Differential regulation of cell functions by CSD peptide subdomains

Background

In fibrotic lung diseases, expression of caveolin-1 is decreased in fibroblasts and monocytes. The effects of this deficiency are reversed by treating cells or animals with the caveolin-1 scaffolding domain peptide (CSD, amino acids 82–101 of caveolin-1) which compensates for the lack of caveolin-1. Here we compare the function of CSD subdomains (Cav-A, Cav-B, Cav-C, Cav-AB, and Cav-BC) and mutated versions of CSD (F92A and T90A/T91A/F92A).

Methods

Migration toward the chemokine CXCL12 and the associated expression of F-actin, CXCR4, and pSmad 2/3 were studied in monocytes from healthy donors and SSc patients. Fibrocyte differentiation was studied using PBMC from healthy donors and SSc patients. Collagen I secretion and signaling were studied in fibroblasts derived from the lung tissue of healthy subjects and SSc patients.

Results

Cav-BC and CSD at concentrations as low as 0.01 μM inhibited the hypermigration of SSc monocytes and TGFβ-activated Normal monocytes and the differentiation into fibrocytes of SSc and Normal monocytes. While CSD also inhibited the migration of poorly migrating Normal monocytes, Cav-A (and other subdomains to a lesser extent) promoted the migration of Normal monocytes while inhibiting the hypermigration of TGFβ-activated Normal monocytes. The effects of versions of CSD on migration may be mediated in part via their effects on CXCR4, F-actin, and pSmad 2/3 expression. Cav-BC was as effective as CSD in inhibiting fibroblast collagen I and ASMA expression and MEK/ERK signaling. Cav-C and Cav-AB also inhibited collagen I expression, but in many cases did not affect ASMA or MEK/ERK. Cav-A increased collagen I expression in scleroderma lung fibroblasts. Full effects on fibroblasts of versions of CSD required 5 μM peptide.

Conclusions

Cav-BC retains most of the anti-fibrotic functions of CSD; Cav-A exhibits certain pro-fibrotic functions. Results obtained with subdomains and mutated versions of CSD further suggest that the critical functional residues in CSD depend on the cell type and readout being studied. Monocytes may be more sensitive to versions of CSD than fibroblasts and endothelial cells because the baseline level of caveolin-1 in monocytes is much lower than in these other cell types.     

管氏肿腿蜂对锈色粒肩天牛的防治试验

利用管氏肿腿蜂进行了防治锈色粒肩天牛幼虫的试验,结果表明:锈色粒肩天牛幼虫的寄生死亡率可达40%~70%,而且幼虫的寄生死亡率随着放蜂量的增加而提高,按虫蜂比1∶1、1∶5和1∶10分别放蜂,寄生死亡率依次为35.4%、48.3%和68.9%;最佳放蜂时间为8月中旬,此时放蜂的校正寄生率为55.67%,明显地高于7月份和9月份。     

Cytokine regulation of pulmonary fibrosis in scleroderma

Pulmonary fibrosis occurs in up to 70% of scleroderma patients and progresses to cause severe restrictive lung disease in about 15% of patients. The mechanisms that cause pulmonary fibrosis in scleroderma remain incompletely understood. Increased amounts of mRNA or protein for multiple profibrotic cytokines and chemokines have been identified in lung tissue or broncholveolar lavage samples from scleroderma patients, when compared to healthy controls. These cytokines include transforming growth factor (TGF)-β, connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), oncostatin M (OSM), monocyte chemotactic factor-1 and pulmonary and activation-regulated chemokine (PARC). Potential cellular sources of these profibrotic cytokines and chemokines in scleroderma lung disease include alternatively activated macrophages, activated CD8+ T cells, eosinophils, mast cells, epithelial cells and fibroblasts themselves. This review summarizes the literature on involvement of cytokines and chemokines in the development of pulmonary fibrosis in scleroderma.     

A novel cellulase free alkaliphilic xylanase from alkali tolerant Penicillium citrinum: production, purification and characterization

AIMS: The enzymatic hydrolysis of xylan has potential economic and environment-friendly applications. Therefore, attention is focused here on the discovery of new extremophilic xylanase in order to meet the requirements of industry. METHODS AND RESULTS: An extracellular xylanase was purified from the culture filtrate of P. citrinum grown on wheat bran bed in solid substrate fermentation. Single step purification was achieved using hydrophobic interaction chromatography. The purified enzyme showed a single band on SDS-PAGE with an apparent molecular weight of c. 25 kDa and pI of 3.6. Stimulation of the activity by beta mercaptoethanol, dithiotheritol (DTT) and cysteine was observed. Moderately thermostable xylanase showed optimum activity at 50 degrees C at pH 8.5. CONCLUSION: Xylanase purified from P. citrinum was alkaliphilic and moderately thermostable in nature. SIGNIFICANCE AND IMPACT OF THE STUDY: The present work reports for the first time the purification and characterization of a novel endoglucanase free alkaliphilic xylanase from the alkali tolerant fungus Penicillium citrinum. The alkaliphilicity and moderate thermostability of this xylanase may have potential implications in paper and pulp industries.     

人工扩繁管氏肿腿蜂的蜂种复壮研究

利用中间寄主黄粉甲Tenebrio molitor L.蛹大量扩繁管氏肿腿蜂Scleroderma guani Xiao et Wu经多代后寄生效果下降,系由蜂种退化所致:利用一种中间寄主导致蜂种的营养来源单一;采用同一种群的蜂及较低的蜂虫比造成近亲繁殖。据此设计复壮措施:利用自然寄主回接、杂交和控制交尾方式。结果表明:(1)回接1代,其子代蜂种的寄生率和寄生成功率分别提高26%和28%~33%。(2)用外缘蜂种与本群蜂种杂交,其子代蜂的发育历期比对照少4d,寄生率和寄生成功率分别提高22%和17%。(3)控制交尾方式促进蜂种复壮。     

Ultrastructural characterization of olfactory sensilla and immunolocalization of odorant binding and chemosensory proteins from an ectoparasitoid Scleroderma guani (Hymenoptera: Bethylidae)

The three-dimensional structures of two odorant binding proteins (OBPs) and one chemosensory protein (CSP) from a polyphagous ectoparasitoid Scleroderma guani (Hymenoptera: Bethylidae) were resolved bioinformatically. The results show that both SguaOBP1 and OBP2 are classic OBPs, whereas SguaCSP1 belongs to non-classic CSPs which are considered as the "Plus-C" CSP in this report. The structural differences between the two OBPs and between OBP and CSP are thoroughly described, and the structural and functional significance of the divergent C-terminal regions (e.g., the prolonged C-terminal region in SguaOBP2 and the additional pair of cysteines in SguaCSP1) are discussed. The immunoblot analyses with antisera raised against recombinant SguaOBP1, OBP2, and CSP1, respectively, indicate that two SguaOBPs are specific to antennae, whereas SguaCSP1, which are more abundant than OBPs and detected in both male and female wasps, expresses ubiquitously across different tissues.We also describe the ultrastructure of the antennal sensilla types in S. guani and compare them to 19 species of parasitic Hymenoptera. There are 11 types of sensilla in the flagellum and pedicel segments of antennae in both male and female wasps. Seven of them, including sensilla placodea (SP), long sensilla basiconica (LSB), sensilla coeloconica (SC), two types of double-walled wall pore sensilla (DWPS-I and DWPS-II), and two types of sensilla trichodea (ST-I and ST-II), are multiporous chemosensilla. The ultralsturctures of these sensilla are morphologically characterized. In comparison to monophagous specialists, the highly polyphagous generalist ectoparasitoids such as S. guani possess more diverse sensilla types which are likely related to their broad host ranges and complex life styles. Our immunocytochemistry study demonstrated that each of the seven sensilla immunoreacts with at least one antiserum against SguaOBP1, OBP2, and CSP1, respectively. Anti-OBP2 is specifically labeled in DWPS-II, whereas the anti-OBP1 shows a broad spectrum of immunoactivity toward four different sensilla (LSB, SP, ST-I and ST-II). On the other hand, anti-CSP1 is immunoactive toward SP, DWPS-I and SC. Interestingly, a cross co-localization pattern between SguaOBP1 and CSP1 is documented for the first time. Given that the numbers of OBPs and CSPs in many insect species greatly outnumber their antennal sensilla types, it is germane to suggest such phenomenon could be the rule rather than the exception.     

贮藏条件对川硬皮肿腿蜂存活率的影响

在相对湿度为50%~70%的条件下,设置5个温度梯度,将川硬皮肿腿蜂SclerodermasichuanensisXiao雌成蜂分别进行直接贮藏和定期补充15%蜂蜜水后贮藏,并对该蜂在不同条件下的贮藏存活率进行了比较。结果表明,贮藏温度和补充营养对川硬皮肿腿蜂雌成蜂的存活率有显著影响,其中6~15℃下贮藏相同时间的蜂存活率较高,比较适合该蜂的贮藏,而在12℃贮藏相同时间的供试蜂存活率最高,最适该蜂的贮藏。除此之外,在贮藏期间适时添加补充营养也能大大延长川硬皮肿腿蜂雌成蜂的贮藏寿命,但补充营养对该蜂存活率的影响大小与贮藏温度有关。     

Mycotoxins and toxigenic fungi in sago starch from Papua New Guinea

AIMS: To assay sago starch from Papua New Guinea (PNG) for important mycotoxins and to test fungal isolates from sago for mycotoxin production in culture. METHODS AND RESULTS: Sago starch collected from Western and East Sepik Provinces was assayed for aflatoxins, ochratoxin A, cyclopiazonic acid, sterigmatocystin, citrinin and zearalenone and all 51 samples were negative. Frequently isolated species of Penicillium (13), Aspergillus (five) and Fusarium (one) were cultured on wheat grain, and tested for the production of ochratoxin A, cyclopiazonic acid, sterigmatocystin, citrinin, patulin and penicillic acid. All 12 isolates of P. citrinin and one of two A. flavipes isolates produced citrinin. A single isolate of A. versicolor produced sterigmatocystin. No other mycotoxins were detected in these cultures. CONCLUSIONS: No evidence was found of systemic mycotoxin contamination of sago starch. However, the isolation of several mycotoxigenic fungi shows the potential for citrinin and other mycotoxins to be produced in sago stored under special conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: Sago starch is the staple carbohydrate in lowland PNG and the absence of mycotoxins in freshly prepared sago starch is a positive finding. However, the frequent isolation of citrinin-producing fungi indicates a potential health risk for sago consumers, and food safety is dependant on promoting good storage practices.