Serum levels of lipocalin-2 in patients with Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is the second most common neurodegenerative disease. Evidence has shown that lipocalin-2 (LCN2) is involved in the pathological process of PD. We aimed to explore whether serum levels of LCN2 could be a biomarker of PD. METHODS: We recruited consecutive PD patients and healthy controls (HC) in our hospital from June 2020 to July 2020. Serum LCN2 levels were detected using the LCN2 enzyme-linked immunosorbent assay (ELISA) kit. The motor section of the Unified Parkinson's Disease Rating Scale (UPDRS III) and the Hoehn and Yahr Staging Scale (H&Y) were assessed on admission to evaluate disease severity in patients with PD. Cognitive status was measured by the Montreal Cognitive Assessment (MoCA). RESULTS: We finally recruited 75 patients, including 40 PD patients and 35 HC. Serum LCN2 levels were not significantly increased in PD patients compared with HC (4.9 [- 0.7 to 18.6] vs 1.9 [- 1.5 to 16.9] ng/mL, P = 0.33). Besides, there was no significant difference in LCN2 levels between patients at early and advanced stage of PD (P = 0.75), as well as between cognitively impaired PD patients, PD patients with normal cognition, and HC (P = 0.30). Moreover, LCN2 had no correlation with disease duration (r = - 0.1, P = 0.37), UPDRS III score (r = 0.07, P = 0.65), and MoCA score (r = 0.221, P = 0.17). CONCLUSIONS: Overall, our study suggests that serum LCN2 levels may not be a biomarker for PD.

Enhanced hydrogen generation by reverse spillover effects over bicomponent catalysts.

The contribution of the reverse spillover effect to hydrogen generation reactions is still controversial. Herein, the promotion functions for reverse spillover in the ammonia borane hydrolysis reaction are proven by constructing a spatially separated NiO/Al2O3/Pt bicomponent catalyst via atomic layer deposition and performing in situ quick X-ray absorption near-edge structure (XANES) characterization. For the NiO/Al2O3/Pt catalyst, NiO and Pt nanoparticles are attached to the outer and inner surfaces of Al2O3 nanotubes, respectively. In situ XANES results reveal that for ammonia borane hydrolysis, the H species generated at NiO sites spill across the support to the Pt sites reversely. The reverse spillover effects account for enhanced H2 generation rates for NiO/Al2O3/Pt. For the CoOx/Al2O3/Pt and NiO/TiO2/Pt catalysts, reverse spillover effects are also confirmed. We believe that an in-depth understanding of the reverse effects will be helpful to clarify the catalytic mechanisms and provide a guide for designing highly efficient catalysts for hydrogen generation reactions.

In situ tuning of electronic structure of catalysts using controllable hydrogen spillover for enhanced selectivity.

In situ tuning of the electronic structure of active sites is a long-standing challenge. Herein, we propose a strategy by controlling the hydrogen spillover distance to in situ tune the electronic structure. The strategy is demonstrated to be feasible with the assistance of CoOx/Al2O3/Pt catalysts prepared by atomic layer deposition in which CoOx and Pt nanoparticles are separated by hollow Al2O3 nanotubes. The strength of hydrogen spillover from Pt to CoOx can be precisely tailored by varying the Al2O3 thickness. Using CoOx/Al2O3 catalyzed styrene epoxidation as an example, the CoOx/Al2O3/Pt with 7 nm Al2O3 layer exhibits greatly enhanced selectivity (from 74.3% to 94.8%) when H2 is added. The enhanced selectivity is attributed to the introduction of controllable hydrogen spillover, resulting in the reduction of CoOx during the reaction. Our method is also effective for the epoxidation of styrene derivatives. We anticipate this method is a general strategy for other reactions.

Cigarette smoke extract inhibits the proliferation of alveolar epithelial cells and augments the expression of P21WAF1.

Cigarette smoking is intimately related with the development of chronic obstructive pulmonary diseases, and alveolar epithelium is a major target for the exposure of cigarette smoke extract. In order to investigate the effect of cigarette smoke extract on the proliferation of alveolar epithelial cell type II and its relationship with P21WAF1, the alveolar epithelial type II cell line (A549) cells were chosen as surrogate cells to represent alveolar epithelial type II cells. MTT assay was used to detect cell viability after interfered with different concentrations of cigarette smoke extract. It was observed cigarette smoke extract inhibited the growth of A549 cells in a dose-and time-dependent manner. The morphological changes, involving the condensation and margination of nuclear chromatin, even karyorrhexis, were observed by both Hoechst staining and electronic microscopy. Flow cytometry analysis demonstrated the increased cell percentages in G1 and subG1 phases after the cells were incubated with cigarette smoke extract. The expression of p21WAF1 protein and mRNA was also significantly increased as detected by the methods of Western blot or reverse transcription-polymerase chain reaction respectively. In conclusion, cigarette smoke extract inhibits the proliferation of alveolar epithelial cell type II and blocks them in G1/S phase. The intracellular accumulation of P21WAF1 may be one of the mechanisms which contribute to cigarette smoke extract-induced inhibition of cell proliferation.

Cigarette smoke extract inhibits the proliferation of alveolar epithelial cells and induces apoptosis.

Cigarette smoke extract (CSE) contains abundant oxidants and free radicals. Oxidative stress caused by cigarette smoking results in the destruction of the alveolar cell walls and emphysema. However, there exists discrepancy about how CSE works in the process. In the present study, we observed the effect of CSE on the cell growth of type II alveolar epithelial cell-derived A549 cell line, and provided molecular understanding of this effect. The MTT assay results showed that CSE decreased the cell viability of A549 cells in a dose- and time-dependent manner, and cell cycle was arrested in G(1)/S phase. Furthermore, CSE-induced apoptosis of A549 cells was verified by Hoechst 33258 staining, electron microscopy in morphology, and the appearance of DNA fragmentation and annexin V-FITC/propidium iodide (PI) staining assay at molecular level. It was found that CSE treatment resulted in the upregulation of Fas/APO-1 receptor and activation of caspase-3. CSE also initiated accumulation of intracellular reactive oxygen species, which was detected by laser confocal microscopy. Taken together, CSE could inhibit the cell growth and induce apoptosis of A549 cells through Fas receptor pathway. Oxidative stress caused by CSE may be the radical factor leading to apoptosis as well as cell growth inhibition in alveolar epithelial cells.

[Melatonin in in vitro apoptosis of H22 hepatocarcinoma cells].

OBJECTIVE: To study the effect of melatonin (MLT) in in vitro apoptosis of hepatocarcinoma cells and its mechanism. METHODS: The apoptotic cells, bcl-2 and bax were detected through immunocytochemical method (ICC) and Tolt-mediated x-duTP nick end labeling (TUNEL). Computer image analysis system was used to quantify the expression of bcl-2 and bax by detecting the absorbance value of positive products. Apoptosis index (AI) was used to quantify the number of apoptotic cells. RESULTS: In vitro, AI increase was both concentration- and time-dependent through TUNEL. During the same duration, AI of medium dose group was higher than that of low dose and control group (P < 0.05); AI of high dose, medium dose and 5-Fu group were higher than those of low dose and control group (P < 0.01), however, there was no significant difference between the low dose and control group (P > 0.05). At the same dose, in high dose, medium dose and 5-Fu group, the change of AI showed significant difference from 24 to 36 hours (P < 0.05). The expression of bcl-2 was down-regulated as the MLT increased, and there was significant difference between the low dose and control group (P < 0.01). But, the expression of bax was up-regulated as the dose of MLT increased, showing significant difference between the high dose and control groups (P < 0.01). As time went on, the expression of bcl-2 was decreased and in every group, with the change in absorbance value of bcl-2 significantly different from 24 to 36 hours (P < 0.05), whereas that of bax remained almost unchanged. The ratio of bax/bcl-2 was increased with the increase in the concentration of MLT. CONCLUSION: Melatonin may induce apoptosis in the hepatocarcinoma cells which is concentration- and time-dependent, in which bcl-2 and bax are involved.

Inhibition of expression of hypoxia-inducible factor-1alpha mRNA by nitric oxide in hypoxic pulmonary hypertension rats.

In order to study the effect of nitric oxide (NO) on the expression of hypoxia-inducible factor-1 alpha (HIF-1alpha) mRNA in hypoxic pulmonary hypertension (HPH) rats, 30 healthy male Wistar rats were randomly divided into normoxic control group, chronic hypoxic group and hypoxia plus L-arginine (L-Arg) group. The animal model of HPH was developed. The mean pulmonary arterial pressure (mPAP) was measured by inserting a microcatheter into the pulmonary artery. The HIF-1alpha mRNA expression levels were detected by in situ hybridization (ISH) and semiquantitative RT-PCR. It was found that after 14 days hypoxia, the mPAP in normoxic control group (17.6 +/- 2.7 mmHg, 1 mmHg=0.133 kPa) was significantly lower than that in chronic hypoxic group (35.8 +/- 6.1 mmHg, t=0.2918, P<0.05) and mPAP in chronic hypoxic group was higher than that in hypoxia plus L-arginine group (24.4 +/- 3.8 mmHg, t=0.2563, P<0.05). ISH showed that the expression of HIF-1alpha mRNA in the intraacinar pulmonary arteriolae (IAPA) in normoxic control group (0.1076 +/- 0.0205) was markedly weaker than that in chronic hypoxic group (0.3317 +/- 0.0683, t=3.125, P<0.05) and that in chronic hypoxic group was stronger than that in hypoxia plus L-arginine group (0.1928 +/- 0.0381, t=2.844, P<0.05). RT-PCR showed that the content of HIF-1alpha mRNA in chronic hypoxic group (2.5395 +/- 0.6449) was 2.16 times and 1.75 times higher than that in normoxic control group (1.1781 +/- 0.3628) and hypoxia plus L-arginine group (1.4511 +/- 0.3981), respectively. It is concluded that NO can reduce the mPAP by the inhibition of the expression of HIF-1alpha mRNA, which may be one of the mechanisms through which NO affects the pathogenesis of HPH.

Construction of eukaryotic expression plasmid of human PRX3 and its expression in HEK-293FT cells.

To construct the eukaryotic expression plasmid of human PRX3 and measure its expression in the HEK-293FT cells, the full-length coding region of human PRX3 was cloned by PCR and inserted into the eukaryotic expression vector pcDNA4-Xpress (A). HEK-293FT cells were transiently transfected with the recombinant plasmid. Western blot and immuofluorescence were used to detect the expression of the fusion protein. In the experiment, restriction analysis identified the construction of the recombinant plasmid and the inserted sequence was identical with that published on GenBank. Western blot and immunofluorescence confirmed the expression of the recombinant protein in transfected HEK-293FT cells. It was concluded that the eukaryotic expression plasmid of human PRX3 was constructed successfully and the recombinant could be expressed efficiently in HEK-293FT cells, which provides a sound basis for the further study on human PRX3.

[Changes of the actin and transforming growth factor-beta1 expression in the small airways of the rat with chronic obstructive lung disease].

OBJECTIVE: To study the roles of actin and transforming growth factor (TGF)-beta(1) in the injury repair and the development of emphysema. METHODS: Wistar rats were randomly divided into two groups: the smoking and infection group (group SI) and the control group (group C). The rats of group SI received smoking irritation accompanying with repeated intranasal infection. Subgroups of the experimental animals were killed in the 2nd, 4th, 8th and 16th weeks respectively. The morphological changes of lungs were compared and PaO(2), PaCO(2) as well as the right ventricular systolic pressure (RVSP) were analysed. The lung sections were stained with immunohistochemistry for actin and TGF-beta(1). RESULTS: In comparison with animals of group C, thickening of the bronchiolar walls, narrowing of bronchiolar lumens, and area of emphysema were much severe in animals of group SI (P < 0.05). The muscularization of intra-alveolar arteries in group SI in the 16th week was apparent in comparing with that in group C (P < 0.05). PaO(2) values in group SI were significantly decreased, and RVSP values in group SI were significantly increased in the 8th and 16th week (P < 0.05). Actin expression was increased in animals of group SI in the 4th and 8th week (0.24 +/- 0.06 and 0.25 +/- 0.05) in comparing with that of group C (0.09 +/- 0.03) (P < 0.05). Animals of group SI showed a significant increase of TGF-beta(1) in lung tissue in different periods as mentioned in above (33.33 +/- 12.11, 45.71 +/- 15.12, 71.43 +/- 16.76 and 86.25 +/- 20.66 respectively). CONCLUSIONS: The increased expression of actin and TGF-beta(1) protein in small airways induced by smoking irritation and Klebsiella Pneumoniae may interfere with the repair response, and contributes to the development of emphysema.

Expression of hypoxia-inducible factor-1 alpha and endothelin-1 gene in hypoxic pulmonary hypertension.

OBJECTIVE: To investigate the expression of hypoxia-inducible factor-1 alpha (HIF-1alpha) and endothelin-1 (ET-1) gene in hypoxic pulmonary hypertension (HPH). METHODS: The animal model of HPH was replicated. The elastic fiber staining was applied to show the intraacinar pulmonary artery (IAPA). Radioimmunoassay (RIA) and in situ hybridization (ISH) were used for detection of HIF-1a and. ET-1. RESULTS: ISH showed that HIF-1alpha mRNA was expressed in the IAPA of all hypoxic rat. The expression was stronger in the H14 d (0.256 9 +/- 0.046 8) and H28 d (0.225 8 +/- 0.045 3) groups than in the H5 d (0.1455 +/- 0.072 2) and control (0.110 9 +/- 0.022 4) groups (P < 0.05), the expression of ET-1 mRNA in the H14 d (0.412 2 +/- 0.078 3) and H28 d (0.368 4 +/- 0.072 9) groups was also stronger than that in the H5 d (0.201 7 +/- 0.034 9) and control (0.185 5 +/- 0.036 1) groups (P < 0.05). The amount of ET-1 in pulmonary arteial blood in the H14 d [(158.78 +/- 25.14) pg/ml] and H28 d [(142.93 +/- 23.38) pg/ml] groups was significantly higher than that in the H5 d [(79.68 +/- 12.54) pg/ml] and control [(65.37 +/- 10.82) pg/ml] groups (P < 0.05). The mean pulmonary arterial pressure (mPAP) in the H14 d [(34.0 +/- 5.8) mm Hg] and H 28 d [(29.0 +/- 4.7) mm Hg] groups was markedly higher than that in the H5 d [(19.0 +/- 3.5) mm Hg] and control [(17.0 +/- 2.8) mm Hg] groups (P < 0.05). A positive rank correlation existed between the mPAP and the amount of ET-1 (rs = 0.747, P < 0.05). CONCLUSIONS: Expression of HIF-1alpha and ET-1 mRNA in IAPA increase under long-term hypoxic condition and both show consistent expression, indicating that the expression of HIF-1a and ET-1 gene contribute to pathogenesis of HPH.

[Effects of cigarette smoke extract on the proliferation and the expression of TGF-beta1 and EGF in human embryonic lung fibroblasts].

OBJECTIVE: To observe the effects of cigarette smoke extract (CSE) on the proliferation and the expression of TGF-beta(1) and EGF in human embryonic lung fibroblasts (HELF). METHODS: The cultures of HELF were incubated with CSE (1:50, 1:25 and 1:10) for examining the effects of CSE on the proliferation and the proliferating cell nuclear antigen (PCNA) levels in HELF. The total RNA was extracted from the cells incubated with CSE at different doses. The expression levels of TGF-beta(1) mRNA were evaluated by reverse transcription-polymerase chain reaction (RT-PCR). The mRNA levels of TGF-beta(1) were corrected by GAPDH transcripts. TGF-beta(1) and EGF protein levels were determined by immunocytochemistry. RESULTS: The proliferation of HELF was inhibited by CSE in a dose-dependent manner. CSE also decreased the PCNA levels of HELF at all doses (P < 0.05). CSE stimulated TGF-beta(1) mRNA and protein expression of HELF at lower concentrations (1:50 and 1:25, P < 0.05). TGF-beta(1) mRNA and protein production were not increased by CSE at a higher concentration (1:10, P > 0.05). Decreased expression of EGF protein was observed in HELF treated by CSE (1:25 and 1:10, P < 0.05). CONCLUSIONS: CSE can inhibit the proliferation of HELF and the effect may involve the abnormal expression of TGF-beta(1) and EGF in HELF.