Lung histomorphological alterations in rats exposed to cigarette smoke and electronic cigarette vapour.

Electronic cigarettes are becoming increasingly common as a form of nicotine usage, known as vaping. Numerous studies have demonstrated that using electronic cigarettes may lead to nicotine dependence and has a potentially harmful impact on health. The present study compared the impact of electronic and conventional cigarettes on lung tissue. The experiment included 30 male Wistar rats. The animals were divided into three groups: Group A was exposed to electronic cigarette liquid vapour; group B to conventional smoke; and group C constituted the control group without exposition to the nicotine. In both experimental groups numerous alterations were observed, including a collapse of parenchyma, hyperhagia, hyperplasia of type II of pneumocytes, collagen deposition and an increased number of macrophages within thickened alveolar septa. Additionally, an initial elastolysis was observed. The elastic fibers were disrupted, sparse, irregular and thickened, whereas the numbers of α-SMA positive myofibroblasts and blood vessels were highest in the group exposed to conventional cigarette smoke. In conclusion, the usage of the electronic cigarettes leads to milder pathological alterations compared with traditional cigarette smoking. Nevertheless, the histopathological damage caused by vaping may lead to the development of alterations in the lung tissue which consequently hinder gas exchange.

CB2R agonist prevents nicotine induced lung fibrosis.

INTRODUCTION: Nicotine stimulates fibroblast proliferation while increasing inflammation and fibrosis of tissues. The cannabinoid receptor 1 (CB1R) is mainly located in the CNS, while cannabinoid receptor 2 (CB2R) is located in the immune cells within the body. CB2R regulates inflammatory processes and fibroblast function. PURPOSE: We investigated the impact of CB2R agonist, JWH 133 and the antagonist, AM630 on lung tissue, applied directly before nicotine application. MATERIAL AND METHODS: 40 mice were placed into 4 groups. The experimental groups received nicotine intraperitoneally at a dose of 0.05 mg/kg of body weight (BW) for 14 days. Group B also received AM630 (0.5mg/kg of BW), while Group A was administered with JWH133 (1 mg/kg of BW). Group N received nicotine alone. The Control group C received 0.9% NaCl. After decapitation, lung tissues were stained with H&E, Trichrome Masson's method, and IHC against CTGF and α-SMA. The digital image processing system Image J with the IHC profiler plugins was then employed, optical density and IHC optical density score were calculated. RESULTS: In the N group, an increase in the thickness of alveolar spaces (9.16 SD4.95µm vs. 4.77SD2.99µm in the C group), leukocytes infiltration and collagen deposition has been observed(OD: 0.20 SD0.0vs 0.07SD0.04 in the C group). In the B group, the alveolar space thickness has been the highest (11.57SD8.13µm). Furthermore, in this group, hyperaemia, destruction of lung structure, hyperplasia of II type pneumocyte and interstitial fibrosis has been observed (OD: 0.23 SD0.08). In contrast, the lung tissue of the A group has had normal structure and the thinnest alveolar septum (3.88 SD2.64µm). The expression of CTGF and α-SMA has been the highest in the B group. CONCLUSION: Nicotine induces interstitial lung fibrosis that is enhanced by the CB2R antagonist and diminished by the CB2R agonist. Therefore, the CB2R agonist may offer a protection against fibrosis.

P53 protein in proliferation, repair and apoptosis of cells.

The p53 protein is an important factor of many intra- and extracellular processes. This protein regulates the repair of cellular DNA and induces apoptosis. It is also responsible for the regulation of the senescence and the cell entering the subsequent stages of the cellular cycle. The protein p53 is also involved in inhibiting angiogenesis and the induction of oxidative shock. In our study, we examined the activity of p53 protein in the uterine epithelial cells in rats treated with cladribine. Its action is mainly based on apoptosis induction. We compared the activity of p53 protein in cells with a high apoptosis index and in cells with active repair mechanisms and high proliferation index. We observed stronger p53 protein expression in the epithelial cells of the materials taken 24 h after the last dose of 2-CdA associated with the active process of apoptosis and inhibition of proliferation. After 4 weeks from the last dose of cladribine, the stronger expression of p53 protein was associated with both the existing changes in the cell's genome, the effects of the ongoing repair mechanisms, as well as the high proliferation activity.