Pulmonary injury induced by mustard vesicants and radiation is characterized by DNA damage, oxidative stress, and inflammation. This is associated with increases in levels of inflammatory mediators, including tumor necrosis factor (TNF)α in the lung and upregulation of its receptor TNFR1. Dysregulated production of TNFα and TNFα signaling has been implicated in lung injury, oxidative and nitrosative stress, apoptosis, and necrosis, which contribute to tissue damage, chronic inflammation, airway hyperresponsiveness, and tissue remodeling. These findings suggest that targeting production of TNFα or TNFα activity may represent an efficacious approach to mitigating lung toxicity induced by both mustards and radiation. This review summarizes current knowledge on the role of TNFα in pathologies associated with exposure to mustard vesicants and radiation, with a focus on the therapeutic potential of TNFα-targeting agents in reducing acute injury and chronic disease pathogenesis.

The purpose of this study is to elucidate the impact of bleomycin on the degree of lung injury and development of mediastinal fat-associated lymphoid clusters (MFALCs) in the lymphoproliferative mouse model (MRL/MpJ-Faslpr/lpr “Lpr”) and its control strain (MRL/MpJ “MpJ”). We analyzed immune cells, the degree of proliferation, lymphatic vessels (LVs), and high endothelial venules (HEVs) in lungs and MFALCs in Lpr and MpJ mice on the 7th and 21st days following intranasal instillation of either bleomycin (BLM group) or PBS (PBS group). The BLM group showed a significant increase in the size of MFALCs, lung injury score, and positive area ratios of LVs, HEVs, and immune cells (especially macrophages, B- and T-lymphocytes) on both days 7 and 21. Interestingly, the lungs in the BLM group on day 21 showed higher collagen deposition and cellular infiltration in MpJ and Lpr, respectively. Moreover, significant positive correlations were observed between the size of MFALCs and lung injury. In conclusion, BLM could exert lung fibrosis or lymphoproliferative infiltration in chronic stages in MpJ and Lpr, respectively, and this varied effect could be due to the variations in the degree of immune cell proliferation and the development of LVs and HEVs among the studied strains.

Necrotising enterocolitis (NEC) is a devastating gastrointestinal disease of prematurity that typically develops after the administration of infant formula, suggesting a link between nutritional components and disease development. One of the most significant complications that develops in patients with NEC is severe lung injury. We have previously shown that the administration of a nutritional formula that is enriched in pre-digested Triacylglyceride that do not require lipase action can significantly reduce the severity of NEC in a mouse model. We now hypothesise that this ‘pre-digested fat (PDF) system’ may reduce NEC-associated lung injury. In support of this hypothesis, we now show that rearing newborn mice on a nutritional formula based on the ‘PDF system’ promotes lung development, as evidenced by increased tight junctions and surfactant protein expression. Mice that were administered this ‘PDF system’ were significantly less vulnerable to the development of NEC-induced lung inflammation, and the administration of the ‘PDF system’ conferred lung protection. In seeking to define the mechanisms involved, the administration of the ‘PDF system’ significantly enhanced lung maturation and reduced the production of reactive oxygen species (ROS). These findings suggest that the PDF system protects the development of NEC-induced lung injury through effects on lung maturation and reduced ROS in the lung and also increases lung maturation in non-NEC mice.

Diabetes is a devastating global health problem and is considered a predisposing factor for lung injury progression. Furthermore, previous reports of the authors revealed the role of mediastinal fat-associated lymphoid clusters (MFALCs) in advancing respiratory diseases. However, no reports concerning the role of MFALCs on the development of lung injury in diabetes have been published. Therefore, this study aimed to examine the correlations between diabetes and the development of MFALCs and the progression of lung injury in a streptozotocin-induced diabetic mouse model. Furthermore, immunohistochemical analysis for immune cells (CD3+ T-lymphocytes, B220+ B-lymphocytes, Iba1+ macrophages, and Gr1+ granulocytes), vessels markers (CD31+ endothelial cells and LYVE-1+ lymphatic vessels “LVs”), and inflammatory markers (TNF-α and IL-5) was performed. In comparison to the control group, the diabetic group showed lung injury development with a significant increase in MFALC size, immune cells, LVs, and inflammatory marker, and a considerable decrease of CD31+ endothelial cells in both lung and MFALCs was observed. Furthermore, the blood glucose level showed significant positive correlations with MFALCs size, lung injury, immune cells, inflammatory markers, and LYVE-1+ LVs in lungs and MFALCs. Thus, we suggest that the development of MFALCs and LVs could contribute to lung injury progression in diabetic conditions.

Polyphenols have been described to have a wide range of biological activities, and many reports, published during recent years, have highlighted the beneficial effects of phenolic compounds, illustrating their promising role as therapeutic tools in several acute and chronic disorders. The purpose of study was to evaluate, in an already-assessed model of lung injury caused by bleomycin (BLM) administration, the role of resveratrol and quercetin, as well as to explore the potential beneficial properties of a mango leaf extract, rich in mangiferin, and a grape leaf extract, rich in dihydroquercetin (DHQ), on the same model. Mice were subjected to intra-tracheal administration of BLM, and polyphenols were administered by oral route immediately after BLM instillation and daily for 7 d. Treatment with resveratrol, mangiferin, quercetin and DHQ inhibited oedema formation and body weight loss, as well as ameliorated polymorphonuclear infiltration into the lung tissue and reduced the number of inflammatory cells in bronchoalveolar lavage fluid. Moreover, polyphenols suppressed inducible nitric oxide synthase expression, and prevented oxidative and nitroxidative lung injury, as shown by the reduced nitrotyrosine and poly (ADP-ribose) polymerase levels. The degree of apoptosis, as evaluated by Bid and Bcl-2 balance, was also suppressed after polyphenol treatment. Finally, these natural products down-regulated cyclo-oxygenase-2, extracellular signal-regulated kinase phosphorylated expression and reduced NF-κBp65 translocation. Our findings confirmed the anti-inflammatory effects of resveratrol and quercetin in BLM-induced lung damage, and highlight, for the first time, the protective properties of exogenous administration of mangiferin and DHQ on experimental pulmonary fibrosis.

Heat shock protein 70 (HSP70) is reported as the main factor responsible for the beneficial effects of glutamine (GLN) and as a negative regulator of high mobility group box protein-1 (HMGB-1) expression. Our aim was to determine whether GLN attenuates acute lung injury (ALI) by the inhibition of HMGB-1 expression during sepsis. Male Sprague–Dawley rats were subjected to caecal ligation and puncture (CLP) to induce sepsis. GLN or saline was administered through tail vein 1 h after CLP. Then, quercetin (Q), an inhibitor of HSP70, was utilised to assess the role of the enhanced HSP70. We observed the survival of the subjects. At 24 h post-CLP, we measured lung HSP70, phosphorylated heat shock factor-1 (HSF-1-p) and HMGB-1 expressions, NF-κB DNA-binding activity and ALI occurrence. We also measured serum HSP70, IL-6 and HMGB-1 concentrations. GLN improved survival during sepsis. In GLN-treated rats, lung HSP70 and HSF-1-p expressions were enhanced, lung HMGB-1 expression and NF-κB DNA-binding activity were suppressed, and ALI was attenuated. Furthermore, in GLN-administered rats, serum HSP70 concentration was higher, and serum IL-6 and HMGB-1 concentrations were lower than those in non-treated rats. Q inhibited the enhancement of HSP70 and HSF-1-p expressions and abrogated the GLN-mediated benefits. In conclusion, GLN attenuated ALI and improved survival by the inhibition of HMGB-1 expression during sepsis in rats. These benefits were associated with the enhancement of HSP70 expression by GLN.

Pneumocystis carinii pneumonia (PCP) is a life-threatening infection that occurs in immunocompromised individuals, particularly those with advanced human immunodeficiency virus (HIV) infection. Interestingly, morbidity and mortality is related to the underlying cause of immunosuppression, with AIDS patients faring better than oncology patients for example. In addition, the prognosis of PCP has been correlated with markers of inflammation rather than with organism numbers. There is now increasing evidence that lung damage occurring during PCP is a result of the type and extent of the host inflammatory response to P. carinii rather than a result of direct damage by the organism. This review will discuss the experimental and clinical data demonstrating how the host-mediated inflammatory response to infection with P. carinii determines the ultimate outcome of PCP. A better understanding of the pathophysiology of PCP should lead to the development of improved therapies for the treatment of PCP.