IL-27 mediates anti-inflammatory effect in cigarette smoke induced emphysema by negatively regulating IFN-γ producing cytotoxic CD8+ T cells in mice.

Chronic airway inflammation mediated by CD8+ T lymphocytes contributes to the pathogenesis of Chronic obstructive pulmonary disease (COPD). Deciphering the fingerprint of the chronic inflammation orchestrated by CD8+ T cells may allow the development of novel approaches to COPD management. Here, the expression of IL-27 and IFN-γ+ CD8+ Tc1 cells were evaluated in patients with COPD and in cigarette smoke-exposed mice. The production of IL-27 by marrow-derived dendritic cells (mDCs) in response to cigarette smoke extract (CSE) was assessed. The role of IL-27 in IFN-γ+ CD8+ Tc1 cells was explored. We demonstrated that elevated IL-27 was accompanied by an exaggerated IFN-γ+ CD8+ Tc1 response in a smoking mouse model of emphysema. We noted that lung dendritic cells were one of the main sources of IL-27 during chronic cigarette smoke exposure. Moreover, CSE directly induced the production of IL-27 by mDCs in vitro. IL-27 negatively regulated the differentiation of IFN-γ+ CD8+ Tc1 cells isolated from cigarette smoke-exposed mice in a STAT1- and STAT3-independent manner. Systemic administration of recombinant IL-27 attenuated IFN-γ+ CD8+ Tc1 response in the late phase of cigarette smoke exposure. Our results uncovered that IL-27 negatively regulates IFN-γ+ CD8+ Tc1 response in the late stage of chronic cigarette smoke exposure, which may provide a new strategy for the anti-inflammatory treatment of smoking-related COPD/emphysema.

A Cys2/His2 Zinc Finger Protein Acts as a Repressor of the Green Revolution Gene SD1/OsGA20ox2 in Rice (Oryza sativa L.).

Gibberellins (GAs) play important roles in the regulation of plant growth and development. The green revolution gene SD1 encoding gibberellin 20-oxidase 2 (GA20ox2) has been widely used in modern rice breeding. However, the molecular mechanism of how SD1/OsGA20ox2 expression is regulated remains unclear. Here, we report a Cys2/His2 zinc finger protein ZFP207 acting as a transcriptional repressor of OsGA20ox2. ZFP207 was mainly accumulated in young tissues and more specifically in culm nodes. ZFP207-overexpression (ZFP207OE) plants displayed semidwarfism phenotype and small grains by modulating cell length. RNA interference of ZFP207 caused increased plant height and grain length. The application of exogenous GA3 could rescue the semidwarf phenotype of ZFP207OE rice seedlings. Moreover, ZFP207 repressed the expression of OsGA20ox2 via binding to its promoter region. Taken together, ZFP207 acts as a transcriptional repressor of SD1/OsGA20ox2 and it may play a critical role in plant growth and development in rice through the fine-tuning of GA biosynthesis .

Clinical characteristics of pulmonary cryptococcosis coexisting with lung adenocarcinoma: Three case reports.

BACKGROUND: Pulmonary cryptococcosis (PC) is an invasive fungal disease caused mainly by Cryptococcus (C.) neoformans or C. gattii. It may be present in immunocompetent or immunocompromised patients. The radiographic features of PC vary, and the most common computed tomography manifestation is the presence of solitary or multiple pulmonary nodules or masses distributed in the outer zone of the lung field. The appearance of nodular or mass-like PC on computed tomography scans resembles that of primary or metastatic lung cancers, and differential diagnosis is sometimes difficult. The coexistence of PC and malignant tumors is rarely observed. CASE SUMMARY: This paper reports three cases of PC combined with lung adenocarcinoma diagnosed by video-assisted thoracic surgery lung biopsy, which were successfully managed by early diagnosis and treatment. CONCLUSION: The present case report might serve as a reminder not to neglect PC coexisting with adenocarcinoma. Early diagnosis and treatment lead to a better prognosis.

OsSYP121 Accumulates at Fungal Penetration Sites and Mediates Host Resistance to Rice Blast.

Magnaporthe oryzae is a fungal pathogen that causes rice (Oryza sativa) blast. SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) are key components in vesicle trafficking in eukaryotic cells and are known to contribute to fungal pathogen resistance. Syntaxin of Plants121 (SYP121), a Qa-SNARE, has been reported to function in nonhost resistance in Arabidopsis (Arabidopsis thaliana). However, the functions of SYP121 in host resistance to rice blast are largely unknown. Here, we report that the rice SYP121 protein, OsSYP121, accumulates at fungal penetration sites and mediates host resistance to rice blast. OsSYP121 is plasma membrane localized and its expression was obviously induced by the rice blast in both the blast-resistant rice landrace Heikezijing and the blast-susceptible landrace Suyunuo (Su). Overexpression of OsSYP121 in Su resulted in enhanced resistance to blast. Knockdown of OsSYP121 expression in Su resulted in a more susceptible phenotype. However, knockdown of OsSYP121 expression in the resistant landrace Heikezijing resulted in susceptibility to the blast fungus. The POsSYP121 ::GFP-OsSYP121 accumulated at rice blast penetration sites in transgenic rice, as observed by confocal microscopy. Yeast two-hybrid results showed that OsSYP121 can interact with OsSNAP32 (Synaptosome-associated protein of 32 kD) and Vesicle-associated membrane protein714/724. The interaction between OsSYP121 and OsSNAP32 may contribute to host resistance to rice blast. Our study reveals that OsSYP121 plays an important role in rice blast resistance as it is a key component in vesicle trafficking.

Cigarette Smoke Induction of Interleukin-27/WSX-1 Regulates the Differentiation of Th1 and Th17 Cells in a Smoking Mouse Model of Emphysema.

IFN-γ-producing CD4+ T (Th1) cells and IL-17-producing CD4+ T (Th17) cells play a critical role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the immune regulation between Th1 and Th17 cells remains unclear. Previous studies have demonstrated that interleukin-27 (IL-27)/WSX-1 exerted pro- or anti-inflammatory effects in many acute inflammatory diseases by modulating T cell-mediated immune response, but little was known about its role in chronic inflammatory disease, especially in smoking-related lung diseases. Considering IL-27 is an important regulator in T lymphocytes immune responses and was found markedly increased in patients with COPD, we hypothesized that IL-27/WSX-1 may exert immuno-regulatory effects on the differentiation of Th1 and Th17 cells in smoking-related COPD. In this study, we aimed to evaluate the expression of IL-27 in patients with COPD and explore the role of IL-27/WSX-1 on Th1 and Th17 cells differentiation in a smoking mouse model of emphysema. We found that elevated expression of IL-27 was associated with increased proportion of Th1 cells and Th17 cells in patients with COPD and demonstrated parallel findings in cigarette smoke-exposed mice. In addition, cigarette smoke exposure upregulated the expression of IL-27R (WSX-1) by naive CD4+ T cells in mice. In vitro, IL-27 significantly augmented the secretion of IFN-γ by naive CD4+ T cells via a T-bet, p-STAT1, and p-STAT3-dependent manner, but inhibited the production of IL-17 by a ROR-γt and p-STAT1-dependent way. Furthermore, anti-IL27 treatment dramatically decreased the expression of IFN-γ-producing CD4+ T cells in cigarette smoke-exposed mice. These findings proposed that IL-27 has functions for promoting the expression of Th1 cells but inhibiting the expression of Th17 cells in vitro and IL-27 neutralization-attenuated Th1-mediated inflammation in vivo, suggesting targeting IL-27/WSX-1 may provide a new therapeutic approach for smoking-related COPD.

Infiltration of IL-17-Producing T Cells and Treg Cells in a Mouse Model of Smoke-Induced Emphysema.

Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible chronic inflammatory disease associated with the accumulation of activated T cells. To date, there is little information concerning the intrinsic association among Th17, Tc17, and regulatory T (Treg) cells in COPD. The objective of this study was to investigate the variation of lungs CD4(+)Foxp3(+) Treg cells and IL-17-producing CD4 and CD8 (Th17 and Tc17) lymphocytes in mice with cigarette-induced emphysema. Groups of mice were exposed to cigarette smoke or room air. At weeks 12 and 24, mice were sacrificed to observe histological changes by HE stain. The frequencies of Th17 (CD4(+)IL-17(+)T), Tc17 (CD8(+)IL-17(+)T), and Treg (CD4(+)Foxp3(+)T) cells in lungs from these mice were analyzed by flow cytometry. The mRNA levels of orphan nuclear receptor ROR γt and Foxp3 were performed by real-time quantitative polymerase chain reaction. The protein levels of interleukin-17 (IL-17), IL-6, IL-10, and transforming growth factor-beta (TGF-ß1) were measured by enzyme-linked immunosorbent assay. Cigarette smoke caused substantial enlargement of the air spaces accompanied by the destruction of the normal alveolar architecture and led to emphysema. The frequencies of Th17 and Tc17 cells, as well as the expressions of IL-6, IL-17, TGF-ß1, and ROR γt were greater in the lungs of cigarette smoke (CS)-exposed mice, particularly in the 24-week CS-exposed mice. The frequencies of Treg cells and the expressions of IL-10 and Foxp3 were lower in CS-exposed mice compared to control group. More important, the frequencies of Tregs were negatively correlated with Th17 cells and with Tc17 cells. Interestingly, a significant portion of the cells that infiltrate the lungs was skewed towards a Tc17 phenotype. Our findings suggest the contribution of Th17, Tc17, and Treg cells in the pathogenesis of COPD. Rebalance of these cells will be helpful for developing and refining the new immunological therapies for COPD.

Persistence of Th17/Tc17 cell expression upon smoking cessation in mice with cigarette smoke-induced emphysema.

Th17 and Tc17 cells may be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD), a disease caused predominantly by cigarette smoking. Smoking cessation is the only intervention in the management of COPD. However, even after cessation, the airway inflammation may be present. In the current study, mice were exposed to room air or cigarette smoke for 24 weeks or 24 weeks followed by 12 weeks of cessation. Morphological changes were evaluated by mean linear intercepts (Lm) and destructive index (DI). The frequencies of CD8(+)IL-17(+)(Tc17) and CD4(+)IL-17(+)(Th17) cells, the mRNA levels of ROR gamma and IL-17, and the levels of IL-8, TNF-alpha, and IFN-gamma in lungs or bronchoalveolar lavage fluid of mice were assayed. Here we demonstrated that alveolar enlargement and destruction induced by cigarette smoke exposure were irreversible and that cigarette smokeenhanced these T-cell subsets, and related cytokines were not significantly reduced after smoking cessation. In addition, the frequencies of Th17 and Tc17 cells in lungs of smoke-exposed mice and cessation mice were positively correlated with emphysematous lesions. More important, the frequencies of Tc17 cells were much higher than Th17 cells, and there was a significantly positive correlation between Th17 and Tc17. These results suggested that Th17/Tc17 infiltration in lungs may play a critical role in sustaining lung inflammation in emphysema. Blocking the abnormally increased numbers of Tc17 and Th17 cells may be a reasonable therapeutic strategy for emphysema.

[Expression of interleukin-21 in the lungs of mice with emphysema and its effects on the differentiation of CD4+ T cell].

OBJECTIVE: To evaluate the expression of interleukin (IL)-21 in a cigarette smoke-induced mice model of emphysema and explore its effects on the differentiation of CD4(+)T cell. METHODS: Twenty male Balb/c mice were randomly divided into two groups: control group and smoke-exposed group. Morphological changes were evaluated by mean linear intercepts and alveolar destructive index. The proportion of CD4(+)IL-21R(+)T cells in lungs of mice was determined by flow cytometry. And the levels of IL-21 in lungs of mice were analyzed by enzyme-linked immunosorbent assay (ELISA). Fresh lung mononuclear cells were isolated from the smoke-exposed group and divided further into two sub-groups: blank sub-group and co-culture sub-group. Two sub-groups were cultured in medium with or without IL-21 for 24 h and 48 h. The proportions of Th1 and Th17 cells in cell culture medium were determined by flow cytometry. RESULTS: Mean linear intercepts and alveolar destructive index in the smoke-exposed group ((48.6 ± 4.8) µm and 44.9 ± 2.8) were significantly higher than the control group ((32.4 ± 4.0) µm and 28.1 ± 2.1, both P < 0.05). In lungs, the percentage of CD4(+)IL-21R(+)T cells in the smoke-exposed group (4.1% ± 1.5%) significantly increased than that in the control group (1.4% ± 0.4%) (P < 0.05). The levels of IL-21 in lung of the smoke-exposed group ((851 ± 28) ng/L) were higher than those in the control group ((415 ± 39) ng/L, P < 0.05). In lungs, the levels of IL-21 had positive correlations with mean linear intercepts and alveolar destructive index (r = 0.892 and 0.955, both P < 0.05). The percentages of Th1 and Th17 cells in cell culture medium of the co-culture sub-group for 24 h and 48 h significantly increased versus those in the blank group (all P < 0.05). CONCLUSION: IL-21 may participate in the occurrence and development of emphysema through the induced differentiation of CD4(+)T cells and the promotion of Th1 and Th17-cell responses in lungs.

Overexpression of the Qc-SNARE gene OsSYP71 enhances tolerance to oxidative stress and resistance to rice blast in rice (Oryza sativa L.).

OsSYP71 is an oxidative stress and rice blast response gene that encodes a Qc-SNARE protein in rice. Qc-SNARE proteins belong to the superfamily of SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors), which function as important components of the vesicle trafficking machinery in eukaryotic cells. In this paper, 12 Qc-SNARE genes were isolated from rice, and expression patterns of 9 genes were detected in various tissues and in seedlings challenged with oxidative stresses and inoculated with rice blast. The expression of OsSYP71 was clearly up-regulated under these stresses. Overexpression of OsSYP71 in rice showed more tolerance to oxidative stress and resistance to rice blast than wild-type plants. These results indicate that Qc-SNAREs play an important role in rice response to environmental stresses, and OsSYP71 is useful in engineering crop plants with enhanced tolerance to oxidative stress and resistance to rice blast.

Th17 cell enhances CD8 T-cell cytotoxicity via IL-21 production in emphysema mice.

Emphysema is a T-cell mediated autoimmune disease caused predominantly by cigarette smoking. Th17 cells and related cytokines may contribute to this disorder. However, the possible implication of Th17 cells in regulating inflammatory response in emphysema remains to be elucidated. In the current study, we tested the protein levels of IL-17 and IL-21 in peripheral blood and lung tissues from cigarette-smoke- (CS-) exposed mice and air-exposed mice, analyzed the frequencies of CD4(+)IL-17(+)(Th17) cells, IL-21(+)Th17 cells, and CD8(+)IL-21R(+) T cells in peripheral blood and lung tissues of mice, and their relationship with emphysematous lesions, and explored the impact of IL-21 on cytotoxic CD8(+) T cells function in vitro. It was found that the frequencies of Th17, IL-21(+)Th17, and CD8(+)IL-21R(+) T cells and the levels of IL-17 and IL-21 of CS-exposed mice were much higher than those of the air-exposed mice and correlated with emphysematous lesions. Additionally, the number of IL-21(+)Th17 cells positively correlated with the number of CD8(+)IL-21R(+) T cells. The in vitro experiments showed that IL-21 significantly augmented the secretion of perforin and granzyme B in CD8(+) T cells from CS-exposed mice. These data indirectly provide evidence that Th17 cells could be involved in the control of the local and system inflammatory response in emphysema by regulating CD8(+) cytotoxic T-cell function.

[The expression and mechanisms of interleukin-17 in CD(8)(+) T cells of mice with cigarette smoke-induced emphysema].

OBJECTIVE: To evaluate the expression of Tc17 in a cigarette smoke-induced mice model of emphysema. To explore the probable mechanisms about how Tc17 cells to elevate in lungs of mice. METHODS: Forty male Balb/c mice were randomly divided into four groups, including control group (12 weeks, C12), control group (24 weeks, C24), smoke-exposure group (12 weeks, S12) and smoke-exposure group (24 weeks, S24), 10 mice each group, Emphysema of mice was observed by HE pigmentation. Morphological changes were evaluated by mean linear intercepts (Lm) and destructive index (DI). The proportion of CD(8)(+)IL-17(+)Tc17, CD(8)(+)IL-17(+) CC chemokine receptor type 6 (CCR6)(+) and 6CCR6(+)Tc17 cells in lungs of mice was determined by flow cytometry. The mRNA expressions of retinoid-related orphan nuclear receptor (RORγt) and IL-17 were evaluated by real-time PCR. The levels of IL-1ß, IL-6, IL-23, transforming growth factor ß (TGFß) and CC chemokine ligand 20(CCL20) were tested by ELISA. Correlations among these indexes were analyzed. RESULTS: Lm and DI were significantly higher in S12 and S24 than in C12 and C24, S24 in particular (t value 4.378 - 15.188, all P < 0.05). The percentages of Tc17 in S12 and S24 [(9.28 ± 1.12)%, (13.13 ± 3.56)%] was significantly increased as compared with that in C12 and C24 [(2.40 ± 0.60)%, (2.64 ± 0.96)%], S24 in particular. The mRNA levels of RORγt and IL-17 in S12 and S24 were higher than in C12 and C24, S12 and S24 in particular. There was significant difference (all P < 0.05). The frequency of Tc17 cells had a positive correlation with Lm and DI (r value were 0.734 and 0.884 respectively, P < 0.01). The percentages of CD(8)(+)IL-17(+)CCR6(+)T cells and CCR6(+)Tc17 were significantly elevated in S12 and S24 compared to C12 and C24, S24 in particular (all P < 0.05). There was positive correlation between Tc17 cell ratio and CCL20 levels (r = 0.899, P < 0.01). The levels of IL-1ß, IL-6, IL-23 and TGFß in S12 and S24 were significantly increased as compared with that in C12 and C24. There was significant difference (all P < 0.05). Meanwhile, the frequency of Tc17 cells had a positive correlation with IL-1ß, IL-6, IL-23, and TGFß. CONCLUSIONS: An up-regulation of proportions Tc17 in lungs of cigarette smoke-induced emphysema mice were detected. The CCR6/CCL20 axis and the increased IL-1ß, IL-6, IL-23 and TGFß probably contributed to this up-regulation.

[Mechanisms and dynamics of Th17 cells in mice with cigarette smoke-induced emphysema].

OBJECTIVE: To evaluate the expression of Th17 cell in a cigarette smoke-induced mice model of emphysema and explore the probable mechanisms of its elevation. METHODS: Forty male Balb/c mice were randomly divided into 4 groups: control group for 12 weeks (C12), control group for 24 weeks (C24), smoke-exposure group for 12 weeks (S12) and smoke-exposure group for 24 weeks (S24)(n = 10 each). Morphological changes were evaluated by mean linear intercepts (Lm) and destructive index (DI). The percentages of Th17, Th1, Th17/Th1, CD4(+)IL-17(+)CCR6(+)T and CCR6(+)Th17 cells were determined by tetra-color flow cytometry while the levels of interleukin (IL)-1ß, IL-6, IL-23, transforming growth factor (TGF)-ß, interferon (IFN)-γ and CC chemokine ligand (CCL)-20 assayed by enzyme-linked immunosorbent assay (ELISA). RESULTS: The values of Lm [(39 ± 4) µm, (47 ± 7) µm] and DI [(39.1 ± 1.6), (45.2 ± 3.1)] were significantly higher in S12 and S24 than those in C12 [(33 ± 3) µm, (28.2 ± 1.6)] and C24 [(32 ± 4) µm, (28.9 ± 2.1)], particularly in C24 (all P < 0.05). The percentages of Th17 cell [(3.27 ± 1.12), (7.19 ± 2.24)], Th17/Th1 cell [(0.61 ± 0.30), (1.82 ± 0.52)] and Th1 cell [(10.02 ± 3.68), (26.21 ± 6.04)] in the lungs of S12 and S24 significantly increased than those in C12 [(1.80 ± 0.75), (0.27 ± 0.12), (3.75 ± 1.72)] and C24 [(1.99 ± 0.59), (0.28 ± 0.11), (4.16 ± 1.32)], particularly in C24 (all P < 0.01). The percentages of Th17, Th17/Th1 and Th1 cells in the lungs of S12 and S24 had a positive correlation with Lm and DI (all P < 0.01). The percentages of CD4(+)IL-17(+)CCR-6(+)T cell [(0.69 ± 0.34), (1.11 ± 0.48)] and CCR6(+)Th17 cell [(12.23 ± 2.13), (18.65 ± 1.17)] were significantly elevated in S12 and S24 compared to those in C12 [(0.22 ± 0.18), (6.55 ± 2.13)] and C24 [(0.25 ± 0.17), (7.29 ± 1.57)], particularly in C24 (all P < 0.05). Furthermore, a positive correlation between CCR6(+)Th17 cell and emphysematous lesions was also found (all P < 0.05). The levels of IL-1ß, IL-6, IL-23, TGF-ß, IFN-γ and CCL20 significantly increased in S12 and S24 as compared with those of C12 and C24 (all P < 0.05). Meanwhile, the percentage of Th17 cell had a positive correlation with IL-1ß, IL-6, IL-23, TGF-ß, IFN-γ and CCL20. CONCLUSION: There is an up-regulated expression of Th17 in lungs of cigarette smoke-induced emphysema mice. The CCR6/CCL20 axis and the elevated levels of IL-1ß, IL-6, IL-23, TGF-ß and IFN-γ may be related with the above effect.

[Effect of interleukin-17-producing CD4+ T helper lymphocytes on cigarette smoke-induced lung inflammation and emphysema in mice].

OBJECTIVE: To evaluate the expression and the role of Th17 in cigarette smoke-induced lung inflammation and emphysema in mice. METHODS: Forty male BALB/c mice were randomly divided into 4 groups, including a control group C12, a control group C24, a smoke-exposure 12 week group (S12) and a smoke-exposure 24 week group S24 (n = 10 each). Morphological changes were evaluated by mean linear intercepts and destructive index (DI). The proportion of CD(4)(+)IL-17(+)Th17, CD(4)(+)IFN-γ(+)Th1, CD(4)(+)IL-17(+)IFN-γ(+)T(Th17/Th1), CD(8)(+)IFN-γ(+)Tc1, CD(8)(+)IL-21R(+) and CD(4)(+)IL-17(+)IL-21(+) T cells in lungs of mice was determined by flow cytometry. The mRNA expressions of RORγt and IL-17 were evaluated by real-time PCR. RESULTS: Mean linear intercepts and DI were significantly higher in S12 and S24 groups [(39 ± 4) µm, (47 ± 7) µm], (39.1 ± 1.6, 45.2 ± 3.1) as compared to C12 [(32 ± 4) µm, 28.2 ± 1.6] and C24 groups [(33 ± 3) µm, 28.9 ± 2.1], all P < 0.05. The percentage of Th17 of S12 and S24 groups [(3.3 ± 1.1)%, (7.2 ± 2.2)%] was significantly increased as compared with that of C12 and C24 groups [(1.8 ± 0.8)%, (2.0 ± 0.6)%], all P < 0.05. The mRNA levels of RORγt [(25 ± 4), (35 ± 3)] and IL-17 [(26 ± 3), (36 ± 3)] in S12 and S24 groups were higher than in C12 [(10 ± 5), (13 ± 5)] and C24 groups [(11 ± 7), (8 ± 6)], all P < 0.05. The percentage of Th1, Th17/Th1 and Tc1 cells of S12 and S24 groups [(10.0 ± 3.7)%, (26.2 ± 6.0)%], [(0.61 ± 0.30)%, (1.82 ± 0.52)%], [(17.0 ± 4.5)%, (26.8 ± 8.5)%] was significantly increased as compared with that of C12 [(3.8 ± 1.7)%, (0.27 ± 0.17)%, (4.8 ± 1.9)%] and C24 groups [(4.2 ± 1.3)%, (0.28 ± 0.11)%, (5.2 ± 1.0)%], all P < 0.05. Moreover, the frequency of Th17 cells had a positive correlation with Th1, Tc1 cells and emphysematous lesions (r = 0.519 - 0.797, all P < 0.01). In addition, a positive correlation between Th17/Th1 cells and emphysematous lesions was also found (r = 0.742, 0.802, all P < 0.01). The percentage of CD(4)(+)IL-17(+)IL-21(+) T cells was significantly increased in S12 and S24 groups [(0.19 ± 0.04)%, (0.55 ± 0.24)%] compared to controls [(0.07 ± 0.03)%, (0.08 ± 0.03)%], all P < 0.05. Meanwhile, as compared with that of the controls [(1.22 ± 0.31), (1.34 ± 0.18)], the percentage of CD(8)(+)IL-21R(+) T cells was also increased in S12 and S24 groups [(2.94 ± 1.26), (4.12 ± 2.26)], but there were no differences among smoke-exposure groups (P > 0.05). The frequency of CD(4)(+)IL-17(+)IL-21(+) T cells had a positive correlation with Th1, Tc1 cells and emphysematous lesions (r = 0.694 - 0.754, all P < 0.05). And the frequency of CD(8)(+)IL-21R(+) T cells also had a positive correlation with emphysematous lesions (r = 0.516, 0.725, all P < 0.05). CONCLUSIONS: Cigarette smoke increased the expression and the activity of Th17 in mice. Th17 may play a potential (active) role in the development of lung inflammation through IL-21/IL-21R pathway.

Functional analysis of a novel Cys2/His2-type zinc finger protein involved in salt tolerance in rice.

The Cys2/His2-type zinc finger proteins have been implicated in different cellular processes involved in plant development and stress responses. Through microarray analysis, a salt-responsive zinc finger protein gene ZFP179 was identified and subsequently cloned from rice seedlings. ZFP179 encodes a 17.95 kDa protein with two C2H2-type zinc finger motifs having transcriptional activation activity. The real-time RT-PCR analysis showed that ZFP179 was highly expressed in immature spikes, and markedly induced in the seedlings by NaCl, PEG 6000, and ABA treatments. Overexpression of ZFP179 in rice increased salt tolerance and the transgenic seedlings showed hypersensitivity to exogenous ABA. The increased levels of free proline and soluble sugars were observed in transgenic plants compared to wild-type plants under salt stress. The ZFP179 transgenic rice exhibited significantly increased tolerance to oxidative stress, the reactive oxygen species (ROS)-scavenging ability, and expression levels of a number of stress-related genes, including OsDREB2A, OsP5CS OsProT, and OsLea3 under salt stress. Our studies suggest that ZFP179 plays a crucial role in the plant response to salt stress, and is useful in developing transgenic crops with enhanced tolerance to salt stress.

The OsDHODH1 gene is involved in salt and drought tolerance in rice.

In the present paper, we identified and cloned OsDHODH1 encoding a putative cytosolic dihydroorotate dehydrogenase (DHODH) in rice. Expression analysis indicated that OsDHODH1 is upregulated by salt, drought and exogenous abscisic acid (ABA), but not by cold. By prokaryotic expression, we determined the enzymatic activity of OsDHODH1 and found that overproduction of OsDHODH1 significantly improved the tolerance of Escherichia coli cells to salt and osmotic stresses. Overexpression of the OsDHODH1 gene in rice increased the DHODH activity and enhanced plant tolerance to salt and drought stresses as compared with wild type and OsDHODH1-antisense transgenic plants. Our findings reveal, for the first time, that cytosolic dihydroorotate dehydrogenase is involved in plant stress response and that OsDHODH1 could be used in engineering crop plants with enhanced tolerance to salt and drought.

Increased tolerance of rice to cold, drought and oxidative stresses mediated by the overexpression of a gene that encodes the zinc finger protein ZFP245.

ZFP245 is a cold- and drought-responsive gene that encodes a zinc finger protein in rice. The ZFP245 protein localizes in the nucleus and exhibits trans-activation activity. Transgenic rice plants overexpressing ZFP245 were generated and found to display high tolerance to cold and drought stresses. The transgenic plants did not exhibit growth retardation, but showed growth sensitivity against exogenous abscisic acid, increased free proline levels and elevated expression of rice pyrroline-5-carboxylatesynthetase and proline transporter genes under stress conditions. Overproduction of ZFP245 enhanced the activities of reactive oxygen species-scavenging enzymes under stress conditions and increased the tolerance of rice seedlings to oxidative stress. Our data suggest that ZFP245 may contribute to the tolerance of rice plants to cold and drought stresses by regulating proline levels and reactive oxygen species-scavenging activities, and therefore may be useful for developing transgenic crops with enhanced tolerance to abiotic stress.

Overexpression of a TFIIIA-type zinc finger protein gene ZFP252 enhances drought and salt tolerance in rice (Oryza sativa L.).

We previously identified a salt and drought stress-responsive TFIIIA-type zinc finger protein gene ZFP252 from rice. Here we report the functional analysis of ZFP252 using gain- and loss-of-function strategies. We found that overexpression of ZFP252 in rice increased the amount of free proline and soluble sugars, elevated the expression of stress defense genes and enhanced rice tolerance to salt and drought stresses, as compared with ZFP252 antisense and non-transgenic plants. Our findings suggest that ZFP252 plays an important role in rice response to salt and drought stresses and is useful in engineering crop plants with enhanced tolerance to salt and drought stresses.

A novel rice C2H2-type zinc finger protein lacking DLN-box/EAR-motif plays a role in salt tolerance.

A cDNA for the gene ZFP182, encoding a C2H2-type zinc finger protein, was cloned from rice by RT-PCR. ZFP182 codes an 18.2 kDa protein with two C2H2-type zinc finger motifs, one nuclear localization signal and one Leu-rich domain. The DLN-box/EAR-motif, which exists in most of plant C2H2-type zinc finger proteins, does not exist in ZFP182. The expression analysis showed that ZFP182 gene was constitutively expressed in leaves, culms, roots and spikes at the adult rice plants, and markedly induced in the seedlings by cold (4 degrees C), 150 mM NaCl and 0.1 mM ABA treatments. The approximate 1.4 kb promoter region of ZFP182 gene was fused into GUS reporter gene and transformed into tobacco. The histochemical analysis revealed that GUS expression could not be detected in transformed tobacco seedlings under normal conditions, but strongly observed in tobacco leaf discs and the vascular tissue of roots treated with NaCl or KCl. Expression of ZFP182 in transgenic tobacco and overexpression in rice increased plant tolerance to salt stress. These results demonstrated that ZFP182 might be involved in plant responses to salt stress.