[Effect of actin-related protein 2-3 complex on phagocytosis defect of alveolar macrophages in a mouse model of chronic obstructive pulmonary disease].

Objective: To investigate the role of actin-related protein 2-3 complex (Arp2/3) complex on phagocytosis of alveolar macrophages (AMs) in a mouse model of chronic obstructive pulmonary (COPD). Methods: Forty mice were randomly divided into healthy control group, healthy Arp2/3 complex inhibitor (CK666) group, COPD group and COPD CK666 group with 10 mice in each group. COPD group and COPD CK666 group were established by cigarette smoke exposure, and the control group had no smoke exposure. After 90 days of molding, AMs were isolated from lung tissue of mice in each group. Mean fluorescence intensity (MFI) and the positive percent of AMs engulfing fluorescein isothiocyanate-labeled Escherchina coli (FITC-E.coli) (AM%) were detected by flow cytometry. Western blot was applied to detect protein. Laser scanning confocal microscopy was used to measure the mean optical density of Arp2, F-actin and engulfed FITC-E. coli and quantify the colocalization of Arp2 and F-actin by a Manders' overlap coefficient. Scanning electron microscopy was used to observe the ultrastructure of AM phagocytizing FITC-E.coli. Results: Phagocytosis of AM: MFI and AM% in the COPD group were significantly decreased than those in the healthy control group[(4 702±243), (8 684±234) and (32.21±1.66)%, (65.88±1.77)%, all P<0.01]. MFI and AM% in the COPD CK666 group [(3 597±307), (22.09±1.89)%] and in the healthy CK666 group [(7 446±236), (50.09±1.64)%] were decreased compared to those in their respective control groups (all P<0.01). The expressions of protein of Arp2 and F-actin in the COPD group were significantly decreased than those in the healthy control group (0.508±0.025, 0.813±0.040 and 0.462±0.029, 0.720±0.039) (all P<0.01). The F-actin in the COPD CK666 group (0.265±0.014) and in the healthy CK666 group (0.637±0.032) were significantly decreased compared to those in their respective control groups (all P<0.01). The mean optical density of Arp2, F-actin and FITC-E.coli in the COPD group were significantly decreased compared to those in the healthy group (34.43±0.56, 142.83±1.90 and 61.59±0.70, 145.93±3.05 and 41.49±0.33, 189.17±2.60) (all P<0.01); the mean optical density of F-actin, FITC-E. coli in the COPD CK666 group (37.73±1.04, 28.84±2.95) and in the healthy CK666 group (137.07±1.35, 157.46±1.00) were significantly decreased compared to those in their respective control groups (all P<0.01). The Manders' overlap coefficient of Arp2 and phalloidin' coefficient in the COPD group (0.395±0.014) were significantly decreased than the healthy control group (0.395±0.014 and 0.880±0.002, P<0.01). The Manders' overlap coefficient of Arp2 and phalloidin' coefficient in the COPD CK666 group (0.297±0.006) and in the healthy CK666 group (0.737±0.031) were significantly decreased compared to those in their respective control groups (all P<0.01). Shape of AM: Long filopodia protruding and plentiful dorsal ruffle can be seen in AM from the healthy control group; AM pseudopods extension and dorsal ruffle reduced in the health CK666 group; there were pseudopods and dorsal ruffle defects in the COPD group and the COPD CK666 group. Positive correlations existed between the proteins of Arp2, F-actin with MFI. Positive correlations also existed between the Manders' overlap coefficient of Arp2 and phalloidin' coefficient with MFI. Conclusion: Decreased activity of Arp2/3 complex leads to low phagocytosis of AM in COPD mice, and AM in COPD mice is more sensitive to Arp2/3 complex inhibitor.

[The effect of fine particles on the phagocytosis of alveolar macrophages potentially by Arp2/3 complex in a mouse model of chronic obstructive pulmonary disease].

Objective: To investigate the mechanism of fine particulate matter (PM2.5) on the phagocytosis of alveolar macrophages (AM) in mice with chronic obstructive pulmonary disease (COPD) through actin-related protein (Arp) 2/3 complex. Methods: Forty mice were divided into healthy control(A) group, healthy PM2.5 (B) group, COPD(C) group, and COPD PM2.5(D) group according to the random number table method. A mouse model of COPD was established by cigarette smoke exposure method. PM2.5 (662 µg/m(3)) model was established by continuously inhalation for 90 days in healthy PM2.5 group and COPD PM2.5 group. Flow cytometry was used to detect the ability of AM to phagocytose fluorescein isothiocyanate-labeled E.coli (FITC-E.coli), expressed as mean fluorescence intensity (MFI) and percentage of phagocytic positive cells (phagocytosis percentage); Western blotting was used to detect AM Arp2 and F-actin content, and laser confocal microscopy for AM Arp2 and F-actin and phagocytic FITC-E.coli average optical density and colocalization of Arp2 and F-actin, while scanning electron microscopy was used to observes the morphology of AM after phagocytizing FITC-E.coli. Results: AM phagocytosis: MFI and phagocytosis percentage in the COPD group [4 656±251, (31.9±1.7)%] were lower than the healthy control group [8 657±247, (65.7±1.9)%] (both P<0.01); and healthy PM2.5 group and COPD PM2.5 group [7 653±228, (47.9±1.6)% and 3 660±237, (19.2±1.2)%] were lower than the respective control groups (all P<0.01), and the decrease in the COPD group was more pronounced. AM Arp2, F-actin content: the COPD group (0.51±0.02, 0.46±0.03) were lower than the healthy control group (0.81±0.04, 0.71±0.04, both P<0.01); the healthy PM2.5 group and the COPD PM2.5 group [(0.64±0.03, 0.56±0.04) and (0.29±0.02, 0.26±0.02)] were lower than the respective control groups (all P<0.01), and the decrease in COPD group was more significant. Arp2, F-actin, and phagocytic FITC-E.coli mean optical density values: the COPD group (33.0±2.3, 62.0±0.7, 41.0±0.4) were lower than the healthy control group (141.0±4.2, 145.0±2.9, 189.0±2.6, both P<0.01); the healthy PM2.5 group and the COPD PM2.5 group (127.0±2.8, 124.0±0.7, 154.0±0.9, and 24.0±2.4, 37.0±0.4, 29.0±0.8) were lower than the respective control groups (all P<0.01), and the decrease in the COPD group was more significant. Colocalization of AM Arp2 and F-actin: Montessori colocalization coefficient (MOC) (0.38±0.03) in the COPD group was lower than the healthy control group (0.88±0.03, P<0.01); healthy PM2.5 group and COPD PM2.5 group [(0.58±0.03) and (0.14±0.02)] were lower than the respective control groups (both P<0.01), and the decrease in COPD group was more significant. Morphology of AM phagocytosis of FITC-E.coli: AM in the healthy control group was obviously deformed, and the surface of the cell membrane was slightly wrinkled and high, and the free edge of the micro-pleated fold had a long and dense filamentous pseudopodia extension. The changes of morphology of AM in the COPD group was not obvious, the micro-wrinkles on the surface of the cell membrane were rare, and the filopodia poorly extended or even absent. The AM form of the healthy PM2.5 group changed slightly, mostly irregular circular or elliptical. The micro-wrinkles on the surface of the cell membrane were less and flat, and the filopodia protrudes short and less; the AM form of the COPD PM2.5 group was stiff, and the micro-wrinkles on the surface of the cell membrane were few and flat, no obvious filopodia or protrusions. Correlation analysis: After basal state and PM2.5 intervention, AM Arp2, F-actin content and MOC values of Arp2 and F-actin were positively correlated with MFI. Conclusions: The phagocytic function of AM in COPD mice was low, which was related to the abnormal rearrangement of cytoskeleton involved in Arp2/3 complex and F-actin. It was speculated that PM2.5 might inhibit Arp2/3 complex and F-actin. The cytoskeletal rearrangement of proteins was involved in the aggravation of AM phagocytosis in mice with COPD.

4-dehydroxyepisarcovagine A, a new steroidal alkaloid from Sarcococca pruniformis Lindl.

A new steroidal alkaloid, 4-dehydroxyepisarcovagine A (1), along with seven known alkaloids, sarcovagine D (2), sarcovagenine C (3), epoxysarcovagenine D (4), Pachysamine L (5), Pachysamine E (6), sarcovagine A (7) and sarcovagine B (8), was isolated from the roots and stems of Sarcococca pruniformis Lindl. The structure of compound 1 was elucidated by means of spectroscopic analysis.

Association study of the 5-HT(6) receptor polymorphism (C267T) and symptomatology and antidepressant response in major depressive disorders.

The serotonergic neurotransmitter system has been implicated in the pathogenesis of major depressive disorder (MDD). Of the 14 human serotonin (5-HT) receptors, the 5-HT(6) receptor may be a candidate for the study of MDD because of its relative abundance in certain limbic areas and its high affinity to several antidepressants. The present study tested the hypothesis that a 5-HT(6) genetic polymorphism (C267T) is associated with the clinical manifestations of, and/or antidepressant response in, MDD. The Hamilton Depression Rating Scale was used to assess 57 MDD patients before antidepressant treatment, with 34 patients completing the 4-week treatment and evaluation. The results of the association study provide that the 5-HT(6) C267T genetic variant does not play a major role in producing the clinical manifestations or antidepressant response for MDD patients. Further study with a functional 5-HT(6) polymorphism is needed to explore the role of 5-HT(6) in the pathogenesis of MDD.