The Role of Tumor Necrosis Factor Alpha and TNF Superfamily Members in Bone Damage in Patients with End-Stage Chronic Obstructive Lung Disease Prior to Lung Transplantation

Inflammatory Cytokine Elaboration Following Secondhand Smoke (SHS) Exposure Is Mediated in Part by RAGE Signaling

The receptor for advanced glycation end products (RAGE) is a key contributor to immune and inflammatory responses in myriad diseases. RAGE is a transmembrane pattern recognition receptor with a special interest in pulmonary anomalies due to its naturally abundant pulmonary expression. Our previous studies demonstrated an inflammatory role for RAGE following acute 30-day exposure to secondhand smoke (SHS), wherein immune cell diapedesis and cytokine/chemokine secretion were accentuated in part via RAGE signaling. However, the chronic inflammatory mechanisms associated with RAGE have yet to be fully elucidated. In this study, we address the impact of long-term SHS exposure on RAGE signaling. RAGE knockout (RKO) and wild-type (WT) mice were exposed to SHS using a nose-only delivery system (Scireq Scientific, Montreal, Canada) for six months. SHS-exposed animals were compared to mice exposed to room air (RA) only. Immunoblotting was used to assess the phospho-AKT and phospho-ERK activation data, and colorimetric high-throughput assays were used to measure NF-kB. Ras activation was measured via ELISAs. Bronchoalveolar lavage fluid (BALF) cellularity was quantified, and a mouse cytokine antibody array was used to screen the secreted cytokines. The phospho-AKT level was decreased, while those of phospho-ERK, NF-kB, and Ras were elevated in both groups of SHS-exposed mice, with the RKO + SHS-exposed mice demonstrating significantly decreased levels of each intermediate compared to those of the WT + SHS-exposed mice. The BALF contained increased levels of diverse pro-inflammatory cytokines in the SHS-exposed WT mice, and diminished secretion was detected in the SHS-exposed RKO mice. These results validate the role for RAGE in the mediation of chronic pulmonary inflammatory responses and suggest ERK signaling as a likely pathway that perpetuates RAGE-dependent inflammation. Additional characterization of RAGE-mediated pulmonary responses to prolonged exposure will provide a valuable insight into the cellular mechanisms of lung diseases such as chronic obstructive pulmonary disease.

Main Pathogenic Mechanisms and Recent Advances in COPD Peripheral Skeletal Muscle Wasting

Chronic obstructive pulmonary disease (COPD) is a worldwide prevalent respiratory disease mainly caused by tobacco smoke exposure. COPD is now considered as a systemic disease with several comorbidities. Among them, skeletal muscle dysfunction affects around 20% of COPD patients and is associated with higher morbidity and mortality. Although the histological alterations are well characterized, including myofiber atrophy, a decreased proportion of slow-twitch myofibers, and a decreased capillarization and oxidative phosphorylation capacity, the molecular basis for muscle atrophy is complex and remains partly unknown. Major difficulties lie in patient heterogeneity, accessing patients' samples, and complex multifactorial process including extrinsic mechanisms, such as tobacco smoke or disuse, and intrinsic mechanisms, such as oxidative stress, hypoxia, or systemic inflammation. Muscle wasting is also a highly dynamic process whose investigation is hampered by the differential protein regulation according to the stage of atrophy. In this review, we report and discuss recent data regarding the molecular alterations in COPD leading to impaired muscle mass, including inflammation, hypoxia and hypercapnia, mitochondrial dysfunction, diverse metabolic changes such as oxidative and nitrosative stress and genetic and epigenetic modifications, all leading to an impaired anabolic/catabolic balance in the myocyte. We recapitulate data concerning skeletal muscle dysfunction obtained in the different rodent models of COPD. Finally, we propose several pathways that should be investigated in COPD skeletal muscle dysfunction in the future.

Blocking tumor necrosis factor-α delays progression of chronic obstructive pulmonary disease in rats through inhibiting MAPK signaling pathway and activating SOCS3/TRAF1

The present study was conducted in order to study the detailed molecular mechanism of tumor necrosis factor (TNF)-α in chronic obstructive pulmonary disease (COPD). The rats were treated with cigarette smoke (CS) and lipopolysaccharide (LPS) to establish the COPD model. Next, the changes in lung injury in COPD rats with TNF-α knockdown was tested. Meanwhile, the regulation of TNF-α on MAPK pathway and its downstream molecules (SOCS3/TRAF1) was determined by western blotting. On this basis, the activation of MAPK and inhibition of SOCS3/TRAF1 was also examined. Subsequently, the lung function was tested with the plethysmograph, the cells of bronchoalveolar lavage fluid was counted and classified. Furthermore, lung tissue sections were stained with hematoxylin and eosin to verify whether the treatment of MAPK pathway and downstream molecules affected the effect of TNF-α knockdown on COPD. The present study showed that TNF-α knockdown could alleviate the decrease in the function and inflammatory injury of the lungs of rats with COPD. Western blot analysis verified that TNF-α knockdown could inhibit the activation of MAPK pathway and increase the expression of SOCS3/TRAF1. The following experimental results showed that the relief of lung injury caused by TNF-α knockdown could be deteriorated by activating MAPK pathway. It was also found that the symptom of COPD was decreased following transfection with sh-TNF-α but worsened by SOCS3/TRAF1 knockdown. Overall, TNF-α knockdown inhibited the activation of MAPK pathway and increased the expression of SOCS3/TRAF1, thus delaying the process of COPD.

Therapeutic effects of thymoquinone in doxorubicin-induced hepatotoxicity via oxidative stress, inflammation and apoptosis

Cancer is a lethal disease that is characterized by uncontrolled cell division and proliferation, and it results in death in many organisms. Doxorubicin (DOX) is a therapeutic agent used for treatment of many cancer types, but it induces serious hepatotoxicity. In this study, we aimed to determine possible hepato-therapeutic effects of thymoquinone (THQ) on DOX-induced hepatotoxicity in rats. Rats were divided into five groups (n = 8): Control, THQ (10 mg/kg/day/i.p for 14 days), Olive Oil (equal volume with THQ for 14 days), DOX (single dose, 15 mg/kg/i.p on 7th day) and DOX + THQ (10 mg/kg/day/i.p and DOX 15 mg/kg/i.p on 7th day). At the end of the experiment, liver tissues were extracted and evaluated histopathologically. eNOS, iNOS and Cas-3 immunostaining were performed to determine the expression levels. TUNEL method was used to determine apoptotic index. Furthermore, liver tissue total antioxidant status (TAS), total oxidant status (TOS), TNF-α and TGF-β levels were measured by ELISA assay. The DOX group showed histopathological deterioration compared to Control group. Moreover, apoptotic index, eNOS, iNOS and Cas-3 expressions increased in DOX group. While TAS level of the DOX group decreased, TOS level increased. TNF-α and TGF-β levels increased in DOX group. However, there was improvement in DOX + THQ group compared to DOX group. Moreover, apoptotic cell number, eNOS, iNOS and Cas-3 expressions decreased in DOX + THQ group compared to DOX group. We concluded that thymoquinone can be used as a phytotherapeutic for reducing DOX-induced liver damage.

The Pathophysiology of Osteoporosis after Spinal Cord Injury

Spinal cord injury (SCI) affects approximately 300,000 people in the United States. Most individuals who sustain severe SCI also develop subsequent osteoporosis. However, beyond immobilization-related lack of long bone loading, multiple mechanisms of SCI-related bone density loss are incompletely understood. Recent findings suggest neuronal impairment and disability may lead to an upregulation of receptor activator of nuclear factor-κB ligand (RANKL), which promotes bone resorption. Disruption of Wnt signaling and dysregulation of RANKL may also contribute to the pathogenesis of SCI-related osteoporosis. Estrogenic effects may protect bones from resorption by decreasing the upregulation of RANKL. This review will discuss the current proposed physiological and cellular mechanisms explaining osteoporosis associated with SCI. In addition, we will discuss emerging pharmacological and physiological treatment strategies, including the promising effects of estrogen on cellular protection.

Effect of Pingchuan Guben decoction on patients with chronic obstructive pulmonary disease: Results from a randomized comparative effectiveness research trial

Chronic obstructive pulmonary disease (COPD) is known to be a systemic low-grade ongoing inflammation exerting major health and economic burden worldwide. Complementary and alternative medicines, such as Traditional Chinese Medicine, are widely used for the treatment of patients with COPD. The present study was designed to investigate the efficacy of Pingchuan Guben decoction on patients with COPD through a double-blinded, open-labeled, randomized controlled trial. A total of 86 patients were randomly assigned to two groups, with 43 patients in the intervention group and 43 cases in the control group. The patients in the control group were treated with conventional western medicine, and the intervention group received a combination of conventional western medicine and Pingchuan Guben decoction. After 12 weeks of treatment, the mean 6-minute walking distance, forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC) and FEV1/FVC in the intervention group were significantly higher than those of the control group (P<0.05). The levels of inflammation factors and protease molecules were significantly ameliorated in the intervention group compared with the control group (P<0.05). The levels of Kelch-like ECH-associated protein 1 (Keap1), nuclear factor-E2-related factor-2 (Nrf2), superoxide anions, malondialdehyde, glutathione S-transferase and glutathione peroxidase were significantly more improved in the intervention group compared with those in the control group over the 12-week study period (P<0.05). Therefore, combinations of western medicine with Pingchuan Guben decoction may exert therapeutic effects on patients with COPD via modulations of inflammation factors and protease molecules, as well as the activation of the Keap1/Nrf2 signaling pathway.