti-toxin human monoclonal antibodies (HMab) as treatment for C. difficile infection has been investigated in animal models and human clinical trials as an alternative to or in combination with traditional antibiotic therapy. While HMab therapy appears to be a promising option, how systemically administered IgG antibodies protect the colonic mucosa during Clostridium difficile infection is unknown. Using the gnotobiotic piglet model of Clostridium difficile infection, we administered a mixture of anti-TcdA and anti-TcdB HMabs systemically to piglets infected with either pathogenic or non-pathogenic C. difficile strains. The HMabs were present throughout the small and large intestinal tissue of both groups, but significant HMabs were present in the lumen of the large intestines only in the pathogenic strain-infected group. Similarly, HMabs measured in the large intestine over a period of 2-4 days following antibody administration were not significantly different over time in the gut mucosa among the groups, but concentrations in the lumen of the large intestine were again consistently higher in the pathogenic strain-infected group. These results indicate that systemically administered HMab IgG reaches the gut mucosa during the course of CDI, protecting the host against systemic intoxication, and that leakage through the damaged colon likely protects the mucosa from further damage, allowing initiation of repair and recovery.

Serum procalcitonin and C-reactive protein for differentiating bacterial infection from disease activity in patients with systemic lupus erythematosus.

OBJECTIVE: To study the clinical value of procalcitonin (PCT) and C-reactive protein (CRP) in differentiating bacterial infection from disease activity in systemic lupus erythematosus (SLE) patients. METHOD: PCT and CRP in active SLE patients complicated with and without bacterial infection were retrospectively studied. Bacterial infection was diagnosed by positive culture results or typical symptoms and signs combined with positive response to antibiotics. Disease activity of SLE was assessed by systemic lupus erythematosus disease activity index (SLEDAI). RESULT: One hundred and fourteen active SLE patients were recruited, 47 of which were with bacterial infection and 67 were non-infected. PCT and CRP levels were significantly elevated in patients with bacterial infection (P < 0.05). The ideal cutoff value for PCT was 0.38 ng/ml, at which the sensitivity (74.5%) and specificity (95.5%) combined the best. The negative predictive value and positive predictive value to detect bacterial infection were 84.2% and 92.1%, respectively. PCT but not the CRP level in the septic patients was significantly higher than that of non-septic ones. Meanwhile, in patients with SLEDAI score of > 10, both PCT and CRP levels were higher in patients with bacterial infection, but the difference was only statistically significant for PCT (P < 0.05). PCT was significantly reduced after anti-bacterial treatment. CONCLUSION: PCT test is superior to CRP test in detecting superimposed bacterial infection in active SLE patients. The levels of PCT are correlated with the severity of bacterial infection and can be used to monitor the response to antibiotic treatment.

Elevation of serum procalcitonin in patients after chemical pleurodesis with intrapleural injection of OK-432.

INTRODUCTION: In patients with refractory pleural effusion or pneumothorax, fever and elevated level of white blood cell count (WBC) are frequently observed after chemical pleurodesis with intrapleural injection of OK-432, which make it difficult to differentiate whether it was from the side effects of OK-432 or concurrent bacterial infection. OBJECTIVE: Procalcitonin (PCT) levels were measured before and after pleurodesis so as to discuss whether PCT is useful for distinguishing between the side effects of OK-432 and concurrent bacterial infection. METHOD: Twenty-six patients with refractory pleural effusion or pneumothorax who underwent chemical pleurodesis with intrapleural injection of OK-432 at the First Affiliated Hospital of Sun Yat-sen University between August 2010 and August 2012 were included in our study. Levels of PCT and WBC were measured before and after pleurodesis. RESULT: Of all 26 patients, 22 patients were with refractory pleural effusion, and the other four were with pneumothorax. The median serum levels of PCT and WBC elevated from 0.155 to 1.470 ng/mL (P = 0.009) and from 5.920 to 10.475 × 10(9) /L (P = 0.000), respectively. No patient was given antibiotics and fever subsided. CONCLUSION: Intrapleural injection of OK-432 could increase the serum level of PCT and WBC with no bacterial infection. The serum PCT level may not be useful to distinguish whether fever was caused by the side effects of OK-432 or concurrent bacterial infection.

Pulmonary cryptococcosis in non-AIDS patients

OBJECTIVE: To investigate the clinical features, management, and prognosis of pulmonary cryptococcosis in non-acquired immunodeficiency syndrome (AIDS) patients. METHOD: 24 cases of pulmonary cryptococcosis with accurate pathological diagnosis were retrospectively studied. RESULTS: 15 male patients and nine female patients were diagnosed at the first affiliated hospital of Sun Yat-sen University from November 1999 to November 2011. The mean age at the time of diagnosis was 44.2 ± 11.3 years (range: 24 to 65 years). Among these patients, 13 had other comorbidities. 15 were symptomatic and the other nine were asymptomatic. The most common presenting symptoms were cough, chest tightness, expectoration, and fever. None had concurrent cryptococcal meningitis. The most frequent radiologic abnormalities on chest computed tomography (CT) scans were solitary or multiple pulmonary nodules, and masses or consolidations, and most lesions were located in the lower lobes. All patients had biopsies for the accurate diagnosis. Among the 24 patients, nine patients underwent surgical resections (eight had pneumonectomy via thoracotomy and one had a pneumonectomy via thoracoscopy). Five of the patients who underwent surgery also received antifungal drug therapy (fluconazole) for one to three months after the surgery. The other 15 only received antifungal drug therapy (fluconazole or voriconazole) for three to six months (five patients are still on therapy). The follow-up observation of 19 patients who had already finished their treatments lasted from two to 11 years, and there was no relapse, dissemination, or death in any of these patients. CONCLUSION: Non-AIDS patients with pulmonary cryptococcosis have a good prognosis with appropriate management.

Pulmonary cryptococcosis in non-AIDS patients.

OBJECTIVE: To investigate the clinical features, management, and prognosis of pulmonary cryptococcosis in non-acquired immunodeficiency syndrome (AIDS) patients. METHOD: 24 cases of pulmonary cryptococcosis with accurate pathological diagnosis were retrospectively studied. RESULTS: 15 male patients and nine female patients were diagnosed at the first affiliated hospital of Sun Yat-sen University from November 1999 to November 2011. The mean age at the time of diagnosis was 44.2±11.3 years (range: 24 to 65 years). Among these patients, 13 had other comorbidities. 15 were symptomatic and the other nine were asymptomatic. The most common presenting symptoms were cough, chest tightness, expectoration, and fever. None had concurrent cryptococcal meningitis. The most frequent radiologic abnormalities on chest computed tomography (CT) scans were solitary or multiple pulmonary nodules, and masses or consolidations, and most lesions were located in the lower lobes. All patients had biopsies for the accurate diagnosis. Among the 24 patients, nine patients underwent surgical resections (eight had pneumonectomy via thoracotomy and one had a pneumonectomy via thoracoscopy). Five of the patients who underwent surgery also received antifungal drug therapy (fluconazole) for one to three months after the surgery. The other 15 only received antifungal drug therapy (fluconazole or voriconazole) for three to six months (five patients are still on therapy). The follow-up observation of 19 patients who had already finished their treatments lasted from two to 11 years, and there was no relapse, dissemination, or death in any of these patients. CONCLUSION: Non-AIDS patients with pulmonary cryptococcosis have a good prognosis with appropriate management.